Rural-urban differences in use of health services before and after dementia diagnosis: a retrospective cohort study.

BACKGROUND: Rural-urban differences in health service use among persons with prevalent dementia are known. However, the extent of geographic differences in health service use over a long observation period, and prior to diagnosis, have not been sufficiently examined. The purpose of this study was to examine yearly rural-urban differences in the proportion of patients using health services, and the mean number of services, in the 5-year period before and 5-year period after a first diagnosis of dementia. METHODS: This population-based retrospective cohort study used linked administrative health data from the Canadian province of Saskatchewan to investigate the use of five health services [family physician (FP), specialist physician, hospital admission, all-type prescription drug dispensations, and short-term institutional care admission] each year from April 2008 to March 2019. Persons with dementia included 2,024 adults aged 65 years and older diagnosed from 1 April 2013 to 31 March 2014 (617 rural; 1,407 urban). Matching was performed 1:1 to persons without dementia on age group, sex, rural versus urban residence, geographic region, and comorbidity. Differences between rural and urban persons within the dementia and control cohorts were separately identified using the Z-score test for proportions (p < 0.05) and independent samples t-test for means (p < 0.05). RESULTS: Rural compared to urban persons with dementia had a lower average number of FP visits during 1-year and 2-year preindex and between 2-year and 4-year postindex (p < 0.05), a lower likelihood of at least one specialist visit and a lower average number of specialist visits during each year (p < 0.05), and a lower average number of all-type prescription drug dispensations for most of the 10-year study period (p < 0.05). Rural-urban differences were not observed in admission to hospital or short-term institutional care (p > 0.05 each year). CONCLUSIONS: This study identified important geographic differences in physician services and all-type prescription drugs before and after dementia diagnosis. Health system planners and educators must determine how to use existing resources and technological advances to support care for rural persons living with dementia.

Hydrochlorothiazide use and risk of keratinocyte carcinoma and melanoma: A multisite population-based cohort study.

BACKGROUND: The association between hydrochlorothiazide (HCTZ) and skin cancer remains controversial. OBJECTIVE: To determine whether HCTZ is associated with an increased risk of skin cancer compared with angiotensin-converting enzyme inhibitors and calcium channel blockers. METHODS: Two new-user, active comparator cohorts were assembled using 6 Canadian databases. Site-specific hazard ratios (HRs) with 95% CIs were estimated using standardized morbidity ratio weighted Cox proportional hazard models and pooled using random-effects meta-analysis. RESULTS: HCTZ was not associated with an overall increased risk of keratinocyte carcinoma compared with angiotensin-converting enzyme inhibitors or calcium channel blockers, although increased risks were observed with longer durations (≥10 years; HR: 1.12; 95% CI: 1.03-1.21) and higher cumulative doses (≥100,000 mg; HR: 1.49; 95% CI: 1.27-1.76). For melanoma, there was no association with angiotensin-converting enzyme inhibitors, but a 32% increased risk with calcium channel blockers (crude incidence rates: 64.2 vs 58.4 per 100,000 person-years; HR: 1.32; 95% CI: 1.19-1.46; estimated number needed to harm at 5 years of follow-up: 1627 patients), with increased risks with longer durations and cumulative doses. LIMITATIONS: Residual confounding due to the observational design. CONCLUSIONS: Increased risks of keratinocyte carcinoma and melanoma were observed with longer durations of use and higher cumulative doses of HCTZ.

Association between asthma control trajectories in preschoolers and disease remission.

INTRODUCTION: Early disease morbidity has been associated with asthma persistence in wheezing preschoolers; however, whether asthma control trajectories shortly after diagnosis could influence remission is unknown. We examined the association between asthma control trajectories 2 years post-diagnosis in preschoolers and subsequent disease remission. METHODS: We conducted a multicentre population-based retrospective cohort study consisting of 48 687 children with asthma diagnosed before 5 years old and born between 1990 and 2013 in four Canadian provinces who had prolonged disease activity post-diagnosis. Prolonged disease activity was defined as one or more medical visits or medications for asthma every 6-month period for at least four of the six periods post-diagnosis. Follow-up began at 3 years post-diagnosis (at cohort entry). Remission was defined as 2 consecutive years without drug claims or medical visits for asthma or asthma-like conditions following cohort entry. Asthma control trajectories, ascertained over four 6-month periods following diagnosis using a validated index, were classified as: "controlled throughout", "improving control", "worsening control", "out of control throughout" and "fluctuating control". Adjusted Cox models estimated associations between asthma control trajectories and time to remission. A random effects meta-analysis summarised province-specific hazard ratios (HRs). RESULTS: The pooled remission rate was 8.91 (95% CI 8.80-9.02) per 100 person-years. Compared with children controlled throughout, poorer asthma control was associated with incrementally lower hazard ratios of remission in four other trajectories: improving control (HR 0.89, 95% CI 0.82-0.96), fluctuating control (HR 0.78, 95% CI 0.71-0.85), worsening control (HR 0.68, 95% CI 0.62-0.75) and out of control throughout (HR 0.52, 95% CI 0.45-0.59). CONCLUSIONS: Asthma control trajectories 2 years following a diagnosis in preschoolers were associated with remission, highlighting the clinical relevance of documenting control trajectories in early life.

Effectiveness and safety among direct oral anticoagulants in nonvalvular atrial fibrillation: A multi-database cohort study with meta-analysis.

AIMS: There are conflicting signals in the literature about comparative safety and effectiveness of direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (NVAF). METHODS: We conducted multicentre matched cohort studies with secondary meta-analysis to assess safety and effectiveness of dabigatran, rivaroxaban and apixaban across 9 administrative healthcare databases. We included adults with NVAF initiating anticoagulation therapy (dabigatran, rivaroxaban or apixaban), and constructed 3 cohorts to compare DOACs pairwise. The primary outcome was pooled hazard ratio (pHR) of ischaemic stroke or systemic thromboembolism. Secondary outcomes included pHR of major bleeding, and a composite of stroke, major bleeding, or all-cause mortality. We used proportional hazard Cox regressions models, and pooled estimates were obtained with random effect meta-analyses. RESULTS: The cohorts included 73 414 new users of dabigatran, 92 881 of rivaroxaban, and 61 284 of apixaban. After matching, the pHRs (95% confidence intervals) comparing rivaroxaban initiation to dabigatran were: 1.11 (0.93, 1.32) for ischaemic stroke or systemic thromboembolism, 1.26 (1.09, 1.46) for major bleeding, and 1.17 (1.05, 1.30) for the composite endpoint. For apixaban vs dabigatran, they were: 0.91 (0.74, 1.12) for ischaemic stroke or systemic thromboembolism, 0.89 (0.75, 1.05) for major bleeding, and 0.94 (0.78 to 1.14) for the composite endpoint. For apixaban vs rivaroxaban, they were: 0.85 (0.74, 0.99) for ischaemic stroke or systemic thromboembolism, 0.61 (0.53, 0.70) for major bleeding, and 0.82 (0.76, 0.88) for the composite endpoint. CONCLUSION: We found that apixaban use is associated with lower risks of stroke and bleeding compared with rivaroxaban, and similar risks compared with dabigatran.

Regional variation in the potentially inappropriate first-line use of fluoroquinolones in Canada as a key to antibiotic stewardship? A drug utilization review study.

BACKGROUND: Serious adverse effects of fluoroquinolone antibiotics have been described for more than decade. Recently, several drug regulatory agencies have advised restricting their use in milder infections for which other treatments are available, given the potential for disabling and possibly persistent side effects. We aimed to describe variations in fluoroquinolone use for initial treatment of urinary tract infection (UTI), acute bacterial sinusitis (ABS), and acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in the outpatient setting across Canada. METHODS: Using administrative health data from six provinces, we identified ambulatory visits with a diagnosis of uncomplicated UTI, uncomplicated AECOPD or ABS. Antibiotic exposure was determined by the first antibiotic dispensed within 5 days of the visit. RESULTS: We identified 4,303,144 uncomplicated UTI events among 2,170,027 women; the proportion of events treated with fluoroquinolones, mostly ciprofloxacin, varied across provinces, ranging from 18.6% (Saskatchewan) to 51.6% (Alberta). Among 3,467,678 ABS events (2,087,934 patients), between 2.2% (Nova Scotia) and 11.2% (Ontario) were dispensed a fluoroquinolone. For 1,319,128 AECOPD events among 598,347 patients, fluoroquinolones, mostly levofloxacin and moxifloxacin, ranged from 5.8% (Nova Scotia) to 35.6% (Ontario). The proportion of uncomplicated UTI and ABS events treated with fluoroquinolones declined over time, whereas it remained relatively stable for AECOPD. CONCLUSIONS: Fluoroquinolones were commonly used as first-line therapies for uncomplicated UTI and AECOPD. However, their use varied widely across provinces. Drug insurance formulary criteria and enforcement may be a key to facilitating better antibiotic stewardship and limiting potentially inappropriate first-line use of fluoroquinolones.

Comparison of the accuracy of classification models to estimate healthcare use and costs associated with COPD exacerbations in Saskatchewan, Canada: A retrospective cohort study.

OBJECTIVE: COPD is a high-cost disease and results in frequent contacts with the healthcare system. The study objective was to compare the accuracy of classification models with different covariates for classifying COPD patients into cost groups. METHODS: Linked health administrative databases from Saskatchewan, Canada, were used to identify a cohort of newly diagnosed COPD patients (April 1, 2007 to March 31, 2011) and their episodes of healthcare encounters for disease exacerbations. Total costs of the first and follow-up episodes were computed and patients were categorized as persistently high cost, occasionally high cost, and persistently low cost based on cumulative cost distribution ranking using the 75th percentile cutoff for high-cost status. Classification accuracy was compared for seven multinomial logistic regression models containing socio-demographic characteristics (i.e., base model), and socio-demographic and prior healthcare use characteristics (i.e., comparator models). RESULTS: Of the 1182 patients identified, 8.5% were classified as persistently high cost, 26.1% as occasionally high cost, and the remainder as persistently low cost. The persistently high-cost and occasionally high-cost patients incurred 10 times ($12 449 vs $1263) and seven times ($9334 vs $1263) more costs in their first exacerbation episode than persistently low-cost patients, respectively. Classification accuracy was 0.67 for the base model, whereas the comparator model containing socio-demographic and number of prior hospital admissions had the highest accuracy (0.72). CONCLUSIONS: Costs associated with COPD exacerbation episodes are substantial. Adding prior hospitalization to socio-demographic characteristics produced the highest improvements in classification accuracy. Accurate classification models are important for identifying potential healthcare cost management strategies.

Simultaneous temporal trends in dementia incidence and prevalence, 2005-2013: a population-based retrospective cohort study in Saskatchewan, Canada.

BACKGROUND: Original studies published over the last decade regarding time trends in dementia report mixed results. The aims of the present study were to use linked administrative health data for the province of Saskatchewan for the period 2005/2006 to 2012/2013 to: (1) examine simultaneous temporal trends in annual age- and sex-specific dementia incidence and prevalence among individuals aged 45 and older, and (2) stratify the changes in incidence over time by database of identification. METHODS: Using a population-based retrospective cohort study design, data were extracted from seven provincial administrative health databases linked by a unique anonymized identification number. Individuals 45 years and older at first identification of dementia between April 1, 2005 and March 31, 2013 were included, based on case definition criteria met within any one of four administrative health databases (hospital, physician, prescription drug, and long-term care). RESULTS: Between 2005/2006 and 2012/2013, the 12-month age-standardized incidence rate of dementia declined significantly by 11.07% and the 12-month age-standardized prevalence increased significantly by 30.54%. The number of incident cases decreased from 3,389 to 3,270 and the number of prevalent cases increased from 8,795 to 13,012. Incidence rate reductions were observed in every database of identification. CONCLUSIONS: We observed a simultaneous trend of decreasing incidence and increasing prevalence of dementia over a relatively short 8-year time period from 2005/2006 to 2012/2013. These trends indicate that the average survival time of dementia is lengthening. Continued observation of these time trends is warranted given the short study period.

Measuring care trajectories using health administrative databases: a population-based investigation of transitions from emergency to acute care.

BACKGROUND: A patient's trajectory through the healthcare system affects resource use and outcomes. Data fields in population-based administrative health databases are potentially valuable resources for constructing care trajectories for entire populations, provided they can capture patient transitions between healthcare services. This study describes patient transitions from the emergency department (ED) to other healthcare settings, and ascertains whether the discharge disposition field recorded in the ED data was a reliable source of patient transition information from the emergency to the acute care settings. METHODS: Administrative health databases from the province of Saskatchewan, Canada (population 1.1 million) were used to identify patients with at least one ED visit to provincial teaching hospitals (n = 5) between April 1, 2006 and March 31, 2012. Discharge disposition from ED was described using frequencies and percentages; and it includes categories such as home, transfer to other facilities, and died. The kappa statistic with 95 % confidence intervals (95 % CIs) was used to measure agreement between the discharge disposition field in the ED data and hospital admission records. RESULTS: We identified N = 1,062,861 visits for 371,480 patients to EDs over the six-year study period. Three-quarters of the discharges were to home, 16.1 % were to acute care in the same facility in which the ED was located, and 1.6 % resulted in a patient transfer to a different acute care facility. Agreement between the discharge disposition field in the ED data and hospital admission records was good when the emergency and acute care departments were in the same facility (κ = 0.77, 95 % CI 0.77, 0.77). For transfers to a different acute care facility, agreement was only fair (κ = 0.36, 95 % CI 0.35, 0.36). CONCLUSIONS: The majority of patients who attended EDs did not transition to another healthcare setting. For those who transitioned to acute care, accuracy of the discharge disposition field depended on whether the two services were provided in the same facility. Using the hospital data as reference, we conclude that the discharge disposition field in the ED data is not reliable for measuring transitions from ED to acute care.

Incidence and prevalence of dementia in linked administrative health data in Saskatchewan, Canada: a retrospective cohort study.

BACKGROUND: Determining the epidemiology of dementia among the population as a whole in specific jurisdictions - including the long-term care population-is essential to providing appropriate care. The objectives of this study were to use linked administrative databases in the province of Saskatchewan to determine the 12-month incidence and prevalence of dementia for the 2012/13 period (1) among individuals aged 45 and older in the province of Saskatchewan, (2) according to age group and sex, and (3) according to diagnosis code and other case definition criteria. METHODS: We used a population-based retrospective cohort study design and extracted data from 10 provincial health databases linked by a unique health services number. The cohort included individuals 45 years and older at first identification of dementia between April 1, 2001 and March 31, 2013 based on case definitions met within any one of four administrative health databases (Hospital Discharge Abstracts, Physician Service Claims, Prescription Drug, and RAI-MDS, i.e., Long-term Care). RESULTS: A total of 3,270 incident cases of dementia (7.28 per 1,000 PAR) and 13,012 prevalent cases (28.16 per 1,000 PAR) were identified during 2012/13. This study found the incidence rate increased by 2.8 to 5.1 times and the prevalence rate increased by 2.6 to 4.6 times every 10 years after 45 years of age. Overall, the age-standardised incidence rate was significantly lower among females than males (7.04 vs. 7.65 per 1,000 PAR) and the age-standardised prevalence rate was significantly higher among females than males (28.92 vs. 26.53 per 1,000 PAR). Over one-quarter (28 %) of all incident cases were admitted to long-term care before a diagnosis was formally recorded in physician or hospital data, and nearly two-thirds of these cases were identified at admission with impairment at the moderate to very severe level or a disease category of Alzheimer's disease/other dementia. CONCLUSIONS: Linking multiple sources of registry data contributes to our understanding of the epidemiology of dementia across multiple segments of the population, inclusive of individuals residing in long-term care. This information is foundational for public awareness and policy recommendations, health promotion and prevention strategies, appropriate health resource planning, and research priorities.

Predictive performance of comorbidity measures in administrative databases for diabetes cohorts.

BACKGROUND: The performance of comorbidity measures for predicting mortality in chronic disease populations and using ICD-9 diagnosis codes in administrative health data has been investigated in several studies, but less is known about predictive performance with ICD-10 data and for other health outcomes. This study investigated predictive performance of five comorbidity measures for population-based diabetes cohorts in administrative data. The objectives were to evaluate performance for: (a) disease-specific and general health outcomes, (b) data based on the ICD-9 and ICD-10 diagnoses, and (c) different age groups. METHODS: Performance was investigated for heart attack, stroke, amputation, renal disease, hospitalization, and death in all-age and age-specific cohorts. Hospital records, physician billing claims, and prescription drug records from one Canadian province were used to identify diabetes cohorts and measure comorbidity. The data were analysed using multiple logistic regression models and summarized using measures of discrimination, accuracy, and fit. RESULTS: In Cohort 1 (n = 29,058), for which only ICD-9 diagnoses were recorded in administrative data, the Elixhauser index showed good or excellent prediction for amputation, renal disease, and death and performed better than the Charlson index. Number of diagnoses was a good predictor of hospitalization. Similar results were obtained for Cohort 2 (n = 41,925), in which both ICD-9 and ICD-10 diagnoses were recorded in administrative data, although predictive performance was sometimes higher. For age-specific models of mortality, the Elixhauser index resulted in the largest improvement in predictive performance in all but the youngest age group. CONCLUSIONS: Cohort age and the health outcome under investigation, but not the diagnosis coding system, may influence the predictive performance of comorbidity measure for studies about diabetes populations using administrative health data.

Prescription ranitidine use and population exposure in 6 Canadian provinces, 1996 to 2019: a serial cross-sectional analysis.

BACKGROUND: Ranitidine was the most prescribed histamine-2 receptor antagonist (H2RA) in Canada when recalled in 2019 because of potential carcinogenicity. We sought to compare geographic and temporal patterns in use of prescription ranitidine and 3 other HRAs and estimated population exposure to ranitidine in 6 provinces between 1996 and 2019. METHODS: This population-based serial cross-sectional study used prescription claims for H2RAs dispensed from community pharmacies in Nova Scotia, Ontario, Manitoba, Saskatchewan, Alberta and British Columbia. We estimated the period prevalence of ranitidine use per 100 population by province, age category and sex. We estimated exposure to ranitidine between 2015 and 2019 using defined daily doses (DDDs). RESULTS: Overall, 2.4 million ranitidine prescriptions were dispensed to patients aged 65 years and older, and 1.7 million were dispensed to younger adults. Among older adults, the median period prevalence of ranitidine use among females was 16% (interquartile range [IQR] 13%-27%) higher than among males. Among younger adults, the median prevalence was 50% (IQR 37%-70%) higher among females. Among older adults, between 1996 and 1999, use was highest in Nova Scotia (33%) and Ontario (30%), lower in the prairies (Manitoba [18%], Saskatchewan [26%], Alberta [17%]) and lowest in BC (11%). By 2015-2019, use of ranitidine among older adults dropped by at least 50% in all provinces except BC. We estimate that at least 142 million DDDs of prescribed ranitidine were consumed annually in 6 provinces (2015-2019). INTERPRETATION: Over the 24-year period in 6 provinces, patients aged 65 years and older were dispensed 2.4 million prescriptions of ranitidine and younger adults were dispensed 1.7 million prescriptions of ranitidine. These estimates of ranitidine exposure can be used for planning studies of cancer risk and identifying target populations for cancer surveillance.

Utilization of Health Services Before and After Diagnosis in a Specialist Rural and Remote Memory Clinic.

Background: Limited research exists on the use of specific health services over an extended time among rural persons with dementia. The study objective was to examine health service use over a 10-year period, five years before until five years after diagnosis in the specialist Rural and Remote Memory Clinic (RRMC). Methods: Clinical and administrative health data of RRMC patients were linked. Annual health service utilization of the cohort (N = 436) was analyzed for 416 patients pre-index (57.5% female, mean age 71.2 years) and 419 post-index (56.3% female, mean age 70.8 years). Approximately 40% of memory clinic diagnoses were Alzheimer's disease (AD), 20% non-AD dementia, and 40% mild or subjective cognitive impairment or other condition. Post-index, 188 patients (44.9%) moved to permanent long-term care and were retained in the sample; 121 patients died (28.9%) and were removed yearly. Results: Over the ten-year study period, a significant increase occurred in the average number of FP visits, all-type drug prescriptions, and dementia-specific drug prescriptions (all p <.001). The highest proportion of patients hospitalized was observed one year pre-index, the highest average number of specialist visits was observed one year post-index, and both demonstrated a significant decreasing trend in the five-year post-index period (p = .037). Conclusions: A pattern of increasing FP visits and drug prescriptions over an extended period before and after diagnosis in a specialist rural and remote memory clinic highlights a need to support FPs in post-diagnostic management. Further research of longitudinal patterns in health service utilization is merited.

Health service use before and after dementia diagnosis: a retrospective matched case-control study.

OBJECTIVES: This study investigated patterns in health service usage among older adults with dementia and matched controls over a 10-year span from 5 years before until 5 years after diagnosis. DESIGN: Population-based retrospective matched case-control study. SETTING: Administrative health data of individuals in Saskatchewan, Canada from 1 April 2008 to 31 March 2019. PARTICIPANTS: The study included 2024 adults aged 65 years and older living in the community at the time of dementia diagnosis from 1 April 2013 to 31 March 2014, matched 1:1 to individuals without a dementia diagnosis on age group, sex, rural versus urban residence, geographical region and comorbidity. OUTCOME MEASURES: For each 5-year period before and after diagnosis, we examined usage of health services each year including family physician (FP) visits, specialist visits, hospital admissions, all-type prescription drug dispensations and short-term care admissions. We used negative binomial regression to estimate the effect of dementia on yearly average health service utilisation adjusting for sex, age group, rural versus urban residence, geographical region, 1 year prior health service use and comorbidity. RESULTS: Adjusted findings demonstrated that 5 years before diagnosis, usage of all health services except hospitalisation was lower among persons with dementia than persons without dementia (all p<0.001). After this point, differences in higher health service usage among persons with dementia compared to without dementia were greatest in the year before and year after diagnosis. In the year before diagnosis, specialist visits were 59.7% higher (p<0.001) and hospitalisations 90.5% higher (p<0.001). In the year after diagnosis, FP visits were 70.0% higher (p<0.001) and all-type drug prescriptions 29.1% higher (p<0.001). CONCLUSIONS: Findings suggest the year before and year after diagnosis offer multiple opportunities to implement quality supports. FPs are integral to dementia care and require effective resources to properly serve this population.

Association Between Asthma Control Trajectories in Preschoolers and Long-Term Asthma Control.

BACKGROUND: The potential influence of asthma control in early life on long-term outcomes in childhood remains largely unknown. OBJECTIVE: To examine whether asthma control trajectories in the 2 years after diagnosis in preschoolers are associated with long-term unsatisfactory asthma control. METHODS: We conducted a multicenter population-based retrospective cohort study, including four Canadian provincial birth cohorts derived from administrative databases. We included preschoolers (aged <5 years) with a diagnosis of asthma, defined as having one hospitalization or two physician visits for asthma within 2 years. Asthma control trajectories, ascertained over four 6-month periods after diagnosis using a validated index, were classified as controlled throughout, improving control, fluctuating control, worsening control, and out of control throughout. Long-term unsatisfactory control was defined as four or more short-acting ß2-agonist average doses per week or an exacerbation, measured within 6 months before index ages 6, 8, 10, 12, 14, and 16 years. Average risk ratios for long-term unsatisfactory control across all index ages were estimated using a robust Poisson model by province and meta-analyzed with a random effects model. RESULTS: In 50,188 preschoolers with asthma, the pooled average risk of having unsatisfactory control at any index age was 42% (95% confidence interval, 34.6-49.4). Compared with children who were controlled throughout, incrementally higher average risk ratios (95% confidence interval) of long-term unsatisfactory control were observed in each trajectory: improving control, 1.38 (1.28-1.49); fluctuating control, 1.54 (1.40-1.68); worsening control, 1.70 (1.55-1.86) and out of control throughout, 2.00 (1.80-2.21). CONCLUSIONS: Suboptimal asthma control trajectories shortly after a preschool diagnosis were associated with long-term unsatisfactory asthma control. Early control trajectories appear to be promising for predicting the risk for long-term adverse outcomes.

Unmet need and psychological distress predict emergency department visits in community-dwelling elderly women: a prospective cohort study.

BACKGROUND: Unmet need to perform activities of daily living (ADL) is associated with increased use of urgent health services by the elderly. However, the reported associations may be confounded by psychological distress. We examine the independent effects of unmet need and psychological distress upon emergency department (ED) visits. METHODS: We conducted a prospective study of randomly selected community-dwelling adults aged ≥ 75. We report here the results for women only (n = 530). In-person interviews collected data on self-reported unmet need and the 14-item l'Indice de détresse psychologique de Santé Québec psychological distress scale. ED visits were identified from an administrative database. Multivariable logistic regression was used to identify predictors of any ED visit in the 6 months following the baseline interview. RESULTS: In multivariable analysis, unmet need in instrumental ADL was associated with subsequent ED visits (odds ratio = 1.57, 95% confidence interval = 1.02-2.41), as was psychological distress (odds rate = 1.30, 95% confidence interval = 1.02-1.67). The magnitude of the association between unmet need and ED visits was overestimated in statistical models that did not adjust for psychological distress. CONCLUSIONS: Both unmet need and psychological distress were independent predictors of ED visits. Future investigations of unmet need and health services utilization should include psychological distress to control for confounding and improve the internal validity of statistical models.

Comparing comorbidity measures for predicting mortality and hospitalization in three population-based cohorts.

BACKGROUND: Multiple comorbidity measures have been developed for risk-adjustment in studies using administrative data, but it is unclear which measure is optimal for specific outcomes and if the measures are equally valid in different populations. This research examined the predictive performance of five comorbidity measures in three population-based cohorts. METHODS: Administrative data from the province of Saskatchewan, Canada, were used to create the cohorts. The general population cohort included all Saskatchewan residents 20+ years, the diabetes cohort included individuals 20+ years with a diabetes diagnosis in hospital and/or physician data, and the osteoporosis cohort included individuals 50+ years with diagnosed or treated osteoporosis. Five comorbidity measures based on health services utilization, number of different diagnoses, and prescription drugs over one year were defined. Predictive performance was assessed for death and hospitalization outcomes using measures of discrimination (c-statistic) and calibration (Brier score) for multiple logistic regression models. RESULTS: The comorbidity measures with optimal performance were the same in the general population (n = 662,423), diabetes (n = 41,925), and osteoporosis (n = 28,068) cohorts. For mortality, the Elixhauser index resulted in the highest c-statistic and lowest Brier score, followed by the Charlson index. For hospitalization, the number of diagnoses had the best predictive performance. Consistent results were obtained when we restricted attention to the population 65+ years in each cohort. CONCLUSIONS: The optimal comorbidity measure depends on the health outcome and not on the disease characteristics of the study population.

Higher mortality rates associated with rheumatoid arthritis in Saskatchewan, Canada, 2001-2019.

OBJECTIVES: To estimate provincial all-cause mortality rates of Saskatchewan people with rheumatoid arthritis (RA) for comparison with the general population over time and between different geographic regions. METHODS: Saskatchewan provincial administrative health databases (2001-2019) were utilized as data sources. Two RA case definitions were employed: (1) ≥ 3 physician billing diagnoses, at least 1 from a specialist (rheumatologist, general internist or orthopaedic surgeon) within 2 years; (2) ≥ 1 hospitalization diagnosis (ICD-9 code 714, and ICD-10-CA codes M05, M06). Data from these definitions were combined to create an administrative data RA cohort. All-cause mortality rates across geographic regions, between rural/urban residences and between sexes were examined. RESULTS: Over an 18-year span, between fiscal-year 2001-2002 and fiscal-year 2018-2019, age- and sex-adjusted mortality rates ranged from 17.10 to 21.04 (95% CI 14.77, 19.44; 18.03, 24.05)/1000 RA person-years, compared with mortality rates for the general Saskatchewan population without RA, which ranged from 9.37 to 10.88 (95% CI 9.23, 9.51; 10.72, 11.05)/1000 person-years. Fiscal-year mortality rate ratios ranged from 1.82 to 2.13 (95% CI 1.56, 2.13; 1.83, 2.46). Provincial mortality rates were higher in men than in women for both general and RA populations. Northern Saskatchewan mortality rates were significantly higher in the general population but did not achieve significance compared with other provincial regions for the RA population. Regression analysis identified age, male sex, RA and geographic region as factors contributing to increased mortality. A trend towards lower mortality rates over time was observed. CONCLUSION: Higher mortality rates were observed in the RA population overall. Men had higher mortality rates, as did residents of Northern Saskatchewan compared with residents of other regions for the general population.

RéSUMé: OBJECTIFS: Estimer les taux de mortalité provinciaux, toutes causes confondues, des habitants de la Saskatchewan atteints de polyarthrite rhumatoïde (PR) pour les comparer aux taux dans la population générale au fil du temps et entre différentes régions géographiques. MéTHODE: Nos données sont extraites des bases de données administratives sur la santé de la Saskatchewan (2001­2019). Deux définitions de cas ont été employées pour la PR : 1) ≥ 3 factures de diagnostic médical, dont au moins une d'un(e) spécialiste (rhumatologue, interniste général[e] ou chirurgien[ne] orthopédiste) en l'espace de deux ans; 2) ≥ 1 diagnostic d'hospitalisation (code CIM-9 714 et codes CIM-10-CA M05 et M06). Les données de ces définitions ont été combinées pour créer une cohorte de personnes atteintes de PR dans les données administratives. Les taux de mortalité toutes causes confondues entre les régions géographiques, entre les lieux de résidence urbains et ruraux et entre les sexes ont été examinés. RéSULTATS: En l'espace de 18 ans, entre les exercices 2001-2002 et 2018-2019, les taux de mortalité rajustés selon l'âge et le sexe ont varié entre 17,10 et 21,04 (IC de 95 % : 14,77-19,44; 18,03-24,05)/1000 personnes-années pour les personnes atteintes de PR, tandis que les taux de mortalité de la population générale de la Saskatchewan non atteinte de PR se sont situés entre 9,37 et 10,88 (IC de 95 % : 9,23-9,51; 10,72-11,05)/1000 personnes-années. Les rapports de taux de mortalité par exercice ont varié entre 1,82 et 2,13 (IC de 95 % : 1,56-2,13; 1,83-2,46). Les taux de mortalité provinciaux des hommes étaient supérieurs à ceux des femmes, tant dans la population générale que chez les personnes atteintes de PR. Les taux de mortalité dans le Nord de la Saskatchewan étaient sensiblement plus élevés que dans les autres régions de la province pour la population générale, mais pas sensiblement plus élevés pour la population atteinte de PR. Selon les analyses de régression, l'âge, le sexe masculin, la PR et la région géographique étaient des facteurs contribuant à une mortalité accrue. Une tendance à la baisse des taux de mortalité au fil du temps a été observée. CONCLUSION: Dans la population atteinte de PR, des taux de mortalité plus élevés ont été observés globalement. Dans la population générale, les taux de mortalité des hommes et ceux des résidents du Nord de la Saskatchewan étaient plus élevés que ceux des résidents des autres régions.

Predictors of hip fractures and mortality in long-term care homes in Saskatchewan: Does vitamin D supplementation play a role?

High rates of hip fracture (HF) in long-term care (LTC) lead to increased hospitalization and greater risk of death. Supplementation of residents with vitamin D3 (vitD) has been recommended, but may be infrequently acted upon. Using a prospective cohort design, we explored use of vitD at doses ≥800 IU for hip fractures (HF) and for mortality among permanent LTC residents in Saskatchewan between 2008 and 2012, using provincial administrative health databases (N = 23178). We used stepwise backward regression with Cox proportional hazard multivariate analysis for time to first HF or to death upon entry into LTC (excluding the first three months), the association of daily vitD (determined during the first three months), age, sex, age*sex interaction, prior HF, osteoporosis diagnosis and Charlson Comormidity Score (CCS) was determined. Users of VitD were more likely older, women and those with previous HF. For HF, no significant impact of vitD or CCS was found. Models for mortality, stratified by sex, showed in women only, that vitD use resulted in a significant inverse association with time to death [HR (0.91(0.87-0.96)]; for men it was 0.94(0.88-1.01). The impact of VitD supplementation in LTC deserves further investigation, however, the mechanisms for its effect on mortality remain unclear.

Comparative effectiveness and safety of direct oral anticoagulants versus vitamin K antagonists in nonvalvular atrial fibrillation: a Canadian multicentre observational cohort study.

BACKGROUND: Direct oral anticoagulants (DOACs) have widely replaced warfarin for stroke prevention in nonvalvular atrial fibrillation. Our objective was to compare the safety and effectiveness of DOACs (dabigatran, rivaroxaban, apixaban) versus warfarin for stroke prevention in nonvalvular atrial fibrillation in the Canadian setting. METHODS: We conducted a population-based observational multicentre cohort study with propensity score matching and subsequent meta-analysis. We used health care databases from 7 Canadian provinces (British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec and Nova Scotia). Patients with nonvalvular atrial fibrillation who initiated anticoagulation therapy in 2009-2017 were matched to an equal number who initiated warfarin. The primary outcome was the pooled hazard ratio (HR) for ischemic stroke or systemic embolization. Secondary outcomes included pooled HRs for major bleeding; a composite outcome of stroke, systemic embolization, major bleeding and all-cause mortality; and myocardial infarction. We modelled HRs using proportional hazard Cox regression with inverse probability of censoring weights, and estimated pooled HRs with random-effect meta-analyses. RESULTS: We included 128 273 patients who initiated anticoagulation with a DOAC (40 503 dabigatran, 49 498 rivaroxaban and 38 272 apixaban) and 128 273 patients who initiated anticoagulation with warfarin. The pooled HR for ischemic stroke or systemic embolization comparing DOACs to warfarin was 1.02 (95% confidence interval [CI] 0.87 to 1.19). Direct oral anticoagulants were associated with lower rates of major bleeding (pooled HR 0.81, 95% CI 0.69 to 0.97), the composite outcome (pooled HR 0.81, 95% CI 0.74 to 0.89) and all-cause mortality (pooled HR 0.81, 95% CI 0.78 to 0.85). INTERPRETATION: In this real-world study, DOACs were associated with similar risks of ischemic stroke or systemic embolization, and lower risks of bleeding and total mortality compared to warfarin. These findings support the use of DOACs for anticoagulation in nonvalvular atrial fibrillation. TRIAL REGISTRATION: ClinicalTrials.gov, no. NCT03596502.

Incidence and prevalence of rheumatoid arthritis in Saskatchewan, Canada: 2001-2014.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic inflammatory and destructive arthritis. Understanding the incidence and prevalence of RA within the province facilitates appropriate health care resource planning. OBJECTIVE: To estimate the incidence/prevalence of RA over time for the overall provincial population, for specific age range categories, and for gender. METHODS: Saskatchewan Provincial Administrative Health Databases (2001-2014) were utilized as data sources. Two RA case-definitions were employed: 1) > three physician billing diagnoses, at least one of which was submitted by a specialist (rheumatologist, general internist or orthopedic surgeon) within 2 years; 2) > one hospitalization diagnosis (ICD-9-CM code-714, and ICD-10-CA code-M05). Data from these definitions were combined to identify incident and prevalent RA cases. Using this data, annual incidence and prevalence rates were calculated for the provincial population, specified age range categories and gender categories. RESULTS: The number of RA cases meeting the case definition increased from 3731 to 6223 over the study period. The incidence of RA disease demonstrated variation within the study period with age and sex adjusted incidence ranging from 33.6 (95% CI 29.9-37.6) per 100,000 to 73.1 (95% CI 67.6-79.0) per 100,000. The prevalence of RA increased over time from 482 (95% CI 466.7-497.7) per 100,000 in 2001-2002 to 683.4 (95% CI 666.6-700.6) per 100,000 in 2014-2015. Both incidence and prevalence rates rose with increasing age. Women were found to have higher incidence and prevalence rates compared to men. CONCLUSION: In Saskatchewan, the overall prevalence of RA is rising while there has been variability in the incidence.