The human health effects of unconventional oil and gas (UOG) chemical exposures: a scoping review of the toxicological literature.

Many chemicals associated with unconventional oil and natural gas (UOG) are known toxicants, leading to health concerns about the effects of UOG. Our objective was to conduct a scoping review of the toxicological literature to assess the effects of UOG chemical exposures in models relevant to human health. We searched databases for primary research studies published in English or French between January 2000 and June 2023 on UOG-related toxicology studies. Two reviewers independently screened abstracts and full texts to determine inclusion. Seventeen studies met our study inclusion criteria. Nine studies used solely in vitro models, while six conducted their investigation solely in animal models. Two studies incorporated both types of models. Most studies used real water samples impacted by UOG or lab-made mixtures of UOG chemicals to expose their models. Most in vitro models used human cells in monocultures, while all animal studies were conducted in rodents. All studies detected significant deleterious effects associated with exposure to UOG chemicals or samples, including endocrine disruption, carcinogenicity, behavioral changes and metabolic alterations. Given the plausibility of causal relationships between UOG chemicals and adverse health outcomes highlighted in this review, future risk assessment studies should focus on measuring exposure to UOG chemicals in human populations.

The human health effects of unconventional oil and gas development (UOGD): A scoping review of epidemiologic studies.

OBJECTIVE: Unconventional oil and gas development (UOGD, sometimes termed "fracking" or "hydraulic fracturing") is an industrial process to extract methane gas and/or oil deposits. Many chemicals used in UOGD have known adverse human health effects. Canada is a major producer of UOGD-derived gas with wells frequently located in and around rural and Indigenous communities. Our objective was to conduct a scoping review to identify the extent of research evidence assessing UOGD exposure-related health impacts, with an additional focus on Canadian studies. METHODS: We included English- or French-language peer-reviewed epidemiologic studies (January 2000-December 2022) which measured exposure to UOGD chemicals directly or by proxy, and where health outcomes were plausibly caused by UOGD-related chemical exposure. Results synthesis was descriptive with results ordered by outcome and hierarchy of methodological approach. SYNTHESIS: We identified 52 studies from nine jurisdictions. Only two were set in Canada. A majority (n = 27) used retrospective cohort and case-control designs. Almost half (n = 24) focused on birth outcomes, with a majority (n = 22) reporting one or more significant adverse associations of UOGD exposure with: low birthweight; small for gestational age; preterm birth; and one or more birth defects. Other studies identified adverse impacts including asthma (n = 7), respiratory (n = 13), cardiovascular (n = 6), childhood acute lymphocytic leukemia (n = 2), and all-cause mortality (n = 4). CONCLUSION: There is a growing body of research, across different jurisdictions, reporting associations of UOGD with adverse health outcomes. Despite the rapid growth of UOGD, which is often located in remote, rural, and Indigenous communities, Canadian research on its effects on human health is remarkably sparse. There is a pressing need for additional evidence.

RéSUMé: OBJECTIF: L'exploitation pétrolière et gazière non conventionnelle (EPGNC, parfois appelée « fracturation ¼ ou « fracturation hydraulique ¼) est un processus industriel d'extraction du méthane et/ou de gisements de pétrole. De nombreux produits chimiques utilisés dans l'EPGNC ont des effets indésirables connus sur la santé humaine. Le Canada est un grand producteur de gaz dérivé de l'EPGNC, dont les puits sont souvent situés à l'intérieur et autour de communautés rurales et autochtones. Nous avons mené une étude de champ pour déterminer l'étendue des données de recherche évaluant les effets sur la santé de l'exposition à l'EPGNC, en nous concentrant plus particulièrement sur les études canadiennes. MéTHODE: Nous avons inclus des études épidémiologiques en anglais ou en français évaluées par les pairs (janvier 2000 à décembre 2022) qui mesuraient l'exposition directe ou indirecte aux produits chimiques de l'EPGNC et dans lesquelles les résultats cliniques étaient plausiblement causés par l'exposition aux produits chimiques liés à l'EPGNC. La synthèse des résultats est descriptive, et les résultats sont ordonnés selon les résultats cliniques et l'approche méthodologique. SYNTHèSE: Nous avons identifié 52 études menées dans neuf juridictions. Deux seulement étaient canadiennes. La majorité (n = 27) faisaient appel à des cohortes rétrospectives ou étaient des études cas-témoins. Près de la moitié (n = 24) portaient sur les issues de la grossesse, et la majorité (n = 22) déclaraient une ou plusieurs associations indésirables significatives entre l'exposition à l'EPGNC et : l'insuffisance de poids à la naissance; la petite taille du bébé pour son âge gestationnel; la naissance avant terme; et une ou plusieurs anomalies congénitales. D'autres études faisaient état d'effets indésirables, dont l'asthme (n = 7), les troubles respiratoires (n = 13), les troubles cardiovasculaires (n = 6), la leucémie aiguë lymphoblastique infantile (n = 2) et la mortalité toutes causes confondues (n = 4). CONCLUSION: Il existe dans différents pays un corpus croissant d'études qui font état d'associations entre l'EPGNC et des résultats sanitaires indésirables. Malgré la croissance rapide de l'EPGNC, souvent présente dans des communautés éloignées, rurales et autochtones, la recherche canadienne sur ses effets sur la santé humaine est remarquablement clairsemée. Il y a un besoin urgent de recueillir d'autres données probantes à ce sujet.

The association of facility ownership with COVID-19 outbreaks in long-term care homes in British Columbia, Canada: a retrospective cohort study.

BACKGROUND: Long-term care (LTC) in Canada is delivered by a mix of government-, for-profit- and nonprofit-owned facilities that receive public funding to provide care, and were sites of major outbreaks during the early stages of the COVID-19 pandemic. We sought to assess whether facility ownership was associated with COVID-19 outbreaks among LTC facilities in British Columbia, Canada. METHODS: We conducted a retrospective observational study in which we linked LTC facility data, collected annually by the Office of the Seniors Advocate BC, with public health data on outbreaks. A facility outbreak was recorded when 1 or more residents tested positive for SARS-CoV-2 between Mar. 1, 2020, and Jan. 31, 2021. We used the Cox proportional hazards method to calculate the adjusted hazard ratio (HR) of the association between risk of COVID-19 outbreak and facility ownership, controlling for community incidence of COVID-19 and other facility characteristics. RESULTS: Overall, 94 outbreaks involved residents in 80 of 293 facilities. Compared with health authority-owned facilities, for-profit and nonprofit facilities had higher risks of COVID-19 outbreaks (adjusted HR 1.99, 95% confidence interval [CI] 1.12-3.52 and adjusted HR 1.84, 95% CI 1.00-3.36, respectively). The model adjusted for community incidence of infection (adjusted HR 1.12, 95% CI 1.07-1.17), total nursing hours per resident-day (adjusted HR 0.84, 95% CI 0.33-2.14), facility age (adjusted HR 1.01, 95% CI 1.00-1.02), number of facility beds (adjusted HR 1.20, 95% CI 1.12-1.30) and facilities with beds in shared rooms (adjusted HR 1.16, 95% CI 0.73-1.85). INTERPRETATION: Findings suggest that ownership of LTC facilities by health authorities in BC offered some protection against COVID-19 outbreaks. Further study is needed to unpack the underlying pathways behind this observed association.

Characterizing people with frequent emergency department visits and substance use: a retrospective cohort study of linked administrative data in Ontario, Alberta, and B.C., Canada.

BACKGROUND: Substance use is common among people who visit emergency departments (EDs) frequently. We aimed to characterize subgroups within this cohort to better understand care needs/gaps, and generalizability of characteristics in three Canadian provinces. METHODS: This was a retrospective cohort study (April 1st, 2013 to March 31st, 2016) of ED patients in Ontario, Alberta, and British Columbia (B.C.) We included patients ≥ 18 years with substance use-related healthcare contact during the study period and frequent ED visits, defined as those in the top 10% of ED utilization when all patients were ordered by annual ED visit number. We used linked administrative databases including ED visits and hospitalizations (all provinces); mental heath-related hospitalizations (Ontario and Alberta); and prescriptions, physician services, and mortality (B.C.). We compared to cohorts of people with (1) frequent ED visits and no substance use, and (2) non-frequent ED visits and substance use. We employed cluster analysis to identify subgroups with distinct visit patterns and clinical characteristics during index year, April 1st, 2014 to March 31st, 2015. RESULTS: In 2014/15, we identified 19,604, 7,706, and 9,404 people with frequent ED visits and substance use in Ontario, Alberta, and B.C (median 37-43 years; 60.9-63.0% male), whose ED visits and hospitalizations were higher than comparison groups. In all provinces, cluster analyses identified subgroups with "extreme" and "moderate" frequent visits (median 13-19 versus 4-6 visits/year). "Extreme" versus "moderate" subgroups had more hospitalizations, mental health-related ED visits, general practitioner visits but less continuity with one provider, more commonly left against medical advice, and had higher 365-day mortality in B.C. (9.3% versus 6.6%; versus 10.4% among people with frequent ED visits and no substance use, and 4.3% among people with non-frequent ED visits and substance use). The most common ED diagnosis was acute alcohol intoxication in all subgroups. CONCLUSIONS: Subgroups of people with "extreme" (13-19 visits/year) and "moderate" (4-6 visits/year) frequent ED visits and substance use had similar utilization patterns and characteristics in Ontario, Alberta, and B.C., and the "extreme" subgroup had high mortality. Our findings suggest a need for improved evidence-based substance use disorder management, and strengthened continuity with primary and mental healthcare.

People who make frequent emergency department visits based on persistence of frequent use in Ontario and Alberta: a retrospective cohort study.

BACKGROUND: The factors that underlie persistent frequent visits to the emergency department are poorly understood. This study aimed to characterize people who visit emergency departments frequently in Ontario and Alberta, by number of years of frequent use. METHODS: This was a retrospective cohort study aimed at capturing information about patients visiting emergency departments in Ontario and Alberta, Canada, from Apr. 1, 2011, to Mar. 31, 2016. We identified people 18 years or older with frequent emergency department use (top 10% of emergency department use) in fiscal year 2015/16, using the Dynamic Cohort from the Canadian Institute of Health Information. We then organized them into subgroups based on the number of years (1 to 5) in which they met the threshold for frequent use over the study period. We characterized subgroups using linked emergency department, hospitalization and mental health-related hospitalization data. RESULTS: We identified 252 737 people in Ontario and 63 238 people in Alberta who made frequent visits to the emergency department. In Ontario and Alberta, 44.3% and 44.7%, respectively, met the threshold for frequent use in only 1 year and made 37.9% and 38.5% of visits; 6.8% and 8.2% met the threshold for frequent use over 5 years and made 11.9% and 13.2% of visits. Many characteristics followed gradients based on persistence of frequent use: as years of frequent visits increased (1 to 5 years), people had more comorbidities, homelessness, rural residence, annual emergency department visits, alcohol- and substance use-related presentations, mental health hospitalizations and instances of leaving hospital against medical advice. INTERPRETATION: Higher levels of comorbidities, mental health issues, substance use and rural residence were seen with increasing years of frequent emergency department use. Interventions upstream and in the emergency department must address unmet needs, including services for substance use and social supports.

Subgroups of people who make frequent emergency department visits in Ontario and Alberta: a retrospective cohort study.

BACKGROUND: The population that visits emergency departments frequently is heterogeneous and at high risk for mortality. This study aimed to characterize these patients in Ontario and Alberta, compare them with controls who do not visit emergency departments frequently, and identify subgroups. METHODS: This was a retrospective cohort study that captured patients in Ontario or Alberta from fiscal years 2011/12 to 2015/16 in the Dynamic Cohort from the Canadian Institute for Health Information, which defined people with frequent visits to the emergency department in the top 10% of annual visits and randomly selected controls from the bottom 90%. We included patients 18 years of age or older and linked to emergency department, hospitalization, continuing care, home care and mental health-related hospitalization data. We characterized people who made frequent visits to the emergency department over time, compared them with controls and identified subgroups using cluster analysis. We examined emergency department visit acuity using the Canadian Triage and Acuity Scale. RESULTS: The number of patients who made frequent visits to the emergency department ranged from 435 334 to 477 647 each year in Ontario (≥ 4 visits per year), and from 98 840 to 105 047 in Alberta (≥ 5 visits per year). The acuity of these visits increased over time. Those who made frequent visits to the emergency department were older and used more health care services than controls. We identified 4 subgroups of those who made frequent visits: "short duration" (frequent, regularly spaced visits), "older patients" (median ages 69 and 64 years in Ontario and Alberta, respectively; more comorbidities; and more admissions), "young mental health" (median ages 45 and 40 years in Ontario and Alberta, respectively; and common mental health-related and alcohol-related visits) and "injury" (increased prevalence of injury-related visits). INTERPRETATION: From 2011/12 to 2015/16, people who visited emergency departments frequently had increasing visit acuity, had higher health care use than controls, and comprised distinct subgroups. Emergency departments should codevelop interventions with the identified subgroups to address patient needs.

Characteristics of frequent emergency department users in British Columbia, Canada: a retrospective analysis.

BACKGROUND: Frequent emergency department users disproportionately account for rising health care costs. We aimed to characterize frequent emergency department users in British Columbia, Canada. METHODS: We performed a retrospective analysis using health administrative databases. We included patients aged 18 years or more with at least 1 emergency department visit from 2012/13 to 2015/16, linked to hospital, physician billing, prescription and mortality data. We used annual emergency department visits made by the top 10% of patients to define frequent users (≥ 3 visits/year). RESULTS: Over the study period, 13.8%-15.3% of patients seen in emergency departments were frequent users. We identified 205 136 frequent users among 1 196 353 emergency department visitors. Frequent users made 40.3% of total visits in 2015/16. From 2012/13 to 2015/16, their visit rates per 100 000 BC population showed a relative increase of 21.8%, versus 13.1% among all emergency department patients. Only 1.8% were frequent users in all study years. Mental illness accounted for 8.2% of visits among those less than 60 years of age, and circulatory or respiratory diagnoses for 13.3% of visits among those aged 60 or more. In 2015/16, frequent users were older and had lower household incomes than nonfrequent users; the sex distribution was similar. Frequent users had more prescriptions (median 9, interquartile range [IQR] 5-14 v. 1, IQR 1-3), primary care visits (median 15, IQR 9-27 v. 7, IQR 4-12) and hospital admissions (median 2, IQR 1-3 v. 1, IQR 1-1), and higher 1-year mortality (10.2% v. 3.5%) than nonfrequent users. INTERPRETATION: Emergency department use by frequent users increased in BC between 2012/13 and 2015/16; these patients were heterogenous, had high mortality and rarely remained frequent users over multiple years. Our results suggest that interventions must account for heterogeneity and address triggers of frequent use episodes.

Identifying subgroups and risk among frequent emergency department users in British Columbia.

Objective: Frequent emergency department (ED) users are heterogeneous. We aimed to identify subgroups and assess their mortality. Methods: We identified patients ≥18 years with ≥1 ED visit in British Columbia from April 1, 2012 to March 31, 2015, and linked to hospitalization, physician billing, prescription, and mortality data. Frequent users were the top 10% of patients by ED visits. We employed cluster analysis to identify frequent user subgroups. We assessed 365-day mortality using Kaplan-Meier curves and conducted Cox regressions to assess mortality risk factors within subgroups. Results: We identified 4 subgroups. Subgroup 1 ("Elderly") had median age 77 years (interquartile range [IQR]: 66-85), 5 visits/year (IQR: 4-6), median 8 prescription medications (IQR: 5-11), and 24.7% mortality. Subgroup 2 ("Mental Health and Alcohol Use") had median age 48 years (IQR: 34-61), 13 visits/year (IQR: 10-16), and 12.3% mortality. They made a median 31 general practitioner visits (IQR: 19-51); however, only 23.7% received a majority of services from 1 primary care physician. Subgroup 3 ("Young Mental Health") had median age 39 years (IQR: 28-51), 5 visits/year (IQR: 4-6), and 2.2% mortality. Subgroup 4 ("Short-term") had median age 50 years (IQR: 34-65), 4 visits/year (IQR: 4-5) regularly spaced over a short term, and 1.4% mortality. Male sex (all subgroups), long-term care ("Mental Health and Alcohol Use;" "Young Mental Health"), and rural residence ("Elderly" in long-term care; "Young Mental Health") were associated with increased mortality. Conclusions: Our results identify frequent user subgroups with varying mortality. Future research should explore subgroups' unmet needs and tailor interventions toward them.

Evaluation of an initiative to improve advance care planning for a home-based primary care service.

BACKGROUND: Advance care planning (ACP) is a process that enables individuals to describe, in advance, the kind of health care they would want in the future. There is evidence that ACP reduces hospital-based interventions, especially at the end of life. ACP for frail older adults is especially important as this population is more likely to use hospital services but less likely to benefit from resource intensive care. Our study goal was to evaluate whether an approach to ACP developed for frail older adults, known as the Palliative and Therapeutic Harmonization or PATH, demonstrated an improvement in ACP. METHODS: The PATH approach was adapted to a primary care service for homebound older adults in Vancouver, Canada. This retrospective chart review collected surrogate measures related to ACP from 200 randomly selected patients enrolled in the service at baseline (prior to June 22, 2017), and 114 consecutive patients admitted to the program after implementation of the PATH ACP initiative (October 1, 2017 to May 1, 2018). We compared the following surrogate markers of ACP before and after implementation of the PATH model, chart documentation of: frailty stage, substitute decision-maker, resuscitation decision, and hospitalization decision. A composite ACP documentation score that ascribed one point for each of the above four measures (range 0 to 4) was also compared. For those with documented resuscitation and hospitalization decisions, the study examined patient/ substitute decision-maker expressed preferences for do-not-resuscitate and do-not-hospitalize, before and after implementation. RESULTS: We found the following changes in ACP-related documentation before and after implementation: frailty stage (27.0% versus 74.6%, p < .0001); substitute decision-maker (63.5% versus 71.9%, p = 0.128); resuscitation decision documented (79.5% versus 67.5%, p = 0.018); and hospitalization decision documented (61.5% versus 100.0%, p < .0001); mean (standard deviation) composite ACP documentation score (2.32 (1.16) versus 3.14 (1.11), p < .0001). The adjusted odds ratios (95% confidence intervals) for an expressed preference of do-not-resuscitate and do-not-hospitalize after implementation were 0.87 (0.35, 2.15) and 3.14 (1.78, 5.55), respectively. CONCLUSIONS: Results suggest partial success in implementing the PATH approach to ACP in home-based primary care. Key contextual enablers and barriers are important considerations for successful implementation.

Long-Term Care Facility Ownership and Acute Hospital Service Use in British Columbia, Canada: A Retrospective Cohort Study.

OBJECTIVE: Previous studies report higher hospitalization rates in for-profit compared with nonprofit long-term care facilities (LTCFs), but have not included staffing data, a major potential confounder. Our objective was to examine the effect of ownership on hospital admission rates, after adjusting for facility staffing levels and other facility and resident characteristics, in a large Canadian province (British Columbia). DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: Our cohort included individuals resident in a publicly funded LTCF in British Columbia at any time between April 1, 2012 and March 31, 2016. MEASURES: Health administrative data were extracted from multiple databases, including continuing care, hospital discharge, and Minimum Data Set (MDS 2.0) assessment records. Cox extended hazards regression was used to estimate hospitalization risk associated with facility- and resident-level factors. RESULTS: The cohort included 49,799 residents in 304 LTCF facilities (116 publicly owned and operated, 99 for-profit, and 89 nonprofit) over the study period. Hospitalization risk was higher for residents in for-profit (adjusted hazard ratio [adjHR] 1.34; 95% confidence interval [CI] 1.29-1.38) and nonprofit (adjHR 1.37; 95% CI 1.32-1.41) facilities compared with publicly owned and operated facilities, after adjustment for staffing, facility size, urban location, resident demographics, and case mix. Within subtypes, risk was highest in single-site facilities: for-profit (adjHR 1.42; 95% CI 1.36-1.48) and nonprofit (adjHR 1.38, 95% CI 1.33-1.44). CONCLUSIONS AND IMPLICATIONS: This is the first Canadian study using linked health data from hospital discharge records, MDS 2.0, facility staffing, and ownership records to examine the adjusted effect of facility ownership characteristics on hospital use of LTCF residents. We found significantly lower adjHRs for hospital admission in publicly owned facilities compared with both for-profit and nonprofit facilities. Our finding that publicly owned facilities have lower hospital admission rates compared with for-profit and nonprofit facilities can help inform decision-makers faced with the challenge of optimizing care models in both nursing homes and hospitals as they build capacity to care for aging populations.

Advance Care Planning and Decision-Making in a Home-Based Primary Care Service in a Canadian Urban Centre.

BACKGROUND: Advance care planning (ACP) is a process that enables individuals to describe, in advance, the kind of health care they would want in the future, and has been shown to reduce hospital-based interventions at the end of life. Our goal was to describe the current state of ACP in a home-based primary care program for frail homebound older people in Vancouver, Canada. We did this by identifying four key elements that should be essential to ACP in this program: frailty stage, documentation of substitute decision-makers, and decision-making with regard to both resuscitation (i.e., do not resuscitate (DNR)) and hospitalization (i.e., do not hospitalize (DNH)). While these elements are an important part of the ACP process, they are often excluded from common practice. METHODS: This was a cross-sectional, observational study of data abstracted from 200 randomly selected patient electronic medical records between July 1 and September 30, 2017. We describe the association between demographic characteristics, comorbidities, and four key elements of ACP documentation and decision-making as documented in the clinical record using bivariate comparison, a logistic regression model and multiple logistic regression analysis. RESULTS: In 73% (n=146) of the patient records, there was no explicit documentation of frailty stage. Sixty-four per cent had documentation of a substitute decision-maker. Of those who had their preferences documented, 90.6% (n=144/159) indicated a preference for DNR, and 23.6% (n=29/123) indicated a preference for DNH. In multiple regression modeling, a diagnosis of dementia and older age were associated with documentation of a DNR preference, adjusted odds ratio (AOR) = 4.79 (95% CI 1.37, 16.71) and AOR = 1.14 (95% CI 1.05, 1.24), respectively. Older age, male sex, and English identified as the main language spoken were associated with a DNH preference. AOR = 1.17 (95% CI 1.06, 1.28), AOR = 4.19 (95% CI 1.41, 12.42), and AOR = 3.42 (95% CI 1.14, 10.20), respectively. CONCLUSIONS: Clinician documentation of some elements of ACP, such as identification of a substitute decision-maker and resuscitation status, have been widely adopted, while other elements that should be considered essential components of ACP, such as frailty staging and preferences around hospitalization, are infrequent and provide an opportunity for practice improvement initiatives. The significant association between language and ACP decisions suggests an important role for supporting cross-cultural fluency in the ACP process.

An International Mapping of Medical Care in Nursing Homes.

Nursing home (NH) residents are increasingly in need of timely and frequent medical care, presupposing not only available but perhaps also continual medical care provision in NHs. The provision of this medical care is organized differently both within and across countries, which may in turn profoundly affect the overall quality of care provided to NH residents. Data were collected from official legislations and regulations, academic publications, and statistical databases. Based on this set of data, we describe and compare the policies and practices guiding how medical care is provided across Canada (2 provinces), Germany, Norway, and the United States. Our findings disclose that there is a considerable difference to find among jurisdictions regarding specificity and scope of regulations regarding medical care in NHs. Based on our data, we construct 2 general models of medical care: (1) more regulations-fee-for-service payment-open staffing models and (2) less regulation-salaried positions-closed staffing models. Some evidence indicates that model 1 can lead to less available medical care provision and to medical care provision being less integrated into the overall care services. As such, we argue that the service models discussed can significantly influence continuity of medical care in NH.