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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Cholinesterase inhibitors are commonly used to treat dementia. These drugs enhance the effects of acetylcholine, and reports suggest they may precipitate bradycardia in some patients. We aimed to examine the association between use of cholinesterase inhibitors and hospitalization for bradycardia.
We examined the health care records of more than 1.4 million older adults using a case-time-control design, allowing each individual to serve as his or her own control. Case patients were residents of Ontario, Canada, aged 67 y or older hospitalized for bradycardia between January 1, 2003 and March 31, 2008. Control patients (3:1) were not hospitalized for bradycardia, and were matched to the corresponding case on age, sex, and a disease risk index. All patients had received cholinesterase inhibitor therapy in the 9 mo preceding the index hospitalization. We identified 1,009 community-dwelling older persons hospitalized for bradycardia within 9 mo of using a cholinesterase inhibitor. Of these, 161 cases informed the matched analysis of discordant pairs. Of these, 17 (11%) required a pacemaker during hospitalization, and six (4%) died prior to discharge. After adjusting for temporal changes in drug utilization, hospitalization for bradycardia was associated with recent initiation of a cholinesterase inhibitor (adjusted odds ratio [OR] 2.13, 95% confidence interval [CI] 1.29-3.51). The risk was similar among individuals with pre-existing cardiac disease (adjusted OR 2.25, 95% CI 1.18-4.28) and those receiving negative chronotropic drugs (adjusted OR 2.34, 95% CI 1.16-4.71). We found no such association when we replicated the analysis using proton pump inhibitors as a neutral exposure. Despite hospitalization for bradycardia, more than half of the patients (78 of 138 cases [57%]) who survived to discharge subsequently resumed cholinesterase inhibitor therapy.
Among older patients, initiation of cholinesterase inhibitor therapy was associated with a more than doubling of the risk of hospitalization for bradycardia. Resumption of therapy following discharge was common, suggesting that the cardiovascular toxicity of cholinesterase inhibitors is underappreciated by clinicians.
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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