The Variation of Statin Use Among Nursing Home Residents and Physicians: A Cross-Sectional Analysis

Abstract

OBJECTIVES: To examine the variability of statin use among nursing home residents and prescribing physicians, and to assess statin use by resident frailty. DESIGN: Population-based, cross-sectional analysis. SETTING: All nursing home facilities (N = 631) in Ontario, Canada between April 1, 2013 and March 31, 2014. PARTICIPANTS: All adults aged 66 years and older who received a full clinical assessment while residing in a nursing home facility and their assigned, most responsible, physician. MEASUREMENTS: Statin use on date of clinical assessment. Resident- and physician-level characteristics ascertained through clinical assessment and health administrative data. Resident frailty was derived using a previously validated index. RESULTS: Among 76,226 nursing home residents assigned to 1,919 physicians, 25,648 (33.6%) were statin users. There were 13,331 (30.1%) statin users among the 44,290 residents categorized as frail. In an adjusted mixed-effects logistic regression model, frail residents (adjusted odds ratio = 0.62, 95% confidence interval 0.58-0.65) were significantly less likely to be statin users compared with non-frail residents. After adjustment for resident characteristics, the intraclass correlation coefficient indicated that between-physician variability accounted for 9.1% of the residual unexplained variation in statin use (P < .001). Among the 894 physicians assigned 20 or more residents, funnel plots confirmed there were more low-outlying (17.4%) and high-outlying (12.0%) prescribers of statins than expected by chance. Physicians who were high-outlying prescribers had higher historical rates of statin prescribing. CONCLUSIONS AND RELEVANCE: Statin prescribing was substantial within nursing homes, even among frail residents. After controlling for resident characteristics, the likelihood of statin prescribing varied significantly across physicians. Further studies are required to evaluate the risks and benefits of statin use, and discontinuation, among nursing home residents to better inform clinical practice in this setting.