Disability data are essential for policy. Yet, the predominant use of disability prevalence for service planning reflects dichotomous counting, increasingly less compatible with current disability thinking. Difficulties relate to variations in rates, the lack of matching with needs, and the use of prevalence to compare disability situations. From the perspective of Primary Health Care (PHC), we explore methods for disability counting regarding the usefulness of prevalences in identifying persons with disabilities and meeting their needs with local service implementation. First, we analyze the methods and results of six national cross-sectional studies in Ecuador. Then, we present a case about an exploratory needs-driven method for disability counting in a local PHC setting. The analysis of variations in rates focuses the attention on reasons for and risks of a priori exclusion of persons with disabilities from services. Longitudinal disability counting as a collateral result of meeting needs in the PHC setting yields local disability data worthy of further exploration. Thinking about disability counting from a PHC scope in a developing country prompted reflection on the comparison of prevalences to evaluate disability situations. Findings invite further exploration of the needs-driven counting method, its contributions to planning local services, and complementarity with cross-sectional disability counting. Countries that ratify the Convention on the Rights of Persons with Disabilities will “undertake to collect appropriate information, including statistical and research data, to enable them to formulate and implement policies to give effect to the present Convention” . Three aDisability prevalence is one of the most frequently mentioned indicators in disability data. Since the release of the World Report on Disability in 2011, many documents begin by mentioning that about 15% of world’s population experiences disability . There iOne problem concerns the wide range of disability rates. Cross-country disability rates range from 4.3% (Norway and Ireland) to 35.9% (Swaziland), implying “substantially greater variations across countries in reported disability than may be plausible” [A second problem is that knowing how many people have disabilities does not necessarily lead to identifying and meeting disability-related needs. Whereas disability rates are often the first and only mentioned data, it is the nature of need and demand of persons with disabilities that are paramount for policy and planning. Research shows that “the simple reporting of only the prevalence of disability fails to capture the differences between communities” and “does not highlight the needs of different age groups or across different levels of severity” . CountinA third difficulty is that using the rates for evaluation of disability situations and policy implementation can lead to confusion as evaluation implies comparison and data may be compared in different ways, for example, with previous disability rates. Yet, a lower rate is not necessarily evidence of good governance and policies. Indeed, “there may even be a risk that measuring disability prevalence is used as evidence that action is planned or taken” . FurtherIn past decades, the disability concept has evolved from a consequence of disease and impairment at individual level to a biopsychosocial paradigm in which “disability results from the interaction between persons with impairments and attitudinal and environmental barriers that hinders their full and effective participation in society on an equal base with others”, as stated in the Convention on the Rights of Persons with Disabilities . DisabilThis study is part of an ongoing research project on strategies to improve matching health service delivery to local disability-related needs, initiated by the local primary health and community-based rehabilitation center in Quito, Ecuador. The general objective of this paper is to explore methods to identify persons with disabilities and their needs over time from the perspective of Primary Health Care (PHC), as a primordial step in defining, implementing, and evaluating community-based health services on the basis of the local population’s disability profile. The specific objectives of this paper are to (1) summarize results of Ecuadorian national surveys on disability and to reflect on the usefulness of the widely varying disability prevalences, and (2) present a longitudinal community-based method for identifying needs of persons with disabilities that mainly relies on self-perception, and to explore if and how this method can be complementary to national cross-sectional identification methods for local disability-related service implementation.Methods and results of this paper are structured in two parts corresponding to the cross-sectional dichotomous and the longitudinal needs-driven approaches to disability counting. After briefly outlining the Ecuadorian context, the first part deals with a comparison of the methods and results of six national Ecuadorian cross-sectional disability prevalence studies, as a background to disability statistics in the country. The findings of this analysis set the scene for the second part, in which we present a case report on exploratory longitudinal disability counting in a local PHC setting in Ecuador, promoting better information systems for local disability data collection for local disability policies and service implementation.We carried out a bibliographic review of national studies on identifying and counting persons with disabilities published by the Ecuadorian government since the local Health Center started its activities in 1994. Six cross-sectional studies were identified. We examined the official reports and final documents, retrieved from the National Council on Disabilities , and compared their methodology and results, focusing our archival analysis on specific topics such as the definition of disability and the purpose of counting, methods for data collection and data analyses, reasons for specific methodological choices, and study results. Comparative content analysis allowed data triangulation in order to corroborate data or to understand the reasons that explain the discovered differences .Data on the way of identifying and supplying disability-related needs and demands and on the registration of data of persons with disabilities in the PHC setting were collected through long-term participatory observation and from administrative databases and clinical files from 1994 to 2020. A preliminary report on this local method of collecting disability data was presented for discussion to the organization’s board and team, which allowed for a validity check of findings by triangulation among researchers. The case report presented in this paper describes, first, the dynamic between the evolving disability concept, the longitudinal identification of persons with disabilities and their needs and demands, and the organization of supply in the health center. Then, we focus on the reliability and validity of local disability data, particularly regarding the disability rate.Since 1994, the Ecuadorian population has grown from approximately 11,200,000 people to more than 17,000,000 in 2020. In this time, the median age increased from 21 to 27.9 years and life expectancy from 70.5 to 77.2 years. The annual population growth rate is now 1.4%. The under-five mortality rate decreased from 42.9 per 1000 live births in 1994 to 14 per 1000 live births. The Ecuadorian Human Development Index value for 2019 is 0.76, which put the country in the high human development category, positioned at rank 86 out of 189 countries and territories. Yet, according to the definition of the International Monetary Fund, Ecuador still is a developing country, with a gross domestic income per capita of 6184 USD in 2019. Ecuador belongs to the quintile of the countries with the greatest inequality, with a Gini coefficient that has fluctuated between 45 and 50 over the past ten years . InequalIn this dynamic, diverse, and divergent context, six national cross-sectional studies on disability data were carried out between 1994 and 2012. To set the scene for the analysis and comparison of methods and results, we summarize in Current Situation of Persons with Disabilities in Ecuador. The study yields a high disability rate, without taking into account children younger than 5 years—more than 10% of the Ecuadorian population at the time.A research group from the National Council on Disability , the Central University of Ecuador , and the Spanish Institute for Migrations and Social Services  carried out the cross-sectional ESADE study titled Consistent with international concerns about underestimation of disability rates in low-income countries, the ESADE researchers stated that due to prejudice and misconceptions of the family and the Ecuadorian society, there is a tendency to hide problems related to deficiency, disability, and handicap, which may have led to subregistration of the real prevalence of people with disabilities, as persons “may feel stigma or shame at identifying themselves as disabled” ,21,22,23The sum of the percentages of each deficiency type is exactly 100%, equal to the entire universe of deficiencies. The sum of the absolute numbers of all these deficiencies is 1,600,000, a number equal to 13.2% of the Ecuadorian population in 1996 . Yet, imThe use of an a priori disability screener based on self-reporting, as implemented in the censuses, is a common first step in formulating disability policy, which begins by searching for persons with disabilities for whom, subsequently and in an exclusive way, disability-related services will be planned. Both rates from the censuses, conducted by the Ecuadorian National Institute of Statistics and Census , are considerably lower than the currently estimated 15% worldwide average, giving weight to the generally accepted statement that “countries reporting a low disability prevalence rate—predominantly developing countries—tend to collect disability data through censuses” . FrequenThe World Report on Disability used two sources to estimate global disability prevalence: the World Health Survey (WHS) and the Global Burden of Disease . The WHS“Possible self-reported responses to the questions on difficulties in functioning included: no difficulty, mild difficulty, moderate difficulty, severe difficulty, and extreme difficulty”, and composite disability scores were calculated to produce a continuous score range . AfterwaWeighted data sets from 59 countries, including Ecuador, were used to calculate the estimated prevalence of disability in the world’s population of adults aged 18 years and older. Data from 11 developed and high-income countries were unweighted without the report giving specific reasons for this matter .The World Report on Disability states that “across all 59 countries, the average prevalence rate in the adult population derived from the WHS was 15.6%” . At the This National Survey on Disability, inserted in the quarterly National Survey of Employment, Unemployment, and Underemployment, conducted by INEC, was conducted by nearly the same group of researchers from the National Disability Council as the research team for the ESADE study, and there are other similarities between both surveys. The total numbers of persons with disabilities, including a small number of children with disabilities younger than five years in the Encuesta Nacional de Discapacidades (END), are nearly the same. Furthermore, its estimated disability rate, mentioned in the comprehensive compilation of country-reported disability rates from censuses and surveys in the World Report on Disability, is close to the result of the ESADE study . The useIn this case, the END report contains a table that lists persons with disabilities aged five years or older with an impairment together with persons with disabilities aged five years or older with mild to moderate activity limitation and participation restriction, and another group with severe limitation and restriction. Along with a small group of children with disabilities younger than five years, the sum of these four groups equals 1,608,334 persons, presented as the Ecuadorian universe of persons with disabilities see .The END report defines a person with disability as “a person who experiences some degree of activity limitation and participation restriction, originated in an impairment” . This meTo fulfill the commitment acquired by signing the Convention of Rights of Persons with Disabilities in 2007, the Ecuadorian government conducted an action research called the Manuela Espejo Solidarity Mission (MSME) to obtain detailed information for disability policy, as one of the first needs detected was the lack of information about persons with disabilities, in terms of their residence, health status, and socioeconomic situation . In addiAs a way of self-reporting, the whole population was asked to hoist a white flag in any house in which a person with disability was living. Local authorities and social organizations were requested to assist in this identification process. At the moment, no explicit definition of “person with disability” was given . People A biopsychosocial disability paradigm was established as the conceptual framework, but the brigades, consisting of Ecuadorian general practitioners, military personnel for guidance and GPS management, and community leaders, along with Cuban specialists in clinical genetics and defectology, worked from a strong biomedical and disorder-based perspective . Type anThe report mentions that once a priority need was detected, persons with severe functioning limitations were provided with special medical assistance, delivery of technical aids, and eventually any other required support, such as housing. Persons with mild to moderate functioning limitations were excluded from the universe of persons with disabilities entitled to services, as well as persons with temporal disabilities or with somatic or visceral disabilities, except for chronic renal failure . The repWhile initially about 1,000,000 persons identified themselves as a person with disability, this study ultimately registered 293,743 persons with disabilities, equivalent to a rate of 2.02% ,26. ThisThe high disability rates of ESADE and END are the closest to the estimated global WHO rate of 15%. Yet, the analysis of the results of these studies corroborates remarks in the World Report on Disability about poor data quality, as confusion about the measurement unit resulted in higher than the actual rates in both studies .The ICF-based WHS also yields a high rate, corroborating that “countries reporting higher disability prevalence tend to collect their data through surveys and apply a measurement approach that records activity limitations and participation restrictions in addition to impairments” . The MSMThe low disability rate in the MSME also relates to the use of a high threshold. By including only persons with severe functioning difficulties in its universe of persons with disabilities entitled to services, professional second opinion excluded three quarters of persons who had self-reported as persons with disabilities. Otherwise, the WHS used a gradient from no limitations to severe functioning difficulties in all the persons from the sample, followed by an a posteriori cutoff. This approach yields higher disability rates and reduces the risk of exclusion.Self-reporting was also used in the national censuses, but in both studies, far fewer persons than in the MSME labeled themselves as persons with disabilities. As previously noted, respondents may deny their condition due to negative cultural attitudes. Nevertheless, stigma and shame appeared of little importance when hoisting flags in the MSME, in which a positive qualification as a person with disability entailed an immediate benefit.The comparison of disability rates from these cross-sectional studies confirms that disability counting is strongly influenced by the researchers’ methodological decisions and choices, particularly on the purpose of measuring, the disability paradigm, the choice between the use of surveys in samples, the use of closed yes–no questions or self-reporting in general populations without prior definition of disability, and the implementation of thresholds.The foregoing analysis proves that choosing data from cross-sectional studies for disability service planning and evaluation in a PHC setting, which aims to address local disability-related needs and demands over time and for all its users, is not straightforward. We describe an exploratory method that may be complementary to the aforementioned a priori counting methods, addressing some of the issues observed in the national cross-sectional studies.Since 1994, the nonprofit organization Tapori Paladines de la Felicidad has been offering comprehensive PHC for local villagers who live in the suburban north of Quito, Ecuador. Annually, around one thousand families, who mainly live within a radius of 10 km, make use of the services of the community Health Center. In 2000, an estimate of 39,619 people lived in that rural area. The population on the outskirts of the large city grew much faster than the national growth rate, and in 2020 almost 73,472 people lived in the same area, now suburban, with the population nearly doubling in 20 years. The distribution of age and ethnic groups is in accordance with national data and great national inequality also is reflected in the local population. In terms of income inequality, the families who use the PHC services mainly belong to the two poorest quintiles of the Ecuadorian and the local population. Every year, between 2500 and 3000 medical consultations are attended, for an average of 1200 different persons. Around 150 of them are persons with disabilities, who are seen in almost 20% of the total number of medical consultations.Initially, services included health promotion, disease prevention, and curative care. In response to population demands, rehabilitation services were progressively integrated into the setting since 1996. At the time, there were no accessible health services designed to restore or improve the individual’s level of functioning in the village and surroundings. Persons with disabilities hardly participated in social life, and local conceptions of disability alternated between considering it either a punishment or a gift from God, to be accepted with resignation. Health professionals were confronted with persons with disabilities whose health-care-related needs were not addressed, despite options for services existed in theory. This marked the starting point of the gradual development of a community-based rehabilitation component in the Health Center.Therapy initially focused on the development of motor and communications skills, based on a biomedical and individual disability paradigm. Through word-of-mouth advertising, persons with other functional difficulties found their way to the Health Center and implicit needs of persons with disabilities gradually converted into expressed demands. Daily experience taught that disability is far from being solely a biomedical health issue and the rehabilitation team, which initially consisted of a general practitioner, a psychologist, and a physiotherapist, grew into an interdisciplinary 14-member team that now offers, in addition to individual therapy, three modalities of day-care, learning, and working. Team members now opt explicitly for a biopsychosocial disability paradigm that takes into account all the components and interactions of the ICF.The state-of-the-art of this evolving disability concept is reflected in interdisciplinary and multisector teamwork and in the nature and implementation of resources, for example, in the structure of the internal information system. Today, this two-part information system is structured as follows: a person-based archive with individual medical records of slightly fewer than 10,000 persons, and an administrative system that, in addition to logistical, financial, and organizational information, contains an Excel file (beginning in 2016) with consolidated disability-related data of all the persons whose individual medical record includes a specific file on functioning and disability. Since 2007, this individual specific file has been added to the medical file of all persons with disabilities who have ever used the services of the Health Center from 1994 to the present day. This is done gradually for new persons with disabilities or retroactively for persons who have previously used the service. In the consolidating administrative Excel file, the person with disability is included only once and is never excluded, regardless of whether the use of services is constant or not, or has been discontinued in the meantime, by death or for any other reason. There are no multiple entries of the same service user over time.The team’s GPs add the specific file to the individual health record when individuals, their close relatives, or, ultimately, team members of the Health Center perceive and report impairment or biological dysfunction, lasting difficulties in performing daily life activities, and participation in society. Disabling health conditions and impaired body structures and functions often trigger visits to the Health Center. Nonetheless, disability identity, outsourced by the use of the specific file that includes the ICF diagram, is only assigned when difficulties exist in all three ICF functioning domains, including activity limitations and restrictions in participation, and when the person cannot fulfill the social role expected by the local population . The useNo core questions about specific functional difficulties are used in the Health Center to determine whether someone is or is not a person with disability and eligible for services, and no thresholds on the scale of human functioning other than those that are socio-culturally determined are applied. Yet, daily practice has also shown that strictly dividing the population into “persons with disabilities” and “temporally nondisabled persons” is difficult . For thiIn the summarizing administrative Excel file, the research team categorizes available and useful data from the individual files according to the ICF classification, including specific data, such as the age of mothers at delivery in the case of disabling prenatal or perinatal biomedical and contextual factors, or data on specific important life events, corresponding to the personal factors component of the ICF. The information in the consolidated Excel file is updated quarterly with data on new admissions or on pertinent changes in a person’s disability situation. New information is added without deleting previous data. Data are also not deleted when, for example, someone stops using the service or in the event of death. In this way, every person with disability who makes use of the services in the Health Center has an individual report on disability-related events and functioning during the life course . The conIn a previous paper, we described in detail the process of implementing the ICF in the individual medical files of persons with disability in the PHC setting, and we present the case of a person with disability during life course with six connected ICF diagrams . In the A priori identifying and counting of persons with disabilities was not a goal in this PHC setting, and it was certainly not a prerequisite for proffering services. However, as a collateral result of the dialectical process of identifying needs and service implementation, the PHC setting has a historical archive with validated information on persons with disabilities. These data make it possible to calculate the period prevalence of disability from the general population sample, understood as the ratio of the number of persons with disabilities to the number of all the persons who have used the Health Center’s services from 1994 until 2020.During this period, we opened 10,106 general clinical files and disability identity was assigned in 473 cases See . LongituThe list includes persons with disabilities at all stages, children as well as adults, and persons with all types of impairment. Almost half of this group experiences severe functional difficulties, defined as a condition in which the support or care of a third person is required, most of the time or permanently. This results in an estimated rate of persons with severe disabilities that is close to the average prevalence of persons with significant difficulties of 2.2% in the WHS . The remResearchers’ bias related to the biomedical entry-point for identification of persons with disabilities could be a reliability concern. Nonetheless, we consider that the risk is minimal because the health professionals imposed no predetermined or fixed definition of disability. In addition, over time, the concept of disability evolved from a biomedical paradigm focused on impairment to a broader biopsychosocial disability paradigm that links disability with social and environmental barriers, and difficulties with the full exercise of human rights. Disability identity is never imposed but is mainly assigned based on self-perception of difficulties with functioning by the person with disability, or, by default, based on proxy reporting by close relatives or health professionals, and is supported by validated information in the ICF diagram.By not using objective indicators or a validated measurement scale, the definition of disability and the assignment of the identity of a disability can be perceived as subjective and affect credibility of the findings. Yet, continuity of care in this locally embedded PHC setting enhances the internal validity of disability rating as the observational and participatory collection of data over time allows for precise and updated information, and minimizes false positive or negative results. Well-functioning people will not persist in presenting themselves as a person with disability for benefits that are obtained only by working to improve functioning and by investing personal resources. Moreover, trust and a long-term relationship decrease shame and perceived stigma. Continuity of care also favors the identification of persons with mild disabilities whose functional problems may be less noticeable. Their risk of exclusion from eligibility for services is minimal because no a priori criteria or a posteriori cutoff related to disability types or severity of functional difficulties are applied.Regarding external validity, the PHC disability rate cannot be generalized. The Health Center’s universe of patients is not a representative sample of the total Ecuadorian population and not even for the total local population, especially in terms of economic inequality and geographical diversity. Otherwise, the implementation of disability-related services probably attracted persons with disabilities for whom services were not available or accessible before.The discussion on variations in disability rates affirms that disability counting is not an objective and uniform procedure, focusing the attention on influencing factors at risk of being excluded from services in the a priori identification of persons with disabilities. We suggest considering contributions of longitudinal needs-driven a posteriori disability counting for local policy planning and service implementation, complementary to cross-sectional disability counting, and we present a reflection on the use of disability rates for the evaluation of disability situations from the perspective of PHC in the Global South.Our analysis of reasons for variations in national disability rates corroborates the “illusory character of the disability concept as an entity of known and fixed dimensions” . Before In line with current international recommendations, we suggest joint use of different cross-sectional methods to overcome disadvantages and shortcomings of each, as separate use is not sufficiently accurate to determine the function of populations ,11,33. TThose who count must keep in mind that they bear responsibility in determining whether individuals are entitled to services or left behind with unmet disability-related needs. In order to not only generate data and measure exclusion in the predefined group of persons with disabilities but to also identify and include a priori excluded persons, the cross-sectional methods can be combined with longitudinal counting methods, for example, continuous administrative registration of data as part of the normal operation of a service or program or the PHC method presented.Yet, a still worrying observation is that all of the cross-sectional identification methods first define who belongs to the group of persons with disabilities and then decide on the services to be implemented, based on characteristics and needs of this established separate universe. These a priori counting methods entail the risk of leaving persons with disabilities behind as decisions on disability paradigm, methods for data collection, and thresholds may already exclude them from this universe at the outset. This turns politicians, members of the international community, researchers, epidemiologists, and health professionals into powerful intervening actors, especially when decisions are not always made on a scientific basis, but respond to practical, ideological, and even political issues. Data from the national studies show that children, persons with intellectual disabilities, and persons with mild and moderate disabilities are especially at risk. Yet, their a priori exclusion from services misses the opportunity to prevent their probable deterioration due to unmet disability-related needs, while focusing on intervention in these groups would likely produce the most gain in population health ,8. Thosethose who are counted, our findings on underreporting and the resulting exclusion from services are inconclusive. Persons may not perceive their disability as they have interiorized their difficulties as normal, or they may not know about the options for dealing with difficulties, as was seen when starting up the service in the PHC setting. Otherwise, it might be interesting to consider social resilience, understood as the ability of social actors to cope with adversities, as an intervening factor when exploring why the percentage of persons with mild to moderate disabilities is much lower in the PHC setting in a developing country than in the WHS, while both use a biopsychosocial disability paradigm. Without denying the negative effect of stigmatization and negative cultural attitude, we suggest further research into generally accepted statements regarding underreporting, since a negative answer on a closed question about disability identity during censuses is perhaps not always a culturally negatively influenced answer but rather a reflection of functioning coping mechanisms at the individual and social level.From the side of upside–down method for disability counting in the PHC setting, where disability-related health services were gradually implemented based on perceived needs and demands without any a priori searching for and counting of persons with disabilities, is worthy of further investigation, based on the arguments that support reliability and validity of the estimated disability rate. The aforementioned problem, that knowing how many persons have disabilities is not the same as knowing their needs, is not an issue here. First, needs are identified based on self-perception, without thresholds on the continuum of functioning. Only then persons will be assigned to the universe of persons with disabilities, which provides data on disability to the consolidating information system. Continuity of care strengthens the identification of persons with disabilities, which are not as readily apparent as physical or sensory disabilities, for example, children with behavioral problems or with learning difficulties, and persons with mild difficulties or with mental problems. The identification of these persons, who perhaps were not taken into account in cross-sectional counting, may be a valuable contribution of disability-inclusive PHC to the reduction of the risk of their exclusion from services and to the development of an accurate local population’s disability profile, as disability data on national level may not reflect intracountry differences or specific characteristics of which being aware of is important for local disability policy planning and service implementation [The entation .These findings prompt to check reliability and validity of disaggregated data from the consolidating Excel file and to explore their usefulness, not only for the persons with disabilities but also for the temporally nondisabled persons. For example, a prevention program that tackles specific social characteristics can be developed based on the analysis of local data on biomedical etiology of disabilities. Disaggregated local data can also be compared to national data to learn from differences, in particular on disability types or age groups that may be over- or underreported.In response to the generalizability concern, we suggest a pilot study on the adoption of the Health Center’s method for identifying and addressing disability-related needs in other PHC settings as universal coverage in accessible Health Centers and the joint use of data from different sources may favor internal and external validity and contribute to the evaluation of intracountry differences. Similar to the sentinel general practices in Europe that help policy makers define and assess health and disability policies, data from their registers of service utilization could be combined and cross-analyzed . By upscWe present this reflection on the comparison of disability rates to evaluate disability situations, as thinking about disability counting from the perspective of PHC in the Global South led to the questioning of some fixities . There iOne problem with disability rates is that they only reflect part of the complex reality of human functioning. In addition to comparing numbers of persons with disabilities, differences in the range of disability types and the degree of functional limitations should be analyzed. We must also take into account disabling factors and unmet needs, existing services and service utilization, and even different perceptions related to the same “objective” difficulties with body structures and functioning. When using data for evaluating disability situations and policy implementation, disability statistics should look beyond the scope of disability rates and not be limited to the comparison of numbers of persons with disabilities.A second pitfall when using disability rates for evaluation relates to which specific values are being compared. In the case of this study, prevalences from different studies carried out during particular periods within a population group are compared. Bearing in mind the aforementioned research-design-related reasons for differences in cross-sectional studies, rates should be checked for their mutual comparability before drawing any conclusion from the differences. Disability rates from different population groups are also often compared with the average of many other rates, such as the comparison of national rates with the global prevalence of 15%, or as relative values among each other.Yet, the comparison of different relative values is not that simple and there is great temptation to consider one value as an absolute and correct reference or golden standard, as, for example, in the case of cross-country comparisons. In this comparison, it is expected that low- and middle-income countries will yield higher disability rates than countries with high incomes, as it is generally assumed that persons with disabilities are more likely to be poor and that poverty contributes to perpetuating disability ,38. Low-Nevertheless, a slippery slope of flawed arguments may lead to false conclusions because “longitudinal data sets to establish the causal relation between disability and poverty are seldom available, even in developed countries” , and theFrom the perspective of cultural relativism, instead of debating who is wrong or right when using disability rates to evaluate disability situations and policy implementation, it might be better to focus on why differences exist and what they tell us. A fair reference point might be individual or local populations’ expectations about functioning. If so, longitudinal self-reporting without the implementation of a priori criteria or any a posteriori cutoff, such as used by the PHC setting, would be a legitimate approach to counting disability.Identifying and counting persons with disabilities, expressed in terms of national disability prevalence, yields confusing information. Statistics should be handled with care when it comes to local disability policy planning, service implementation, and evaluation. They carry an insidious risk of a priori exclusion of persons with disabilities from services because of researchers’ methodological decisions, as the analysis of the six cross-sectional Ecuadorian national studies has shown. Those who are not counted remain invisible for disability policy.A needs-driven method for identifying persons with disabilities and collecting disability data in a community-based PHC setting can contribute to local disability policy planning, by providing more nuanced information about a local population’s disability profile and reducing the risk of exclusion from services. Counting disability in this way reflects an evolving disability paradigm and moves beyond a quantitative a priori and dichotomous approach. It also shows the importance of disability counting from a personal perspective, understanding disability as a universal experience, without thresholds on the continuum of functioning, and from a life course approach. We suggest that data from different PHC’s can be gathered in a systematic way and be combined to complete cross-sectional dataset. A comparison with national and intranational datasets can lead to interesting analyses, for example, of within-country and cross-country variations.Our reflections on the comparison of disability rates to evaluate disability situations and policy implementation invite us to think about why differences exist and what these differences tell us, rather than discussing who is wrong or right. We suggest future research on statements about underreporting, where so far only stigmatization and negative cultural attitude are pointed out as causes.Our findings are in line with current international guidelines for disability measurement and statements on the need to combine different disability measurement methods in order to overcome disparities and confusing data and to avoid exclusion. From a disability-inclusive PHC perspective, we share an a posteriori longitudinal data collection experience, mainly based on self-reported functional limitations and assessed with the ICF, which can be combined with a priori counting methods, objective impairment screeners, and other rapid assessment tools for activity limitations and participation restrictions. Our findings encourage building the capacity of local stakeholders to collect and analyze disability data and to contribute to the development of comprehensive modular tools in order to broaden and refine disability data for disability policy.A possible weakness in disability counting in the PHC setting is the perception of subjectivity in defining who is and who is not a person with disability, as we did not use any objective instrument for measuring disability, except for an open ICF-based framework. A second weakness is that only local data are provided, which might lead to selection bias and not be representative for the total population. This could be overcome by organizing “sentinel PHCs” on a national scale. We emphasize that this study is exploratory and will contribute to further research on our findings and ideas, exploring validity and usefulness of disaggregated data for local population’s disability planning. The usefulness of health service utilization as proxy-for-need in disability counting may be questioned and limited, as there is strong evidence that persons with disabilities have poor access to health care . In theoThe analysis and comparison of disability rates from the national cross-sectional studies confirm that dichotomous counting is influenced by the researchers’ methodological decisions and yields data that are confusing and may not be useful for local disability planning. Data collection on disability in a community-based PHC setting, without any a priori searching for and counting of persons with disabilities but along with the dialectical process of identification of needs and service implementation, may provide a reliable and credible estimate of disability rate and other data for local disability planning and service implementation. Given the exploratory character of our study, findings on the a posteriori method for disability counting provide ideas and insights that may improve matching disability-related needs with local health service delivery, and reduce the risk of exclusion from services. It may open new paths for future research on its complementarity with a priori cross-sectional methods for counting persons with disabilities, as a contribution to more nuanced data for local disability policy and to the global change in disability thinking and counting.


At present, the application of artificial intelligence (AI) based on deep learning in the medical field has become more extensive and suitable for clinical practice compared with traditional machine learning. The application of traditional machine learning approaches to clinical practice is very challenging because medical data are usually uncharacteristic. However, deep learning methods with self-learning abilities can effectively make use of excellent computing abilities to learn intricate and abstract features. Thus, they are promising for the classification and detection of lesions through gastrointestinal endoscopy using a computer-aided diagnosis (CAD) system based on deep learning. This study aimed to address the research development of a CAD system based on deep learning in order to assist doctors in classifying and detecting lesions in the stomach, intestines, and esophagus. It also summarized the limitations of the current methods and finally presented a prospect for future research. In recent years, the application of artificial intelligence (AI) based on deep learning in the medical field has become more extensive and suitable for clinical practice compared with traditional machine learning. Constructing a computer-aided diagnosis (CAD) system based on deep learning to assist doctors in diagnosis is of great significance, because diagnosing lesions in the stomach, intestines, and esophagus is laborious for doctors. In addition, misdiagnoses can occur based on a subjective judgment.Deep learning is a novel research direction in the field of machine learning. It is based on the self-learning ability to learn complex and abstract features, rather than on traditional machine learning with manual features. Initially, deep learning did not attract much attention from researchers because of hardware limitations; however, it has greatly developed with the continuous progress of computer processing power. Deep learning can help learn the internal regularity and representation levels of training data, and the information obtained is of great help for interpreting the data. Deep learning has led to many achievements in object detection, image segmentation, and classification applications. Compared with traditional machine learning algorithms, deep learning approaches are usually more accurate and robust.From a technical point of view, deep learning algorithms can make use of a convolutional neural network (CNN) to analyze complex information, which is usually an advantage over manual feature extraction, but it requires learning a great deal of data for accurate inference and analysis. A representative CNN framework is mainly composed of multiple convolutional layers, pooling layers, and fully connected layers, as shown in With the continuous progress of deep learning technology, a large number of researchers are paying close attention to its possible application in medical research. This is mainly on account of the characteristics of medical data, which are usually unstructured texts, images, or videos instead of data with distinct characteristics. For example, the endoscopic images of a normal esophagus, early esophageal cancer (EC), gastric cancer, and duodenal ulcer are shown in Helicobacter pylori (HP) infection. This study is focused on the research progress of the CAD system based on deep learning to assist doctors in the diagnosis and analysis of gastric, intestinal, and esophageal lesions. The study also presents a concise discussion on deep learning. The main structure of the manuscript is as follows. Gastric cancer is one of the most common types of cancer worldwide; the mortality of gastric cancer is very high. A large number of people die each year from gastric cancer, and about 70% patients with gastric cancer miss the optimal treatment time because their lesions are not found in time .The use of pathological sections is a dependable method to diagnose gastric cancer at present. However, the number of experienced doctors is small, and producing specialized doctor is a time-consuming process. The application of AI technology based on deep learning for object detection and classification has gradually become more popular in the medical field. Ikenoyama et al.  comparedIn a study that included gastric endoscopic images, Hirasawa et al.  proposedTo overcome the low PPV of the SSD architecture, Sakai et al.  proposedIn 2019, Cao et al.  developeZhang et al.  considerIn addition, both Uemura et al. and Tahara et al. found a close relationship between HP infection and gastric cancer ,10. GoodFor establishing an automatic diagnostic system based on deep learning that predicted the HP infection level using gastrointestinal endoscopic images to improve the accuracy and speed of endoscopic examination, Itoh et al.  created Gastrointestinal endoscopy plays a pivotal role in the diagnosis and treatment of colorectal cancer (CRC), which is the third leading cause of cancer death in the world .Studies have revealed that most CRCs originate from colon adenomas , which aThe difficulty in detecting colorectal polyps automatically is not only the variation inside colorectal polyps, but also the small difference between normal mucosa and polyps, which is the bottleneck of the manual extraction method. In contrast, deep learning methods can extract more detailed information and features of polyps from endoscopy images at a pixel level through end-to-end learning. A large number of research outcomes have demonstrated that the polyp feature information extracted by the deep learning method is markedly better than that extracted by other hand-crafted extraction methods, because it can be better suited to the intricate clinical environment and is more suitable for the automatic detection and classification of colorectal polyps in clinical practice.Tajbakhsh et al.  construcTraining the CNN is difficult because of the tendency of labeled datasets in the medical domain to be small. Employing a transfer learning method is an alternative approach, by making full use of the learned information from other domains’ large datasets to deal with this problem . When a EC is one of the most common types of malignant cancer and was the sixth leading cause of cancer death worldwide in 2018 . EC has In 2019, Cai et al.  proposedt). Each patch that had an output probability was compared with t to decide whether it was a noncancerous region. The performance of this system was evaluated by leave-one-patient-out cross-validation and finally realized a sensitivity and specificity of 94.0% and 88.0%, respectively. Compared with other systems based on the same dataset, the performance of this system was superior to that of others. Hashimoto et al. [ESCC still has the highest incidence. However, EAC incidence has been growing promptly all over the world in the last few years, and is expected to realize further growth . Barretto et al.  designedo et al.  also diso et al.  found thGastrointestinal endoscopy plays a very important role in the diagnosis and treatment of gastrointestinal diseases. More doctors are needed who can perform accurate diagnosis and treatment because of the increasing incidence of gastrointestinal diseases in recent years. A CAD system based on the deep learning algorithm has been explored by a large number of researchers in order to reduce the burden of doctors and to improve the accuracy of diagnosing lesions in the stomach, intestines, and esophagus.This study reviewed the research progress of the CAD system based on deep learning for assisting doctors with classifying and detecting gastric, intestinal, and esophageal diseases. As observed in Compared with the traditional machine learning methods, CAD systems based on deep learning can effectively improve diagnosis performance and reduce the rate of misdiagnosis and missed diagnosis, while reducing the burden on doctors. It is of great significance to help doctors carry out a remote diagnosis for improving the level of medical diagnosis in remote areas. However, it is difficult to understand the inner workings of CAD systems based on deep learning because the feature activities of each layer are usually complex and abstract to fully understand ,41, whicIn addition, by summarizing the current research methods, we find that besides the unique shortcomings of the current model, some common limitations still need to be resolved. First of all, training an accurate neural network needs a lot of data. However, it is difficult to obtain and label large amounts of data in the medical field, which makes the trained model prone to overfitting. Second, most training data come from a single research center or hospital; hence, the designed model can only perform well on a specific dataset, but performs poorly on other datasets. Third, most of the current CAD systems depend on high-quality images to make a diagnosis. The performance of the systems using low-quality images (such as blurry or low-resolution images) for training cannot be determined. Fourth, the neural network contains a large number of parameters, and hence it is time-consuming to diagnose the corresponding diseases. Thus, it is difficult to meet the real-time requirements of clinical practice, especially on a 3D model. Fifth, the current CAD system is usually based on the 2D CNN of 2D images to diagnose gastrointestinal endoscopic lesions. However, the information provided by 2D images is limited, and sometimes it cannot fully represent the lesions. In contrast, the 3D CNN model based on videos or 3D images can make full use of temporal and spatial information. Therefore, much work still needs to be done on the research of 3D CAD systems. Furthermore, each of the aforementioned models is only effective for a specific disease and fails to realize information interaction between diseases, thus limiting the application of the models. Finally, although researchers have developed a variety of systems, the performance of these models cannot be uniformly compared because of the different datasets and evaluation criteria used in each system. Thus, the lack of a unified dataset and common criteria for verification is also detrimental to the development of CAD systems.In conclusion, a CAD system based on the deep learning method can automatically extract and recognize features. Using the deep learning method rather than traditional machine learning can effectively reduce the omission of feature information and make full use of the feature information to improve the performance of diagnosing lesions in the stomach, intestines, and esophagus. It can also assist endoscopists through auxiliary advice and reducing their burden. Moreover, it is of great help to solve the problem of insufficient medical resources in remote areas by employing an online CAD system.We think that it is necessary to make improvements in the following aspects in order to promote the further development of CAD systems. Initially, the dataset for training needs to be augmented as much as possible and needs to be collected from a wide range of sources in order to obtain a network model with a better generalization ability. Then, to deal with the shortage of training data, both weakly supervised learning methods and transfer learning methods are excellent for avoiding the annotation of a large amount of data. We intend to use a few-shot learning strategy to achieve excellent diagnostic accuracy based on a small amount of labeled data in the following research. Third, some image preprocessing techniques, such as image deblurring and resolution improvement, can be used to improve the performance of the model when low-quality images are input. We still need to make further improvements on 3D CAD systems in order to acquire more feature information, and should implement further speed optimization to achieve real-time clinical applications while ensuring excellent performance, especially on 3D models. Furthermore, when something goes wrong in one part of the body, it often sets off alarms elsewhere because the body is a collaborative group of organs. Therefore, when constructing a CAD system, we should pay more attention to the transfer of the feature information of different diseases, try to find the relationship among different diseases, and establish a CAD system that can diagnose multiple related diseases. More importantly, the trust between CAD systems and doctors should be built by increasing the interpretability of CNN. Last, but not least, a unified validation dataset and common criteria are needed to make accurate comparisons among various CAD systems so as to facilitate further development.


Formative assessment (FA) has been used to facilitate EFL learning and teaching. However, due to factors such as task complexity and time constraints, FA implementation faces a variety of challenges, especially in countries with an exam-oriented education system. Drawing on the case of EFL teachers from Chinese public secondary schools, this study examines the features of FA practice and explains their underlying aspects in an EFL exam-oriented context from a social psychology perspective. It adopts a mixed-methods research approach. Guided by the theory of planned behavior, 10 English teachers from Guangdong province in China were interviewed to establish an item pool for a structured questionnaire. A total of 161 English teachers from four cities in Guangdong province took part in the subsequent survey. The results revealed that the participating teachers have an implicit understanding of FA, based primarily on its literal meaning and their own teaching experience. They know and follow FA methods but lack confidence about their own practice. Regional differences were significant. Possible reasons for the perceptions and practices of Chinese EFL teachers from public secondary schools are the teachers’ own attitudes, the influence of other stakeholders, and the limitations of the FA methods. The study elucidates the features of FA practice and its mechanism in an EFL exam-oriented context. Gaokao) and the high school entrance examinations (Zhongkao) have been regarded as the primary purpose of teaching practice. “Teaching to the test” is common in the EFL classroom. The new national English curriculum standards highlighted the role of FA in EFL practice. Teachers are being encouraged to improve the effectiveness of their instruction by integrating teaching and assessment , influence of other stakeholders , and disadvantages of FA methods . The same results were found for the independent variables, professional title and teaching grade. The data suggest that the independent variables of gender, years of teaching experience, professional title, and teaching grade did not influence teachers’ responses to items relating to the three reasons. For teachers with different educational backgrounds, a statistically significant difference was found between teachers with a Bachelor’s degree and teachers holding a Master’s degree with regard to the influence of other stakeholders .The independent-samples post hoc test results, presented in p = 0.02 < 0.05) and D (p = 0.00 < 0.05). Regarding the variable of influence of other stakeholders, post hoc tests also show that the mean scores for teachers from city A were significantly higher than those for teachers from cities B (p = 0.01 < 0.05) and D (p = 0.02 < 0.05).In terms of the variable of teachers’ own attitudes, the Fisher’s least significant differences In short, the results indicate that the state of the current classroom practice of FA is not positive. Specifically, the data reveal that teachers’ deep understanding of FA principles has not been fully developed. The results of the survey of classroom practice demonstrate that the extent of the implementation of FA methods in the exam-oriented educational context is limited. FA practice is closely linked to SA practice, and the formative use of summative tests is the most acceptable strategy. The possible reasons for the current situation can be categorized as three factors, teachers’ own perceptions toward FA theories, the influence of the important referents, and the limitations of FA methods. In addition, teachers’ attitudes toward these factors differ according to their educational background and the region.This study attempts to contribute to our understanding of the features and underlying causes of implementing FA within an exam-oriented education system.With regard to RQ 1, the consistent findings reported in the qualitative and quantitative data show that, in general, EFL teachers in Chinese secondary schools know the FA construct and its effects but are profoundly lacking in understanding. These findings are consistent with a case study conducted by The second research question addresses the FA practice of Chinese EFL teachers in public secondary schools. The findings suggest that teachers adopt diverse methods with different degrees of frequency. Data from the interviews affirm the role of feedback without grades or scores, confirming Secondary education in China is exam-oriented, suggesting that teachers and students place extreme emphasis on grades and rankings. It is not surprising that teachers make full use of summative tests to assess whether students’ learning practice is efficient. Previous studies have reported the necessity to establish coherent FA and SA systems to encourage teachers to carry out varied assessment practices to facilitate students’ learning . The finAlthough the findings of the current investigation are not positive, they have value in that they may draw the attention of EFL teachers in China to the formative use of summative tests in their particular context. They need to know that FA strategies are closely related to their daily classroom practice. The present research shows that the exam-oriented educational context has a significant impact on how assessment is carried out in the classroom. The strategy of the formative use of summative tests is one of the situated FA strategies. Concerning the third research question, this study explains the findings in terms of TPB . The finThe influence exerted by other stakeholders is a second factor of importance. The attitudes of school leaders, colleagues, and students exert a specific effect on teachers’ willingness to implement FA. An individual’s intention is likely to be influenced by the attitudes of important others . ParticiThe disadvantages of the various FA methods constitute another noteworthy factor. The ANOVA results indicate no statistically significant difference between the teachers’ biographical information  and their view of this factor. Therefore, it may be inferred that most participants acknowledge the disadvantages of some FA methods. The disadvantages mentioned in this study suggest that the extra work involved in applying FA methods is onerous and that some of the methods are difficult to implement in actual classroom settings. This finding corresponds to similar findings of studies reporting that teachers are deterred by the complicated work involved in methods such as keeping portfolios .In line with the framework established in the literature review, this study uncovers the mechanism of FA implementation in the exam-dominated context from the social psychological perspective. The reality of FA practice was affected by the teachers’ own perceptions, the influence of other stakeholders, and by the disadvantages of FA methods, all of which correspond to the TPB. Teachers’ negative beliefs about the efficacy of FA methods would influence their willingness to perform FA. This suggests that teacher trainers should be cautious about the interpretation of FA theories and principles and that they should build teachers’ confidence in the practice of FA. Teachers’ perceptions of social pressure are also a major factor. Their decisions to transform FA methods into practice are influenced by their social network. Policy-makers should be more aware of the impact of related stakeholders and should target them to explain and promote FA practice. The typical features of schooling in China, such as teachers’ workload, time constraints, and class size, raise teachers’ concerns regarding the disadvantages of FA methods. These factors seem to exert a negative influence on teachers’ willingness to perform FA.The present study explored FA practice in Chinese public secondary schools from the teachers’ perspective, examining factors that may influence its implementation under the framework of the TPB. The findings show that Chinese EFL teachers are not well informed about FA theory. The study also shows that the teachers prefer to use those FA methods that are easy to control and involve less work. From the TPB perspective, teachers’ beliefs about attitudes toward FA, along with the influence of other stakeholders and the disadvantages of FA methods, were found to be the root causes of this situation.Gaokao and Zhongkao should be the only gate-keeping exams for learners.The study enriched our understanding of FA in a secondary educational context, in which all stakeholders are under heavy examinations pressure. It should be noted that the implementation of the FA mechanism in some circumstances is complex. It is also susceptible to the influence of the local educational context. The use of the TPB to probe the implementation of FA in an exam-oriented context contributes to the existing knowledge of FA from two aspects. First, it has the potential to gain a complete and structural understanding of EFL teachers’ decisions regarding FA and the underlying reasons behind their attitudes and practices. Previous studies have tended to focus on the effectiveness of FA strategies. The investigation of the factors related to teachers’ attitudes, subjective norms, and perceived behavioral control has extended our knowledge of how teachers’ attitudes, the influence of other stakeholders, and the disadvantages of the FA methods could have a role in shaping the current FA situation. Second, it provides a process-oriented perspective examining the FA mechanism. According to the TPB, a person’s behavioral responses to a trigger can best be understood as the outcome of the interaction between attitudes, subjective norms, and behavioral control , 1991. IThis study has some limitations. Semi-structured interviews may not provide sufficient data to frame a questionnaire, and it may not be possible to generalize the results to other educational contexts or to a society that is quite different from Chinese context. Moreover, drawing on the case of Guangdong province, this study addressed the reality of FA practice and its underlying reasons only from the point of view of teachers. Other evidence such as data from classroom observation could be considered in the future investigation of EFL teachers’ daily assessment practice. In addition, future researchers could explore the perceptions of other stakeholders, for example, students. Finally, further comparative studies should be conducted of FA practice in countries with exam-oriented education systems and in countries with less exam-dominated education systems.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by The Center for Language Cognition and Assessment, School of Foreign Studies, South China Normal University, Guangzhou, China. Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.JZ collected and analyzed the data and wrote the initial draft of the manuscript. LH conceived the study and revised the manuscript substantially. Both authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Low-performance concrete (LPC) is characterized by its low strength and commonly by the presence of large aggregates. This type of concrete was used for construction of load carrying, commonly unreinforced walls in old buildings. The resistance of these buildings with LPC squat walls (of relatively low height-to-length ratio), to in plane horizontal loads, was experimentally investigated in this study. The low compressive strength of these walls, well below that of standard concrete, requires estimation of the relation between the actual LPC compressive strength and its tensile strength, and identification of their failure mode and corresponding shear capacity when subjected to in plane horizontal loads. In this study, compressive and splitting tensile strengths of authentic LPC specimens were measured, and based on them, a relation between the compressive and tensile strengths is proposed. Then, diagonal compression tests were performed on authentic LPC specimens, as well as specimens made of standard concrete. These tests yielded the expected mode of failure of vertical cracking and their analysis shows that their shear capacity needs to be evaluated based on their tensile strength . Thus, the load-bearing  capacity to prevent diagonal tension failure of an unreinforced LPC wall can be evaluated by comparing the LPC tensile strength to the major principal stress caused by the load. Assessment of the tensile strength can be based on the relation between the compressive and tensile strengths proposed in this work. Assessment of existing concrete buildings requires, as a first step, the knowledge of the mechanical properties of the concrete. When dealing with standard concrete, most of its mechanical properties  are related by empirical expressions to its compressive strength ,2. HowevVery few studies of the mechanical properties of LPC have been performed ,5,7. Manpecimens ,9. The fpecimens .This paper presents an experimental research of LPC mechanical properties and shear capacity of old unreinforced squat walls, made of this concrete and subjected to in plane loads. The research goals were to obtain the compressive–tensile strength relation for LPC, realizing that this relation cannot be taken from standard concrete and to evaluate the shear capacity of these walls. In order to achieve the first goal, compressive and splitting tensile tests were performed. The second goal was achieved by performing diagonal compression tests and by analyzing their results, thus providing an insight into the correlation between the concrete tensile strength and the shear capacity of unreinforced LPC squat walls. The shear capacity  is also examined analytically and against well known expressions from the literature ,9. AccorThis study dealt with non-standard concrete (LPC) of which old existing buildings were constructed. Thus, the experimental program had two main goals. The first goal was to obtain the compressive–tensile strength relation. The second goal was to evaluate the shear capacity of LPC squat walls that comprise the gravitational load carrying structural system of these buildings. Therefore, the experimental program consisted of three test types: standard tests of compressive and splitting tensile strengths were performed to obtain the first goal and for the second one, non-standard diagonal compression tests were conducted. The latter tests were adopted from a testing procedure of masonry .The study of LPC required coping with the challenge of testing specimens that would best represent the properties of this non-standard concrete. Thus, special effort was made to extract authentic specimens from old existing buildings at several different locations as illustrated in The authentic specimens were extracted from five different existing buildings and are represented in the following sections by two letters (representing the places from which they were extracted): LO , BZ , DH , TA , and SY (Sde Yaakov). The laboratory-reproduced LPC specimens are denoted PCLAB, and those of the control low strength standard concrete are denoted CON80, CON120, and CLAB. H and D are the specimen’s height and diameter, respectively). The resulted maximum measured stresses  Linear Variable Differential Transformers (LVDTs) with a gauge length of ∼500 mm for CON80, LO, and DH specimens and ∼600 mm for CON120 specimens . MoreoveThe load was applied through two steel loading shoes that were attached at the top and bottom sides of the specimens to prevent local failure b. This sAll the diagonal compression specimens failed after a vertical crack initiated at their center part and propagated both upward and downward, as expected, see The maximum load, opagated c,g. Ther acr see i.The response of the specimens was almost linear up to the maximum load . This is evident from the load–strain curves shown in Analysis of the current experimental results can be used for provision of the relation between the compressive and tensile strengths of the non-standard, low-performance concrete. Additionally, they provide information regarding the tensile strength of LPC by both splitting tests and diagonal compression tests (DCT). The DCT results also allow to assess the main mechanism that controls the resistance to horizontal loads of existing unreinforced, non-slender LPC walls, as explained in the following sections.The measured LPC compressive and tensile strengths have been used to assess the relations between them. Thus, the tensile strengths, Equation  is plottThis relationship provides a reasonable (as well as conservative) evaluation of the LPC tensile strength based on the mean compressive strength measured from the samples of existing structures. Note also that Equation  merges wion  were originally developed in order to evaluate the shear capacity of masonry walls. The failure mode of the specimens tested in DCT resembles splitting failure, where a vertical crack initiates at the specimen center and then propagates towards its upper and lower loaded edges see also . On the P is the vertical load, and h and t are the specimen’s width and thickness, respectively , which has been evaluated byrefer to  with w=hby RILEM  and by Aby RILEM  to be 0.mens see  a linearsoftware  and the In addition to confirming the observed failure and the principal stress causing it, the FEA results were used to evaluate the coefficient for the principal stress at a distance refer to i. This wEquation  the majoEquation  :VRd,c,minP were Substituting these variables and the mean compressive strength of the control specimens 17.3 MPa  in Equat17.3 MPa  yields 3pecimens . Thus, tConsidering that old LPC walls do not (or hardly) include any reinforcement, their resistance to horizontal forces, prior to an application of strengthening materials, is controlled by two main types of mechanisms: resistance which is dominated by the wall overall stability  or sliding (commonly near their base) and, in the case of squat walls, by diagonal tensile failure . Once itThen, the concrete uniaxial tensile strength has to be assessed. This can be done based on the material mean compression strength Equation , while cEquation :(6)ft=0.The resistance of old buildings with unreinforced LPC squat walls (of relatively low height-to-length ratio), to in plane horizontal loads, was investigated in an experimental study. LPC is characterized by its low strength and, commonly, by the presence of large aggregates. While some of these old buildings are demolished to allow new construction, there are many one- or two-story buildings, which are still in use and are not planned to be replaced in the foreseen future. These buildings were built with LPC walls that carry the gravitational loads. The low compressive strength of these walls, well below that of standard concrete, requires estimation of the relation between the actual LPC compressive strength and its tensile strength, and identification of their failure mode and corresponding shear capacity, in case of being subjected to horizontal loads. The actual compressive strength is commonly obtained from cylinders that can be extracted from the existing wall, yet because of the inclusion of large stones in these walls, it was not clear to what extent these results or results from splitting tensile tests can be used for this evaluation. The experimental research reported in this paper comprised testing authentic specimens that were extracted from existing buildings at different locations as well as laboratory-reproduced LPC specimens and control specimens made of standard concrete. The main findings of this study, which refer to concrete compressive cylinder strengths up to 14 MPa, are as follows.Compressive and splitting tensile strengths of authentic and reproduced LPC specimens were measured.Based on these measurements, a relation between the tensile and compressive strengths is proposed, pointing also to the range of possible scatter, which should be examined by the designer when coming to assess the capacity of an existing wall. Note that this new relation is different than that of standard concrete and therefore the findings of this study allow engineers to properly evaluate the mechanical properties of LPC.Then, based on the use of relatively large stones in LPC walls, diagonal compression tests (DCT) were performed on authentic LPC specimens, as well as control specimens made of standard concrete. These tests are usually performed on masonry specimens and here they were adopted to study the shear capacity of LPC specimens.These tests yielded the expected mode of failure of vertical cracking, caused by principal tension stresses, perpendicular to the external load line of action and corresponding to diagonal tension failure, when the DCT rhombus specimens are considered as cartesian rectangular ones acted by horizontal and normal forces.To the best of the authors knowledge, DCT was used in this research for the first time for LPC specimens. For this specimen type, it was found that major principal (tensile) stress is best evaluated by the RILEM approach or by FEM analysis.Analysis of the measured maximum load, as well as the specimen dimensions, corresponding to those of squat walls, show that their shear capacity needs to be evaluated based on their tensile strength .Thus, the load-bearing  capacity to prevent diagonal tension failure of an unreinforced LPC wall can be evaluated by comparing the LPC tensile strength to the major principal stress caused by the load. Assessment of the tensile strength can be based on the proposed compressive–tensile strength relation.


To aid in the selection of the most suitable therapeutic option in patients with diagnosis of rheumatoid arthritis according to the phase of disease, through the review of articles that identify omics biological markers.A systematic review in PubMed/Medline databases was performed. We searched articles from August 2014 to September 2019, in English and Spanish, filtered by title and full text; and using the terms "Biomarkers" AND “Rheumatoid arthritis".This article supplies an exhaustive review from research of objective measurement, omics biomarkers and how disease activity appraise decrease unpredictability in treatment determinations, and finally, economic, and clinical outcomes of treatment options by biomarkers’ potential influence. A total of 122 articles were included. Only 92 met the established criteria for review purposes and 17 relevant references about the topic were included as well. Therefore, it was possible to identify 196 potential clinical biomarkers: 22 non-omics, 20 epigenomics, 33 genomics, 21 transcriptomics, 78 proteomics, 4 glycomics, 1 lipidomics and 17 metabolomics.A biomarker is a measurable indicator of some, biochemical, physiological, or morphological condition; evaluable at a molecular, biochemical, or cellular level. Biomarkers work as indicators of physiological or pathological processes, or as a result of a therapeutic management. In the last five years, new biomarkers have been identified, especially the omics, which are those that proceed from the investigation of genes (genomics), metabolites (metabolomics), and proteins (proteomics). These biomarkers contribute to the physician choosing the best therapeutic option in patients with rheumatoid arthritis. We could associate a better outcome in the patient’s treatments reducing unpredictability of the management.We made a review searching for the biomarkers associated with the different phases of rheumatoid arthritis.Rheumatoid arthritis (RA) is a chronic autoimmune disease which is progressive and often disabling characterized by joint inflammation and pain; it requires monitoring of disease activity to decide the optimal treatment. Decreased quality of life, reduction of function and work participation are associated with mental and physical health of the patients. The use of biomarkers as monitors of disease development may aid providers improve non-biologic and biologic drugs . BiomarkThe aim of RA therapy is to keep and increase a prolonged state of health associated with quality of life by controlling symptoms, preventing structural joint damage, normalizing physical function, and getting better function in their activities. However, in patients with RA, treated either with methotrexate or biologic disease-modifying anti-rheumatic drugs (DMARDs), only 40–60% of them respond effectively as measured by at least 50% of improvement of signs and symptoms of the disease (by ACR criteria), whereas 15–30% develop adverse drug events [On the other hand, in 2013 it was reported a systematic review of the International Journal of Rheumatology that approximately 50% of RA patients in Europe interrupted their biological therapy of the TNF inhibitor group during the first five years of use as a result of ineffectiveness or adverse drug reactions . SimilarRA is a major current public health problem, in terms of deterioration in the quality of life and the generation of high costs for the health system. Although in recent years, better health results have been achieved with the incorporation of disease modifying drugs , it is evident that there is a need to better redirect resources and take advantage of the window of opportunity of the disease.Pharmacokinetics and pharmacodynamics of drugs, becomes a fundamental and additional instrument to those already existing, which allows us to determine the choice of a more effective and safer drug that meets the particular needs of the patient. Genetic information is expressed at the level of proteins and metabolites; therefore, it is necessary to determine specific predictors or biomarkers for different phases of rheumatoid arthritis, especially the OMICS that include pharmacogenomics, metabolomics, and proteomics Fig. .Biomarkers are interaction parameters that provide information on an objectively measurable physiological, biochemical, or morphological change that can be evaluable at the molecular, biochemical or cellular level and that acts as an indicator of a functional biological process or a pathogenic state, or as a response to medical treatment . BiologiBiomarkers are classified according to the information they provide and according to their nature. These biomarkers are important for identification of individuals in a population, that may be sensitive to a certain health problem. These kinds of biomarkers are classified as biomarkers of exposure, effect and susceptibility.Exposure biomarkers evaluate the presence in an organism of an exogenous substance, a metabolite or product of the interaction between xenobiotic agent  and a molecule or target cell.Prognostic Biomarkers report about progression of disease; this is, if disease improves or worsens after corresponding treatment. EphB4 membrane receptor is a prognostic biomarker of colon cancer .Biomarkers of susceptibility are indicators of the inherited or acquired capacity of a given organism to respond to exposure to xenobiotic substances.Biomarkers according to their nature are classified into omics that come from the study of genes (genomics), proteins (proteomics) and metabolites (metabolomics); epigenetics that come from changes that occur in DNA and that are related to some pathology, and microRNA molecules that are expressed in different amounts in either normal or cancerous cells (genomics/transcriptomics) .Diagnostic biomarker: used to detect or confirm presence of a disease or certain condition, or to identify individuals with a subtype of disease. For example: HbA1c is commonly the most used biomarker to diagnose prediabetes and diabetes .Prognostic biomarker: used to identify probability of a clinical event, disease recurrence or progression in patients with a diagnosis of a disease or medical condition of interest. For example: increasing prostate-specific antigen (PSA) as predictor of clinical progression for prostate cancer .Safety biomarker: used to indicate the likelihood, presence, or extent of toxicity as an adverse effect measured before or after exposure to a medical product or derived from environmental causes. For example: transaminases have been selected as biomarkers for potentially hepatotoxic drugs .Monitoring biomarker: measured in series to assess the level of a disease or medical condition, or the evidence of exposure to (or the effect of) a medical product or environmental agent. For example: B-type natriuretic peptide as a measure of vascular and ventricular function in pediatric pulmonary arterial hypertension .Pharmacodynamic response biomarker: used to demonstrate that in exposition to medical products or environmental causes in an individual there is a biological reaction. For example: International Standardized Ratio (INR) for anticoagulant treatment, which has special interest in the adjustment of drug .According to the Food and Drug Administration, biomarkers are classified as follows , 11:DiagHigh specificity: measurement of a biomarker must be specific to a disease.Specimen: collection of samples should be minimally invasive. For example, saliva is better than urine and urine better than blood.Representativeness: levels of biomarkers in the selection sample should be representative of levels of biomarkers in the organism.Stability: kinetics must be known .Ideal biomarkers should provide diagnostic, prognostic, and therapeutic information; additionally, they have to be obtainable from patient's clinical data, and should possess chemical-analytical characteristics such as:Regarding pharmacological safety of patients, ideal biomarkers should be aimed at health care processors. So, it is advisable to guide pharmacotherapeutic follow-up and programs for appropriate use of drugs through these pointing elements (tracers or markers). In this sense, detection of these elements is highly recommended, by means of information systems , such as: identification of some medications, laboratory tests, symptoms or diagnoses and medical notes or phrases in clinical histories, known as markers or bookmarks .A systematic review was performed in PubMed/Medline databases. We searched articles from August 2014 to September 2019, in English and Spanish, filtered by title, full text, and using the terms "biomarkers" AND "Rheumatoid Arthritis". Inclusion criteria defined articles that reported biomarkers in different phases of rheumatoid arthritis and drug specific uses  and the American College of Rheumatology (ACR), with the objective to improve the classification in diagnosis based on existing criteria. It was also proposed as a tool to take advantage of therapeutic opportunity in early stages of disease. On the other hand, these new criteria highlight the importance of using biomarkers to support therapeutic decisions in the clinical field .Within these new clinical findings, rheumatoid factor (RF), anti-cyclic citrullinated peptide (ACPA) and acute phase reactants (APR) are so far the most commonly used biomarkers in clinical settings to guide diagnosis and prognosis of RA. And since its description in 1940, RF continues being the most used laboratory tool for diagnosis and prognosis of RA in early stages of disease. However, its use and interpretation has been conditioned since the appearance of ACPAs as more specific markers (95% -98% vs. 85%) and similarly sensitive than RF (60–80% vs. 65%-80%). In addition, the value of ACPA can predict development of disease and response to specific therapies (high levels—low levels).Despite their wide use, both RF and ACPA, as well as APR (they are nonspecific of the RA and sometimes they do not change with progression) have proved to be insufficient to respond satisfactorily to the high heterogeneity of RA. However, in the last five years omic approaches have had a gradual and homogeneous increase in the discovery and proposal of new biomarkers that could solve difficult questions about decision making in clinical settings.Consequently, the so far approved biomarker is ideal and robust enough to be the only clinical criteria for diagnosis or prediction of disease with high reliability, specificity, and sensitivity. In this case, not only a biomarker but also a panel or group of biomarkers -that reflect the multifactor nature of the disease state of RA—should be considered. At present, the right choice of candidate biomarkers offers additional and objective information that, when used in conjunction with traditional tools and techniques, represents a potential opportunity to make more informed and integrative clinical decisions that lead to a more precise medical care model. This model will allow stratification of RA patients according to the level of risk and degree of therapeutic opportunity.In this sense, a patient can benefit from previous diagnosis, stratification in response to severity of disease progress, prediction of response to a specific therapy, and prediction of toxicity reactions or identification of prognostic value avoiding ineffective treatments which can favor exposure to side effects. This allows access to timely care that improves the quality of life and better control of disease, offers a valuable degree of prevention, reduces costs to the health system, and contributes to the possibility of developing new therapies Table .Table 2AAmong the phase 1 biomarkers possess both protective and present actions in patients at risk for RA, this in RF-positive and RF-negative patients. In particular cases such as calgranulin C provides a differentiating characteristic against other inflammatory arthritis , as well as applications in experimental evaluation .Therefore, it is useful in the application of disease diagnosis, prognostic factor, choice and monitoring of the best possible treatment, and evaluation of therapeutics in a simple, minimally invasive way and without additional risk for the patient . The rapUsefulness of using biomarkers for health contributes to selection of medicines, evaluation of progression of diseases and their treatment. In same way, technological developments make it possible for implemented biomarkers to adjust more and more to the concept of an ideal biomarker; that is, they are increasingly specific and fundamental in the development of different biomedical disciplines, Allow the development of strategies and policies that include patients with rheumatoid arthritis and improve their quality of life.The clinic importance of the biomarkers in RA is still uncertain. This diagnosis is still based on clinical findings and blood tests with non-omic biomarkers. There are many associations that are not totally useful for the diagnosis of RA through omic-biomarkers. Although most of them are related to the characteristics of the disease and their possible outcomes, it has not been possible to perform the diagnostic process with biomarkers alone. However, the usefulness of biomarkers could be established as predictors of disease and outcomes. This could be beneficial in determining the natural history of patients depending on the stage of the disease by personalizing each case.Therefore, we provide an overview of the pharmacogenomics of RA and the possibility of using omic biomarkers with potential to be used in clinical practice and to support pharmacotherapeutic decisions in order to improve response and safety to treatment.The relevance of this study lies in providing the possibility to encourage the investigation of omic biomarkers -selected for their biological importance in AR- either in pharmacokinetic and pharmacodynamic processes, to provide additional tools that facilitate the identification of individuals at risk of suffering adverse events or individuals likely to fail treatment. Therefore, it is expected that the information generated can be used in daily clinical practice, helping to choose the best therapeutic option, at the right time with the least possible risk (greater effectiveness and safety) in patients with rheumatoid arthritis .Globally, there is not a totally effective medication in all patients, and each individual has a different response to drug treatment. This could be explained due to a modification in pharmacokinetics and pharmacodynamics properties of drugs related with genetic environmental conditions. In this context, the investigation of omic biomarkers has been more successful in the identification and explanation of the alteration of pharmacological response, compared to investigations of candidate genes of disease. Therefore, this paper should make a contribution to the selection of the best therapeutic management in patients with RA according to the phase of disease and is a basis to continue the research aimed at the identification of omic biomarkers according to stage of RA and treatment phase.As observed in this systematic review, in the last decade a great effort has been made to find omic biomarkers capable of predicting the response to therapy in a patient with rheumatoid arthritis. Many biomarkers have been explored and, even though several omic biomarkers have been identified, there are limitations with respect to their specificity, ease of sampling, representativeness, and stability to predict response. Thus, more comprehensive research is still needed in the identification of omic biomarkers in different phases of rheumatoid arthritis with promising next-generation sequencing and nuclear magnetic resonance techniques.