Site-level variability in the processes of care and outcomes over time among patients with COVID-19 and myocardial injury: Insights from the American Heart Association's COVID-19 Cardiovascular Disease Registry.

Background: Elevated cardiac troponin (cTn) levels in patients with COVID-19 has been associated with worse outcomes. Guidelines on best practices of those patients remain uncertain. Methods: We included patients with COVID-19 and cTn above the assay-specific upper limit of normal (ULN) enrolled in the American Heart Association's COVID-19 registry between March 2020-January 2021. Site-level variability in invasive coronary angiography, LVEF assessment, ICU utilization, and inpatient mortality were determined by calculating adjusted median odds ratio (MOR) using hierarchical logistic regression models. Temporal trends were assessed with Cochran-Armitage trend test. Results: Among 32,636 patients, we included 6234 (19.4 %) with cTn above ULN (age 68.7 ± 16.0 years, 56.5 % male, 51.5 % Caucasian), of whom 1365 (21.6 %) had ≥5-fold elevations. Across 55 sites, the median rate of invasive coronary angiography was 0.1 % with adjusted MOR 1.5(1.0,2.3), median LVEF assessment was 25.5 %, MOR 3.0(2.2,3.9), ICU utilization was 41.7 %, MOR 2.2(1.8,2.6), and mortality was 20.9 %, MOR 1.7(1.5,2.0). Over time, we noted a significant increase in invasive coronary angiography (p-trend = 0.001), and LVEF assessment (p-trend<0.001), and reduction in mortality (p-trend<0.001), without significant change in ICU admissions (p-trend = 0.08). Similar variability and temporal trends were seen among patients with ≥5-fold cTn elevation. Conclusions: The use of invasive coronary angiography among patients with COVID-19 and myocardial injury was very low during the early pandemic. We found moderate institutional variability in processes of care with an uptrend in invasive catheterization and LVEF assessment, and downtrend in mortality. Comparative effectiveness studies are needed to examine whether variability in care is associated with differences in outcomes.

Testing the impact of overt and covert ordering interventions on sustainable consumption choices: A randomised controlled trial.

Food products have significant impacts on the environment over their life cycle. We investigated whether displaying products in ascending order of carbon footprint in an online supermarket environment can shift consumer choices towards more sustainable options. We examined whether the effect of the ordering intervention differs when the ordering is overt (information about the ordering is explicit), compared to when it is covert (participants not told about the ordering). We conducted a three-arm parallel-group randomised trial using 1842 online participants from England, Wales, and Northern Ireland. Participants shopped for a meal, choosing one product from each of six product categories in a simulated online supermarket. Six products were listed vertically on each product-category page. Products were randomly ordered for the control arm but ordered by carbon footprint in the covert and overt ordering arms. In the overt ordering arm, a statement was displayed at the top of each product page about the ordering of products. The primary outcome was whether one of the three most sustainable products was chosen in each product category. There was no effect of the covert ordering on the probability of choosing more sustainable products compared with the control arm (OR = 0.97, 95% CI 0.88-1.07, p = 0.533). Furthermore, we did not find evidence that the effects of the covert ordering and overt ordering differed (p = 0.594). Within the control condition, products in different positions were chosen with similar frequencies, suggesting that product positioning does not have an impact on choices. This may explain why re-ordering products had no effect. In the overt condition, only 19.5% of people correctly answered that the products were ordered according to sustainability in a follow-up question, suggesting that they didn't notice the statement. Results suggest that choices for grocery products might be too ingrained to be changed by subtle rearrangements of choice architecture like the ordering interventions, and highlight the difficulty of conveying information effectively to consumers in the online grocery shopping environment.

Association of body mass index with COVID-19-related neurologic sequelae: a retrospective cohort study.

We sought to explore the relationship between body mass index (BMI) and neurologic outcomes following acute COVID-19 infection. We conducted a retrospective electronic medical record-based cohort study enrolling adults with laboratory-confirmed acute COVID-19 infection who presented to 1 of 12 academic and community hospitals in Southwestern Ontario, Canada between April 1, 2020 and July 31, 2021. Primary subjective (anosmia, dysgeusia, and/or headache) and objective (aseptic meningitis, ataxia, delirium, encephalopathy, encephalitis, intracranial hemorrhage, ischemic stroke, and/or seizure) composite neurologic outcomes were assessed, comparing obese and overweight individuals to those with underweight/normal BMI indices, adjusting for baseline characteristics. Secondary outcomes (severity of illness, length of hospital stay, SARS-CoV-2 viral load, mortality) were similarly analyzed. A total of 1437 enrolled individuals, of whom 307 (21%), 456 (32%), and 674 (47%) were underweight/normal, overweight, and obese, respectively. On multivariable analysis, there was no association between BMI category and the composite outcome for subjective (odds ratio [OR] 1.17, 95% CI 0.84-1.64, Bonferroni p = 1.00 for obese; OR 1.02, 95% CI 0.70-1.48; Bonferroni p = 1.00 for overweight) and objective (OR 0.74, 95% CI 0.42-1.30, p = 0.29 for obese; OR = 0.80, 95% CI 0.45-1.43, p = 0.45 for overweight) neurologic manifestations. There was no association between BMI category and any secondary outcome measure and no evidence of effect modification by age or sex. This study demonstrates the absence of an association between BMI and neurologic manifestations following acute COVID-19 illness. Prospective studies using standardized data collection tools and direct measures of body fat are warranted to obtain more valid effect estimates.

Airborne transmission of the Delta variant of SARS-CoV-2 in an auditorium.

The Delta variant of SARS-CoV-2 has inflicted heavy burdens on healthcare systems globally, although direct evidence on the quantity of exhaled viral shedding from Delta cases is lacking. The literature remains inconclusive on whether existing public health guidance, based on earlier evidence of COVID-19, should respond differently to more infectious viral strains. This paper describes a study on an outbreak of the Delta variant of COVID-19 in an auditorium, where one person contracted the virus from three asymptomatic index cases sitting in a different row. Field inspections were conducted on the configuration of seating, building and ventilation systems. Numerical simulation was conducted to retrospectively assess the exhaled viral emission, decay, airborne dispersion, with a modified Wells-Riley equation used to calculate the inhalation exposure and disease infection risks at the seat level. Results support the airborne disease transmission. The viral emission rate for Delta cases was estimated at 31 quanta per hour, 30 times higher than those of the original variant. The high quantity of viral plume exhaled by delta cases can create a high risk zone nearby, which, for a mixing ventilation system, cannot be easily mitigated by raising mixing rates or introducing fresh air supply. Such risks can be reduced by wearing an N95 respirator, less so for social distancing. A displacement ventilation system, through which the air is supplied at the floor and returned from the ceiling, can reduce risks compared with a mixing system. The study has implications for ventilation guidelines and hygiene practices in light of more infectious viral strains of COVID-19.

Development and consensus process for a clinical pathway for the assessment and management of chemotherapy-induced peripheral neuropathy.

BACKGROUND: Cancer patients treated with neurotoxic chemotherapy are at risk of developing neurological symptoms that can impact functional capacity and quality of life. However, there are no standardised pathways to assess and manage chemotherapy-induced peripheral neurotoxicity (CIPN). This study aimed to determine consensus on statements regarding a CIPN assessment and management clinical pathway. METHODS: A CIPN clinical pathway (CIPN-path) was developed and reviewed by an expert multi-disciplinary panel and consumers. Agreement with 18 statements regarding four content themes (pretreatment review, screening and assessment, management and referral, and CIPN-path feasibility) were assessed by 70 Australian respondents (68 health professionals, 2 consumers), using a 2-stage Delphi survey process to reach consensus. Respondents rated statements using a 5-point Likert scale to determine the level of agreement, with consensus defined as ≥ 80% of respondents agreeing with each statement. RESULTS: The consensus was reached for 14 of 18 items after stage 1 and all items after stage 2. Feedback was obtained for all items to refine the CIPN-path. There was an agreement on important characteristics of the CIPN-path, including pretreatment screening, regular patient-reported assessment, and a stepped-care approach to investigating and managing symptom burden. There was a lack of agreement on who should oversee CIPN assessment, which may differ according to the structure and resources of each site. CONCLUSIONS: There was an overall agreement concerning the CIPN-path to assess and manage CIPN, which may be adapted accordingly to the resources of each clinic. The CIPN-path may assist teams across different health services in identifying CIPN symptoms, aiding decision-making, and reducing morbidity from CIPN.

A systematic review of the prediction of hospital length of stay: Towards a unified framework.

Hospital length of stay of patients is a crucial factor for the effective planning and management of hospital resources. There is considerable interest in predicting the LoS of patients in order to improve patient care, control hospital costs and increase service efficiency. This paper presents an extensive review of the literature, examining the approaches employed for the prediction of LoS in terms of their merits and shortcomings. In order to address some of these problems, a unified framework is proposed to better generalise the approaches that are being used to predict length of stay. This includes the investigation of the types of routinely collected data used in the problem as well as recommendations to ensure robust and meaningful knowledge modelling. This unified common framework enables the direct comparison of results between length of stay prediction approaches and will ensure that such approaches can be used across several hospital environments. A literature search was conducted in PubMed, Google Scholar and Web of Science from 1970 until 2019 to identify LoS surveys which review the literature. 32 Surveys were identified, from these 32 surveys, 220 papers were manually identified to be relevant to LoS prediction. After removing duplicates, and exploring the reference list of studies included for review, 93 studies remained. Despite the continuing efforts to predict and reduce the LoS of patients, current research in this domain remains ad-hoc; as such, the model tuning and data preprocessing steps are too specific and result in a large proportion of the current prediction mechanisms being restricted to the hospital that they were employed in. Adopting a unified framework for the prediction of LoS could yield a more reliable estimate of the LoS as a unified framework enables the direct comparison of length of stay methods. Additional research is also required to explore novel methods such as fuzzy systems which could build upon the success of current models as well as further exploration of black-box approaches and model interpretability.

Recurrent transitions to Little Ice Age-like climatic regimes over the Holocene.

Holocene climate variability is punctuated by episodic climatic events such as the Little Ice Age (LIA) predating the industrial-era warming. Their dating and forcing mechanisms have however remained controversial. Even more crucially, it is uncertain whether earlier events represent climatic regimes similar to the LIA. Here we produce and analyse a new 7500-year long palaeoclimate record tailored to detect LIA-like climatic regimes from northern European tree-ring data. In addition to the actual LIA, we identify LIA-like ca. 100-800 year periods with cold temperatures combined with clear sky conditions from 540 CE, 1670 BCE, 3240 BCE and 5450 BCE onwards, these LIA-like regimes covering 20% of the study period. Consistent with climate modelling, the LIA-like regimes originate from a coupled atmosphere-ocean-sea ice North Atlantic-Arctic system and were amplified by volcanic activity (multiple eruptions closely spaced in time), tree-ring evidence pointing to similarly enhanced LIA-like regimes starting after the eruptions recorded in 1627 BCE, 536/540 CE and 1809/1815 CE. Conversely, the ongoing decline in Arctic sea-ice extent is mirrored in our data which shows reversal of the LIA-like conditions since the late nineteenth century, our record also correlating highly with the instrumentally recorded Northern Hemisphere and global temperatures over the same period. Our results bridge the gaps between low- and high-resolution, precisely dated proxies and demonstrate the efficacy of slow and fast components of the climate system to generate LIA-like climate regimes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00382-021-05669-0.

Chemotherapy-Induced Peripheral Neurotoxicity in Cancer Survivors: Predictors of Long-Term Patient Outcomes.

BACKGROUND: Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major adverse effect of cancer treatment. However, its impact remains poorly understood. This study aimed to investigate the impact associated with CIPN on the lives of cancer survivors. PATIENTS AND METHODS: A volunteer sample of 986 individuals who had received neurotoxic chemotherapy completed an anonymous, cross-sectional survey. Outcomes assessed included CIPN symptoms, pain, neuropathic pain, quality of life (QoL), physical activity, and comorbid health conditions via the Self-Administered Comorbidity Questionnaire. RESULTS: Respondents had a mean age of 58 years (SD, 10.7), and 83.2% were female. Most were treated for breast (58.9%) or colorectal cancer (13.5%); had received docetaxel (32.7%), paclitaxel (31.6%), or oxaliplatin (12.5%); and had completed treatment 3.6 ± 3.5 years previously. We found that 76.5% of respondents reported current CIPN. Respondents reporting severe CIPN had poorer QoL, more comorbidities, and higher body mass index, and more often received multiple neurotoxic chemotherapies than those with mild CIPN. Respondents who completed the survey ≤1 year after completing chemotherapy did not differ in reported CIPN or pain compared with respondents who completed chemotherapy ≥6 years earlier. However, respondents who completed chemotherapy ≥6 years earlier reported better QoL. Multivariable linear regression analyses revealed predictors of CIPN severity as follows: F(7, 874) = 64.67; P<.001; R2 = 0.34, including pain (ß = -0.36; P<.001), burning pain (ß = 0.25; P<.001), sex (male sex associated with greater CIPN: ß = 0.14; P<.001), years since completing chemotherapy (shorter time associated with greater CIPN; ß = -0.10; P<.001), age (ß = 0.80; P=.006), number of comorbid conditions (ß = 0.07; P=.02), and body mass index (ß = 0.07; P=.02). CONCLUSIONS: Respondents with a high CIPN symptom burden experienced poorer general health and QoL. Improvements in CIPN may be more likely soon after treatment. However, improvements in QoL may occur over time in those with chronic symptoms. CIPN seems to have lasting impacts on cancer survivors, and understanding risk factors is important to enable the design of further preventive and therapeutic management strategies.

Backyard poultry cases in UK small animal practices: Demographics, health conditions and pharmaceutical prescriptions.

BACKGROUND: Backyard poultry ownership is of keen interest in the United Kingdom. However, despite this, little is known about veterinary care engagement and outcomes of visits in this group of species. METHODS: This study described and characterised veterinary practice-visiting backyard poultry, utilising electronic health record data supplied by veterinary practices voluntarily participating in the Small Animal Veterinary Surveillance Network between 1st April 2014 and 31st March 2019. RESULTS: In total, 4424 recorded poultry consultations originating from 197 veterinary practices (352 sites) were summarised. Chicken consultation (n = 3740) peak incidence was in early summer (April-June), relative to all recorded species. More chickens resided in rural (incident rate ratio = 2.5, confidence interval [CI] 2.3-2.6, p <0.001) or less deprived areas. Non-specific clinical signs were commonly recorded (17.6% of chicken consultations, CI 15.9-19.2), as were those indicative of advanced disease. This latter finding was reflected in prescribed management strategies, with euthanasia comprising 29.8% (CI 27.0-32.6) of consultations. Antimicrobials were commonly prescribed (33.0% of consultations, CI 29.8-36.2), 43.8% of which included antimicrobials considered 'highest priority critically important' by the World Health Organisation. CONCLUSION: Our findings indicate a need to tailor antimicrobial prescription guidance to the backyard poultry setting. In addition, late presentation of disease, vague clinical descriptions in clinical narratives and high euthanasia rates show that disease identification, management and knowledge of poultry health and welfare among owners and veterinary surgeons can be improved.

Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset.

CRU TS (Climatic Research Unit gridded Time Series) is a widely used climate dataset on a 0.5° latitude by 0.5° longitude grid over all land domains of the world except Antarctica. It is derived by the interpolation of monthly climate anomalies from extensive networks of weather station observations. Here we describe the construction of a major new version, CRU TS v4. It is updated to span 1901-2018 by the inclusion of additional station observations, and it will be updated annually. The interpolation process has been changed to use angular-distance weighting (ADW), and the production of secondary variables has been revised to better suit this approach. This implementation of ADW provides improved traceability between each gridded value and the input observations, and allows more informative diagnostics that dataset users can utilise to assess how dataset quality might vary geographically.

Multi-century trends to wetter winters and drier summers in the England and Wales precipitation series explained by observational and sampling bias in early records.

Globally, few precipitation records extend to the 18th century. The England Wales Precipitation (EWP) series is a notable exception with continuous monthly records from 1766. EWP has found widespread use across diverse fields of research including trend detection, evaluation of climate model simulations, as a proxy for mid-latitude atmospheric circulation, a predictor in long-term European gridded precipitation data sets, the assessment of drought and extremes, tree-ring reconstructions and as a benchmark for other regional series. A key finding from EWP has been the multi-centennial trends towards wetter winters and drier summers. We statistically reconstruct seasonal EWP using independent, quality-assured temperature, pressure and circulation indices. Using a sleet and snow series for the UK derived by Profs. Gordon Manley and Elizabeth Shaw to examine winter reconstructions, we show that precipitation totals for pre-1870 winters are likely biased low due to gauge under-catch of snowfall and a higher incidence of snowfall during this period. When these factors are accounted for in our reconstructions, the observed trend to wetter winters in EWP is no longer evident. For summer, we find that pre-1820 precipitation totals are too high, likely due to decreasing network density and less certain data at key stations. A significant trend to drier summers is not robustly present in our reconstructions of the EWP series. While our findings are more certain for winter than summer, we highlight (a) that extreme caution should be exercised when using EWP to make inferences about multi-centennial trends, and; (b) that assessments of 18th and 19th Century winter precipitation should be aware of potential snow biases in early records. Our findings underline the importance of continual re-appraisal of established long-term climate data sets as new evidence becomes available. It is also likely that the identified biases in winter EWP have distorted many other long-term European precipitation series.

Research into the views of two child reference groups on the arts in research concerning wellbeing.

Introduction: This paper explores an aspect of the process and outcomes of two children's reference groups: the ways the young members of the reference groups consider the role of the arts in research concerning wellbeing.Methods: Two case studies draw on qualitative data from the projects offering insight into child reference group work over the life of a research project: from recommendations to implementation.Results: The findings demonstrate that both reference groups enabled the research to achieve a fuller engagement with meaning making in relation to data collection by consulting with children.Conclusion: The data reveal how the members offered "insider knowledge" to the researchers concerning the role of the arts in research concerning wellbeing. Themes within the analysis about the impact of the reference group's knowledge and recommendations on the research project's data collection methods include the role of the arts connected to empathy, safety and confidentiality and in relation to difference and choice.The Research in England was supported by the LankellyChase Foundation.

Exploring semantic deep learning for building reliable and reusable one health knowledge from PubMed systematic reviews and veterinary clinical notes.

BACKGROUND: Deep Learning opens up opportunities for routinely scanning large bodies of biomedical literature and clinical narratives to represent the meaning of biomedical and clinical terms. However, the validation and integration of this knowledge on a scale requires cross checking with ground truths (i.e. evidence-based resources) that are unavailable in an actionable or computable form. In this paper we explore how to turn information about diagnoses, prognoses, therapies and other clinical concepts into computable knowledge using free-text data about human and animal health. We used a Semantic Deep Learning approach that combines the Semantic Web technologies and Deep Learning to acquire and validate knowledge about 11 well-known medical conditions mined from two sets of unstructured free-text data: 300 K PubMed Systematic Review articles (the PMSB dataset) and 2.5 M veterinary clinical notes (the VetCN dataset). For each target condition we obtained 20 related clinical concepts using two deep learning methods applied separately on the two datasets, resulting in 880 term pairs (target term, candidate term). Each concept, represented by an n-gram, is mapped to UMLS using MetaMap; we also developed a bespoke method for mapping short forms (e.g. abbreviations and acronyms). Existing ontologies were used to formally represent associations. We also create ontological modules and illustrate how the extracted knowledge can be queried. The evaluation was performed using the content within BMJ Best Practice. RESULTS: MetaMap achieves an F measure of 88% (precision 85%, recall 91%) when applied directly to the total of 613 unique candidate terms for the 880 term pairs. When the processing of short forms is included, MetaMap achieves an F measure of 94% (precision 92%, recall 96%). Validation of the term pairs with BMJ Best Practice yields precision between 98 and 99%. CONCLUSIONS: The Semantic Deep Learning approach can transform neural embeddings built from unstructured free-text data into reliable and reusable One Health knowledge using ontologies and content from BMJ Best Practice.

De-escalation of antianginal medications after successful chronic total occlusion percutaneous coronary intervention: Frequency and relationship with health status.

BACKGROUND: Successful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) can markedly reduce angina symptom burden, but many patients often remain on multiple antianginal medications (AAMs) after the procedure. It is unclear when, or if, AAMs can be de-escalated to prevent adverse effects or limit polypharmacy. We examined the association of de-escalation of AAMs after CTO PCI with long-term health status. METHODS: In a 12-center registry of consecutive CTO PCI patients, health status was assessed at 6 months after successful CTO PCI with the Seattle Angina Questionnaire and the Rose Dyspnea Scale. Among patients with technical CTO PCI success, we examined the association of AAM de-escalation with 6-month health status using multivariable models adjusting for revascularization completeness and predicted risk of post-PCI angina (using a validated risk model). We also examined predictors and variability of AAMs de-escalation. RESULTS: Of 669 patients with technical success of CTO PCI, AAMs were de-escalated in 276 (35.9%) patients at 1 month. Patients with AAM de-escalation reported similar angina and dyspnea rates at 6 months compared with those whose AAMs were reduced (any angina: 22.5% vs 20%, P = .43; any dyspnea: 51.8% vs 50.1%, P = .40). In a multivariable model adjusting for complete revascularization and predicted risk of post-PCI angina, de-escalation of AAMs at 1 month was not associated with an increased risk of angina, dyspnea, or worse health status at 6 months. CONCLUSIONS: Among patients with successful CTO PCI, de-escalation of AAMs occurred in about one-third of patients at 1 month and was not associated with worse long-term health status.

Enhancing the defensibility of examiners' marks in high stake OSCEs.

BACKGROUND: Most assessments in health professions education consist of knowledge-based examinations as well as practical and clinical examinations. Among the most challenging aspects of clinical assessments is decision making related to borderline grades assigned by examiners. Borderline grades are commonly used by examiners when they do not have sufficient information to make clear pass/fail decisions. The interpretation of these borderline grades is rarely discussed in the literature. This study reports the application of the Objective Borderline Method (version 2, henceforth: OBM2) to a high stakes Objective Structured Clinical Examination undertaken at the end of the final year of a Medicine program in Australia. METHODS: The OBM2 uses all examination data to reclassify borderline grades as either pass or fail. Factor analysis was used to estimate the suitability of data for application of OBM2. Student's t-tests, utilising bootstrapping, were used to compare the OBM2 with 'traditional' results. Interclass correlations were used to estimate the association between the grade reclassification and all other grades in this examination. RESULTS: The correlations between scores for each station and pass/fail outcomes increased significantly after the mark reclassification, yet the reclassification did not significantly impact on students' total scores. Examiners, students and program leaders expressed high levels of satisfaction and the Faculty's Curriculum Development Committee has decided that the OBM2 will be used for all future clinical examinations. Implications of the OBM2 are discussed. CONCLUSIONS: The OBM2 provides a feasible, defensible and acceptable solution for classification of borderline grades as either pass or fail.

Do Inequalities in Neighborhood Walkability Drive Disparities in Older Adults' Outdoor Walking?

Older residents of high-deprivation areas walk less than those of low-deprivation areas. Previous research has shown that neighborhood built environment may support and encourage outdoor walking. The extent to which the built environment supports and encourages walking is called "walkability". This study examines inequalities in neighborhood walkability in high- versus low-deprivation areas and their possible influences on disparities in older adults' outdoor walking levels. For this purpose, it focuses on specific neighborhood built environment attributes (residential density, land-use mix and intensity, street connectivity, and retail density) relevant to neighborhood walkability. It applied a mixed-method approach, included 173 participants (≥65 years), and used a Geographic Information System (GIS) and walking interviews (with a sub-sample) to objectively and subjectively measure neighborhood built environment attributes. Outdoor walking levels were measured by using the Geographic Positioning System (GPS) technology. Data on personal characteristics was collected by completing a questionnaire. The results show that inequalities in certain land-use intensity (i.e., green spaces, recreation centers, schools and industries) in high- versus low-deprivation areas may influence disparities in older adults' outdoor walking levels. Modifying neighborhood land use intensity may help to encourage outdoor walking in high-deprivation areas.

Demographics of dogs, cats, and rabbits attending veterinary practices in Great Britain as recorded in their electronic health records.

BACKGROUND: Understanding the distribution and determinants of disease in animal populations must be underpinned by knowledge of animal demographics. For companion animals, these data have been difficult to collect because of the distributed nature of the companion animal veterinary industry. Here we describe key demographic features of a large veterinary-visiting pet population in Great Britain as recorded in electronic health records, and explore the association between a range of animal's characteristics and socioeconomic factors. RESULTS: Electronic health records were captured by the Small Animal Veterinary Surveillance Network (SAVSNET), from 143 practices (329 sites) in Great Britain. Mixed logistic regression models were used to assess the association between socioeconomic factors and species and breed ownership, and preventative health care interventions. Dogs made up 64.8% of the veterinary-visiting population, with cats, rabbits and other species making up 30.3, 2.0 and 1.6% respectively. Compared to cats, dogs and rabbits were more likely to be purebred and younger. Neutering was more common in cats (77.0%) compared to dogs (57.1%) and rabbits (45.8%). The insurance and microchipping relative frequency was highest in dogs (27.9 and 53.1%, respectively). Dogs in the veterinary-visiting population belonging to owners living in least-deprived areas of Great Britain were more likely to be purebred, neutered, insured and microchipped. The same association was found for cats in England and for certain parameters in Wales and Scotland. CONCLUSIONS: The differences we observed within these populations are likely to impact on the clinical diseases observed within individual veterinary practices that care for them. Based on this descriptive study, there is an indication that the population structures of companion animals co-vary with human and environmental factors such as the predicted socioeconomic level linked to the owner's address. This 'co-demographic' information suggests that further studies of the relationship between human demographics and pet ownership are warranted.