The purpose of this qualitative study was to examine how Covid-19 restrictions influenced dog owners’ relationships and sense of connection with their canine companions. Data were collected through an on-line survey and themes from open-ended questions were coded by the researchers using directed content analysis. Results highlighted a strong human–animal appreciation, and that dog ownership during this pandemic diminished participants’ sense of isolation and loneliness, as well as supported their mental/physical health.The Covid-19 pandemic has been found to negatively impact the psychological well-being of significant numbers of people globally. Many individuals have been challenged by social distancing mandates and the resultant social isolation. Humans, in our modern world, have rarely been as isolated and socially restricted. Social connectedness and support are critical protective factors for human survival and well-being. Social isolation can lead to loneliness, boredom, and can become a risk factor for physical and mental health issues such as anxiety and depression. The attachments formed with dogs, however, can be as strong or even stronger than human connections, and has been shown to relate to fewer physical health and mental health problems, as well as decrease isolation and loneliness. The purpose of this qualitative research was to examine the thoughts, experiences and concerns of 4105 adults regarding their companion dog during the initial months of Covid-19. Data were collected between March 31st–April 19th, 2020 via online survey and themes were coded by the researchers using directed content analysis. Results highlighted a strong human–animal appreciation, and that dog ownership during this pandemic diminished participants’ sense of isolation and loneliness, as well as supported their mental/physical health. The Covid-19 pandemic has impacted people’s lives in profound ways. Many individuals have been affected by financial/work losses, yet perhaps even more have been challenged by social distancing mandates and the resultant social isolation. Most humans, in our modern world, have rarely been as isolated and socially restricted. Countless individuals, due to social distancing and stay-at-home mandates accompanying the initial stages of Covid-19 were physically separated from friends and family. For many people during this time, mobile phones and online platforms replaced in-person contact as a primary source of social connection and support ,3. The iIn addition to social isolation, a great amount of uncertainty accompanies a pandemic, with a tolerance of uncertainty playing a significant role in one’s experiences of anxiety, distress, and loss of control ,8,9. Pan“Humankind has always known what to do next, with their lives generally following a regular trail. But this sudden cataclysmic turn of events (Covid-19) has brought them face to face with a dire reckoning—how to live with oneself. It is indeed a frightening realization when a whole generation or two knows how to deal with a nuclear fallout but are at their wit’s end on how to spend time with oneself (p. 525).”Recent studies suggest that the pandemic negatively impacted the psychological well-being of significant numbers of people. A US study by Palsson, Ballou, and Gray  found 90A plethora of research supports the premise of a strong bond between humans and their companion dogs ,20,21. DIn 2017, there were reportedly 90 million owned dogs in the United States . Given tDog owners were recruited via requests posted online and direct personal solicitations to the survey entitled “Pet dogs during the time of Covid-19”. A cover letter explaining the goal of the study, the affiliation of researchers, and a link to the Qualtrics survey website was sent to potential participants. Eligible participants were required to be at least 18 years of age, from any country, and must have been living with a companion dog during the time of the Covid-19 pandemic. The study was approved by the Institutional Review Board at Colorado State University (20-10003H). Survey respondents were recruited through social media outlets and human animal focused organizations . Participants completed the anonymous survey on the Internet.At the time of data analysis, there were 4105 respondents to the survey (received between 31 March–19 April 2020). Respondents included a majority of females (88.3%) living in the United States (80.7%), and those between ages 50–59 (23.8%). The majority of respondents lived with one other adult in the home (61.7%), had no children living at home (80.5%) and lived within a community that had implemented significant social interaction restrictions (78.0%) See .To capture the unique experiences of living with a companion dog during the time of a pandemic, the research team created a novel survey tool. In addition to sociodemographic variables, the survey inquired about participants’ levels of social restriction, and access to social support, dog food, and medical care. Survey items then delved into coping status and the human–animal bond. The survey consisted of Likert-scale items  and four open-ended questions that invited participants to share their thoughts about pandemic-related changes in their relationships with their dogs, stressors, and other ways in which Covid-19 impacted their relationships or feelings about living with their dog.Due to the large number of responses, a representative sample, using a systematic sampling method, was selected for each of the four open-ended questions. The initial sampling step included cleaning the data and removing of fields with no qualitative responses. Next, researchers utilized a random number generator in Excel to randomly sort participants on each of the four questions. Finally, the first 10% (N = 410) of the randomized responses for each open-ended question were chosen for analysis. Thus, respondents were not pre-examined to “cherry-pick.” As long as the starting point is randomized, systematic sampling is considered to be a type of probability sampling for selecting a random sample .The researchers exported all responses to the qualitative questions into an Excel file. Each row of the file was a different respondent, and each column was a question of the survey the participants answered. Within the Excel file, four separate tabs/folders were created to individually hold the 10% of culled data for each of the four open-ended questions. Next, data from each of the Excel tabs were pulled and saved into individual Microsoft Word tables, one for each qualitative question. The first column of the table included each participant’s response to the question and the subsequent columns provided space for the coding data from that individual’s response. The researchers saved the data to secure individual computers for analysis in Microsoft Word.Researchers used directed content analysis, a qualitative method guided by theory or prior research , to analThe responses were first independently coded by all three authors and then reviewed by all three until consensus was reached and tracked in a master codebook. As noted above, the emerging themes were identified and categorized and new codes developed as needed. In addition to the coding, networks were created to assist in the analysis of themes among subgroups of participants.The research team kept an audit trail throughout data analysis to track emerging themes, code definitions, as well as code and meaning saturation . As new Each of the four open-ended questions resulted in different themes. The presentation of results includes a synopsis of responses for each question and introduces the most prevalent themes and how they related to participants’ experiences in coping during the pandemic.Q1. There are many stressors that can come with Covid-19. Do you feel that having a dog adds, reduces, or has no impact on your stress level?Given the onslaught of changes and uncertainty resulting from Covid-19, we were concerned how quarantine orders limited access to resources and fears about one’s own health and what may happen in the future would impact participants. Thus, we asked if participants felt that having a dog reduces, adds, or has no impact on their stress level, and to elaborate on their responses. The majority of respondents (76.8%) stated that having a dog reduced their level of distress, while a few individuals (6.4%) shared that their dog added stress during the pandemic. A small number (12.0%) felt that their dog had no impact on their stress level. The three most common themes in participants’ responses to this question all related to ways in which their dog reduce their stress: displaces worry/serves as a distraction from Covid-19 (14.0%); diminishes feelings of isolation and loneliness (13.2%); and improves their mental health (11.0%).The majority of respondents stated that having a canine companion ameliorated their stress related to the uncertainty, loss, and grief associated with Covid-19. The most common response among participants was the way in which their dogs helped to displace their worry and distract them from the everyday challenges resulting from Covid-19. A respondent echoed the sentiment of others that caring for their dog “Overall lowers my stress level, as I have to concentrate on caring for him rather than being anxious about myself.” Dogs’ playful spirits also fostered joy, silliness, and opportunities to laugh, when laughter often felt silenced by the pandemic. For example, “My dog does not know what is going on in the world, she does her happy doggy-things and takes me with her in a moment where there are no worries, just joy”. As individuals adjusted to new schedules and increased time at home, caring for dogs provided a semblance of structure. Daily walking and feeding routines also nurtured a sense of normalcy during the surreal state of the pandemic. One participant explained, “Having a being and tasks and activities to do that are about something other than Covid related, good distraction, something that remains normal”. Canine companions nourished their humans’ abilities to find moments of distraction from the pandemic and opportunities to explore purpose and meaning when many of their identities and roles were threatened by the magnitude of loss and uncertainty resulting from Covid-19.Having a dog diminished respondents’ overwhelming sense of isolation and loneliness and provided a sense of connection with another living being and the outside world. Due to social distancing restrictions, canine companions often filled central roles in social support systems, especially for individuals living alone during the lock-down stages of the pandemic. Many individuals felt isolated from their former worlds and shared the following sentiments: “Companionship is necessary. (My dog) is a member of our family and we are able to interact, talk, touch, etc. with her. Knowing that she enjoys our company is nice too”. Often, dogs derive great comfort in the company of their humans and express these sentiments through cuddles, kisses, and snuggles. These moments of affection nurture humans’ desires for physical touch. Participants provided accolades for their dogs: “Having a dog reduces my stress as it creates predictable routines and a living being I can interact with when I am socially distancing from others. Additionally, my pet helps me connect with nature and is entertaining and loving”. Expressions of the love and comfort they derived from their dogs were plentiful in these owners’ descriptions of the positive presence their dogs had in their lives.Living with and caring for a dog brought many secondary mental and physical health benefits to these owners. Since many of these individuals, due to Covid restrictions, were at home much more, the amount of time they spent with their dogs naturally increased. Subsequently, humans had more time to exercise, play, and engage in fun activities with their dogs. Having this new-found bonding time with dogs, “reduces the impact (of Covid), because staying at home with your dog is relaxing, you are exercising and giving love, you are not just thinking about the problems you are having in relation to Covid-19, and it improves your mental and physical health”. Several respondents commented on the health benefits of increased walks with their canine companions: “definitely decreases stress by walking them every day now I keep myself saner and get exercise”. More time playing and exercising with dogs also created work–life balance and time away from human co-quarantine partners, “It forces me to go outside and get fresh air and I have support and company when quarantined with difficult family”. Increased time with canine companions encouraged more physical activities and acted as a buffer from work, relationships, and other pandemic-related stressors.Albeit a small percentage of overall responses, there were three themes that represented the ways in which having a dog during the pandemic increased respondents’ stress: worries about the future (10.1%), negotiating multiple roles and responsibilities (5.1%), and dog behaviors (3.7%). The quick and deadly spread of the virus and persistent scarcity of many necessities  created grave concerns among some participants. Many respondents, especially those who lived alone or were frail, indicated that they were worried about what might happen to their dogs in the event that the respondent contracted Covid-19. They worried about who would provide daily care for their dog should they enter the hospital. Worry presented in the following way:“(My dog) adds (stress) b/c I’m worried about leaving him with others if I need to be hospitalized with C-19. He’s a senior with kidney disease and on his last leg and I fear for his reaction to the changes in his life not only in the short run but also if I die in hospital as I’m a senior.”Through the development of safety plans for their dogs, some people were able to ameliorate their stress:“I live alone and I’ve been worried about what happens to him if I get sick, so that’s been a stressor but I sat down & wrote out instructions for him & just put all his general info down on paper just in case something happens to me and that has significantly reduced the stress with that issue.”Other persistent worries included fear of not being able to access or afford emergency veterinary medical care and specialty dog foods.Transitions from offsite work settings to home offices resulted in numerous stressors for individuals as they attempted to negotiate multiple roles and responsibilities. Individuals had heightened anxieties about how their virtual work world would unfold. They felt competing needs to manage Zoom work meetings while also caring for the emotional and social needs of their dogs. One person explained, “(My dog) adds to the stress because he expects more attention with me being home more”. This added stress also appeared as personal remorse, “like guilt that I’m home but have to work so I can’t spend that time playing”. Due to public health mandates, many of the typical activities that dogs enjoyed as social engagement and stress releases became unavailable. Dogs could no longer go to doggy daycare, dog parks, or participate in service dog activities. As a result, dog behaviors weighed heavier on individuals than before the pandemic. This became most apparent in responses of those that had puppies, “(He) adds stress as he is 1 and still learning what he’s not allowed to do”. Many folks carried an emotional burden of feeling like they were not able to provide for their dog’s social and mental stimulation. One respondent described this added stress, “We can’t leave the house and she’s so unhappy which makes me unhappy. I’m failing her”. Although outside of their control, activity restrictions created an additional layer of stress.Some individuals responded that being a dog guardian during Covid-19 has not impacted or not added additional stress to their daily lives. A few individuals simply responded “no impact”, while others described the buffering effects of having stable access to financial resources, dog walkers, and veterinary care. Respondents in rural areas not yet affected by the pandemic typically described no change in their level of stress: “I am fortunate enough that our situation is minimally impacted by Covid-19 at this time. We live in a remote community, and work from home”. Those who already worked from home reported limited impact on their stress since their daily routines with their dogs remained similar. Public health information demonstrating no possibility for spread of contagion between humans and dogs was included as another reason for not experiencing impact on stress levels.Responses occasionally included a mixture of both adding and reducing stress, underscoring the complexity of how the initial stages of the pandemic affected dog owners; subsequently, these responses were coded for the added stressors, as well as the ways that their dog reduced their stress. For example:On the one hand this situation of emergency and uncertainty increases anxiety about the future and the conditions of future life namely economic and financial risks and the ability to care for my dog and cats with the same availability and quality. On the other hand, the relationship I have with them helps to reassure me and to focus on the emotional and organic relational stability that we maintain and which is so essential. Overall, participants extolled the benefits of having a dog during the pandemic as their canine companions created a sense of connection, a calming presence, and a distraction from the news and the wrath of Covid-19.Q2. Do you feel the increased amount of time you are spending with your dog is strengthening your relationship or creating strain in the relationship?The aggressive spread of Covid-19 resulted in public health precautions which limited social contact. Individuals in jobs that were not identified as essential to health and service industries shifted from office settings to home settings. Learning in schools moved from in-person to online home education. The increased time at home created opportunities to both strengthen or strain bonds between individuals and their dogs. The majority of respondents (76.8%) claimed that spending more time with their canine companions strengthened their relationships, while a few individuals (3.2%) shared that increased time together placed more strain on their relationship. Several individuals (20%) felt the increased time together both strengthened and strained their relationship with their dog.The three most common themes all related to ways in which the increased time spent with their dog strengthened their relationships: more quality time; increased attunement/intuition; and increased playtime and training time.Many respondents stated that the supplemental time with their companion dogs strengthened their relationship. Participants described their time with their dogs prior to Covid as limited. Due to Covid, they had more time to share with their dogs and could take advantage of more hugs, cuddles, and relaxing time together. Working from home offered “loads of flexibility and spending more time focusing on what they need versus the way it was before Covid when I was always in a hurry”. Increased time appeared mutually beneficial for humans and their canine companions. Participants’ responses indicated they felt their dogs were happier, as well as more joyful and affectionate: “He never leaves my side. He’s happy when I’m around and I get lots of love and furry therapy from him”. Those caring for elderly and frail dogs savored additional precious moments with their dogs: “My dog is basically on hospice and can deteriorate at any time prompting euthanasia. I am pleased to be able to spend this time with him to look after him, provide good care and improve his morale”. In their roles as caregivers, participants cherished the additional quality time to nurture the affection, love, and companionship they shared with their canine companion.Spending more time together resulted in participants expressing increased attunement/intuition with their canine companions (13.7%). Not only did respondents experience an increased understanding of their dog’s needs and emotions; they also felt that their dogs became more attuned to changes in their stress levels. This bi-directional attunement was described as an enhanced ability to read each other’s body language and communicate. Statements of dogs’ increased intuition echoed throughout responses: “Yes, he definitely senses there are major changes and he can sense my children’s anxiety. He tries to be there for everyone. Offering his free petting services.” Given limitations on social contact, canine companions provided emotional connections previously filled by humans. Participants reported that they felt that their dogs intuitively knew when to appear for hugs or to bring moments of laughter and joy. Humans also expressed experiencing a greater sense of trust from their dogs. For instance, “My dog relies on me more now that I am home more often. To me it’s a sign of greater trust”.As participants navigated social distance restrictions and more time at home, many chose to spend their new-found time training and/or playing with their dog. While the closures of dog training facilities, doggy day cares, and dog parks limited the typical structured activities used to train and entertain dogs, daily walks and training activities increased. These included walking on leashes, improving basic obedience, reducing barking, and rough-housing with other animals or small children in the house. Families with puppies portrayed the urgent need to work on puppy behaviors and obedience. Noticeable changes in dogs’ behaviors materialized: “I spend more time walking and training her. She has increased clarity on what I want because of the increased training time”. Playtimes centered on games in the yard and inside the house, going for walks, chasing toys, and interacting with other animals and kids at home. This increased playtime nurtured family bonds: “My dog is so happy to have the entire family home and is going on lots of walks and being more included in family activities in our home”. Overall, most participants expressed the benefits of having more time to spend with their companion dog.The very small number of participants who reported increased time with their dog resulted in straining the relationship (3.2%), explained the strain came from having to negotiate multiple roles and responsibilities and encountering undesirable dog behaviors. For example, one participant noted: “Working from home means that I want to spend time with the dogs but I can’t because I have to work. The dogs are probably wondering why I’m not paying them more attention when I’m home”. One parent explained, “I have a toddler and they are annoying each other and annoying me by having to manage them”.Increased time together and the resultant increased bonds between humans and their canine companions came as a double-edged sword; on the one-hand, attunement and love increased, while on the other hand, these close connections resulted in increased vulnerability for separation anxiety. One-fifth of the participants stated that the increased time at home with their canine companions resulted in mixed feelings about the strength of their relationship. This group of individuals felt that more time together resulted in both the strengthening and straining of their relationship with their dog. Similar to previous responses, reflections of the ways in which relationships improved included more quality time, increased playtime and training time, and providing love and comfort. The strains centered around activity restrictions, dog behaviors, and worries about the future. An example of these mixed feelings appeared as follows:“Dogs definitely like having us here and like to cuddle/be close. But their bad habits are extra annoying because we are home all the time and I feel they are also acting out a bit from boredom since we don’t go to the places we would normally.”With respect to worries about the future, participants most commonly worried about how their dog would respond to them having to return to former work settings. For example: “They now do everything with me and I love it. I think it will strain when I go back to work. They will be depressed”.The final two open-ended questions aimed to gather additional thoughts and feelings from participants about the ways in which Covid-19 impacted their relationship with their canine companions. The broad nature of the questions enabled respondents to further reflect on previously mentioned themes and also offer new or nuanced representation of themes.In the first of these questions, the participants were asked to reflect on additional ways that their relationship with their dog has been impacted since the onset of Covid-19. The majority of responses revealed the positive ramifications of Covid-19 on human-animal bonds. For example, the most common themes focused on the benefit of more quality time in developing a sense of an enhanced bond with their dog. Members of the family who regularly worked away from home assumed new roles in relationship to their dogs and had time to nurture stronger bonds. As portrayed by one spouse, “My husband always works outside of the home but he’s home now working. One of my dogs has taken up a post at my husband’s side, all day, every day. I think he feels much closer to the pets now”. Statements of enhanced bond appeared in descriptions of increased connection, attachment, attunement, and love. As social distancing restrictions created a sense of isolation, dogs offered friendship that, for some, paralleled human bonds. As reflected by a participant, “Having a companion during this uncertain time, when I was unable to see my friends/family, has been a God-send”. While participants searched for meaning in the uncertainty of Covid-19, they discovered that the pandemic opened opportunities to cultivate enhanced bonds with their dogs and reduce their sense of isolation.In addition, high among participants’ concerns were their worries about dog’s well-being. These concerns appeared as worries about access to food, veterinary care, and a newly emerging expression of concern about their dog’s emotional, physical, and social well-being since the onset of Covid-19. Fear resonated throughout responses about the ways in which participants’ emotional presence may negatively influence their canine companions’ emotional health. Due to the increased quality time and augmented attunement and intuition, dogs were observed as carrying the weight of their guardian’s stress. For example, “I think my older dog feels my anxiety and that’s upsetting me. I don’t want her feeling my anxiety so I’m doing my best to play and give her affection”. Participants additionally expressed concern that their work stress and pandemic-related anxiety was rubbing off on their dogs and appearing in their behaviors. One owner proclaimed, “My anxiety related to my work is felt by my dog and exacerbates her anxiety. Her behavior declines as a result and this stresses me more, so it’s a vicious circle”. Responses also echoed stress about not being able to access specialty dog foods or veterinary care. Other initial Covid-19 physical concerns included worry about dogs getting Covid-19, as one participant shared, “I don’t kiss her forehead anymore”. Expressions of worries about dog’s social well-being also centered around their restrictions in being able to carry out therapy dog activities. Participants shared stress in knowing that their dogs were not receiving physical touch, being able to work in their fulfilling roles, or achieve the mental stimulation they typically received from their social activities. One therapy dog owner explained:“She is a therapy dog and a Crisis Response Dog. We travel together to give comfort to those in need, whether special kids or people in hospitals or survivors of mass shootings. She only has me and my husband to care for now so I have had to think of things to keep her busy. She’s used to being on the go.”In their roles as caregivers, dog owners expressed significant worry in meeting their dog’s emotional, physical, and social needs and attempted to protect their dogs from the additional stresses resulting from Covid-19.The last question allowed participants to provide final reflections about living with a dog during Covid-19. Responses resoundingly portrayed gratitude for the ways in which canine companions eased the burdens of the pandemic. Themes that rose to the top among participants’ responses included gratitude, couldn’t live without a dog, dog is like family, and improves mental health. The following paragraphs characterize participants’ feelings about living with a dog during the pandemic.When given the opportunity to share any thoughts or feelings about their canine companions’ presence during Covid-19, more than half of participants expressed gratitude. Participants drew support from the presence of and interactions with their dogs. For example, they incorporated descriptive words about their dogs such as, “joy”, “sanity”, “friendships”, and “a sense of purpose”. For those that live alone, their canine companions appeared as lifesavers, “I was just talking to friends about how glad I am to have a dog right now, and how lonely it would be to be so isolated from people physically without my dog”. Although caring for a dog during the pandemic added additional stressors in navigating new roles, and providing enough exercise and training activities, most people could not imagine spending the lockdown time of the pandemic without their canine companions. In time, most owners adapted to the initial stressors and acknowledged their irreplaceable relationships with their dogs:“I suspect [the dogs] sensed the increased stress in the household - they were certainly more attentive and would actively seek out physical contact. We seem to have adjusted to a new normal now with a lower current level of stress in this "holding pattern" time. I found the contact-seeking helpful, pleasurable and distracting from current events and appreciate my dogs more as a result.”A common expression of gratitude focused on the value of having a canine partner to share the emotional and social roller coaster rides of the pandemic: “I couldn’t have asked for a better quarantine partner!!The challenges resulting from Covid-19 affirmed for many individuals the instrumental roles that their canine companions play in their lives. Many participants proclaimed that they couldn’t live without their dog. The following sentiment resonated throughout responses: “My plan is to never be without a dog(s). I hope I’m never in a position, e.g., going to a nursing home where I couldn’t have them. Dogs are a very, very, very big and important part of my life”. Others reflected on the invaluable role that their dogs play in providing companionship and comfort: “I can’t imagine going through something as scary and isolating as this pandemic without a dog. I am a widow living with my adult daughter and her husband. They are wonderful to have here but I spend every minute with my dogs while I am home. They are truly constant companions”. The enhanced bonds fostered during Covid-19 and time spent caring for and playing with their dogs also left some people describing their dogs as family members. For example, one participant shared that their dog has become “more of a family member in my eyes”.Among the reasons that participants expressed gratitude for their canine companions was the way in which they buffered the distress that they experienced from isolation, grief, loss, and unending uncertainty. As explained by a participant, “Having her in my home during this time of isolation has really helped me stay mentally well also because she gives me purpose and helps me feel less alone”. Caring for a canine companion appeared to foster a sense of control for instance, “Spending time with my dogs helps keep me grounded in the present and gives me other creatures to focus my energy on instead of worrying about things I cannot control”. Daily routines with canine companions also helped participants to live in the moment and appreciate the simple joys in life. This perspective was explained, “Dogs are wonderful especially in unpredictable times. They bring comfort and therapeutic mindfulness to help with stress and anxiety”. In summary, participants felt immense gratitude for the numerous benefits they garnered from their relationships with their canine companions.The thematic results found in this study highlight the strong connections between humans and their dogs and the role this bond played for pet owners during the initial stages of the pandemic. Despite the stressor of a global pandemic, the striking majority of respondents (76.8%) expressed that their dog reduced their level of stress and provided more positive than negative experiences. Having a dog to care for and focus upon also distracted them from their greatest fears and worries and were seen as a calming presence that facilitated groundedness in the moment. At the same time, dogs consistently enabled moments of joy and laughter, supporting positive emotions during stress. Having a canine companion also appears to have had a protective impact on mental and physical health through added daily structure and exercise. A recent study that assessed the role between companion animals and their humans during Covid-19, found that companion animal ownership was related to better mental health scores . In the Spending more time with their dogs, for the majority of respondents, appears to have strengthened the human–companion animal bond and cultivated openings for quality interactions. Participants noted that prior to Covid-19, their busy lives limited the amount of time they could spend with their dogs. Due to Covid-19 restrictions, they were able to reap the benefits of quality time with their dog through physical interactions, play, training, and the opportunity to care for them. In their roles as caregivers, participants cherished additional quality time to nurture the affection, love, and companionship they shared. This was especially true for people with elderly or sick dogs. More time also seemed to enhance participants’ experiences of harmony with their dog, increasing a sense of a reciprocal human–animal empathic connection and attunement.The responses to these open-ended questions suggest that the participants were able to use the survey as a way to express their feelings in an anonymous, safe, way. When given the space to freely comment upon anything regarding their dog during the pandemic, respondents underscored the importance of their human/animal connection. Gratitude was a fundamental theme, and it is clear that dogs provided people with a sense of purpose. Consistent with previous research regarding the human and animal bond ,24, dogsFrom the onset of Covid-19, daily lives changed in unprecedented ways, leaving many individuals scrambling to find food, shelter, work, and a sense of normalcy. For a small subset of respondents, dog companionship compounded these stressors. More time with their canine companion also meant shifting family interactions with their dog, and the subsequent fallout, such as negotiating new relationships. Furthermore, the added responsibility of taking care of a living creature highlighted worries about the future. Strikingly, these worries were not about the participants themselves, but rather, how the pandemic could negatively impact their dog. At the same time, participants were reticent to note something negative about their relationship with their dog, no matter how stressful, without qualifying the statement with something positive. This orientation seems to once again speak to the dog owner’s predominant desire, above all else, to keep their dogs safe, healthy, and thriving.The primary limitation of this study comes from the self-selection process. This sample consisted of US dog owners, primarily female (88.3%), who have access to the Internet, so care should be taken when generalizing to other populations. Additionally, the survey did not include questions about race, ethnicity, or socio-economic status, which are important variables for future studies, especially around the impact of this pandemic. Another limitation of this study involves its cross-sectional design. This study captures a moment in time, right at the beginning of the Covid-19 epidemic, when restrictions were just put in place. Thus, it is not possible to know how experiences have changed over time as the pandemic continues. Future research could explore more longitudinal issues, post-Covid-19, especially regarding the dog-human bond and its continuing impact on psychosocial functioning.The world may be changed forever, with far fewer people going back to traditional work settings, and considerably fewer opportunities for social interactions than there were in the past. Thus, people may continue to feel a sense of disconnect and isolation, especially if they live by themselves. This study furthers the work of Nieforth and O’Haire , demonstMany people are spending more time with their dogs now than prior to Covid-19. It is hoped that this positive impact of Covid-19 does not change as people return to some type of new normal. Policies that support dog ownership would be beneficial, as research has continually shown both the physical and mental health benefits of having a dog  as well


Most data science is about people, and opinions on the value of human data differ. The author offers a synthesis of overly optimistic and overly pessimistic views of human data science: it should become a science, with errors systematically studied and their effects mitigated—a goal that can only be achieved by bringing together expertise from a range of disciplines. Most data science is about people, and opinions on the value of human data differ. The author offers a synthesis of overly optimistic and overly pessimistic views of human data science: it should become a science, with errors systematically studied and their effects mitigated—a goal that can only be achieved by bringing together expertise from a range of disciplines. Académie Française. His talk, published as Essai sur la statistique morale de la France (1833), changed the way that we view data, and it would also change the speaker’s own life, earning him an award and a coveted place in the academy.Ancient folkloric chants of Poitou, which he presumably wrote as a hobby to distract him from his initially dreary-seeming day job of compiling the French state’s crime data. During this time as a data manager, though, something marvelous appears to have occurred to Guerry: data on people were everywhere.On the second of July, 1832, a 29-year-old data scientist named André-Michel Guerry presented a short manuscript at the prestigious Readers in the era of personal computers, mobile phones, satellites, wearables, electronic health records, Google, business intelligence software, the internet, and the modern surveillance state will be as surprised by this insight as they are by tap water. But Guerry  showed the world that we only need to reach out and analyze data that are already out there to learn more about the world and change our understanding of, for example, crime.Soylent Green, “data is people!”In short, data science, since time immemorial, is mostly about humans: to mangle a quote from 1973 cult movie The Good Place , two opposing theses are proposed, which align closely with current data science practice. These are (1) everything is fine and (2) people are terrible. The purpose of this opinion piece is to combine these apparently contradictory theses into a new suggestion: that neither blind optimism nor blind despair are warranted, and data science must concentrate on developing the methodology to deal with the nature of humans and their data.If data are people, how good are people? This appears to be a subject of some disagreement among philosophers, the comprehensive study of which is left as an exercise for the reader. For understanding of the key issues, here, the author will rely on TV. In the show and anti-vaccination opinions through social networks.Data science has long been recognized as carrying great potential to improve people’s lives and gain insight. Some examples of applications currently at various stages of development and deployment include automatic segmentation of radiology images, processing of vast amounts of -omics data in bioinformatics, early warning on sepsis in neonatal intensive care units, prediction of housing market dynamics, or modeling of the spread of both infectious disease Académie, many of its illustrious members must have been pleasantly surprised that all the human data lying around could produce such interesting results.A striking trait of many data scientists is a “can-do” attitude to data. For example, in making the beautiful graph reproduced in problem formulation. For example, to reduce the costs and improve the benefits of treatment for a new infectious disease, one would design a system that will screen potential patients more accurately than is done currently. People that do not need treatment will receive it less often, reducing costs; patients that do need treatment can be recognized earlier, improving survival. We then need data. The ideal data, perfectly measured and perfectly randomized, are not available. But we make do with a large amount of data from an app in which people register their symptoms, as well as from the routine care processes of general practitioners (GPs) and hospitals, in which we find survival data and background variables. The next task is to assess how survival might be predicted from symptoms and background variables, so that we can screen people . Once that is done, and evaluated to everyone’s satisfaction, it is time to implement the screening, perhaps by changing the warning system in the app, or by developing a software plug-in to the GP’s electronic health record. And after the system has been implemented, it will influence actual decision-making, for example by guiding the decision to refer a patient to further care or advising home confinement. We can then keep observing and improving the system.The inner circle in What could possibly go wrong?Lacroix on A-M. Guerry’s Essai sur la statistique morale de la France.The Good Place)”Pobody’s nerfect.”— Eleanor Shellstrop . This becomes a measurement error problem when self-reported symptoms are used to predict survival, which leads to problems when symptoms are used as ground-truth in an machine learning model. And before you start thinking self-reports are worse than so-called “objective data” from administrative records, wearables, apps, and the like, those data have huge errors as well “‘Fair’ is the stupidest word humans ever invented, except for ‘staycation’.”—Shawn “In football, trying to run out the clock and hoping for the best never works. It’s called ‘prevent defense.’ You don’t take any chances and just try and hang on to your lead. But prevent defense just In summary, an, admittedly caricatured, picture of the current situation is this: we either assume everything is fine (idea #1), or we dismiss human data out of hand (idea #2).science of human data science. Good human data science:(1)Acknowledges that errors—in data, modeling decisions, and implementation—are inevitable;(2)Studies the degree to which errors actually affect the output;(3)Removes these effects where necessary, either by preventing the errors or, when this is not possible or cost-effective, by correcting for their effects.Because neither is particularly constructive, we should do neither. Instead, we should concentrate on the In keeping with data science’s engineering roots, good human data science is also good engineering. A good engineer does not just plow ahead, regardless of the terrain. Instead, she designs a solution that uses the available materials, while controlling the risks. These risks have been recognized from the very beginning for human data science; even the person who wrote Guerry’s introduction called human data the “most difficult to handle.” And he was probably being polite.•Work closely with domain experts to formulate a useful problem and operationalize it into a data science project appropriately;•Work closely with domain experts to understand the evidence that including certain variables (features) will yield a net benefit;•Don’t assume measurement error will “cancel out.” Use statistical models to estimate and correct for the effect of measurement errors;•Use causal models and research designs to estimate and correct for the effects of selection error, including missing data;•Investigate any threats to fairness of decision-making, and use appropriate techniques to ensure models do not learn biases;•Use appropriate techniques to explain the model results to users and data subjects;•Work with cognitive scientists to evaluate whether the above actually worked;•Work with social scientists and domain experts to investigate how the data product affects daily practice.Here are some potential things one could do to mitigate risks by approaching human data science as a science:latent variable models and causal modeling can provide a convenient framework to think about some of these issues. For example, latent variable models are a convenient framework to estimate and correct for data issues,First, comprehensive scientific study of data science projects should become routine.Second, human data scientists need to routinely take a much wider view of “model evaluation”; a successful data science project must not only predict well in out-of-sample data, but also generalize to other contexts in which it might be applied, generalize to the concept it was intended to study, reflect uncertainty accurately, improve on what was already there, have benefits that outweigh its costs, and actually achieve its stated goals in social reality. To verify all of these, the Of course no one person can do everything. That is exactly why we should work harder to unite all of the fields that work on these problems.Third, we should collaborate much more. I do not pretend to be the first person to point out these issues are important; many of the points above are already entire research fields, covering swathes of statistics, computer science, ethical and legal scholarship, domain sciences such as medicine and biology, and social science. But, in my opinion, we are not collaborating enough, and we are not bringing in a large enough diversity of perspectives. In going through the data science cycle, it is all too easy to focus on what interests us, to the detriment of the project as a whole. No one person, including your author, is immune to this problem! For example, some research in data science ethics focuses exclusively on ethical, legal, and societal aspects and pass over existing mathematical tooling to weigh the issues in a practical engineering context. Conversely, some other research focuses entirely on the mathematical tooling without considering whether it will be of practical use in a social context: have I done justice to people’s intelligence and autonomy; will people actually react the way I assume they will? I am aware both that my to-do list for the science of human data science is long and that it should be longer. But, if we really want to put human data to good use, it is the work we need to do. The demons are legion, and nobody ever said it was going to be easy to avoid them. But, as André-Michel Guerry, Jason Mendoza, and many others have shown, it will be well worth it. So, let’s science the heck out of human data science!


P < 0.01). Individuals who documented having a lot of friends had 21% fewer symptoms than those with few or no friends (P < 0.01). Social isolation was associated with greater patient-reported PD severity and lower quality of life, although it is unclear whether this is the cause and/or a consequence of the disease. In essence, the Parkinson pandemic and the pandemic of social isolation have been further compounded by the recent COVID-19 pandemic. The results emphasize the need to keep PWP socially connected and prevent loneliness in this time of social distancing. Proactive use of virtual modalities for support groups and social prescribing should be explored.Social isolation and its deleterious effects on health increases with age in the general population. People with Parkinson’s Disease (PWP) are no exception. Social isolation is a risk factor for worsened health outcomes and increased mortality. Symptoms such as depression and sleep dysfunction are adversely affected by loneliness. There is a paucity of research on social isolation in Parkinson’s disease (PD), which is all the more critical now in the setting of social distancing due to COVID-19. The goal of this study was to survey individuals with PD to evaluate whether social isolation is associated with PD symptom severity and quality of life. Only individuals reporting a diagnosis of idiopathic PD were included in this analysis. The primary outcome measures were the Patient-Reported Outcomes in PD (PRO-PD) and questions from PROMIS Global related to social health. PRO-PD scores increased as social performance and social satisfaction scores diminished. Individuals who reported being lonely experienced a 55% greater symptom severity than those who were not lonely ( Social isolation has been defined as the lack of integration of individuals in their social environment. Living alone, possessing fewer social network ties, and minimal social contact are all markers of social isolation. Measuring social isolation has involved an objective quantifiable approach to establish a lack of social contact and smaller social network size. Historically, social isolation has been defined by measures of household content, marital status, and numbers of friends3. Loneliness, in contrast, is an undesirable subjective emotional state in which there is a perception of social isolation, or the felt experience of being lonely. Loneliness has also been described as the dissatisfaction with the discrepancy between desired and actual social relationships4. It is related to “unfulfilled intimate and social needs.” Researchers have identified three dimensions of loneliness reflecting the particular relationships that are missing. Intimate, or emotional, loneliness is the yearning for a close confidante or emotional partner. Relational, or social, loneliness is the longing for close friendships and social companionship. Collective loneliness is the need for a network or community of people who share one’s sense of purpose and interests. Loneliness can be felt if any one of these dimensions is not satisfied and hence it is possible to be happily married and still feel lonely5.Humans are innately social beings and it has been argued that social connection is as basic a human need as food, water, and shelter6,7. When people lack social support and feel isolated they have increased susceptibility to the effects of stress. Loneliness and social network size are both individual predictors of poor immune response, with the worst immune response being in people who are both lonely and lack a social network8.There has been a robust literature on social support and its ability to buffer stress9 and even in middle aged adults10. Loneliness has been shown to affect cognitive processing and can cause a hypervigilance that can predispose to anxiety. Lonely individuals tend to visually fixate more on socially threatening stimuli than on pleasant ones1. Loneliness can disrupt circadian rhythms and lead to more fragmented sleep11. This sleep quality disruption can result in fatigue and increased irritability12.Research on loneliness comes primarily from population-based longitudinal surveys and animal studies designed to evaluate the impact of social deprivation on neuroendocrine activity. In population-based studies, loneliness has been associated with stress-related inflammatory and neuro-endocrine responses in the elderly13. A review of literature on social isolation in aging revealed a detrimental impact on depression, cardiovascular risk, and well-being15. Social support has been shown to contribute to an individual’s capacity for self-management16.In aging populations there have been comparisons in the literature of social isolation being as detrimental to health as smoking or obesity. After accounting for multiple covariates, one key study reported the increased likelihood of death was 26% for reported loneliness, 29% for social isolation, and 32% for living alone17. Parkinson’s disease (PD) is the fastest growing neurological disease, surpassing Alzheimer’s disease. In the time frame of 1990 to 2015, the prevalence of PD has more than doubled and has been predicted to double again by 204018.Due to the so-called “Parkinson Pandemic” neurologists and epidemiologists have already proposed a “call to action”19. There can be a stigma associated with PD in general20. Some patients may find it difficult to communicate due to dysphonia and dysarthria. Masking of faces may lead to misunderstanding during nonverbal communication. PWP may be embarrassed to be seen in public due to tremor or dyskinesia21. Some may have further embarrassment to go to restaurants because of drooling and difficulty handling utensils. Due to unpredictable bladder and bowel issues including incontinence, PWP may need to plan outings around their restroom breaks and consequently want to stay in the confines of their own homes. PWP also may find outings disrupted by the need to use a walker or cane, or the need to pause and take pills multiple times per day. Difficulty commuting due to an inability to drive or ambulating for long distances is another limiting factor. PWP may feel immobile due to issues of poor balance, freezing of gait, or a perceived risk of falling22. This is especially troubling in climates with snow and rain. Apathy and depression can also contribute to further decreased motivation to frequent social functions or to engage actively while in attendance23. There has been little study of social isolation in Parkinson’s disease. A study by the University of Victoria/Parkinson’s Victoria found that 55% of PD patients felt socially isolated. There was a study on loneliness in 70 caregivers of PD patients and 45 % of the sample scored in the “lonely” range16. Depression correlates with social isolation in PD24.There are a multitude of reasons for social isolation in PWP and their caregivers. In some parts of the world, PD itself is thought to be “old age illness” in Swahili language and a dishonor to the PWP’s entire familyAmong the 2138 survey respondents with a diagnosis of parkinsonism, 1795 claimed to have a diagnosis of “Parkinson’s disease/Idiopathic PD.” After data cleaning, 1527 participants with PD were available for this analysis. 1.7% of PRO-PD data points required mean substitution for missing values. At the cohort level, the regression analysis predicted a mean score at diagnosis of 637 with an increase of 31 points per year, 95% CI: 26.8, 35.8 Fig. . IndividR2 = 0.534; P < 0.01). Individuals were asked to rate their overall quality of life (QoL) on a 1–5 scale, with 1=poor and 5=excellent. The higher the QoL score, the more likely the participant was to say they had a lot of friends. The lower the QoL score, the more likely they were to report being lonely. Tremor is one of the most obvious and recognized hallmarks of PD and hence can be a source of social stigma for many patients with PD26. Notably, QoL was only moderately associated with patient-reported tremor intensity . Alternatively, individuals that said “I practice stress management” and those that reported frequent exercise had a statistically slower rate of PD progression. Although not the focus of this study, exercise is the most well-established therapeutic intervention for possibly slowing PD progression28 and is thus presented as a comparator to variables associated with loneliness, friendship, and income. One of the single most impactful modifiable variables associated with increased progression was the affirmative response to the statement, “I am lonely.” Reporting loneliness was as bad if not worse,  for PRO-PD scores as daily exercise was good  for PRO-PD scores.Individuals responding “True” to the statement, “I have a lot of stress” reported a faster rate of PD progression (P < 0.01). Individuals that agreed to the statement “I am lonely” had a PRO-PD score that was 327 points higher than similar participants who did not identify as lonely (P < 0.01)  Fig. . Lonely 01) Fig. . Not uneThe fact that loneliness is associated with worsened QoL is not surprising but to our knowledge, this is the first time that this link has been elucidated in a PD population. Cause and effect cannot be discerned from a cross-sectional analysis though it appears that loneliness is a social determinant that is tremendously relevant and previously overlooked. Social isolation as a risk factor for poor outcome in PD needs more consideration in future research, practice, and policy development, especially given the current social distancing regulations associated with ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic.A broad range of income brackets were represented in this study. Survey respondents were predominantly Caucasian, young, and female, which does not reflect the classic demographic profile of the general PD population. While this study failed to capture a sample reflective of actual demographics of the affected population, younger individuals and women are under-represented in PD research and hence this study contributes to a necessary body of literature.29.Questions and concepts surrounding social isolation can be vague and may be open to interpretation by different individuals. In this study, social isolation was inferred through a number of questions about loneliness, friendships, partnership status, social performance, and social satisfaction. A limitation of subjective measures is the reliance on the patient filling out the questionnaire where the answers could be confounded by issues such as depression, anxiety, apathy, fatigue or pain, or even invalid . Because some symptoms may be in the causal pathway, adjustments were not made for individual variables. Subsequent research should attempt to evaluate the overlap and interplay between individual PD symptoms such as depression, anxiety, fatigue, apathy, etc. and loneliness. Providers should be aware that a subset of patients may feel lonely even when surrounded by people. Similarly, there may be some introverted people that prefer not to have people around them and report no issues with feeling lonely. These data do not address the quality of the relationships experienced by the person with PD, only whether they are married/partnered or have friends30. The fact that the PRO-PD correlated with years since diagnosis, loneliness, and social health provided some assurance that the PRO-PD scale was reflecting what it was designed to measure. A limitation of all novel scales is their lack of historical use and, thus, absence of a track record of success. In this case, the patient is asked to use 33 slider bars to rate the severity of common PD symptoms, on average, over the previous week. This direct questioning of the patient about their symptoms (many of which cannot be objectively measured), makes it a particularly straight-forward tool.The validity and utility of the PRO-PD as an outcome measure is still under confirmation. The PRO-PD has previously been shown to correlate with existing measure of PD severity, specifically the Unified PD Rating Scale, Hoehn & Yahr, PDQ-39, and the Timed-Up-and-Go32. For example the Togetherness Program at CareMore includes home visits, weekly phones calls and connecting patients to existing social programs in the community33. The Veteran’s Administration has recently created the “Compassionate Contact Corps Program” using volunteers to call veterans who are lonely and check in on them. Volunteering can help loneliness as well and so it has been proposed that veterans can be paired up with each other to make such calls34. The National Health Service in the United Kingdom have designed a link worker social prescribing programme35 that was recently highlighted in the NEJM article where they list referrals to group exercise classes, art-based therapies, volunteer opportunities, self-help groups for specific conditions, and community activities such as gardening, cooking and befriending as examples of social interventions36.For individuals who feel unable to influence their social conditions, these results may be especially stressful. Social prescribing is a novel concept in which clinicians recommend or prescribe resources or activities in the community to help patient develop healthy social connections37. Loneliness overlaps with and can be inherited along with anxiety and depression traits. All three of these issues can coexist and have similar manifestations and hence be confounding. All three issues can have negative impacts on mood and can cause social withdrawal which can then lead to a vicious cycle making it harder to connect socially and further deepen loneliness and isolation30. In recent years, group classes and support groups have been increasingly popular in the PD community. It is possible that the social aspects of these programs could be contributing to their perceived benefit by participants.While it is interesting to attempt to understand the possible mechanisms by which loneliness is associated with PD progression Fig. , the mor23. A virtual happy hour or tea party may be helpful to keep patients connected. Proactive phone calls to patients from fellow patients, support group leaders, volunteers, or health care providers should be explored in the vain of social prescribing programs like the CareMore program or the VA Compassionate Contact Corps Program as described above. These calls may be a critical link to the outside world for PWP who may lack a computer, smart phone, internet connection (due to cost or remoteness) or who may be technologically-challenged34.Outside of the SARS-CoV-2 era, there are numerous strategies for promoting activities that encourage social engagement such as boxing, dancing, karate, yoga, meditation group classes, group walks, music classes, and art classes. Book clubs, movie clubs, and other discussion groups might be helpful. Certainly, live in-person support groups that are specifically focused on PD can also be instrumental in providing social connection and support. During the SARS-CoV-2 era, social distancing can significantly worsen social isolation. The “shelter in place” interventions may put a population of vulnerable patients at increased risk for poor outcomes due to a diminished ability to socially engage and exercise. Social distancing intended to prevent the spread of this and future pandemics is expected to put a strain on burned out caregivers who also may be socially isolated. Novel interventions such as virtual support groups using technology where patients can visualize one another on a screen or virtual exercise classes may be a critical source for human connection38. Risks associated with increased social engagement will vary depending on whether the interaction is in person or virtual during this COVID pandemic. The costs and risks associated with virtual social engagement during COVID times are negligible and may in fact have an added benefit to the volunteers that may be enlisted since volunteering itself has been shown to be beneficial for loneliness.While it has yet to be determined whether or not a prescription for social engagement will translate to improved outcomes, health care providers can become more proactive with screening. Since there is a stigma associated with being lonely and patients may be averse to asking for help in this arena, specific screening questions should be developed. It has been noted that men have a harder time acknowledging that they are lonely and hence asking for help13. Compounded with the Parkinson pandemic, this call to action should be intensified. The COVID-19 pandemic, with the need to socially distance, may synergize with these other two pandemics and have the dire consequences of diminishing QoL, social satisfaction, and exacerbating disease severity in individuals living with chronic neurodegenerative disease.These data have tremendous implications in PD research, as social health has not historically been considered in study design and analysis, contributing to a lot of background noise. Researchers should consider asking about, and adjusting for, loneliness as a covariate in models of PD progression. The pandemic of social isolation and loneliness is a mounting concern in our society today and there has been a call to action in highlighting this as a major public health concern akin to a pandemic40. REDCap (Research Electronic Data Capture) is a secure, web-based software platform designed to support data capture for research studies, providing: (1) an intuitive interface for validated data capture; (2) audit trails for tracking data manipulation and export procedures; (3) automated export procedures for seamless data downloads to common statistical packages; and (4) procedures for data integration and interoperability with external sources.In 2013, a prospective observational internet-based study was designed to identify modifiable lifestyle variables associated with the accumulation of patient-reported symptoms over time. The data presented here are a cross-sectional analysis of baseline data from individuals with a self-reported diagnosis of idiopathic PD. The study was approved the Bastyr University IRB (#13A-1332) and listed on ClinicalTrials.gov (#NCT02194816). All individuals confirmed they read and understood the participant information sheet prior to study participation. Due to the nature of this being an online survey, the IRB issued a Waiver of Documentation of Informed Consent. All study participants included in this analysis reviewed the Participant Information Sheet and provided consent via the online survey. Study data were collected and managed using REDCap electronic data capture tools hosted at Bastyr University41. The PRO-PD has since been shown to correlate with years since diagnosis, Hoehn and Yahr, UPDRS, PDQ-39, and PROMIS Global measure of QoL, suggesting patients are able to provide a surrogate marker for their disease42.The Complementary and Alternative Medicine in PD (CAM Care PD) study was designed to identify modifiable variables associated with the rate of patient-reported PD severity and progression. As this analysis utilized an existing database, the data dictionary was reviewed for all assessments related to social health, QoL, and PD severity. The primary outcome measure for PD severity was the cumulative PRO-PD score. This internet-based survey required an outcome measure that could be remotely acquired and was able to capture the patient’s perception of motor and nonmotor symptom severity. The scale needed to measure wellness as well as disease (no ceiling effect) and be useful in early and late disease. Because it is an internet-based survey, the survey could not mandate a physical exam or a face-to-face visit in a clinic. Statistically, the scale needed to be continuous and able to be stratified by symptom. Such a scale did not exist, so the PRO-PD was created to meet the needs of this study according to the principles outlined in “Ideal Properties of PRO Instrument”43, PROMIS Global was chosen as the primary QoL measure for the CAM Care PD study. The PROMIS measure has been validated across diverse, chronic conditions and meets the “Recommended” criteria for utilization by the International Parkinson and Movement Disorder Society Task Force on Rating Scales45 Both PROMIS Global and individual questions from PROMIS were used as outcome measures, the former because it has been validated and the latter because the individual questions were better able to address the scientific question. PROMIS questions related to social satisfaction and activities were used as primary outcome measures for this analysis. For each of the following questions, participants were given the choice between “Excellent,” “Very good,” “Good,” “Fair,” and “Poor,”: “In general, would you say your quality of life is:…”; “In general, how would you rate your satisfaction with your social activities and relationships?”; and “In general, please rate how well you carry out your usual social activities and roles. ” In addition to the validated PROMIS question, two true/false statements were posited to specifically target loneliness and presence of friends- namely “I am lonely” and “I have a lot of friends.”While the PD Questionnaire-39 (PDQ-39) is the most well-established measure of PD QoL, the scale is most useful in highly symptomatic individuals. At the request of NIHLifestyle variables were measured with a set of true/false statements, with participants instructed to “Please mark all boxes you consider TRUE or FALSE over the past 6 months.” Tremor was measured on an unnumbered slider bar with far left (0) representing no tremor and the far right (100) representing a tremor that was “Severe/debilitating.” For the exercise frequency, participants were asking “On how many of the last seven days did you participate in at least 30 min of physical activity?” PROMIS QoL questions were ranked 1 (Poor) through 5 (Excellent). Because several questions on the PROMIS Global rating scale are in the causal pathway for the current study, the primary outcome measure used for this analysis is the single PROMIS question, “In general, would you say your quality of life is: Excellent, Very Good, Good, Fair, Poor.”Multiple linear and logistic regression models were used to examine the association between social health, income, and PD severity, with PRO-PD scores used as the outcome variable. All regression analyses controlled for age, years since diagnosis, income, and gender. For regression analyses, participant records were excluded if age, years since diagnosis, income, and/or gender data was missing. Participants were asked at the start of the survey about the particular status of their diagnosis, with the following options: Parkinson’s disease/ Idiopathic Parkinson’s disease (PD), Parkinsonism, Multiple system atrophy/Shy-Drager syndrome, Progressive supranuclear palsy, Corticobasal degeneration, Dementia with Lewy bodies, Pick’s disease, Olivopontocerebellar atrophy, or other. Only participants reporting a diagnosis of idiopathic PD were used for this analysis. For participants who did not score an element from the 33 individual PRO-PD symptoms, the cohort average for that individual symptom was substituted for any missing value. For other data analyses, such as QoL measures, the most complete dataset was utilized for the relevant variables. The word “progression” is used throughout in places where the regression model adjusted for time, i.e., “years since diagnosis.” All statistical work was done using STATA Version 14  with alpha set to 0.05. No adjustments were made for multiple comparisons to avoid increasing the risk of type II errors, and the failure to detect an association that is present was a priority for this observational study.Further information on research design is available in the Nature Research Reporting Summary linked to this article.reporting summary


In this paper, we propose a unified logical framework for representing and analyzing various forms of correlated information change. Our main thesis is that “logical dynamics,” in the sense of van Benthem (Exploring logical dynamics. CSLI Publications, Stanford,  In this paper, we focus on modeling situations that exhibit a particular form of “correlated information change,” i.e., situations in which the very act of learning new information may influence the result and changes the very phenomenon under study. Examples of correlated information change appear in a number of different areas ranging from quantum mechanics, to logic, medical science and social science. In these areas, different forms of correlated information change have been identified and studied. The quantum observer effect, embodied in the motto that “observation causes perturbation,” lies at the basis of contemporary applications of quantum mechanics to secure communication. The Hawthorne effect (Levitt and List P of the state space). Such structures are special cases of so-called dynamic frames and are well studied in the context of propositional dynamic logic (PDL) , we observe that the original reading of the AGM success postulate can no longer be sustained. Indeed, the case of revision with a Moore sentence, the success postulate (under the above given reading) would force us  to acquire false beliefs!L, i.e., a setting in which theories T can contain the basic sentences (and their Boolean combinations) of a given propositional language but should not contain sentences having modalities that refer to the beliefs of agents. This solution boils down to a belief revision setting that cannot model higher-order reasoning nor any type of revision with sentences that explicitly refer to the beliefs of agents. While this first solution solves the problem on technical grounds, it is not satisfactory as real agents can indirectly learn new facts about the world via higher-order sentences. The second solution we propose focuses on another way to model belief revision. In this second solution, we are still validating the AGM postulates, but we reinterpret them in such a way that they can be made plausible in the context of revision with higher-order information. The latter solution is the one we adopt in the remainder of this section and to explain it we will make use of the tools of dynamic logic.Such examples show that there is a problem with accepting the success postulate  in the context of revision with higher-order information. In essence, there are at least two solutions to this problem. The first solution is to accept that the AGM theory only works with a restricted language the same state as the unrevised beliefs   beliefs are given by putting K can also be defined in terms of conditional beliefs, but we chose here to take it as a primitive operator.)So the language after the learning act).” In this extended setting, the success postulate fails for non-atomic sentences relational presentation, which we adopt here:Using the language nd Smets , we noteic Plaza . The expDefinition[Plausibility Frames and Models] A (single-agent) plausibility frame is a structure S of states and a binary “(im)-plausibility” relation s is at least as plausible as state t.” So, for any given set P-states in the set the most plausibleP-states. The plausibility relation S. A plausibility modelmentclass2pt{minimSemantics for Belief Revision The semantics is given in the usual way, by defining a satisfaction relation K is in fact definable in terms of conditional belief).T-interpretationpairs  of an “ontic state” CDL!) allows us to capture the mentioned scenarios of belief revision with higher-order information. A complete axiomatization of this logic is in our paper  is a non-classical logic with the same syntax as standard propositional logic, but with different laws. We start from the Backus–Naur Form (BNF) of the following language Hilbert Space Semantics The standard semantics for quantum logic is given in terms of the Hilbert space formalism of quantum mechanics. The state of a physical system is represented by a “ray”  of a given Hilbert space H. The possible physical properties (or propositions) of the system correspond to closed linear subspaces of H. A state satisfies a property if it belongs to the corresponding subspace. The sentences of orthogonal subspace tointersection of the two subspaces. The quantum disjunction subspace generated by the union of the two subspaces represented by In the history and development of ortho(modular)quantum logic, we encounter several kinds of axiomatizations ranging from natural deduction systems to Hilbert-style axiomatizations and Gentzen-style sequent calculi. We do not review these systems here, but note that such proof systems have been designed to provide the axioms and/or rules that regulate the operators of the language s, which is taken to be the superposition of two states s, while both s:s may well fail to satisfy locally Boolean, which means that if we restrict the logic to its Boolean fragment then the Sasaki Hook reduces to the classical material implication. In general, however, the classical deduction theorem does fail for it and that result goes hand in hand with the mentioned failure of distributivity of the conjunction and disjunction.Superpositions of physical properties are captured in While it is interesting to compare the behavior of the mentioned quantum operators to their classical counterparts, a clear intuitive physical explanation remains a point of debate. This quest for a physical explanation of the quantum logical principles and laws goes back to Birkhoff and von Neumann who ended their 1936 paper  system collapses to a state satisfying property P.In Baltag and Smets , we haveDefinition [Quantum Test Frames]. Any Hilbert space H can be structured as a quantum test frame, by taking as set of states S the set of all “rays”  of H, taking the family S corresponding to) closed linear subspaces P of H, and taking S by) the projectorS corresponding to) the linear subspace P.p comes from a given set of basic (elementary) propositions The logical language for quantum observations interpretationall formulas orthocomplementimpossibility of a successful test of unitary evolutions (quantum gates):Our models are obtained by extending quantum test frames with a valuation map nd Smets , we extend Smets , we provnd Smets , we addegeneral test frames. These provide a uniform framework for representing conditionals of various kinds , as special case of weakest preconditions of test actions.We proceed now to generalize quantum test frames to obtain the new notion of S, and any subset R]P corresponds to the standard Kripke (semantics for the) modality associated with the accessibility relation R. As well known in Computer Science, when R is interpreted as an “action” or a “program,” R[P] represents the strongest postcondition ensured (on the output) by (doing action) R on P-inputs, while [R]P represents the weakest precondition (on the inputs of R) ensuring that P will be satisfied on the output after (doing action) R. In particular, when Definition [General Test Frames]. A general test frame  is a relational Kripke frameS of states, a family testable propositions , and a family of binary (accessibility) 0.Closure) The familyof testable propositions contains the inconsistent proposition and the tautological one and is closed under arbitrary intersections, weakest preconditions and strongest postconditions: i.e., (1.Testability) If a testable proposition is true, then it can be successfully tested: i.e., if t with (2.Success) A proposition is always true after being successfully tested (and so by 1 the test can be repeated): i.e., if (3.Repeatability) A successful test can be repeated without disturbing the state: i.e., if (4.Redundancy) Repeating a successful test is a redundant action: the same output state can be obtained by testing only once; i.e., if For any binary relation entclass1pt{minimaevery state hassuccessors and no state hassuccessors: i.e., for every state complete lattice when ordered by set-inclusion infimum operation.It follows from the above assumptions that Testable Closure Although in an arbitrary test frame it is possible that not all propositions are testable : namely, the conjunction of all its testable consequences. Epistemically, cl(P) represents the information state of the observer after learningP: the conjunction of all the testable predictions based on only knowing P. For any proposition “testable closure” oftestable closure is always testable , and we have P is successful on any state in T. We putorthocomplement of Possibility and necessity We say that proposition possible at state s  can be obtained as a special case: classical test framesall propositions are testable, so diagonal ofP. In other words, classical PDL tests s iff P is true at s, in which case the state s is left unchanged. It is easy to see that in a classical test frame, all states are normal  representing some kind of idealized, non-disturbing test actions. In this way, we can always compare within the same framework the “real”  test actions with their idealized  counterparts.The Language ofdynamic logic of test (DLT) has the following language:inconsistent proposition ; symbols atomic (elementary) propositionsknown ; classical (unobserved) test action , that can only take place in a state if “dynamic” or non-classical test , that can only take place in a state in which become true, in which the state is indeed changed to any of the “closest” classical observation, by which the observer learns ’dynamic’ or non-classical observation, by which the observer learns quantum measurements.Testable Formulas The testable (or ‘dynamic’) fragmentDLT is the set of all DLT-formulas that do not use any classical tests the formulas of the testable fragment express testable propositions.Abbreviations. We use the following abbreviationsModels A test modelDLT consists of a test frame Semantics Our semantics is really in the spirit of Dynamic Epistemic Logic, although we choose to state it in a form that is inspired from Subset Space Logic (or “topo-logic”), see Moss and Parikh  with s, T), the first component s represents the ontic state , while the second component T represents the information state of the “observer”: in other words, in world  the observes knows only that the observed state is in T. For a given model M, we define a satisfaction relation s, T) and formulas DLT. This is equivalent to extending the interpretation map all formulas, by defining an interpretationboth notations in our recursive definition, as we will do below. For any information state T is the observer’s current information state, then information state after performing a successful  observation ofeven a non-informative observation may disturb the observed state.even a non-informative observation may change the observer’s information state: indeed, we havedifferent from T. In fact, when T is the observer’s information state, then the observer’s (default) beliefs (given her information T).d Parikh .4 We evaknowledge, we put Classical test modality is nothing but classical implication:Classical observation is really the standard update modality (“public announcement”) from Public Announcement Logic:dynamic test, we put dynamic observation, we put all our connectives, with the exception of conjunction, are in fact Kripke modalities : indeed, given any binary relation s, T), we can introduce a Kripke modality by puttingFor basic formulas, we put M and an information state the interpretation inTof any testable formula is a testable proposition: i.e., if Given a model valid on a test models, T) with valid on a test framevalid on a classKof frames if it is valid on all frames in the class K.A formula K, All our modalities For all formulas testable formulas arbitrary (not necessarily testable) For all PDL tests, we show now how our framework subsumes other examples, including plausibility models for belief revision, sphere models for counterfactual reasoning and quantum test frames.Besides classical CDLFrames Conditional Doxastic Logic (CDL) can be obtained as another special case: any plausibility frameconditional doxastic frameall propositions are testable, so conditional doxastic accessibility relationsP-states. It is easy to see that in CDL frames, we have CDL test frame coincide with the corresponding notions as defined in the given plausibility frame. Moreover, in CDL frames conditional beliefand dynamic conditionalare the same notion. As for dynamic observation CDL frames, knowledge coincides with “necessity” . In Lewis frames, all states are normal . In Lewis models, the dynamic conditional Epistemic Counterfactual Logic One should note that our setting adds to counterfactual logic an “observer” and her knowledge K, so we obtain an epistemic counterfactual logic. Note that in Lewis frames, (default) “belief”(as defined above) is the same as knowledge“conditional belief”is the same as knowledge of the counterfactualQuantum Test Frames A Hilbert space H can be structured as a quantum test frame, by taking as set of states S the set of all “rays”  of H, taking the family S corresponding to) closed linear subspaces P of H, and taking S by) the projectorP. Then all states are normal  observations. So, even when restricted to quantum test frames, our logic DLT we obtain a quantum version of Dynamic Epistemic Logic (DEL), which can be used to talk about the informational effects of both classical and quantum measurements. The “purely quantum” DEL is the testable fragment of this logic , whose formulas can always be interpreted as “experimental propositions” describing testable properties of a quantum-informational system. Note that (like the case of Lewis frames), in a quantum test frame “belief”(as defined above) is the same as knowledge“conditional belief”is the same as knowledge of the quantum implicationPDL tests before the action), so they have precondition; in contrast, successful quantum tests s in which potentially true : see Table informational perspective, there are also a number of differences: unobserved tests  involve no informational dynamics (since they do not affect the observing agent), and the question is again meaningless for counterfactual conditionals . In contrast, new knowledge or new beliefs are acquired by the other forms of conditioning . Finally, the informational dynamics is monotonic in the case of classical observations , but it is non-monotonic in the case of belief revision (since old beliefs can be overturned) and of quantum observations .Our unified framework allows us to easily compare the different types of conditionals and forms of learning mentioned above. Quantum test operators mentclass2pt{minimnot claiming to reduce or explain quantum behavior to a purely informational phenomenon. The quantum realm is characterized by the erosion of the sharp classical separation between “ontic” and “epistemic” , as well as information processing , in terms of actual interactions and correlations between actually existing systems. The observer lives in the world, and her learning actions are real physical events, which have real consequences. In this sense, Marx’ famous quote on the imperative to change the world