To validate algorithms using administrative data that characterize ambulatory physician care for patients with a chronic disease.
Seven-hundred and eighty-one people with diabetes were recruited mostly from community pharmacies to complete a written questionnaire about their physician utilization in 2002. These data were linked with administrative databases detailing health service utilization.
An administrative data algorithm was defined that identified whether or not patients received specialist care, and it was tested for agreement with self-report. Other algorithms, which assigned each patient to a primary care and specialist physician, were tested for concordance with self-reported regular providers of care.
The algorithm to identify whether participants received specialist care had 80.4 percent agreement with questionnaire responses (kappa=0.59). Compared with self-report, administrative data had a sensitivity of 68.9 percent and specificity 88.3 percent for identifying specialist care. The best administrative data algorithm to assign each participant's regular primary care and specialist providers was concordant with self-report in 82.6 and 78.2 percent of cases, respectively.
Administrative data algorithms can accurately match self-reported ambulatory physician utilization.
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The aim of this study was to determine whether the incidence of type 2 diabetes differed among elderly users of four major antihypertensive drug classes.
This was a retrospective, observational cohort study of previously untreated elderly patients (aged > or = 66 years) identified as new users of an antihypertensive drug class between April 1995 and March 2000. Using a Cox proportional hazards model, the primary analysis compared diabetes incidence in users of ACE inhibitors, beta-blockers, and calcium channel blockers (CCBs), with thiazide diuretics allowed as second-line therapy. In the secondary analysis, thiazide diuretics were added as a fourth study group.
In the multivariable-adjusted primary analysis (n = 76,176), neither ACE inhibitor use (hazard ratio 0.96 [95% CI 0.84-1.1]) nor beta-blocker use (0.86 [0.74-1.0]) was associated with a statistically significant difference in type 2 diabetes incidence compared with the CCB control group. In the secondary analysis (n = 100,653), compared with CCB users, type 2 diabetes incidence was not significantly different between users of ACE inhibitors (0.97 [0.83-1.1]), beta-blockers (0.84 [0.7-1.0]), or thiazide diuretics (1.0 [0.89-1.2]).
Type 2 diabetes incidence did not significantly differ among users of the major antihypertensive drug classes in this elderly, population-based administrative cohort. These results do not support the theory that different antihypertensive drug classes are relatively more or less likely to cause diabetes.
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
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Largely on the basis of 2 randomized trials published in the 1990s, ß-blockers were initially promoted as an evidence-based intervention for preventing cardiac complications of noncardiac surgery. However, subsequent studies raised concerns about a widespread use of perioperative ß-blockade. Little is known regarding how this changing evidence influenced the use of perioperative ß-blockers in clinical practice.
We conducted a population-based, time-series analysis (April 1999 to March 2010) among residents of Ontario, Canada (age 66 years and older), to evaluate the influence of research publications and practice guidelines on rates of new ß-blocker prescriptions before major elective noncardiac surgery. In an analysis of 249 828 procedures, the rate of new ß-blocker prescriptions increased from 26.3 per 1000 procedures in April 1999 to 62.7 per 1000 procedures in the first quarter of 2005, after which it decreased to 19.7 per 1000 procedures by March 2010. We observed a marked decrease in prescriptions (P=0.004) during early 2005, without any preceding publications that raised concerns about perioperative ß-blockade. There was no change (P=0.98) in prescription rates after the May 2008 publication of a multicenter, randomized trial that showed increased mortality from perioperative ß-blockade. Prescribing trends remain unchanged after revisions of related practice guidelines in 2002 (P=0.28) and 2006 (P=0.53).
After a period characterized by increasing adoption of preoperative ß-blockade between 1999 and 2005, prescriptions rates subsequently fell from 2005 to 2010. Further research is needed to understand the basis for these changes, which are only partially explained by evidence of potential harm.
Diabetic patients with inadequate glycemic control ought to have their management intensified. Failure to do so can be termed "clinical inertia." Because data suggest that specialist care results in better control than primary care, we evaluated whether specialists demonstrated less clinical inertia than primary care physicians.
Using administrative data, we studied all non-insulin-requiring diabetic patients in eastern Ontario aged 65 or older who had A1c results >8% between September 1999 and August 2000. Drug intensification was measured by comparing glucose-lowering drug regimens in 4-month blocks before and after the elevated A1c test and was defined as 1) the addition of a new oral drug, 2) a dose increase of an existing oral drug, or 3) the initiation of insulin. Propensity score-based matching was used to control for confounding between groups.
There were 591 patients with specialist care and 1,911 with exclusively primary care. In the matched cohorts, 45.1% of patients with specialist care versus 37.4% with primary care had drug intensification (P = 0.009). Most of this difference was attributed to specialists' more frequent initiation of insulin in response to elevated A1c.
Fewer than one-half of patients with high A1c levels had intensification of their medications, regardless of specialty of their physician. Specialists were more aggressive with insulin initiation than primary care physicians, which may contribute to the lower A1c levels seen with specialist care. Interventions assisting patients and physicians to recognize and overcome clinical inertia should improve diabetes care in the population.
To compare the operative outcomes of early and delayed cholecystectomy for acute cholecystitis.
Randomized trials comparing early to delayed cholecystectomy for acute cholecystitis have limited contemporary external validity. Furthermore, no study to date has been large enough to assess the impact of timing of cholecystectomy on the frequency of serious rare complications including bile duct injury and death.
This is a population-based retrospective cohort study of patients emergently admitted to hospital with acute cholecystitis and managed with cholecystectomy over the period of April 1, 2004, to March 31, 2011. We used administrative records for the province of Ontario, Canada. Patients were divided into 2 exposure groups: those who underwent cholecystectomy within 7 days of emergency department presentation on index admission (early cholecystectomy) and those whose cholecystectomy was delayed. The primary outcome was major bile duct injury requiring operative repair within 6 months of cholecystectomy. Secondary outcomes included major bile duct injury or death, 30-day postcholecystectomy mortality, completion of cholecystectomy with an open approach, conversion among laparoscopic cases, and total hospital length of stay. Propensity score methods were used to address confounding by indication.
From 22,202 patients, a well-balanced matched cohort of 14,220 patients was defined. Early cholecystectomy was associated with a lower risk of major bile duct injury [0.28% vs 0.53%, relative risk (RR)=0.53, 95% confidence interval [CI]: 0.31-0.90], of major bile duct injury or death (1.36% vs 1.88%, RR=0.72, 95% CI: 0.56-0.94), and, albeit non-significant, of 30-day mortality (0.46% vs 0.64%, RR=0.73, 95% CI: 0.47-1.15). Total hospital length of stay was shorter with early cholecystectomy (mean difference 1.9 days, 95% CI: 1.7-2.1). No significant differences were observed in terms, open cholecystectomy (15% vs 14%, RR=1.07, 95% CI: 0.99-1.16) or in conversion among laparoscopic cases (11% vs 10%, RR=1.02, 95% CI: 0.93-1.13).
These results support the benefit of early overdelayed cholecystectomy for patients with acute cholecystitis.
Comment In: Ann Surg. 2014 Jan;259(1):16-724326747
To examine practice patterns and rates of computed tomography (CT), magnetic resonance imaging (MRI), and abdominal ultrasound (AUS) during staging, treatment and surveillance for cancer patients.
Using Ontario Health Insurance Plan billing data linked to the Ontario Cancer Registry, we determined rates of CT, MRI, and AUS by body site for breast, colorectal, lung, lymphoma, and prostate cancer, from 1998 to 2002. Rates of scans were additionally examined by region of patient residence and time from cancer diagnosis.
The frequency of imaging increased in nearly all scans and tumors over the study period. Rates of peri-diagnosis scans varied substantially by region, ranging from 1.7-fold variation (CT for lung cancer) to 50-fold variation (MRI for breast cancer). For breast cancer, there is possible over-utilization of CT, but overall rates of scanning appear reasonable for the other four cancers.
Considerable regional variation in imaging rates suggests utilization guidelines should be developed or knowledge transfer initiatives are needed to improve compliance to existing guidelines. In breast cancer, there appears to be over-utilization of imaging. Further studies are necessary to determine utilization for each stage, the reason scans were obtained, and the impact of scans on patient outcomes.
There are scarce population-based data on the use, complication rates, and outcomes of patients receiving implantable cardioverter defibrillators (ICDs).
This study sought to describe the methodology of the Ontario ICD Database, a prospective study of all ICD recipients in Ontario, Canada.
In this registry, web-based data collection will be performed in all patients referred to a cardiac electrophysiologist for consideration of an ICD. The variables included in the database were determined by consensus. Outcomes to be assessed will include defibrillator device therapies (e.g., shock or antitachycardia pacing), morbidity, and death. Preliminary statistics are reported after the first 6 months of data collection.
Of 208 total variables selected by consensus, 111 (53.4%) were referral/patient characteristics, 12 (5.8%) were implant-related, and 85 (40.9%) were outcome variables. Among 990 referred patients, 902 were accepted, with the following ICD indications: primary prevention (63.3%), secondary prevention (21.6%), and generator replacement (15.1%). The mean (SD) age of patients with implants was 63.9 +/- 12.6 years, and 79% were men. Among accepted ICD patients, 66% had ischemic heart disease, 23% had nonischemic dilated cardiomyopathy, and 11% had other cardiac conditions. Left ventricular (LV) systolic dysfunction was highly prevalent, with 82% of primary and 44% of secondary prevention patients having LV ejection fraction