Health administrative data can be a valuable tool for disease surveillance and research. Few studies have rigorously evaluated the accuracy of administrative databases for identifying rheumatoid arthritis (RA) patients. Our aim was to validate administrative data algorithms to identify RA patients in Ontario, Canada.
We performed a retrospective review of a random sample of 450 patients from 18 rheumatology clinics. Using rheumatologist-reported diagnosis as the reference standard, we tested and validated different combinations of physician billing, hospitalization, and pharmacy data.
One hundred forty-nine rheumatology patients were classified as having RA and 301 were classified as not having RA based on our reference standard definition (study RA prevalence 33%). Overall, algorithms that included physician billings had excellent sensitivity (range 94-100%). Specificity and positive predictive value (PPV) were modest to excellent and increased when algorithms included multiple physician claims or specialist claims. The addition of RA medications did not significantly improve algorithm performance. The algorithm of "(1 hospitalization RA code ever) OR (3 physician RA diagnosis codes [claims] with =1 by a specialist in a 2-year period)" had a sensitivity of 97%, specificity of 85%, PPV of 76%, and negative predictive value of 98%. Most RA patients (84%) had an RA diagnosis code present in the administrative data within ±1 year of a rheumatologist's documented diagnosis date.
We demonstrated that administrative data can be used to identify RA patients with a high degree of accuracy. RA diagnosis date and disease duration are fairly well estimated from administrative data in jurisdictions of universal health care insurance.
We compared variations among Canadian provinces in rheumatoid arthritis (RA) initiating anti-tumor necrosis factor (TNF) therapy.
Data were obtained from the Optimization of Humira trial (OH) and from the Ontario Biologics Research Initiative (OBRI). Baseline characteristics were compared between regions: Ontario (ON), Quebec (QC), and other provinces (OTH). We compared Ontario OH to OBRI patients who were initiating anti-TNF therapy.
In 300 OH patients, mean age was 54.8 years (13.3). There were 151 (50.3%) ON patients, 57 from QC (19%), and 92 from OTH (30.7%). Regional differences were seen in the number of disease-modifying antirheumatic drugs (DMARD) ever taken (ON: 3.8 ± 1.4, QC: 3.1 ± 1.1, OTH: 3.3 ± 1.4; p
Epidemiologic assessments of sufficiently large populations are required in order to obtain robust estimates of disease prevalence and incidence, particularly when exploring the influence of various factors (age, sex, calendar time). We undertook this study to describe the epidemiology of rheumatoid arthritis (RA) over the past 15 years.
We used the Ontario Rheumatoid Arthritis administrative Database (ORAD), a validated population-based research database of all Ontarians with RA. The ORAD records were linked with census data to calculate crude and age and sex-standardized prevalence and incidence rates from 1996 to 2010. Vital statistics were used to estimate annual all-cause mortality during the study period.
As of 2010, there were 97,499 Ontarians with RA, corresponding to a cumulative prevalence of 0.9%. Age and sex-standardized RA prevalence increased steadily over time from 473 (95% confidence interval [95% CI] 469-478) per 100,000 population (0.49%) in 1996 to 784 (95% CI 779-789) per 100,000 population (0.9%) in 2010. Age and sex-standardized incidence per 100,000 population ranged from 62 (95% CI 60-63) in 1996 to 54 (95% CI 52-55) in 2010. All-cause mortality decreased by a relative 21.4% since 1996.
Over a 15-year period, we observed an increase in RA prevalence over time. This rise may be attributed to the increasing time to ascertain cases (which may have been latent in the population during earlier years of the study), increasing survival, and/or an increase in the aging background population. Incidence appears to be stable.
To estimate the percentage of seniors with rheumatoid arthritis (RA) receiving disease-modifying antirheumatic drugs (DMARDs) within the first year of diagnosis.
We assembled an incident RA cohort from Ontario physician billing data for 1997-2006. We used a standard algorithm to identify 24,942 seniors with RA based on = 2 billing codes = 60 days apart but within 5 years. Drug exposures were obtained from pharmacy claims data. We followed subjects for 1 year, assessing if they had been exposed (defined as = 1 prescription) to 1 or more DMARDs within the first year of RA diagnosis. We assessed secular trends and differences for subjects who had received rheumatology care (defined as = 1 rheumatology encounter) versus those who had not.
In total, only 39% of the 24,942 seniors with new-onset RA identified over 1997-2006 were exposed to DMARD therapy within 1 year of diagnosis. This increased from 30% in 1997 to 53% in 2006. Patients whose care involved a rheumatologist were more likely to be exposed to DMARDs than those who had no rheumatology care. In 2006, 67% of subjects receiving rheumatology care were exposed to DMARDs versus 21% of those with no rheumatology care.
Improvements in RA care have occurred, but more efforts are needed. Subjects receiving rheumatology care are much more likely to receive DMARDs as compared to those with no rheumatology care. This emphasizes the key role of rheumatologists.
Accurate data on the burden of rheumatoid arthritis (RA) are scarce, but critical in helping health care providers and decision makers to optimize clinical and public health strategies for disease management. We quantified the burden of RA in Ontario from 1996 to 2010 by age, sex and health planning region.
We used the Ontario Rheumatoid Arthritis administrative Database (ORAD), a validated population-based cohort of all Ontarians with RA, to estimate the crude prevalence and incidence of RA among men and women, and by age group from 1996 to 2010. Burden by area of patient residence and rheumatology supply also were determined.
The number of RA patients increased over time, from 42,734 Ontarians (0.5%) in 1996 to 97,499 (0.9%) in 2010. On average 5,830 new RA patients were diagnosed each year. In 2010, the burden was higher among females (1.3%) than males (0.5%) and increased with age, with almost half of all RA patients aged 65 years and older. The burden was higher in northern communities (1.0%) than in southern urban areas (0.7%). During the study period, the number of rheumatologists practicing in Ontario remained unchanged (approximately 160).
Over a 15-year period, the number of RA patients more than doubled with no concomitant increase in the number of practicing rheumatologists. We observed considerable regional variation in burden, with the highest rates observed in the north. Our findings highlight the need for regional approaches to the planning and delivery of RA care in order to manage the growing burden.