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.
To assess the risk of systemic adverse events associated with intravitreal injections of vascular endothelial growth factor inhibiting drugs.
Population based nested case-control study.
91,378 older adults with a history of physician diagnosed retinal disease identified between 1 April 2006 and 31 March 2011. Cases were 1477 patients admitted to hospital for ischaemic stroke, 2229 admitted for an acute myocardial infarction, 1059 admitted or assessed in an emergency department for venous thromboembolism, and 2623 admitted for congestive heart failure. Event-free controls (at a ratio of 5:1) were matched to cases on the basis of year of birth, sex, history of the outcome in the previous 5 years, and diabetes.
Exposure to vascular endothelial growth factor inhibiting drugs identified within 180 days before the index date.
After adjustment for potential confounders, participants who had ischaemic stroke, acute myocardial infarction, congestive heart failure, or venous thromboembolism were not more likely than control participants to have been exposed to either bevacizumab (adjusted odds ratios of 0.95 (95% confidence interval 0.68 to 1.34) for ischaemic stroke, 1.04 (0.77 to 1.39) for acute myocardial infarction, 0.81 (0.49 to 1.34) for venous thromboembolism, and 1.21 (0.91 to 1.62) for congestive heart failure) or ranibizumab (adjusted odds ratios 0.87 (0.68 to 1.10) for ischaemic stroke, 0.90 (0.72 to 1.11) for acute myocardial infarction, 0.88 (0.67 to 1.16) for venous thromboembolism, and 0.87 (0.70 to 1.07) for congestive heart failure). Similarly, a secondary analysis of exclusive users of bevacizumab or ranibizumab showed no differences in risk between the two drugs (adjusted odds ratios for bevacizumab relative to ranibizumab of 1.03 (0.67 to 1.60) for ischaemic stroke, 1.23 (0.85 to 1.77) for acute myocardial infarction, 0.92 (0.51 to 1.69) for venous thromboembolism, and 1.35 (0.93 to 1.95) for congestive heart failure). These findings were consistent for all but one outcome in subgroup analyses.
Intravitreal injections of bevacizumab and ranibizumab were not associated with significant risks of ischaemic stroke, acute myocardial infarction, congestive heart failure, or venous thromboembolism.
Cites: Am J Ophthalmol. 2004 Mar;137(3):486-9515013873
Recent evidence suggests that, despite widespread use, self-monitoring of blood glucose levels has little clinical benefit in many patients with diabetes. The impact of more focused public-payer policies for the use of blood glucose test strips may be substantial.
We conducted a cross-sectional analysis of annual prescription claims for test strips between 1997 and 2008 for patients in Ontario aged 65 and older with diabetes. Patients were stratified into 1 of 4 hierarchical groups according to the most intensive glucose-lowering treatment received during each calendar year. Test strip use was calculated annually for each group over the study period, and the effects of 5 hypothetical policy scenarios of more selective test strip use were assessed.
Test strip use increased by almost 250% from 1997 to 2008, with 52.6% (n = 263,513) of included patients receiving a prescription during 2008. Almost half of these patients were at low risk for drug-induced hypoglycemia. In 2008, over 117 million test strips were dispensed in Ontario; however, more focused policy scenarios could have reduced this number by between 9.5 million and 74.5 million test strips.
Many people who self-monitor their blood glucose are at relatively low risk for drug-induced hypoglycemia. The economic benefits associated with more selective testing could be redirected to more effective interventions for patients with diabetes.
High blood pressure is an important and modifiable cardiovascular disease risk factor that remains under-detected and under-treated. Community-level interventions that address high blood pressure and other modifiable risk factors are a promising strategy to improve cardiovascular health in populations. The present study is a community cluster-randomised trial testing the effectiveness of CHAP (Cardiovascular Health Awareness Program) on the cardiovascular health of older adults.
Thirty-nine mid-sized communities in Ontario, Canada were stratified by geographic location and size of the population aged >or=65 years and randomly allocated to receive CHAP or no intervention. In CHAP communities, residents aged >or=65 years were invited to attend cardiovascular risk assessment sessions held in pharmacies over 10 weeks in Fall, 2006. Sessions included blood pressure measurement and feedback to family physicians. Trained volunteers delivered the program with support from pharmacists, community nurses and local organisations.
The primary outcome measure is the relative change in the mean annual rate of hospital admission for acute myocardial infarction, congestive heart failure and stroke (composite end-point) among residents aged >or=65 years in intervention and control communities, using routinely collected, population-based administrative health data.
This paper highlights considerations in design, implementation and evaluation of a large-scale, community-wide cardiovascular health promotion initiative.
Though statins are fully reimbursed by the public drug programs for seniors in British Columbia (BC) and Ontario, Canada, population-based rates of statin prescription are markedly higher in Ontario. We aimed to assess whether new statin users in BC and Ontario differ in terms of their risk for future coronary heart disease (CHD) events.
We collected information for 1998-2001 on demographics, outpatient prescriptions, physician visits, hospital admissions, and vital status from administrative databases to compare the proportions of new statin users aged 66 years and older who had evidence of an acute coronary syndrome (ACS), chronic CHD, neither ACS nor CHD but diabetes, or none of the above.
Approximately 15% and 20% of BC and Ontario seniors, respectively, had filled a statin prescription by 2001. Among new statin users in the two provinces, virtually identical proportions had evidence of ACS (8%), chronic CHD (25%), and diabetes (14%), for an overall proportion of roughly 50% at high risk for CHD events.
New statin users in BC and Ontario were at similar risk for future CHD events. Poorer case selection is unlikely to explain the relatively higher rates of statin prescription in Ontario.
Population rates of upper gastrointestinal (GI) hemorrhage have been observed to increase with the introduction and rapid uptake of selective cyclooxygenase-2 (COX-2) inhibitors. Changes in COX-2 inhibitor use and upper GI bleeding rates in regions with relatively restrictive drug policies (e.g., British Columbia) have not been compared with changes in regions with relatively less restrictive drug policies (e.g., Ontario).
We collected administrative data for about 1.4 million people aged 66 years and older in British Columbia and Ontario for the period January 1996 to November 2002. We examined temporal changes in the prevalence of NSAID use and admissions to hospital because of upper GI hemorrhage in both provinces using cross-sectional time series analysis.
During the period studied, the prevalence of NSAID use in British Columbia's population of older people increased by 25% (from 8.7% to 10.9%; p
Cites: N Engl J Med. 2000 Nov 23;343(21):1520-8, 2 p following 152811087881
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Cites: Pharmacoepidemiol Drug Saf. 2004 Mar;13(3):153-715072114
Although administrative health care databases have long been used to evaluate adverse drug effects, responses to drug safety signals have been slow and uncoordinated. We describe the establishment of the Canadian Network for Observational Drug Effect Studies (CNODES), a collaborating centre of the Drug Safety and Effectiveness Network (DSEN). CNODES is a distributed network of investigators and linked databases in British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec and Nova Scotia. Principles of operation are as follows: (1) research questions are prioritized by the coordinating office of DSEN; (2) the linked data stay within the provinces; (3)?for each question, a study team formulates a detailed protocol enabling consistent analyses in each province; (4) analyses are "blind" to results obtained elsewhere; (5) protocol deviations are permitted for technical reasons only; (6)?analyses using multivariable methods are lodged centrally with a methods team, which is responsible for combining the results to provide a summary estimate of effect. These procedures are designed to achieve high internal validity of risk estimates and to eliminate the possibility of selective reporting of analyses or outcomes. The value of a coordinated multi-provincial approach is illustrated by projects studying acute renal injury with high-potency statins, community-acquired pneumonia with proton pump inhibitors, and hyperglycemic emergencies with antipsychotic drugs. CNODES is an academically based distributed network of Canadian researchers and data centres with a commitment to rapid and sophisticated analysis of emerging drug safety signals in study populations totalling over 40 million.
Cites: N Engl J Med. 2000 Nov 23;343(21):1520-8, 2 p following 152811087881
Cites: Arch Intern Med. 2003 Feb 24;163(4):481-612588209
Cites: Pharmacoepidemiol Drug Saf. 2012 Jan;21 Suppl 1:1-822262586
To assess the degree of concordance between the information (drug quantity, days' supply, and daily dose) recorded on hospital discharge prescriptions and what appears in a public drug insurance electronic claims database.
A retrospective chart audit of hospital discharge prescriptions with linkage to a prescription claims database was conducted. Three hundred and forty-five post-myocardial infarction patients discharged from an Ontario university-affiliated teaching hospital were included. The percentage of linkable records with perfect agreement between the written prescription and the insurance claim was our measure of concordance.
Seventy-seven per cent and 82% of discharge prescriptions were filled within 7 days, and 120 days post-discharge, respectively. Of those dispensed and that contained adequate information, concordance was perfect for days' supply, quantity, and daily dose for 70.7% (95%CI 67.9-73.4%), 65.9% (95%CI 63.2-68.7%), and 75.9% (95%CI 73.2-78.6%) of prescriptions, respectively. For cardiac drugs, which comprised the majority of filled prescriptions, concordance was greater for daily dose and days' supply than for quantity (75.7% [95%CI 72.7-78.6%] and 75.5% [95%CI 72.6-78.4%] vs. 65.3% [95%CI 62.3-68.4%]). Concordance varied by medication type.
Most hospital discharge prescriptions were filled within 1 week. Among the data elements studied, concordance between written prescriptions and insurance claims was greatest for daily dose. Concordance was greater for scheduled cardiac medications than for other medications.
Cardiovascular disease (CVD) is a leading cause of hospitalizations, death, and health care costs. Although studies have shown that modifying CVD risk factors at the patient level improves patient prognosis, the effect of community-wide interventions at the population level has been uncertain.
To evaluate the resource use and cost consequences of a community-wide Cardiovascular Health Awareness Program (CHAP).
Thirty-nine medium-sized communities in Ontario, Canada, participated in a community cluster randomized controlled trial stratified by population size and geographic location. All community-dwelling elderly residents (>65 years) in each community were included. Family physicians, pharmacists, community nurses, local organizations, and volunteers in the intervention communities implemented the program. Rates and costs of CVD hospitalizations, all hospitalizations, emergency department visits, physician visits, and prescription medication use in the year before and after the intervention were compared for the 19 control and 20 CHAP communities by using province-wide linked administrative databases. The cost of implementing and administrating CHAP in each community was combined with total community health care cost to determine the net cost effect.
CHAP was associated with a reduction in CVD hospitalization costs. There were no differences in utilization rates or costs for overall hospitalizations, in visits to emergency rooms, physicians, or specialists, or in the use of prescription medications. Results were robust over a range of cost assumptions.
A community-wide CVD awareness program can be implemented and can reduce CVD-related hospitalization costs at the level of the community without a corresponding increase in overall health care costs.