Patient-centred interventions to help patients with multimorbidity have had mixed results.To assess the effectiveness of a provider-created, patient-centred, multi-provider case conference with follow-up, and understand under what circumstances it worked, and did not work.Mixed-methods design with a pragmatic randomised trial and qualitative study, involving nine urban primary care sites in Ontario, Canada.Patients aged 18–80 years with ≥3 chronic conditions were referred to the Telemedicine IMPACT Plus intervention; a nurse and patient planned a multi-provider case conference during which a care plan could be created. The patients were randomised into an intervention or control group. Two subgroup analyses and a fidelity assessment were conducted, with the primary outcomes at 4 months being self-management and self-efficacy. Secondary outcomes were mental and physical health status, quality of life, and health behaviours. A thematic analysis explored the patients’ experiences of the intervention.P = 0.006). More providers and follow-up hours were associated with poorer outcomes. Five themes were identified in the qualitative study: valuing the team, patients feeling supported, receiving a follow-up plan, being offered new and helpful additions to their treatment regimen, and experiencing positive outcomes.A total of 86 patients in the intervention group and 77 in the control group showed no differences, except that the intervention improved mental health status in the subgroup with an annual income of ≥C$50 000 (β-coefficient 11.003, Overall, the intervention showed improvements only for patients who had an annual income of ≥C$50 000, implying a need to address the costs of intervention components not covered by existing health policies. Findings suggest a need to optimise team composition by revising the number and type of providers according to patient preferences and to enhance the hours of nurse follow-up to better support the patient in carrying out the case conference’s recommendations. The threshold of ≥3 chronic conditions was chosen for two reasons:The number of chronic conditions was validated with the patient’s self-report in the baseline questionnaire.25A pragmatic randomised trial was conducted with nine team-based family practices that were familiar with the intervention  in Toronto, Ontario, Canada. The provincial policy context emphasised innovations for complex patients with high healthcare utilisation.26 The trial was registered in Ontario, Canada (NCTO2742597), and the CONSORT guidelines for pragmatic trials were followed for reporting methods and results.27Ethics approval was received and the protocol has been published.28–30 covering theory, gaps, pre-trial evaluations, and adaptation over time, and contained two key theoretical underpinnings — namely a patient-centred process6 in the patient–provider interaction and an integrated version of the Chronic Care Model.31A patient-centred, multi-provider case conference — the Telemedicine IMPACT Plus (TIP) programme — was developed by the providers, then chosen by the researchers from six programmes identified in a province-wide environmental scan. The intervention was chosen because of its lengthy development and preliminary evaluation. It was developed in a way that aligned with guidelines for complex interventions,32 that had been conducted by the team were lack of empowering patient-centred communication and lack of integrated care among multiple providers in the context of multimorbidity care. Pre-trial evaluations of early versions, which had a longer face-to-face component but less follow-up support, of the intervention revealed enablers of and barriers to patient and provider enthusiasm relating to:33time and scheduling of the multiple providers;33patient need for support to implement recommendations;34patient-centred agenda setting;34 andthe process of identifying and inviting patients;34remuneration of providers.Two evidence gaps from a scoping reviewOver a period of 10 years, the intervention was shortened, provided a telemedicine (video) option in addition to the face-to-face option, and remuneration was negotiated.The patient-centred invitation to patients to engage in the discussion, which was not explicit before, was made explicit and was honed: ‘What are your goals for this session?’ was asked in the context of improved agenda setting.FP (known to the patient);internist;psychiatrist;social worker;physiotherapist;occupational therapist;pharmacist;dietitian; andhome care case manager.A nurse, hired by the programme, met with each patient face to face for approximately 1 hour to understand what mattered to them, and then planned and coordinated a case conference of approximately six providers relevant to that patient from the following:35In preparation for the case conference, the nurse accessed the patient’s file from the FP and forwarded all relevant medical and social history to the intervention team. The providers met (face to face or by video) with the patient for 1–1.5 hours so all parties could, through mutual collaboration, focus on the patient’s goals and develop an agreed care plan. Follow-up was provided by the nurse to help execute the recommendations over the subsequent 4 months. A full description is shown in Supplementary Box S1 using the TIDieR Checklist.8.36 Combining 47 trials from two reviews,8,36 the researchers found that patient-oriented interventions were tested in 36% of trials, organisational interventions were tested in 51% of trials , and training interventions were tested in 13% of trials; training was not an element of the intervention presented here. The focus on patient goals was a common thread in all the patient-oriented interventions; however, TIP’s multi-provider team was unique and not found in any of the 47 interventions — the closest thing being a team comprising the practice nurse, a psychologist, and a psychiatrist.37The literature describes three main intervention types: patient-oriented, organisational, and training interventions.38A pragmatic randomised pilot study to determine the feasibility of suggested outcomes, to estimate recruitment, and to identify effect sizes for sample size calculation was conducted.Patients in the control group received usual care in the office of their FP  and a one-page list of community resources that patients with their conditions could contact if desired. The three-quarters of patients were referred by FPs who worked in an interprofessional team on site and a quarter were not. The three-quarters worked in Ontario’s model of team-based care, called the Family Health Team (FHT), which meant that a nurse practitioner and social worker would be readily available on site; the patients comprising a quarter of the control group were referred by FPs who were in a non-team practice but who could refer patients to medical specialists and health professionals off site.Nine team-based practices and their affiliated practitioners referred eligible patients. There was a two-step recruitment process. Patient selection was based on clinical judgement and clinicians approached patients and requested consent to send their name to the researchers. The project coordinator received names and contact details of patients, and contacted them by telephone to explain the project in detail and obtain signed consent to participate.39 andthe Health Education Impact Questionnaire (heiQ);40the Self-Efficacy for Managing Chronic Disease scale (SEM).Outcomes were assessed at baseline and at 4 months after the case conference, a period considered long enough for the nurse and patient to complete the plan and feasible for follow-up to the trial. Two primary outcome measures were chosen to represent patient education, empowerment, and agency:41VR12 Health Status — Physical Component Score and Mental Component Score;42EQ-5D quality of life;43 andKessler Psychological Distress Scale;44Health Behaviour Survey.There were four secondary outcome measures:26Psychometric properties are available in the protocol article for the project.45 Allowing for a 15% drop-out, the researchers aimed to recruit 150 patients, with 75 in each group.For the two primary outcome measures (heiQ and SEM), comparing mean scores to detect a medium effect size (0.5) with a two-sided α = 0.05 and 80% power resulted in 64 participants being needed in both the intervention group and the control group; this equated to a sample size of = 128.27 regarding assignment of the intervention, sequence generation, allocation concealment, implementation, blinding, and data collection.Individual patients were allocated using randomly sequenced envelopes. Supplementary Box S2 details the procedures using the CONSORT guidelines46 This method is a simple form of mixed effect; it does not explicitly model the random effects but, rather, explicitly models correlations among measurements within a subject. An advantage is that it can effectively handle missing data without strong assumptions that missing data occurred randomly. It also controlled for the baseline outcome measure. Nonetheless, a sensitivity analysis, omitting the lost cases, was conducted.Outcome data were analysed using the mixed model for repeated measures (MMRM).<$50K annual income versus ≥$50K annual income (the sample’s median income); and≥6 morbidities versus fewer .Two exploratory, post-hoc, subgroup analyses were conducted, on:In addition, the relationship between the fidelity of the intervention (involving a subset of 40 patients from the intervention group) and outcomes was analysed using analysis of covariance, controlling for baseline.47 was used to explore the patients’ experiences of context, process, and under what circumstances the intervention worked or failed to work. It was undertaken at the same time as the trial measures were being collected.A thematic analysisParticipants were selected purposively from those in the trial intervention arm. A maximum-variation sample varied by age, sex, and practice.Participants were interviewed 4 months after their TIP case conference at a time and date organised by the study research coordinator. Interviewers had no prior relationship with participants. Before the interview, participants read the letter of information that outlined the reasons for the qualitative study and informed consent for the interview was obtained.Semi-structured individual interviews (Supplementary Box S3) were conducted with each participant alone in their home or the FP’s office. These lasted 30–60 minutes, and were audio-recorded and transcribed verbatim. Four members of the research team trained in conducting qualitative interviews undertook the collection and analysis of the qualitative data; they were not involved in the collection of the trial data.The data analysis was both iterative and interpretive. All transcripts were independently reviewed and coded by the four researchers to determine the key emerging concepts. They then met, shared, and created a consensus that informed the development of the coding template. This process continued until no new themes were identified; the data were input into NVivo 10. In the final step, the research team identified overarching themes and exemplar quotations for each theme.Trustworthiness and credibility were ensured using audio-recordings, verbatim transcripts, independent as well as team analysis, and field notes following each interview. A commitment to reflexivity considered how the researchers’ professional backgrounds , particularly during the coding and interpretation of the data, could influence the findings.48 in that it was older, comprised more females and participants had a higher level of education and a higher income.Baseline patient characteristics are shown in Tables 2P = 0.006). Exploratory analyses regarding the fidelity of the interaction revealed two components that could be altered to improve the intervention, as follows (data not shown):having ≥3 hours (versus fewer hours) of nurse follow-up work within 4 months of the case conference was related to statistically significantly less improvement in primary outcomes from baseline to 4-month follow-up; andhaving ≥6 healthcare providers involved in the intervention (versus <6 providers) was related to less improvement.Subgroup analyses showed no difference in the effect of the intervention for patients with ≥6 chronic conditions versus <6 (data not shown); however, as shown in valuing the team experience;feeling supported in meeting their goals;receiving advice and a follow-up plan;being offered new and helpful additions to their treatment regimen; andexperiencing positive outcomes.The final sample comprised 14 patients , aged 33–80 years. Five themes reflected the patients’ experience of the intervention:The nurse got together a dietitian, my family doctor, a social worker, a psychiatrist, a pharmacist — a whole bunch of people together … We had a video here [at my home] , a conversation and just so everybody was on the same page with what I was doing. It was really good.’‘ This theme included all players sharing the same information and having buy-in to the recommended plans, which participants felt was valuable:‘Because I have various health issues, this gave me some kind of all-in-one resource!!’In addition, the diversity of team members meant connections to a lot of programmes could be made, which was found to be helpful:I had so many appointments after [the consultation] , it was tiring!!’‘ However, a down side was that the new services could be exhausting:‘I felt that they truly were committed to the interview and looking to see if they could help me to reach my goals … It was often they’d have a perspective and then I’d respond to that as well. Or they’d ask me how I felt about that.’The multi-provider case conference made patients feel that they were supported in terms of meeting their goals:‘I was asked, “What do you want from this?” So I said, “I would like to be able to walk a mile … I am not asking to run a marathon, just a mile without pain”.’In addition, their goals were explicitly elicited:‘Well they heard me … they validated me. So that wasn’t happening [before] .’Patients felt validated during the case conference:‘I felt really good coming out of that. That was some of the best answers [ sic] I felt like I’d received up to that point … I came out of it with kind of a list of ideas of different things to try to help improve my condition.’The advice given was considered plentiful, new, and helpful:In some instances, patients felt it was the best part of the programme.‘The nurse came back [to the patient’s home] a week after that with a synopsis of everything that was written down and reviewed everything, not word for word, but the highlights, a summary of everything.’Patients appreciated receiving a summary of the recommendations from the consultation:‘It has been frustrating not to have a little bit more guidance about how to take the individual suggestions and put those into an actual plan … The list I was given seemed to be in the order they thought of them and not really further processed into an actual treatment plan with step-by-step priorities.’A few patients noted that, when presented with only verbal instructions or a list that was not coalesced into a plan, they were left with little guidance at the conclusion of the consultation:‘Clear solutions yeah … a walker … medication … eating … that pleases me very much …’‘As a result of this intervention, the social worker arranged for me to get a walker. So I go out for walks now, which I hadn’t been doing for the longest time. I find it very liberating.’Patients described how receiving new solutions to their health issues enhanced their treatments in spite of some treatments not being covered by the provincial healthcare plan:‘The psychotherapist is a good match for me and positive work is being done. I am over the moon, optimistic.’‘I feel like the physiotherapist has been helping. Yeah, anything that gets your strength back is wonderful … Especially muscles, because you can get them back, and I didn’t know how to do it.’Psychotherapy and physiotherapy were repeatedly mentioned as helpful additions to patients’ treatment regimens:‘So I have had some improvement in being able to do things around the house.’Participants described their health improvements, attributed to the programme, which reflected two dimensions — namely, improved functional ability and a new positive, hopeful attitude:‘I’m feeling better. I don’t have the horrible pain that I had before … I feel that I have the ability to do things now that a few months ago I wouldn’t think of doing.’For some patients, increased function was due to a decrease in pain:‘There are things that I’m looking forward to, which before the intervention I wasn’t.’‘Without it, I would be sitting here miserable … there would have been no hope.’Improved functional ability appeared linked to a sense of hope:The trial found the intervention had no statistically significant effects on the primary outcomes, although one subgroup (those with an income of ≥C$50 000) significantly benefitted in terms of the mental health outcome. Qualitative and fidelity findings revealed aspects of the intervention that could be improved.19 Co-creation of the intervention, as in Mercer et al,15 or provider creation, as in the present study, appear to avoid implementation lapses.One strength was that the intervention was developed by providers and pre-tested before the trial. Intervention failure was not a problem here as it has been with other interventions.8,32A second strength was that the intervention includes an explicit patient-centred component, whereas most intervention studies to date, addressed the organisation of care.8,10–12 and six recent trials.13–18A third strength was the mixed-method design providing insights into how and for whom it works or fails to work; this is important given the neutral or mixed results revealed in recent systematic reviewsOther strengths include susceptibility bias, which was avoided by using envelopes in random sequence, while detection and follow-up bias was avoided by using sealed and opaque envelopes, and having a different staff member administer patient questionnaires.One limitation was the fact that the sample size was relatively small in comparison with other recent trials  and that the sample was unrepresentative of the general population in Ontario, Canada.A second limitation was the lack of cost analyses. Healthcare utilisation outcomes, with their associated cost implications, will be handled in separate analyses that are underway.Third, the qualitative study was not a full process evaluation. Therefore, future studies may want to include a process evaluation involving patients plus providers and decision makers.Fourth, lack of alignment of outcome measures with intervention goals and patient expectations may be a problem.Fifth, fidelity variations in some components of the intervention may have compromised impact.19 because it was provider created, which goes even further than a co-created intervention.15 The lack of impact on outcomes for patients with an income of <C$50 000 contrasts with Mercer et al ’s15 multifaceted intervention, which was effective for patients who were considered to be socioeconomically deprived; they focused on self-management support, more face-to-face time with patients, and continuity of care — aspects of care that could enhance follow-up to the TIP programme. A systematic review8 found improvements in mental health outcomes, as did the present study.The current study advances on previous work by testing an intervention that should enhance everyday practice. This intervention should overcome the problem of implementation lapses found in other studies,Three possible explanations are offered for the neutral results in the pragmatic trial, each of which has implications for practice and research: the usual care received by the control group; the outcome measures; and the intervention itself. Each will be considered in turn. The first possible explanation is that usual care received by the control group may have been beneficial. The authors noted that the majority of control group patients experienced usual care within an Ontario-wide enhanced primary care team model, with interdisciplinary providers and continuity of care. The implication for practice is that some patients may benefit from the features of usual care whereas others may benefit from the multi-provider case conference, and future research can assist family physicians in their selection of which care is beneficial for which patients.With regard to outcome measures, the trial presented here found a positive impact on the mental health outcome for a subgroup of patients and the qualitative findings focused on patients’ functional goals, as well as patients feeling validated, liberated, optimistic, and hopeful. Future research could use existing measures or develop new measures of mental health, patients’ function, and patients feeling validated.18 The number of nurse hours during the followup period, and how these hours are used, may need rethinking; such a rethink could involve increasing the involvement of the FP and the multidisciplinary team in the follow-up to better support the patients. Both of these findings regarding the number of providers and nursing hours imply a level of complexity that led to patient frustration ; solutions to that may be specifically coalescing the plan into written, actionable steps and more support to the patient in carrying out the plan.With regard to the intervention itself, the qualitative findings and the fidelity assessment point out two aspects of the intervention that could be strengthened to enhance patient outcomes. Having ≥6 providers in the case conference was linked to negative outcomes, suggesting that the ideal/optimal team composition may need to be tailored to patient preferences — tailoring has been proposed by others.49 The ≥C$50 000 income group seemed to benefit from the intervention and those <C$50 000 seemed to benefit from usual care. The result, if replicated, could influence decisions in practice such as advocating to ease costs for a lower-income patient, and should encourage policies to cover such services.Patients qualitatively experienced promising effects of the very recommendations that required an extra outlay of costs — that is, those not covered by Ontario, Canada’s universal healthcare system — such as physiotherapy and psychotherapy. As well, patients’ income was implicated in the trial. In Toronto, 36% of people have an income of ≥C$50 000 and 64% <C$50 000.In practice, the intervention could be improved by optimising team composition to align with individual patient preferences and reducing any frustrations for patients by having a clear care plan with actionable steps. For the subgroup of patients experiencing deprivation, additional supports such as identifying sources of financial assistance will be needed.19In research, the differences between income groups need to be replicated. Also piloted, provider-created interventions could be trialled to diminish the difficulties of implementation experienced by some researchers.The study findings support a suggestion that future research assessing interventions for multimorbidity include outcome measures on mental health, patients’ function, and patients feeling validated.In policy, equity in patient-centred multimorbidity care may become an increasingly compelling issue.


Cooking at home is likely to be associated with benefits to diet and health. However, the nuanced perceptions and practices linked to different types of cooking are not yet fully understood. This research aimed to explore the specific concept of ‘home cooking’, using qualitative research from the UK and US. Data from two previously completed studies exploring cooking at home were combined and a new secondary analysis was undertaken using the Framework Method. Data in the first study were drawn from participants in the North East of the UK who were interviewed. Data in the second study were drawn from participants in Baltimore, US, who took part in focus groups. Data from a total of 71 adults (18 UK and 53 US), with diverse sociodemographic characteristics and experiences of cooking, were analysed. In both countries, participants distinguished ‘home cooking’ as a distinct subtype of cooking at home. ‘Home cooking’ was defined in terms of preparing a meal from scratch, cooking with love and care, and nostalgia. Cooking at home had a range of dimensions, and perceptions of ‘home cooking’ tended to focus on social and emotional associations. In future, public health initiatives might, therefore, highlight the potential social and emotional benefits of ‘home cooking’, rather than emphasising implications for physical health. The vast and growing international burden of ill health contributed by diet-related non-communicable diseases (NCDs) such as obesity, type II diabetes, and several types of cancer  has beenThese observations have led some experts to conclude that promoting cooking at home, particularly traditional cooking ‘from scratch’ using basic ingredients, and encouraging the development of cooking skills, could offer one solution for addressing the concerning prevalence of diet-related NCDs . HoweverQualitative research has been used as an effective approach to develop insights into the multifaceted nature of home food preparation behaviours and perceptions ,23,24,25The work presented here aimed to explore the meanings and values embedded in ‘home cooking’, as distinct from other types of cooking at home, using data from two previous qualitative studies in the UK, and the US, that investigated cooking perceptions and behaviour. Combining data from these studies yielded a larger and more diverse participant sample and facilitated exploration of similarities and differences between two developed countries that have both undergone similar food system transitions, and face similar challenges regarding diet-related NCDs. The North East of England and Baltimore experience greater deprivation compared with respective national averages ,27, and The findings from the UK interviews  and US fThis study is reported recognising the principles of the consolidated criteria for reporting qualitative research (COREQ criteria) . The metIn brief, the UK study aimed to investigate home food preparation practices, experiences and perceptions through semi-structured interviews. Participants were purposively recruited from the city of Newcastle upon Tyne and surrounding area in the North East of England. A total of 18 participants were recruited through voluntary organisations, community, health and employment groups, social media and academic networks. A sampling matrix, using information on age, gender, ethnicity, marital status, household composition, and self-reported weight and interest and skills in cooking, was used to ensure a diverse sample. The matrix also included deprivation, using the 2015 Index of Multiple Deprivation (an area-based measure of deprivation using a range of routine statistics) . EligibiThe US study aimed to explore perceptions of concepts related to cooking at home amongst American adults. Specifically, the research sought to examine individuals’ perceptions of what it means ‘to cook’, and to investigate important factors in how cooking is viewed and practiced. The study was undertaken in Baltimore, Maryland, where 53 participants were recruited from two urban neighbourhoods with contrasting sociodemographic populations and levels of neighbourhood socioeconomic disadvantage (based on median income and food access). In common with the UK study, this approach aimed to ensure a diverse participant sample. Volunteers responded to fliers posted at neighbourhood food outlets, libraries, churches and apartment buildings, and participated in one of seven focus groups. Inclusion criteria included being aged 18 years or over and living within the recruitment neighbourhood (based on self-report). Participants were accepted on a first come, first served basis. Group sessions lasted for approximately 90 minutes and were facilitated using an iteratively developed discussion guide, covering a wide range of topics related to perceptions of cooking and cooking behaviour see .In both the UK and US studies, basic field notes were taken, and audio recordings of the sessions were transcribed verbatim by a professional service. All subjects gave their informed consent for inclusion before they participated in the study and the study was conducted in accordance with the Declaration of Helsinki. The UK data collection was approved by Newcastle University Faculty of Medical Sciences Research Ethics Committee, application number 008585 2015. The US data collection was approved by Johns Hopkins University Institutional Review Board, application number 6027.The UK interviews and US focus groups were undertaken discretely. Therefore, the lines of questioning used were tailored to the respective research methods and differed slightly. The secondary analysis presented here, combining datasets from the UK and US studies, provided a novel opportunity to explore in-depth the meanings and understandings of the specific concept of ‘home cooking’. Both primary data collection studies were similar in employing a qualitative approach and focusing on the perceptions and practices involved in preparing food at home. The combined analysis was enriched by comparing ‘home cooking’ between two distinct cultural settings, with differing national influences and sociodemographic characteristics.Framework Analysis  was usedThe findings were drawn from a cross-country sample of 71 participants (18 UK and 53 US), with wide-ranging sociodemographic characteristics. One UK participant withdrew at an early stage in the study after expressing initial interest, leaving data from 71 participants for analysis see . Due to In both countries, the majority of participants were female. The US sample was more ethnically diverse than that drawn from the UK, and participants in the US were generally from older age groups than in the UK. A greater proportion of US participants described their marital status as single, compared with the UK. In terms of self-reported weight status, the majority of UK participants were overweight, whereas most US participants self-reported a normal or healthy weight.Overall, participants in both the UK and US highlighted that practices and perceptions associated with cooking at home could vary greatly between individuals. Participants from both countries also perceived ‘home cooking’ as a distinct subtype of cooking food at home more generally. Emergent themes are described in further detail below, illustrated by participant quotations. The themes highlight the complexity of relationships between cooking and health, social and emotional values, and indicate that ‘home cooking’ as widely perceived is more closely associated with potential social and emotional benefits.Perceptions of cooking at home varied between individuals, in both the UK and US. Although a systematic analysis was not undertaken, these distinctions did not appear to be related to sociodemographic characteristics, and were largely consistent between countries, despite the social and cultural diversity within and between the two participant samples. In the US, however, greater emphasis was placed on the role of heat in the concept of cooking:It’s just that for me, cooking does mean something was heated. US Participant 35, female.Many participants recognised that cooking was a very personal activity, and others’ definitions could differ from their own. As one participant noted:I think that cooking and home cooking means something different to everyone. US Participant 46, male.For some participants, the term cooking at home encompassed all food preparation undertaken in the home, regardless of the extent of incorporating raw or basic ingredients. Viewed from this perspective, cooking at home included for example, heating a pre-prepared pizza in the oven, or adding hot water to a pot of instant noodles. Other participants considered that cooking should incorporate food skills and some degree of personal effort and involvement in the meal, such as chopping, combining and heating ingredients to produce a sauce.Well actually, I’m more of a microwave man, if you want to call that cooking. US Participant 27, male.Throughout the cross-country sample, participants differentiated ‘home cooking’ as a distinct subtype of cooking at home, with unique properties. Three key overlapping themes emerged, which were consistent between participants from both the UK and US: cooking from scratch, demonstration of love and care, and nostalgia. These are presented in turn below, supported by participant quotations.Many participants described ‘home cooking’ as cooking ‘from scratch’ using basic ingredients that were raw or otherwise not processed. This definition of ‘home cooking’ excluded many convenience foods and ready-made products, though appeared to include widely used time-saving ingredients, such as dried pasta and tinned tomatoes. By focusing on the concept of cooking from scratch as the key principle of ‘home cooking’, emphasis was placed on the knowledge, general food skills and technical cooking skills required, and the creativity involved in producing composite meals from basic components. Many participants considered that other types of cooking at home also often included raw ingredients, but that these other types could incorporate convenience foods too. Thus ‘home cooking’ was a special subcategory, undertaken from scratch using basic ingredients only. To me home cooking means making something from scratch rather than from a pre-prepared item. For example I don’t think that if I buy a Pillsbury crust [frozen pastry] that I bring home and thaw and roll out, to me that’s not home cooking because I could have made the crust [pastry] from scratch. US Participant 46, male.Make it from scratch and start on it from fresh fruit and vegetables or whatever you’re doing and you make it yourself. Rather than buying it and warming it up you make it yourself… UK Participant 12, female.Preparing from scratch. So not convenience food, and not ready made chicken cooked from frozen, it’s like buying fresh stuff, cooking it from scratch. UK Participant 11, female.Participants also highlighted the meaning of ‘home cooking’ as a demonstration of love and care. In this context, producing a ‘home cooked’ meal was often an opportunity to fulfil a duty or desire to care for dependents or loved ones, and involved enacting the role of a provider. This description linked with the concept of preparing a meal from scratch, by identifying the personal effort inherently involved in ‘home cooking’, and hence the potential to demonstrate love and appreciation for others through the preparation of a ‘home cooked’ meal.Home cooking? It’s almost one of those warming kind of expressions, isn’t it? You think of mum, you think of a farmer’s wife… It kind of engenders that kind of feeling about it… And, of course, you see that kind of thing outside pubs, don’t you? It kind of pulls you in, home cooked. It’s not saying it was made in a factory or processes. There’s love gone into it. So, to me that’s what that suggests… But yeah, yeah, it’s all that kind of warm, loving, tender, thoughtful preparation of food. UK Participant 3, male.And also the other ingredient about home cooking is the love because it’s something about knowing that somebody took two hours to make this from scratch, winter soup with fresh garlic and you have to do the eggplant [aubergine] first and then you cook it with the other ingredients and it takes so long. One time I made a homemade soup for my pastor. And my pastor’s wife’s comment was, “Oh my goodness, Sister, you can taste the love in it”. US Participant 1, female.You got to put your heart into it. Because when you [are] cooking a home cooked meal, you put love into it. You’ve seen people roll biscuits  and how they shape them and how they want them to all look the same. They are like when you do a meatloaf you got to toss that thing and pat it. You got to put your heart into it. US Participant 40, male.I know she put love and time and energy into that so I guess I still feel like that’s home made even if it has a different—it clearly has a different nutritional value. It clearly has a very different cooking style but I think it’s the love and the effort that went into it. US Participant 33, female.A third theme that emerged from participants’ responses associated ‘home cooking’ with nostalgia. Here, participants’ previous personal experiences shaped their understanding of the nature of ‘home cooking’. Meals cooked at home in childhood or earlier in life were often recalled with fondness. The home setting—often perceived as a secure and loving environment—as the location of food preparation may also have contributed to positive sentiments associated with ‘home cooking’. Favourite meals or those frequently provided by a caregiver were often cited as typical examples of ‘home cooked’ meals. ‘Home cooking’ associated with nostalgia also often appeared to determine the type of cooking practices and meals that participants ideally desired to emulate themselves.Yeah. I think it would probably be an image of what my mum would do. When I was growing up. And that was always a meal from scratch… We very rarely had anything like oven chips or pizza unless it was like a weekend treat. So it would normally be things like—it would always be like your typical kind of meat and two veg… UK Participant 2, female.Like mince and dumplings and things. It makes me think of what your Nana [grandmother] would cook. UK Participant 10, female.Now nobody whip up pancakes no more like they used to: put them on the frying pan, flip them up… Everything now comes quick. That’s not home cooked. It might be cooked at home but it’s not home cooked. US Participant 25, male.Across all these three themes of: cooking from scratch, demonstration of love and care, and nostalgia, ‘home cooking’ was perceived as more time and energy intensive, and sometimes more difficult, than other types of cooking at home, and not necessarily always achievable on a daily basis. ‘Home cooking’ was also highly valued and seen as socially desirable. For participants from both the UK and US, ‘home cooking’ was closely tied to cultural identity and traditions, and relationships with family and friends.It’s like a culture, like my own culture, home cooking my own food from back home where I come from… UK Participant 13, female.That’s home cooking to me, doing it with your friends and family. UK Participant 14, female.Whilst it was important for some participants that their definition of ‘home cooking’ included preparing meals from scratch or using basic ingredients, the strong emotional, social and cultural values of ‘home cooking’ were the defining qualities that differentiated ‘home cooking’ from other types of cooking at home.The main potential benefits associated with ‘home cooking’ were generally based on social, cultural, and emotional gains, and occasionally with dietary advantages derived from using raw foods or traditional cooking techniques that were not reliant on highly processed ingredients. Participants’ accounts of ‘home cooking’ were often associated with positive memories, happiness and with overall wellbeing.I love baking my cakes… More so if I’ve got… if I’ve just got my girls in, weekend… Because it involves them, you see. UK Participant 12, female.Many participants described pleasure in cooking a meal for others, and a sense of satisfaction in creating a dish from basic ingredients. They felt that ‘home cooking’ was important for fostering strong and loving personal connections. Participants stated:So in the house, as long as I’ve cooked the main meal, you feel comfortable because you can have anybody sit and have a meal with you. UK Participant 7, female.I love home cooked food. I came from a family that [were] from the south, North Carolina, South Carolina, Virginia. I ate the gamut of foods, rice, potatoes, whatever. And I like for my food to taste like it was cooked with just a little bit of love going in that gravy, going over them potatoes. It has a certain taste. US Participant 9, female.There were few perceptions of ‘home cooking’ directly related to more clinical concepts of dietary quality and health, such as this participant’s view:To me, what defines home cooking is that you put all of the ingredients in it and the main thing is it’s not pre-packaged, pre-prepared or preserved because the stuff that they’re adding to food now to increase the shelf life, the high fructose corn syrup… and like she said, even what makes the frozen foods last so long is they add a lot of sodium to it. You don’t have that extra stuff going into your diet. You know what you have in it. It’s fresh… And I think that helps even your health because everything affects your health, your mood, the way you feel. I think home cooking is an important necessary ingredient for healthy living. US Participant 1, female.In both the UK and US, perceptions of ‘home cooking’ usually had little association with eating healthily and promoting physical health. Although cooking at home more generally may be used as a strategy to control one’s diet and attempt to eat more healthfully , particiQualitative data from combined UK interviews and US focus groups investigating cooking at home showed that in both countries, ‘home cooking’ was identified as a distinct subtype within the category of cooking at home more generally and values ascribed specifically to ‘home cooking’ were similar. Three key themes concerning the meanings and values inherent in ‘home cooking’ were identified, namely cooking from scratch, demonstration of love and care, and nostalgia.These insights provide additional opportunities for exploring potential relationships between cooking, diet and health. Cooking at home and developing cooking skills have been promoted in both the UK and the US as strategies to help improve diet quality and the prevalence of dietary related NCDs ,28,29. HThis study benefits from a number of strengths. The study design is novel, using qualitative data from two countries to focus specifically on ‘home cooking’ as a subcategory of cooking at home. The UK and US have experienced similar changes in the wider food environment in recent decades and face comparable challenges regarding the high and escalating prevalence of dietary related NCDs. Therefore, exploring the meanings and perceptions of ‘home cooking’ among participants from these two countries provides an opportunity to inform public health promotional messaging, and development of potential future cooking interventions, in both localities. The few previous international comparative studies of cooking have largely been quantitative, and addressed for example time spent on cooking , attitudHowever, the research is also subject to limitations. The combined qualitative data sample was drawn from two separate populations, using different data collection methods. Interviews and focus groups tend to have distinct aims with regards to participant interaction and reaching consensus , which cData analysis in this combined study required data merging, which created an extra analysis step, with associated additional potential for introduction of researcher bias. Nonetheless, at all stages of the research we endeavoured to ensure reflexivity and confront any prior biases and assumptions brought to the study. This was undertaken by cross-checking the interpretation of emergent themes between coauthors and considering the research findings in the context of existing related literature.In common with the majority of qualitative research studies, the findings presented here were generated from a relatively small number of participants and may not necessarily be more widely generalisable. In particular, the nature of cooking at home, and meanings and values attached to associated terminology, are likely to differ from those in less developed countries with more traditional cooking cultures. However, the concordance in themes between participants in both the UK and US, and support for findings from previous studies, suggest that the key concepts identified here are likely to be transferable to other similar population groups, especially those of Northern European heritage.Overall evidence to date indicates that cooking at home more generally may be associated with diet, health and social benefits . HoweverThis research indicated that health did not appear to be a key consideration within the concept of ‘home cooking’. However, potential social advantages were noted. Participants described demonstrating love and care for others through ‘home cooking’ and reflected on pleasurable ‘home cooked’ meals shared with family and friends in the past. This supports evidence that cooking may help facilitate bonding between families and friends . The famDespite the caveats identified around potential diet and health implications of ‘home cooking’ specifically, the broader concept of cooking at home remains integral to most people’s dietary patterns. Cooking from basic ingredients has to a certain extent been declining in high-income countries in recent years ,3, but nOverall, the findings presented here suggest that public health initiatives to tackle diet-related NCDs may involve the promotion of cooking at home as a strategy offering potential diet, health and social benefits. However, such messages should advocate clearly and carefully, and might most successfully focus on potential social and emotional gains. Public health nutrition campaigns should aim to integrate the promotion of cooking with broader dietary guidance, such as recommendations for the consumption of wholegrains and fruit and vegetables . TraininTo our knowledge, this is the first study to directly elicit and describe differences between the specific meanings and values inherent in ‘home cooking’, and those associated with cooking at home more generally. Previous research has indicated that cooking practices and perceptions are shaped both by individual determinants, such as socioeconomic status ,50, and This study builds upon previous evidence indicating that cooking food at home is not one single process or entity, but rather spans several continua of perceptions and behaviours, with associated implications for health ,9,12. ThThe findings reported in this study support previous research indicating that ‘home cooking’ is perceived as a ‘proper’ or superior method of cooking . HoweverThis cross-country study combined qualitative data from the UK and US, highlighting ‘home cooking’ as a concept distinct from cooking at home more generally. Three key emergent themes regarding the meanings and values associated with ‘home cooking’ were identified: cooking ‘from scratch’ using basic ingredients, demonstration of love and care, and nostalgia. These themes suggest that dietary health concepts are not necessarily embedded within interpretations of ‘home cooking’, and greater emphasis is placed on social and emotional associations. Given that cooking at home more generally plays a fundamental role in societal eating patterns, and may offer diet, health and social benefits, public health initiatives should continue to promote cooking at home. However, further research exploring definitions, perceptions and experiences associated with different potential subtypes of cooking at home is required.


In this article, we study the applicability of Benford’s law and Zipf’s law to national COVID-19 case figures with the aim of establishing guidelines upon which methods of fraud detection in epidemiology, based on formal statistical analysis, can be developed. Moreover, these approaches may also be used in evaluating the performance of public health surveillance systems. We provide theoretical arguments for why the empirical laws should hold in the early stages of an epidemic, along with preliminary empirical evidence in support of these claims. Based on data published by the World Health Organization and various national governments, we find empirical evidence that suggests that both Benford’s law and Zipf’s law largely hold across countries, and deviations can be readily explained. To the best of our knowledge, this paper is among the first to present a practical application of Zipf’s law to fraud detection. Confirmed cases of COVID-19, the disease caused by the SARS-CoV-2 virus, were first discovered in the Chinese city of Wuhan in late December of 2019. Shortly thereafter cases began to emerge throughout Asia, Europe, and the Americas, with only a handful of countries successful in containing the disease. The unprecedented nature of the pandemic, the economic damage of which is unrivaled in recent history, has lead to calls for an international inquiry into the global response to the pandemic. Chief among concerns is the validity of case numbers reported by governments, and in particular whether falsified data lead to a failure to take the disease seriously. Operating under the Russian proverb “trust, but verify” there is a clear need for rigorous statistical techniques to detect fraud, if any, in epidemiological data. Such techniques will not only help detect fraudulent behavior, but also verify the authenticity of published case figures and hence restore trust.Fraud detection is often predicated on the assumption that naturally occurring data sets obey certain empirical laws, and hence deviations from these laws are believed to be an indication of modified or falsified data. In the case of epidemiological data, which tracks the development of an epidemic, there are two primary ways in which empirical laws might emerge. The first is the development of the disease over time; the rate and the nature of growth in cases is of particular interest. The second is the distribution of cases over space. Given a country that is divided into sub-national regions, how should the number of cases be distributed across the country? For instance, cases that are disproportionately concentrated in a handful of regions might indicate underreporting in other areas by local authorities.In this paper, we consider two different sources of fraud within epidemiology. The first is fraud at the national level, perpetrated by the central government, perhaps motivated by the desire to avoid travel bans and a decline in tourism, among other reasons. We propose that this might be detected using the well known Benford’s law which defines the distribution of leading significant digits in a data set, and has been observed to occur in many naturally occurring processes in the social and physical sciences. Benford’s law has long served as a litmus test in the detection of financial fraud –3. More A number of empirical works have been published in recent years applying Benford’s law to epidemiology and public health surveillance. Idrovo et al.  applied This paper builds on the existing works in several important ways. First, we go beyond the traditional base 10 Benford’s law by also considering smaller bases, as well as the second digit, expanding the scope of the existing empirical literature as suggested by the results given by Gómez-Camponovo et al. . Second,The second source of fraud is at the sub-national level, with falsified data provided to the central government by local authorities. We propose that Zipf’s law, another well known empirical law, might be employed to detect fraud by both local and central governments. This law emerges naturally from collections of stochastic growth processes with common mean and variance, and hence is highly suited to investigating the spread of disease among collections of similar regional populations; if we have homogeneity between regions in terms of culture, development, and demographics, then they should follow similar growth trajectories depending on the infectiousness of the virus at hand. Under the assumption that Zipf’s law holds for the geographic distribution of a disease, supported by empirical studies including this one, we propose the use of Zipf’s law as a diagnostic tool for flagging anomalous case figures. At the national level, a country with regional case figures that show significant deviations from Zipf’s law might indicate fraud by the central government. At the sub-national level, a country that largely obeys Zipf’s law with the exception of several regions may indicate fraud by the local authorities of the regions in question. The latter interpretation may find particular use by central governments in assessing the accuracy of data provided by local authorities; if the central government does not release figures by region, then it would be difficult for local authorities to falsify data since Zipf’s law concerns the relative sizes of multiple processes. Although the application of Zipf’s law to fraud detection is not as widespread as Benford’s law, we believe this is primarily due to the fact that it is often studied in fields where fraud is not a major concern. This paper therefore is among the first to present a practical application of Zipf’s law to fraud detection. Moreover, the theoretical argument that we present is based on collections of stochastic growth processes that is readily carried over to finance and econometrics, enabling the development of novel fraud detection methods in these fields as well. Finally, Zipf’s law may also be useful in evaluating the performance of public health surveillance systems at the sub-national level; namely, a few regions deviating significantly from Zipf’s law may indicate inadequate epidemiological surveillance systems in these regions relative to the rest. The application of Zipf’s law to public health surveillance is therefore a possible area of future research that builds upon this paper.This paper is organized as follows. First, we present a theoretical argument for the emergence of Benford’s law in epidemiological data, followed by an empirical study examining the goodness of fit of COVID-19 case figures to the theoretical distribution of leading digits predicted by Benford’s law using a chi-squared test. We further provide a detailed explanation of how the observed deviations from Benford’s law are readily explained by government intervention and testing constraints. Next, we present a theoretical argument for the emergence of Zipf’s law in the geographic distribution of cases, and examine the goodness of fit to Zipf’s law using the common ordinary least squares (OLS) and log-log plot approaches, as well as the power law test proposed by Clauset et al. . We discnth leading digit.Benford’s law, also known as the Newcomb-Benford law, states that the leading digits of many naturally occurring processes tend to be small . The lawb ≥ 2, Benford’s law predicts the distribution of the first leading digits d ∈ {1, 2, …, b − 1} to benth leading digit approaches a uniform distribution exponentially fast as n → ∞, and hence the empirical analysis is typically limited to the first few leading digits   I(t) denmic (see . Writingt+1R)I(t)while thby Boyle , Benfordby Boyle  show tha1×At×⋯×A1whereAtθ. In reality, decentralized and centralized preventative measures are likely to be implemented once the outbreak becomes severe, and hence the dynamics of disease transmission are likely to change. Moreover, even if the disease is allowed to spread uncontrollably, it will inevitably burn itself out due to the finite population size. We therefore reiterate that Benford’s law is only expected to hold in the initial stages of an epidemic, and so the time period considered must not be too large in order to ensure that t = 0, 1, …, T, and that major government intervention has not yet been implemented. In addition, it should be noted that asymptomatic cases might exist which tend to have a different basic reproductive number than symptomatic cases. However, the parameter θ is then simply a probability weighted average of the infectiousness of different groups categorized by manifested symptoms. Indeed, the main problem introduced by asymptomatic cases is the difficulty in observing them; absent a comprehensive and ongoing community testing scheme, the observed number of cases is likely to be biased in favor of symptomatic cases. Therefore, the prevalence of asymptomatic cases must be taken into consideration when making inferences.The above explanation assumes a static infectiousness Since we do not observe the spread of the disease directly, reported case figures will be estimates based on diagnostic tests with two primary sources of error. First, only suspected cases are tested, while the remaining cases go unobserved. Second, tests may provide false-positives and false-negatives. Logistical constraints on testing can also cause deviations from Benford’s law which are not necessarily indicative of falsified figures. If a government is constrained by a fixed number of tests per day, while the true case number increases by a rate much larger than this limit, then the cumulative confirmed cases will grow linearly, not exponentially. Berger and Hill  show thab, obeys  to adequately ramp up testing in the early days of the outbreak. Fewer than 4, 000 tests were conducted in the United States by February 28th, exacerbated by the discovery that 160, 000 tests produced throughout February were defective [For the United States, we find that Benford’s law is rejected at the 5% level for times efective . Moreoveefective . We see China’s rejection of Benford’s law in all bases can be explained by a combination of being the epicenter of the outbreak, which naturally causes a backlog of undiscovered cases, difficulties in developing the initial tests, and finally strong government intervention. China’s cumulative case process, given in T ≥ 60, and this is readily explained by government social distancing measures. The start date for France was March 2nd; subsequently on March 17th the French government initiated a lockdown [T = 60. Similarly, the start date for Spain was February 26th, while on March 14th a lockdown was introduced, leaving 43 days for it to affect the rate of transmission [T = 60, combined with the cumulative case process plots in Both France and Spain only reject Benford’s law for lockdown . This gismission . Given tT = 60. Referring to Romania’s cumulative case process plot in T = 20. As previously mentioned, constraints on testing would result in linear growth, and hence logistical constraints causing inadequate testing might explain this. However, we have been unable to find reputable sources that substantiate this explanation, and so the possibility of fraudulent activity cannot be ruled out.Finally, we find that Romania rejects Benford’s law for base 3 at In summary, we find a substantial amount of agreement between COVID-19 case figures and the leading digit frequency distribution predicted by Benford’s law. For all countries that reject Benford’s law at various bases or time periods, we find there are plausible reasons to explain the deviation, including government intervention, constrained testing, and poorly defined start dates. In fact, that Benford’s law only breaks down for some countries following government social distancing measures supports the efficacy of these measures in slowing down transmission of the disease. The results also substantiate the theoretical argument that we have presented to explain why the early stages of an epidemic should give rise to Benford’s law, and hence lay an empirical foundation for developing formal statistical fraud detection techniques in epidemiology.Z1 > Z2 > ⋯ > ZN, in which data points are labeled by their rank (r), Zipf’s law is said to hold if the log-log plot of ln(Zr) and ln(r) is approximately linear. Specifically, the law asserts thatr = 1, 2, …, N, where α, β > 0, and εr is an error term. This linear relationship is also referred to as the rank-size rule; some authors, such as Gabaix [Zipf’s law is an empirical law that has been observed in many naturally occurring data sets of the social and physical sciences. Given a data set s Gabaix , use Zips Gabaix , 33.Zipf’s law has been observed in many fields in the social and physical sciences, including the ranking of city sizes by population . In factSince Zipf’s seminal work, multiple explanations have been proposed to explain the frequent emergence of Zipf’s law in the social sciences. We begin by presenting a brief summary of the explanation given by Gabaix  in the ci at time t among a collection of cities, the total number of which is fixed and finite. Here, the normalized city size is simply the city population divided by the entire urban population, and the initial distribution of cities is arbitrary. It is assumed that the normalized city sizes, at least over a certain range, evolve stochastically over time. Specifically, suppose that in the upper tail the evolution of city sizes is of the formf(γ). Define G = Gt, if it exists, must satisfyG(x) ∝ xβ−, with β > 0, provided that we also have β = 1, which is the proposed explanation for the emergence of Zipf’s law for city sizes. Gabaix [β > 1.Let eader to . Gabaix eader to  notes theader to  these ad. Gabaix  notes th. Gabaix  also poix is sufficiently large, and β > 0. The rank-size relationship  and common variance. This assumption is often referred to as Gibrat’s law, and implies that the proportional rate of growth is independent of the current absolute size. The construction by Gabaix  shows thtionship  is then tionship  holds fox; instead, power laws typically only hold for values greater than some minimum value xmin, which must be estimated. This can be seen in the size rankings of naturally occurring cities [Few empirical phenomena obey power law distributions for all values of g cities , gross dg cities , world cg cities , and Engg cities .Ii(t) is the normalized number of infected in region i. That is, Ii(t) is the number of infected individuals in region i divided by the total number of infected nationally. Considering that the disease is identical across each region, with a given level of infectiousness, and assuming that there is homogeneity between regions in terms of culture, population density, and development, it stands to reason that each region shares a common level of infectiousness θ > 0 and common recovery rate δ > 0. In this case, we again consider the form of model proposed earlier, withi, where Ii(t) are assumed to be normalized, we must haveβ = 1. It is important to note that condition  distance between the empirical and theoretical power law distributions, defined asxmin, and F(x) is the power law distribution of best fit for data above xmin [K. We employ this method to obtain estimates of xmin using the R package poweRlaw.Clauset et al.  note thaove xmin . The proxmin, which is again implemented using the package poweRlaw. The test statistic used is the KS distance  and Russia can be explained by a change in the power law exponent, as shown in the log-log plots of xmin outlined in [The results of each country are summarized in he model  is at lelined in  leads toFor Russia, the first power law applies to the regions of Moscow, Moscow Oblast, Saint Petersburg, Novgorod Oblast, Dagestan, and Murmansk Oblast. With the exception of Dagestan and Murmansk Oblast, these correspond to developed areas in the European part of Russia, which would seem to support the conclusion that the change point relates to level of development. However, Dagestan sits in the North Caucasus and Murmansk Oblast in the far north bordering Finland and Sweden, and so it is difficult to explain how they relate to the highly developed regions surrounding Moscow and Saint Petersburg. It is possible that the first cases in Russia were seeded in larger transport hubs such as Moscow and, by pure chance, also happened to be imported to Dagestan and Murmansk Oblast around the same time, so that they followed similar growth trajectories compared to regions which did not experience their first cases until much later.R2 cannot be explained by a change point; the number of cases in Hubei is disproportionately large relative to the remaining provinces. However, if we assume that sustained community transmission had only just begun in the remaining provinces when COVID-19 was first discovered, the discrepancy might be explained by the significantly different growth trajectories following government intervention. The virus was allowed to spread uncontrollably in Hubei before its detection, but not in the bordering provinces, resulting in vastly different growth trajectories.Meanwhile for China (excluding Hubei) the first power law applies to Heilongjiang, Shanghai, Jilin, Inner Mongolia, Beijing, Shaanxi, Guangdong, Shangdong, Tianjin, Fujian, Shanxi, Liaoning, and Hebei. Note that these mostly comprise of coastal provinces with the exceptions of Inner Mongolia, Shaanxi, and Shanxi. Given that coastal provinces are much more highly developed, and also tend to have a higher population density, it makes sense that a change point would differentiate coastal and inland provinces. When we include Hubei into the analysis of China, the low β cluster around 1, supporting the theoretical argument based on the construction by Gabaix [β = 1. It is interesting to note, however, that these estimates can vary quite significantly for some countries; Canada has an OLS estimate of just 0.34 while the United Kingdom has an OLS estimate of 2.24. This difference is caused by the fact that the Canadian cases are highly concentrated in the provinces of Quebec and Ontario, which together account for 84% of COVID-19 cases in Canada. Meanwhile, for the United Kingdom, the two largest regions account for only 30% of cases. Recalling that Gabaix [β > 1 occurs when “smaller cities grow faster,” the power law exponent estimate reflects the concentration of cases in a country. If β > 1, then smaller disease clusters will catch up with larger clusters, and the overall distribution of disease prevalence will tend to even out.Using the hypothesis test proposed in , we findy Gabaix  which prt Gabaix  notes β In summary, these results provide strong empirical evidence that disease outbreaks across a country obey Zipf’s law, albeit with a power law exponent that is not necessarily close to 1 for all countries. This provides a basis for which fraud detection in epidemiology might be based, along with a potential approach for evaluating the performance of public health surveillance systems at the sub-national level. On the sub-national level, the central government can perform statistical analysis to detect which regional governments report case numbers that deviate significantly from the observed power law. Regions that deviate significantly can then be flagged for further investigation by the relevant central authorities. On the national level, international organizations can track regional case figures of countries and flag nations which display little or no adherence to power law dynamics above any minimal threshold.There are several limitations to the approaches outlined in this paper that should be acknowledged. First, both approaches rely on a testing regime that accurately tracks the number of cases over time. If a significant number of cases are asymptomatic, then any practical testing regime is likely to be inadequate given that asymptomatic cases will generally only be detected through contact tracing and comprehensive community testing. The observed cases will therefore be biased towards symptomatic individuals, which might lead to erroneous conclusions. Hence, the approaches outlined in this paper are less appropriate for epidemics where the proportion of asymptomatic cases is large. Second, the Zipf’s law approach assumes homogeneity between regions and is therefore not suitable for countries where this assumption is violated. For instance, developing countries with large urban and rural disparities are less likely to satisfy this assumption given the impact that population density, lifestyle, and development has on the rate of transmission. Third, the models underlying each approach both assume no government intervention and a small number of cases relative to the population size. As a result, if the epidemic becomes particularly severe, applying these approaches beyond the early stages of the epidemic is likely to lead to erroneous conclusions. Finally, there are clearly some ambiguities in how the timeline of the epidemic should be defined when conducting statistical analysis based on either approach. On the one hand, the beginning of the epidemic should be set to when sustained community transmission first occurs, as opposed to simply when the first cases emerge, which might be difficult to determine with confidence. On the other hand, the end point of the analysis is also somewhat ambiguous; while we are restricted to the early stages of the epidemic, we also hope to maximize the sample size utilized. However, we note that these ambiguities could be addressed by developing nonparametric or semiparametric tests based on moving windows of varying lengths.This paper serves as a preliminary study of fraud detection in epidemiology using Benford’s law and Zipf’s law. We have presented theoretical arguments for why these empirical laws might be expected to emerge within the early stages of an epidemic, upon which statistical techniques for fraud detection may be developed. Although the theoretical constructions that we have proposed to explain the emergence of both laws rely on the same basic model, specifically a stochastic discrete-time compartmental model, each approach examines a different aspect of the data. The Benford’s law approach investigates whether the evolution of the number of cases displays anomalous behavior over time, while the Zipf’s law approach investigates whether there are any irregularities in the observed spatial distribution of cases.The empirical results that we have presented suggest a promising degree of agreement with both Benford’s law and Zipf’s law. During the early days of an epidemic, for which the number of infected individuals is small relative to the population, the cumulative confirmed case process appears to obey Benford’s law to a large degree. Moreover, this agreement appears to hold across a variety of bases, and also to the 2nd digit. This provides a practical means of automatically flagging abnormal case numbers reported by both central and local government agencies; case figures which develop abnormally over time can then be investigated further by the relevant authorities. In addition, we find that the geographic distribution of cases across a country, above a minimal threshold, appears to obey Zipf’s law. This provides a particularly convenient method of fraud detection to central governments due to the asymmetric information possessed between central and local government authorities. Without comprehensive case numbers for other regions, local authorities would be hard pressed to falsify data that consistently obeys Zipf’s law over time.xmin above which the power law holds, however this might itself raise suspicion if case figures are seen as unrealistically low. In the case of finance or econometrics, fraud normally involves inflated figures, and so this approach is not a concern to investigators. This paper therefore presents a foundation upon which further methods of fraud detection may be developed based on the construction by Gabaix [One of the significant contributions of this paper is that we have presented a practical application of Zipf’s law to fraud detection, which has been largely neglected by the fraud detection literature. The argument that we propose to explain the emergence of Zipf’s law in epidemiology is based on collections of stochastic growth processes and so is readily carried over to commonly encountered processes in econometrics and finance, for which there is an increasing need of rigorous statistical methods of fraud detection. Unlike Benford’s law, falsifying data to adhere to Zipf’s law is difficult in the presence of asymmetric information, as the empirical law involves multiple growth processes. For fraud in epidemiology, one approach to falsifying data would be to suppress figures below the minimum value y Gabaix . FurtherWe identify several important areas of further research that build upon this paper. First, more empirical studies should be conducted on past and future epidemics which were not met with widespread travel and social distancing measures. The actions taken by governments throughout the COVID-19 pandemic are unprecedented in scale and are likely to have an effect on the results. If the unmitigated spread of disease, based on data from prior outbreaks, shows a high degree of agreement with the empirical laws, it will help validate the theoretical arguments that we have presented. Second, operating under the assumption that the empirical laws hold, future research should develop more standardized and formal testing procedures with the aim of building a robust framework for the detection of fraudulent epidemiological data, including case studies to examine whether such methods would have detected previous cases of fraud in epidemiology. Future research could also focus on specific types of fraud, with tests tailor-made to identify that particular type of fraud. Finally, similar to the existing works based on Benford’s law, future works could explore the application of Zipf’s law to the evaluation of public health surveillance systems at the sub-national level.S1 File(ZIP)Click here for additional data file.S2 File(ZIP)Click here for additional data file.


In this study, we synthesized findings from qualitative studies to identify the key factors that influence child marriage. We used a meta-ethnographic approach coupled with thematic synthesis. We searched literature from nine databases, which were in English language, covering areas in public health, psychology, and social science between 2008 and 2018. Twelve studies were included in the synthesis. We identified six main themes: human insecurity and conflict; legal issues; family values and circumstances; religious beliefs; individual circumstances, beliefs, and knowledge; and social norms. Our findings highlight the impact of human insecurity and conflict, as well as legal issues. In spite of global progress scaling up legislation against child marriage, the legal framework is insufficiently enforced in many settings. Most of the included studies were from the Middle East, Africa, and South Asia. Studies from other parts of the world such as Latin America and Southeast Asia, which have the highest rates of child marriage, are needed. Child marriage refers to formal or informal marriage that involves children who are below the age of 18 . It is aThere are some theories in cross-cultural perspectives that are relevant to the investigation of factors that influence child-marriage. Kagitcibasi’s theory of family change suggests the link between sociocultural factors and development of the self, and family as a mediator . This moMeta-ethnography is an approach that synthesizes qualitative studies. It consist of seven phases; identifying an intellectual interest, deciding what is relevant, reading the studies, determining how the studies are related, translating the studies into one another, synthesizing translations, and expressing the synthesis . This meChild marriage often results in adverse health, economic, and social consequences . CatalyzThe devastating consequences of child marriage, and the negative impact of this practice on achieving development have been recognized by its inclusion in Goal 5 of the sustainable development goals (SDGs) . EvidencWe applied a thematic synthesis methodology  which coWe considered qualitative studies that meet the following inclusion criteria:Focus on the lived experiences of women who were married before the age of 18, and the perspectives of the stakeholders.Using data collection methods such as interviews, focus group discussions, case studies, or observations.Clearly state that the authors used qualitative methodology in the analysis.Published in English language.Published between Jan 1, 2008 and December 31, 2018.Criteria for exclusion were:Mixed method studies or studies including quantitative data.Focus on maternal care and care of the newborn.Commentary articles.The mixed method studies were not included in this synthesis, as it is difficult to distinguish what were the qualitative findings from quantitative results arising from a mixed-method study.We conducted a literature search using nine electronic databases including PubMed, PsycINFO, CINAHL, Scopus, ProQuest, Web of Science Core Collection, ScienceDirect, Kyoto University Discovery and Google Scholar. The search was conducted between April 2017 and December 2018. Key search words included: “women,” “girl,” “young*,” “teen,” “mother,” “child marriage,” “early marriage,” “teenage marriage,” “health,” “interview,” “focus group*,” “case stud*,” “observ*,” “view*,” “experience*,” “opinion*,” “attitude*,” “percep*,” “belie*,” “feel*,” “know*,” “understand*,” “qualitative.” We combined key words by applying the Boolean operators AND/OR.We screened all titles and abstracts of the initial 3,859 “hits,” and after eliminating duplicates and those not satisfying the inclusion criteria , we filtered 24 potentially eligible studies. We checked their reference lists and identified 11 further studies. Upon reading the articles in full text, we finally selected 12 studies for our analysis. We assessed the quality of the 12 selected studies using the Critical Appraisal Skills Programme (CASP) for qualitative research . This isThree researchers  independently read, reread, and appraised the articles. A three-point rating system developed by Duggleby and colleagues was adopted in this study to quantify the appraisal from the CASP checklist and obtain an overall score of quality . Each ofIn the analysis of the synthesized studies, the steps of thematic synthesis were followed as explained above. First, entire sections of each of the included studies were read and reread by three authors  in order to familiarize with the contents of each article. Subsequently, the text from the results and discussion sections of the included articles were coded inductively and individually “line-by-line” to derive initial codes. In doing so, we categorized the codes into three groups: “first-order” theme representing the perspectives and understanding of the participants with regards to the studies; “second-order” theme representing the primary authors’ interpretations; and “third-order” themes reflecting the researchers’ interpretations . Afterwards, based on the created codes, we developed “descriptive themes” that articulated the holistic perspective of multiple studies by comparing the codes developed for each study. Finally, we generated “analytical themes” by clustering and synthesizing the descriptive themes, and added our original interpretation. Microsoft Excel software was used for data management and analysis. Additionally, a qualitative metasummary was adopted as a way to visually represent the findings of this study by calculating the effect size . For theTwelve articles were included in this meta-synthesis; 6 of which were conducted in the Middle East (Lebanon and Iran), 3 in Africa (Nigeria and Morocco), 2 in South Asia (Pakistan and Afghanistan), and 1 in the United States. Sample sizes ranged from 6 to 125 ; subjects included women who were married before the age of 18; unmarried, divorced, or engaged adult women; and various stakeholders. The most commonly adopted method of data collection was individual interviews . The practice of child marriage was exacerbated by human insecurity and conflict. This theme appeared in nine of the 12 studies –37. In tIn the case of Syrian refugees in Lebanon, many of the participants, parents and adolescent girls, reported feelings of insecurity as they experienced verbal or physical harassment while residing in refugee settlements: “Fear of insecurity is a major factor. They are marrying early because of al Sutra. We have war. Many women are afraid of being raped, and if a married woman is raped, she is more likely to be forgiven by her husband but if an unmarried woman is raped, it will destroy her life” . In the Security concerns were evident both in the home country and in the settlements. There were reports that parents were purposefully sending their daughters from areas of conflict in Syria to get married at a young age in Lebanon, in order to escape the conflict and provide protection for their daughters. Parents were worried that their daughters may experience physical attacks or rape before getting married in Syria, which would not only harm the girls but also hinder their future: “Moreover, they [unmarried adolescent women] were also vulnerable to sexual harassment, and occasionally even rape due to living in unfamiliar and sometimes insecure areas and the breakdown of social networks” . In suchAnother factor causing insecurity among refugee parents or those living in the slums that encouraged early marriage was financial constraints. In the midst of the conflict, families in displaced settlements tended to be of large numbers and parents sought to relieve their responsibilities and reduce the family’s financial burden by letting their daughters get married at an early age: “Some people marry off their daughters at an early age because these are their traditions but others do it to ease the financial pressure. For example, there are fathers who are jobless and who have to provide for 5 or 6 people, so marrying off one of their daughters will help” . This isFor adolescent girls, the fear of not being able to find a suitable partner was a motivation to accept early marriage: “I knew him very well. They were very nice people… he met my criteria. I was going to school that time, but I thought, if I got married I would be better off because my husband had a good condition. I did not want to miss the chance.” Their idea of a perfect suitor was someone with a good personality, whether they know the family of the future husband or not. Further, there was a prevailing belief in the society under study, such as in southeast province in Iran and suburban area in Morocco, that when a girl’s age increases, her opportunities for marriage would diminish. This belief was prominent in the traditional Iranian culture, especially in the rural areas. Thus, it acted as pressure pushing the young unmarried girls to accept to get married at a young age at their first suitable opportunity.Among the 12 articles, legal issues emerged from four studies , 34, 36 In Morocco, despite the introduction of the new Family Code (Moudawana) in 2004 raising the minimum age for marriage from 15 to 18 years of age, there is an increase in the number of young women forced into marriage. There were 41,098 child marriages authorized in 2010, an increase of 23.6% from 2009. Sabbe et al. explored women’s perspectives on marriage and rights in Morocco in relation to the factors that contribute to child and forced marriages . The finSabbe et al. interviewed a broad range of stakeholders in Morocco about their perspectives on factors that contribute to child and forced marriage . Out of Raj et al. identified perspectives on the causes of and potential solutions to child and forced marriage among religious leaders, the police, teachers, and nongovernmental organizations (NGO) and government officials in Kabul, Jalalabad, and Mazar, Afghanistan . RegardiAmong the 12 studies, “family values and circumstances” emerged from 11 studies as a determinant for child marriage –40. The Mangeli et al. explored the perspectives of adolescent mothers in Kerman, Iran, with regards to factors that encouraged them to get married at an early age . “InstabMontazeri et al. interviewed women who visited the health care centers in Ahvaz, Iran, in an effort to understand the determinants of early marriage . “CulturFurthermore, the quality of the suitor seemed to have played a role in the parents urging their children to get married. Parents would encourage their daughter, regardless of her age, to marry a “suitable” candidate who is well educated and of good moral and economical status: “Regardless of girl’ age, if any suitor was morally and economically in good condition, parents would encourage their daughter to marry him: …‘The boy was polite, educated and had a good job. He also had no problem with me to continue my education after getting married. My mom wanted me to marry him’” . FurtherThe theme of religious beliefs appeared in nine of the 12 studies –36, 38. Several studies reported that child marriage was favored, based on the adherence to religious beliefs. As mothers and grandmothers taught their daughters and granddaughters that marriage was a prophet’s recommendation in Islam, an adolescent girl getting married at a young age was perceived as a good thing: “My mother and grandmother advised me to marry as soon as possible because marriage is one of our prophet’s recommendations” . In IslaSeveral studies reported that sexual relationships outside wedlock are considered as a religious taboo among Muslim communities. Because of the religious beliefs, in Islamic countries, the parents favor the decision of early marriage for their daughters when they find out that their daughters are engaging in premarital sex. Due to the fear of pregnancy outside wedlock, the parents quickly marry off their daughters at the first opportunity: “My family believed that marriage can protect me from sin [sex outside marriage]” . FurtherAbortion is forbidden by religion. In a study conducted in Lebanon, there were few women who wanted to interrupt their pregnancies but were unable to find abortion services, as abortion is against local religious practices [ractices . Unmarriractices .Among the 12 articles, individual circumstances, beliefs, and knowledge emerged as facilitators of child marriage from seven studies –38, 40. Loneliness was one of the motivating factors for child marriage. Due to feelings of loneliness, the young female adolescents were encouraged to get married at an early age. The feelings of loneliness stem from the experience of separation from family, friends, school, and other events in their lives: “As I have no sister or brother, father, mother or friends, I decided to get pregnant, no one was beside me” . The lonIn Iran, Montazeri et al. interviewed women who visited health care centers in Ahvaz to understand the determinants of early marriage , and MarThe theme of social norms appeared in 11 of the 12 studies , 40, 41.Some studies highlighted the issue of patriarchal ideology which influenced the decision of child marriage. This is a historically rooted problem, and such ideology is widely accepted among communities in Iran and Morocco as it functions as a powerful influence that places women in a submissive position to men , 34, 38.In Morocco, Iran, and Afghanistan, an unmarried status was considered as a threat to the social order for women and men alike , 36, 38.In some societies in the rural areas, there is a traditional practice of getting a child engaged at birth or during infancy. This is called “bad” or “badal” in Afghanistan, which refers to exchange of a child between the families or the communities in order to resolve conflict between them: “In our culture some girls are engaged at 2 years of age. Then her new family will wait for her for 8 or 9 more years; after that, they compel the family for marriage”  . In thisTo the best of our knowledge, this is the first study where meta-synthesis of the factors that influence child marriage has been performed. We synthesized the findings from 12 qualitative studies. Interviews were conducted among women who were married before the age of 18, as well as among stakeholders such as healthcare professionals, NGOs, and so forth. The majority of the studies were from developing countries in the Middle East (Iran and Lebanon), Africa , and South Asia (Afghanistan and Pakistan). The factors contributing to child marriage are complex and may vary across countries and regions.We highlighted 6 themes and 21 categories. Closely linked and universally addressed themes that were underscored in our findings were: “Family Values and Circumstances,” “Religious Beliefs,” “Individual Circumstances, Beliefs, and Knowledge,” and “Social Norms.” We also found that themes such as “Legal issues” and “Human Insecurity and Conflict” are relatively under-addressed. However, they are gaining more attention due to recent increasing concerns about laws regarding marriage at a young age and conflicts worldwide.“Family Values and Circumstances” seems to be an assortment of poverty and family ideologies that are in part shaped by cultural norms. In many impoverished contexts, marrying off the daughter at an early age is perceived as a strategy for economic survival for the family, and for the girl. Circumstances, in particular, family breakdown, divorce or death of a parent, often perpetuate financial constraints. Child marriage is also influenced by social norms and religious beliefs. In some regions, child marriage is believed to be the practice that preserves the family’s honor, to avoid the shame of having an unmarried daughter engaging in premarital sex or getting pregnant out of wedlock. Furthermore, in some societies, there is social pressure for women who remain unmarried for too long as their sexual purity is brought into question and this may jeopardize the family reputation . In manyGlobally, more countries are recognizing the harmful effects of child marriage, and are joining forces to scale-up legislations against this practice . HoweverOur study also underlines “Human insecurity and conflict” as a driver of child marriage. Growing evidence shows that the rate of child marriage is increasing at an alarming rate in humanitarian setting; nine out of the 10 countries with the highest child marriage rates are considered as either fragile or extremely fragile states . Seven oThere are mixed results of what works in halting child marriage. Kalamar et al. assessed high-quality interventions and evaluations to reduce child marriage in low- and middle-income countries . In theiIt is vital to address the interplay of each of the themes found in this study. For this viewpoint, we refer to the theories of family change and cultural tightness-looseness as the conceptual frameworks. Theory of family change highlighted that family act as a mediator of a young girl’s psychological development, as she grows up within a society and a culture . In addiThis meta-synthesis described the factors that influence child marriage. The factors are intertwined and interventions will not work if they fail to account for all. There have been some encouraging examples as described above. Social change would require multisectoral collaboration by various stakeholders, empowering the girls themselves, their families, and communities. The response must also comprise a combination of concrete actions that lead to social changes.From the results of this meta-synthesis, we also pointed out the lack of diverse studies in terms of income level, cultural and religious background, and geographical region. Most of the qualitative studies were from developing countries in Africa, the Middle East, and South Asia, lacking evidence from other parts of the world, such as Latin America and Southeast Asia, where the rates of adolescent pregnancies are the highest in the world . The lacIn practice, based on the findings of this study, it is important to introduce programs that can improve the enforcement of laws related to child marriage. As we observed, legal frameworks related to child marriage were insufficiently enforced in many settings. Therefore, it is imperative that interventions related to legal issues that prevent child marriage are adequately enforced. Additionally, this study highlighted human insecurity and conflict as factors that affected child marriage. Thus, it is important to include child marriage prevention components in the intervention programs in refugee camps and resettlements in conflict settings.S1 File(PDF)Click here for additional data file.