Association between immigration status and total knee arthroplasty outcomes in Ontario, Canada: a population-based matched cohort study.

BACKGROUND: Immigrants and refugees face unique challenges navigating the health care system to manage severe arthritis, because of unfamiliarity, lack of awareness of surgical options, or access. The purpose of this study was to assess total knee arthroplasty (TKA) uptake, surgical outcomes, and hospital utilization among immigrants and refugees compared with Canadian-born patients. METHODS: We included all adults undergoing primary TKA from January 2011 to December 2020 in Ontario. Cohorts were defined as Canadian-born or immigrants and refugees. We assessed change in yearly TKA utilization for trend. We compared differences in 1-year revision, infection rates, 30-day venous thromboembolism (VTE), presentation to emergency department, and hospital readmission between matched Canadian-born and immigrant and refugee groups. RESULTS: We included 158 031 TKA procedures. A total of 11 973 (7.6%) patients were in the immigrant and refugee group, and 146 058 (92.4%) patients were in the Canadian-born group. The proportion of TKAs in Ontario performed among immigrants and refugees nearly doubled over the 10-year study period (p < 0.001). After matching, immigrants were at relatively lower risk of 1-year revision (0.9% v. 1.6%, p < 0.001), infection (p < 0.001), death (p = 0.004), and surgical complications (p < 0.001). No differences were observed in rates of 30-day VTE or length of hospital stay. Immigrants were more likely to be discharged to rehabilitation (p < 0.001) and less likely to present to the emergency department (p < 0.001) than Canadian-born patients. CONCLUSION: Compared with Canadian-born patients, immigrants and refugees have favourable surgical outcomes and similar rates of resource utilization after TKA. We observed an underutilization of these procedures in Ontario relative to their proportion of the population. This may reflect differences in perceptions of chronic pain or barriers accessing arthroplasty.

Sex-Related Differences in Dispensation of Rheumatic Medications in Older Patients With Inflammatory Arthritis: A Population-Based Study.

OBJECTIVE: The aim of our study was to compare dispensation of rheumatic medications between older male and female patients with early rheumatoid arthritis (RA) and psoriatic arthritis (PsA). METHODS: This retrospective cohort study was performed using health administrative data from Ontario, Canada (years 2010-2017), on patients with incident RA and PsA, who were aged ≥ 66 years at the time of diagnosis. Yearly dispensation of rheumatic drugs was compared between older male and female patients for 3 years after diagnosis using multivariable regression models, after adjusting for confounders. The groups of drugs included in the analysis were disease-modifying antirheumatic drugs (DMARDs) classified as conventional synthetic DMARDs (csDMARDs) and advanced therapy (biologic DMARDs and targeted synthetic DMARDs), nonsteroidal antiinflammatory drugs (NSAIDs), opioids, and oral corticosteroids. Results were reported as odds ratios (ORs) with 95% CIs. RESULTS: We analyzed 13,613 patients (64% female) with RA and 1116 patients (57% female) with PsA. Female patients with RA were more likely to receive opioids (OR 1.39, 95% CI 1.22-1.58 to OR 1.51, 95% CI 1.32-1.72) and NSAIDs (OR 1.14, 95% CI 1.04-1.25 to OR 1.16, 95% CI 1.04-1.30). Dispensation of DMARDs showed no sex difference in either group. Subgroup analyses showed more intense use of advanced therapy in the RA cohort and of csDMARDs in the PsA cohort when patient and physician sex was concordant. CONCLUSION: This study did not identify any sex difference in the use of DMARDs among older patients with RA and PsA. The reasons for the higher use of opioids and NSAIDs among female patients with RA warrant further research.

Early versus late onset interstitial lung disease in rheumatoid arthritis: An observational study of risk factors and mortality in Ontario, Canada.

BACKGROUND AND OBJECTIVE: Interstitial lung disease (ILD) can occur as a manifestation of rheumatoid arthritis (RA) at various times in the disease course. We aimed to identify factors associated with early versus late onset RA-ILD and how the timing of RA-ILD influenced surgical lung biopsy completion and mortality. METHODS: We performed a retrospective observational study using health services data from Ontario, Canada. We identified RA cases between 2000 and 2020 using the Ontario Rheumatoid Arthritis Database. RA-ILD diagnosis required repeat physician visits for ILD, with early RA-ILD defined as within 1 year of RA diagnosis. We performed multivariable logistic regression to identify factors associated with early RA-ILD and surgical lung biopsy completion, and multivariable cox-proportional hazards regression to evaluate the association of early versus late RA-ILD on all-cause and RA-ILD related mortality. RESULTS: In total, we identified 3717 cases of RA-ILD. Older age at RA diagnosis [OR 1.04 (95%CI 1.03-1.05), p < 0.0001], female sex [OR 1.16 (95%CI 1.01-1.35), p = 0.04] and immigrating to Ontario [OR 1.70 (95%CI 1.35-2.14), p < 0.0001] was associated with early RA-ILD. Patients with early versus late RA-ILD experienced similar odds of undergoing a surgical lung biopsy [OR 1.34 (95%CI 0.83-2.16), p = 0.23]. Early RA-ILD was associated with increased all-cause mortality [HR 1.17 (95%CI 1.07-1.29), p = 0.0009], primarily driven by an increase in RA-ILD related mortality [HR 1.45 (95%CI 1.19-1.76), p = 0.0003]. CONCLUSION: Age at RA onset, female sex and immigration status are associated with early RA-ILD. Patients with early RA-ILD experience increased all-cause and RA-ILD related mortality after adjusting for demographics and comorbidities.

Derivation of a Multivariable Psoriatic Arthritis Risk Estimation Tool (PRESTO): A Step Towards Prevention.

OBJECTIVE: A simple, scalable tool that identifies psoriasis patients at high risk for developing psoriatic arthritis (PsA) could improve early diagnosis. We aimed to develop a risk prediction model for the development of PsA and to assess its performance among patients with psoriasis. METHODS: We analyzed data from a prospective cohort of psoriasis patients without PsA at enrollment. Participants were assessed annually by a rheumatologist for the development of PsA. Information about their demographics, psoriasis characteristics, comorbidities, medications, and musculoskeletal symptoms was used to develop prediction models for PsA. Penalized binary regression models were used for variable selection while adjusting for psoriasis duration. Risks of developing PsA over 1- and 5-year time periods were estimated. Model performance was assessed by the area under the curve (AUC) and calibration plots. RESULTS: Among 635 psoriasis patients, 51 and 71 developed PsA during the 1-year and 5-year follow-up periods, respectively. The risk of developing PsA within 1 year was associated with younger age, male sex, family history of psoriasis, back stiffness, nail pitting, joint stiffness, use of biologic medications, patient global health, and pain severity (AUC 72.3). The risk of developing PsA within 5 years was associated with morning stiffness, psoriatic nail lesion, psoriasis severity, fatigue, pain, and use of systemic nonbiologic medication or phototherapy (AUC 74.9). Calibration plots showed reasonable agreement between predicted and observed probabilities. CONCLUSIONS: The development of PsA within clinically meaningful time frames can be predicted with reasonable accuracy for psoriasis patients using readily available clinical variables.

Systemic autoimmune rheumatic diseases and multiple industrial air pollutant emissions: A large general population Canadian cohort analysis.

BACKGROUND: Past investigations of air pollution and systemic autoimmune rheumatic diseases (SARDs) typically focused on individual (not mixed) and overall environmental emissions. We assessed mixtures of industrial emissions of fine particulate matter (PM2.5), nitrogen dioxide (NO2), and sulfur dioxide (SO2) and SARDs onset in Ontario, Canada. METHODS: We assembled an open cohort of over 12 million adults (without SARD diagnoses at cohort entry) based on provincial health data for 2007-2020 and followed them until SARD onset, death, emigration, or end of study (December 2020). SARDs were identified using physician billing and hospitalization diagnostic codes for systemic lupus, scleroderma, myositis, undifferentiated connective tissue disease, and Sjogren's. Rheumatoid arthritis and vasculitis were not included. Average PM2.5, NO2, and SO2 industrial emissions from 2002 to one year before SARDs onset or end of study were assigned using residential postal codes. A quantile g-computation model for time to SARD onset was developed for the industrial emission mixture, adjusting for sex, age, income, rurality index, chronic obstructive pulmonary disease (as a proxy for smoking), background (environmental overall) PM2.5, and calendar year. We conducted stratified analyses across age, sex, and rurality. RESULTS: We identified 43,931 new SARD diagnoses across 143,799,564 person-years. The adjusted hazard ratio for SARD onset for an increase in all emissions by one decile was 1.018 (95% confidence interval 1.013-1.022). Similar positive associations between SARDs and the mixed emissions were observed in most stratified analyses. Industrial PM2.5 contributed most to SARD risk. CONCLUSIONS: Industrial air pollution emissions were associated with SARDs risk.

Understanding sex-related differences in healthcare utilisation among patients with inflammatory arthritis: a population-based study.

OBJECTIVES: Our aim was to compare patterns of musculoskeletal-related healthcare utilisation between male and female patients before and after the diagnosis of inflammatory arthritis (IA). METHODS: We used Ontario administrative health data to create three inception cohorts of adult patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) diagnosed between April 2010 and March 2017. Healthcare utilisation indicators including visits to physicians, and use of musculoskeletal imaging and laboratory tests were assessed in each year for 3 years before and after diagnosis and compared between male and female patients using regression models adjusting for sociodemographic factors and comorbidities. Results were reported as ORs with 95% CIs for female patients compared with male patients. RESULTS: A total of 41 277 patients with RA (69% female), 8150 patients with AS (51% female) and 6446 patients with PsA (54% female) were analysed.Similar trends of sex-related differences were observed in all three cohorts. Before diagnosis, female patients were more likely to visit rheumatologists (OR 1.32-2.28) and family physicians (OR 1.03-1.15) for musculoskeletal reasons, whereas male patients were more likely to visit the emergency for musculoskeletal reasons (OR 0.76-0.87). A similar female predominance was observed regarding musculoskeletal imaging and laboratory tests before diagnosis. After diagnosis, female patients were more likely to remain in rheumatology care (OR 1.12-1.24). CONCLUSION: Female patients with IA have higher healthcare utilisation than male patients which may indicate biological differences in disease course or sociocultural differences in healthcare-seeking behaviour.

Sex- and gender-related differences in psoriatic arthritis.

Psoriatic arthritis (PsA) is an inflammatory musculoskeletal disease with a chronic, progressive course. Various aspects of PsA, including its clinical features, disease course and response to treatment, are influenced by sociodemographic characteristics of the patient. This includes patient sex, the biological attributes associated with being male or female, and gender, a sociocultural construct that comprises attitudes, traits and behaviours associated with being a man or a woman. An understanding of sex- and gender-related differences in PsA, as well as their underlying mechanisms, is therefore important for individualized care. In this narrative review, the influence of sex and gender on PsA manifestation and course, patient function and quality of life, and their association with comorbidities are described. Sex- and gender-related disparities in response to advanced therapies and their potential underlying mechanisms are delineated. Differences in pathophysiological mechanisms between male and female patients including genetics, immune and hormonal mechanisms are discussed. Finally, fertility and pregnancy outcomes in PsA are outlined. By adopting sex and gender lenses, this review is aimed at highlighting key differences between male and female patients with PsA and uncovering mechanisms underlying these differences, ultimately promoting individualized care of men and women with PsA and informing future research in this area.

Survival after surgery for spinal metastases: a population-based study.

BACKGROUND: There are limited published data on population estimates of survival after spinal surgery for metastatic disease. We performed a population-based study to evaluate survival and complications among patients with cancer who underwent surgery for spinal metastases in Ontario, Canada, between 2006 and 2016. METHODS: We used health administrative databases to identify all patients who underwent surgery for spinal metastases in Ontario between Jan. 1, 2006, and Dec. 31, 2016. We assessed overall survival, mortality rates according to primary cancer lesion and complications after surgery. We contrast the results to those for a comparable cohort from 1991 to 1998. RESULTS: A total of 2646 patients (1194 women [45.1%]; mean age 62.5 yr [standard deviation 12.2 yr]) were identified. The median survival time was 236 (interquartile range 84-740) days. Mortality was highest for patients with melanoma, upper gastrointestinal cancer and lung cancer, with 50% dying within 90 days of surgery. The longest median survival times were observed for primary cancers of the thyroid (906 d) and breast (644 d), and myeloma (830 d). Overall 90-day and 1-year mortality rates were 29% and 59%, respectively. CONCLUSION: We identified differential survivorship based on primary tumour type and a shift in the distribution of operations performed for specific primary cancers over the past 2 decades in Ontario. Overall reductions in mortality associated with this shift in treatment may reflect the use of adjuvant therapies and more personalized treatment approaches.

COVID-19 Hospitalizations, Intensive Care Unit Stays, Ventilation, and Death Among Patients With Immune-mediated Inflammatory Diseases Compared to Controls.

OBJECTIVE: To investigate coronavirus disease 2019 (COVID-19) hospitalization risk in patients with immune-mediated inflammatory diseases (IMIDs) compared with matched non-IMID comparators from the general population. METHODS: We conducted a population-based, matched cohort study using health administrative data from January to July 2020 in Ontario, Canada. Cohorts for each of the following IMIDs were assembled: rheumatoid arthritis (RA), psoriasis, psoriatic arthritis (PsA), ankylosing spondylitis, systemic autoimmune rheumatic diseases (SARDs), multiple sclerosis (MS), iritis, inflammatory bowel disease, polymyalgia rheumatica, and vasculitis. Each patient was matched with 5 non-IMID comparators based on sociodemographic factors. We compared the cumulative incidence of hospitalizations for COVID-19 and their outcomes between IMID and non-IMID patients. RESULTS: A total of 493,499 patients with IMID (417 hospitalizations) and 2,466,946 non-IMID comparators (1519 hospitalizations) were assessed. The odds of being hospitalized for COVID-19 were significantly higher in patients with IMIDs compared with their matched non-IMID comparators (matched unadjusted odds ratio [OR] 1.37, adjusted OR 1.23). Significantly higher risk of hospitalizations was found in patients with iritis (OR 1.46), MS (OR 1.83), PsA (OR 2.20), RA (OR 1.42), SARDs (OR 1.47), and vasculitis (OR 2.07). COVID-19 hospitalizations were associated with older age, male sex, long-term care residence, multimorbidity, and lower income. The odds of complicated hospitalizations were 21% higher among all IMID vs matched non-IMID patients, but this association was attenuated after adjusting for demographic factors and comorbidities. CONCLUSION: Patients with IMIDs were at higher risk of being hospitalized with COVID-19. This risk was explained in part by their comorbidities.

COVID-19 Vaccination Uptake Among Individuals With Immune-mediated Inflammatory Diseases in Ontario, Canada, Between December 2020 and October 2021: A Population-based Analysis.

OBJECTIVE: We assessed coronavirus disease 2019 (COVID-19) vaccine uptake among individuals with immune-mediated inflammatory diseases (IMIDs) and the Ontario general population. METHODS: We studied all residents aged ≥ 16 years who were alive and enrolled in the Ontario Health Insurance Plan as of December 14, 2020, when vaccination commenced (n = 12,435,914). Individuals with rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), psoriasis (PsO), and inflammatory bowel disease (IBD) were identified using established disease-specific case definitions applied to health administrative data. Vaccination status was extracted from the provincial COVaxON registry. Weekly cumulative proportions of first and second doses up until October 3, 2021, were expressed as the vaccinated percentage of each disease group, compared to the general Ontario population, and stratified by age. RESULTS: By October 3, 2021, the cumulative percentage with at least 1 dose was 82.1% for the general population, 88.9% for those with RA, 87.4% for AS, 90.6% for PsA, 87.3% for PsO, and 87.0% for IBD. There was also a higher total cumulative percentage with 2 doses among IMIDs (83.8-88.2%) vs the general population (77.9%). The difference was also evident when stratifying by age. Individuals with IMIDs in the youngest age group initially had earlier uptake than the general population but remain the lowest age group with 2 doses (70.6% in the general population vs. 73.7-79.2% across IMID groups). CONCLUSION: While implementation of COVID-19 vaccination programs has differed globally, these Canadian estimates are the first to reassuringly show higher COVID-19 vaccine uptake among individuals with IMIDs.

Effects of hospital funding reform on wait times for hip fracture surgery: a population-based interrupted time-series analysis.

BACKGROUND: Health care funding reforms are being used worldwide to improve system performance but may invoke unintended consequences. We assessed the effects of introducing a targeted hospital funding model, based on fixed price and volume, for hip fractures. We hypothesized the policy change was associated with reduction in wait times for hip fracture surgery, increase in wait times for non-hip fracture surgery, and increase in the incidence of after-hours hip fracture surgery. METHODS: This was a population-based, interrupted time series analysis of 49,097 surgeries for hip fractures, 10,474 for ankle fractures, 1,594 for tibial plateau fractures, and 40,898 for appendectomy at all hospitals in Ontario, Canada between April 2012 and March 2017. We used segmented regression analysis of interrupted monthly time series data to evaluate the impact of funding reform enacted April 1, 2014 on wait time for hip fracture repair (from hospital presentation to surgery) and after-hours provision of surgery (occurring between 1700 and 0700 h). To assess potential adverse consequences of the reform, we also evaluated two control procedures, ankle and tibial plateau fracture surgery. Appendectomy served as a non-orthopedic tracer for assessment of secular trends. RESULTS: The difference (95 % confidence interval) between the actual mean wait time and the predicted rate had the policy change not occurred was - 0.46 h (-3.94 h, 3.03 h) for hip fractures, 1.46 h (-3.58 h, 6.50 h) for ankle fractures, -3.22 h (-39.39 h, 32.95 h) for tibial plateau fractures, and 0.33 h (-0.57 h, 1.24 h) for appendectomy (Figure 1; Table 3). The difference (95 % confidence interval) between the actual and predicted percentage of surgeries performed after-hours - 0.90 % (-3.91 %, 2.11 %) for hip fractures, -3.54 % (-11.25 %, 4.16 %) for ankle fractures, 7.09 % (-7.97 %, 22.14 %) for tibial plateau fractures, and 1.07 % (-2.45 %, 4.59 %) for appendectomy. CONCLUSIONS: We found no significant effects of a targeted hospital funding model based on fixed price and volume on wait times or the provision of after-hours surgery. Other approaches for improving hip fracture wait times may be worth pursuing instead of funding reform.

Fracture Risk in Patients with Myasthenia Gravis: A Population-Based Cohort Study.

BACKGROUND: Prednisone is a common treatment for myasthenia gravis (MG), and osteoporosis is a known potential risk of chronic prednisone therapy. OBJECTIVE: Our aim was to evaluate the risk of serious fractures in a population-based cohort of MG patients. METHODS: An inception cohort of patients with MG was identified from administrative health data in Ontario, Canada between April 1, 2002 and December 31, 2015. For each MG patient, we matched 4 general population comparators based on age, sex, and region of residence. Fractures were identified through emergency department and hospitalization data. Crude overall rates and sex-specific rates of fractures were calculated for the MG and comparator groups, as well as rates of specific fractures. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression. RESULTS: Among 3,823 incident MG patients (followed for a mean of 5 years), 188 (4.9%) experienced a fracture compared with 741 (4.8%) fractures amongst 15,292 matched comparators. Crude fracture rates were not different between the MG cohort and matched comparators (8.71 vs. 7.98 per 1000 patient years), overall and in men and women separately. After controlling for multiple covariates, MG patients had a significantly lower risk of fracture than comparators (HR 0.74, 95% CI 0.63-0.88). CONCLUSIONS: In this large, population-based cohort of incident MG patients, MG patients were at lower risk of a major fracture than comparators. The reasons for this finding are unclear but may highlight the importance osteoporosis prevention.

Health Care Utilization for Musculoskeletal Issues During the Prediagnosis Period in Psoriatic Arthritis: A Population-Based Study.

OBJECTIVE: Information about the prediagnosis period in psoriatic arthritis (PsA) is limited. The present study was undertaken to compare health care utilization related to musculoskeletal issues during a 5-year period prior to the diagnosis of PsA versus that of subjects with no prior inflammatory arthritis within a primary care setting. METHODS: We conducted a population-based, matched cohort study using electronic medical records and administrative data in Ontario, Canada. Age- and sex-matched cohorts of PsA patients and comparators from the same family physicians were assembled. Comparators were not allowed to have prior spondyloarthritis, ankylosing spondylitis, or rheumatoid arthritis billing code diagnoses. The study outcomes included health care utilization and costs related to nonspecific musculoskeletal issues during a 5-year period prior to the index date. RESULTS: We studied 462 PsA patients and 2,310 matched comparators. The odds ratio (OR) related to visiting a primary care physician for nonspecific musculoskeletal issues in patients with PsA was 2.14 (95% confidence interval 1.73-2.64) in the year immediately preceding the index date and was similarly elevated up to 5 years prior. The OR related to using other musculoskeletal-related health care services, including musculoskeletal specialists visits, joint injections, joint imaging, and emergency department visits, was higher in PsA as early as 5 years preceding the index date. Total and musculoskeletal-related health care costs prior to the index date were higher for patients with PsA versus comparators. CONCLUSION: A prodromal PsA phase characterized by nonspecific musculoskeletal symptoms may exist. Further study is needed to determine if this represents a window for earlier diagnosis of PsA.

Trends in mortality and cause-specific mortality among patients with psoriasis and psoriatic arthritis in Ontario, Canada.

BACKGROUND: There is limited information about mortality rates among patients with psoriasis and psoriatic arthritis (PsA) in North America and their change over the past 2 decades. OBJECTIVE: To compare all-cause and cause-specific mortality rates in patients with psoriasis to the general population in Ontario, Canada, from 1996 to 2016. METHODS: We conducted a population-based, retrospective cohort study of adult residents using administrative health data. All-cause and cause-specific standardized mortality rates, standardized mortality ratios, and excess mortality rates were calculated. RESULTS: 176,858 (2,524 deaths) patients with psoriasis and 15,430 (221 deaths) patients with PsA were identified in 2016. Patients with psoriasis and PsA had standardized excess mortality rates of 1.44 and 2.43 per 1000 population, respectively. Standardized mortality rates decreased by approximately 30% over the study period in both disease groups but remained significantly elevated compared to the general population. The leading causes of death in psoriasis and PsA patients were cancer, circulatory disease, and respiratory conditions. LIMITATIONS: We were unable to classify patients according to disease severity. CONCLUSIONS: Despite improvements in psoriasis treatment, the relative excess mortality, which may be related to risk factors for psoriatic disease, remained unchanged, with an average of approximately 1 to 2 extra deaths per 1,000 patients in 2016.

Identifying and Characterizing Psoriasis and Psoriatic Arthritis Patients in Ontario Administrative Data: A Population-based Study From 1991 to 2015.

OBJECTIVES: We assessed the accuracy of case definition algorithms for psoriasis and psoriatic arthritis (PsA) in health administrative data and used primary care electronic medical records (EMR) to describe disease and treatment characteristics of these patients. METHODS: We randomly sampled 30,424 adult Ontario residents from the Electronic Medical Record Primary Care database and identified 2215 patients with any possible psoriatic disease-related terms in their EMR. The relevant patient records were chart abstracted to confirm diagnoses of psoriasis or PsA. This validation set was then linked to health administrative data to assess the performance of different algorithms for physician billing diagnosis codes, hospitalization diagnosis codes, and medications for psoriatic disease. We report the performance of selected case definition algorithms and describe the disease characteristics of the validation set. RESULTS: Our reference standard identified 1028 patients with psoriasis and 77 patients with PsA, for an overall prevalence of 3.4% for psoriasis and 0.3% for PsA. Most patients with PsA (66%) had a rheumatology-confirmed diagnosis, while only 30% of the patients with psoriasis had dermatology-confirmed diagnosis. The use of systemic medications was much more common with PsA than with psoriasis. All algorithms had excellent specificity (97-100%). The sensitivity and positive predictive value were moderate and varied between different algorithms (34-72%). CONCLUSION: The accuracy of case definition algorithms for psoriasis and PsA varies widely. However, selected algorithms produced population prevalence estimates that were within the expected ranges, suggesting that they may be useful for future research purposes.

Trends in the Prevalence and Incidence of Psoriasis and Psoriatic Arthritis in Ontario, Canada: A Population-Based Study.

OBJECTIVE: To estimate the prevalence and incidence of psoriasis and psoriatic arthritis (PsA) over time in Ontario, Canada. METHODS: We performed a population-based study of Ontario health administrative data, using validated case definitions for psoriasis and PsA. We computed the crude and age- and sex-standardized cumulative prevalence and incidence of psoriasis from 2000 to 2015. RESULTS: Among the 10,774,802 individuals ages ≥20 years residing in Ontario in 2015, we identified 273,238 patients with psoriasis and 18,655 patients with PsA, equating to cumulative prevalence estimates of 2.54% and 0.17%, respectively. Correcting the prevalence estimates for imperfect sensitivity and specificity resulted in similar estimates. The male:female ratio was approximately 1.0 for both conditions. For psoriasis, the age- and sex-standardized cumulative prevalence increased from 1.74% in 2000 to 2.32% in 2015. For PsA, the age- and sex-standardized cumulative prevalence increased from 0.09% in 2008 to 0.15% in 2015. Between 2008 and 2015, annual incidence rates for psoriasis decreased, whereas those for PsA remained relatively stable. CONCLUSION: The prevalence and incidence of psoriasis and PsA in Ontario are similar to those observed in Europe and the US. The steady increase in the prevalence of psoriasis and PsA over the past decade may be due to a combination of population aging, population growth, and increasing life expectancy.

Causes of Death in Rheumatoid Arthritis: How Do They Compare to the General Population?

OBJECTIVE: To compare mortality rates, underlying causes of death, excess mortality, and years of potential life lost (YPLL) among patients with rheumatoid arthritis (RA) relative to the general population. METHODS: We studied an inception cohort of 87,114 Ontario-based RA patients and 348,456 age/sex/area-matched general population comparators from years 2000 to 2013. All-cause, cause-specific, and excess mortality rates, mortality rate ratios (MRRs), and the YPLL were estimated. RESULTS: A total of 11,778 RA patients (14%) and 32,472 comparators (9%) died during 508,385 and 1,769,365 patient-years of follow-up, respectively, for corresponding mortality rates of 232 (95% confidence interval [95% CI] 228-236) and 184 (95% CI 182-186) per 10,000 patient-years. The leading causes of death in both groups were diseases of the circulatory system, cancer, and respiratory conditions. Increased mortality for all-cause and specific causes was observed in RA patients relative to the general population. MRRs were elevated for most causes of death. Age-specific mortality ratios illustrated a high excess mortality among RA patients <45 years of age for respiratory disease and circulatory disease. The YPLL for RA patients was 7,436 per 10,000 persons, compared with 4,083 YPLL among those without RA. CONCLUSION: Among most causes of death, mortality rates were increased in RA patients relative to the general population. The potential life years lost (before the age of 75 years) among RA patients was roughly double that among those without RA, reflecting higher rate ratios for most causes of death and RA patients dying at earlier ages.

Primary Care Screening and Comorbidity Management in Rheumatoid Arthritis in Ontario, Canada.

OBJECTIVE: Quality measurement for rheumatoid arthritis (RA) patients has largely focused on care provided by rheumatologists. Our aim was to develop and assess quality measures related to the screening and management of comorbidity in RA patients in primary care. METHODS: We used the primary care Electronic Medical Record Administrative data Linked Database in Ontario, Canada. We harmonized Canadian general population and RA clinical recommendations to develop and assess screening, process, and outcome measures. For each RA patient, 10 non-RA patients were matched by age and sex. Stratified analyses were performed, comparing patients with RA to those without RA, to assess the performance of quality measures. RESULTS: We compared 1,405 RA patients to 14,050 matched non-RA patients (72.8% female; mean age 62.5 years). Compared to non-RA patients, RA patients more frequently had influenza (44.9% versus 40.0%) and pneumococcal (40.4% versus 34.1%) vaccinations and bone mineral density testing (67.4% versus 58.1%). Herpes zoster vaccinations were less frequent among RA patients (13.8% versus 19.5%), as was screening for cervical cancer (58.6% versus 64.0%). No significant differences were observed between RA and non-RA patients in screenings for breast (70.7% versus 73.8%) or colorectal (31.7% versus 34.5%) cancers. Only a quarter of RA patients had a comprehensive cardiovascular risk assessment. No definitive differences were detected in the management of patients who had co-occurring cardiovascular disease or diabetes mellitus. CONCLUSION: For both RA and non-RA patients, compliance with Canadian recommendations for preventive medical services and screening for comorbid conditions in primary care was less than optimal. This indicates key targets for improvement.

The Longterm Effect of Early Intensive Treatment of Seniors with Rheumatoid Arthritis: A Comparison of 2 Population-based Cohort Studies on Time to Joint Replacement Surgery.

OBJECTIVE: Disease-modifying antirheumatic drugs (DMARD) have the greatest effect when initiated early. We evaluated the influence of early exposure to DMARD on time to joint replacement surgery among patients with incident rheumatoid arthritis (RA). METHOD: Using a common protocol, we undertook 2 independent population-based cohort studies of patients with incident RA aged 66 years or older in Ontario (ON) and Quebec (QC) covering the period 2000-2013. We used Cox proportional hazards regression with time-dependent variables measuring duration of drug use in the first year, separately for methotrexate (MTX) and other DMARD, adjusting for baseline demographics, clinical factors, and other potentially confounding drug exposures. Our outcome measure was any joint replacement derived from standardized procedure codes. Adjusted HR and 95% CI were estimated. RESULTS: Among 20,918 ON and 6754 QC patients with RA followed for a median of 4.5 years, 2201 and 494 patients underwent joint replacement surgery for crude event rates of 2.0 and 1.4 per 100 person-years, respectively. Greater cumulative exposure to MTX (HR 0.97, 95% CI 0.95-0.98) and other DMARD (HR 0.98, 95% CI 0.97-0.99) in the first year after diagnosis was associated with longer times to joint replacement in ON, corresponding to a 2-3% decrease in the hazard of surgery with each additional month of early use. Similar results were observed in QC. CONCLUSION: Greater duration of exposure to DMARD soon after RA diagnosis was associated with delays to joint replacement surgery in both provinces. Early intensive treatment of RA may ultimately reduce demand for joint replacement surgery.

Epidemiology of myasthenia gravis in Ontario, Canada.

Incidence and prevalence estimates in myasthenia gravis have varied widely. Recent studies based on administrative health data have large sample sizes but lack rigorous validation of MG cases, and have not examined the North American population. Our aim was to explore trends in MG incidence and prevalence for the years 1996-2013 in the province of Ontario, Canada (population 13.5 million). We employed a previously validated algorithm to identify MG cases. Linking with census data allowed for the calculation of crude- and age/sex-standardized incidence and prevalence rates for the years 1996-2013. The regional distribution of MG cases throughout the province was examined. Mean age at the first myasthenia gravis encounter was 60.2 ± 17.1 years. In 2013, there were 3611 prevalent cases in Ontario, and the crude prevalence rate was 32.0/100,000 population. Age- and sex-standardized prevalence rates rose consistently over time from 16.3/100,000 (15.4-17.1) in 1996 to 26.3/100,000 (25.4-27.3) in 2013. Standardized incidence rates remained stable between 1996 (2.7/100,000; 95% CL 2.3-3.0) and 2013 (2.3/100,000; 2.1-2.6). Incidence was highest in younger women and older men, and geographic variation was evident throughout the province. In conclusion, this large epidemiological study shows rising myasthenia gravis prevalence with stable incidence over time, which is likely reflective of patients living longer, possibly due to improved disease treatment. Our findings provide accurate information on the Canadian epidemiology of myasthenia gravis and burden for health care resources planning for the province, respectively.