Statin use and discontinuation among nursing home residents with advanced dementia

Background The use of statins in elderly individuals with advanced dementia near the end-of-life is controversial. Objective To describe statin use and impact of discontinuation in nursing home residents with advanced dementia. Methods We conducted a cohort study using 2007-2008 Medicare and Minimum Data Set data for 11,786 nursing home residents older than 65 years with recent progression to advanced stage dementia from 5 large states in the U.S.. Residents using statins were identified. Clinical characteristics and 28-day hospitalization risk were compared for residents who discontinued and continued statins. Multivariable Poisson regression controlled for age, sex, advance directives, functional status, eating problems, hospice enrollment, and geographic location of the nursing home. In addition, we conducted a sensitivity analysis using a self-controlled case series (SCCS) approach to examine the role of channeling bias in the risk estimation from the cohort approach. Results: Seventeen percent (17%) of residents with recent progression to advanced dementia (n=2,004) were prescribed statins. These residents had a mean age of 83.1 years, 70.3% were female, and used a mean of 10.2 other medications (SD 4.7, range 1-31). In follow-up, 32.4% (n=649) discontinued statin use. Twenty-five percent (25%) of discontinuations occurred within 30 days of decline, 13.6% between 30-90 days after decline, 9.8% between 90-180 days after decline, and the remaining 51.6% stopped >180 days after decline. Factors independently associated with discontinuation included residence in a nursing home in Florida relative to California; having a do-not-resuscitate order and hospice enrollment was associated with continuation. The 28-day hospitalization risk was higher for residents who discontinued statins compared to those who continued (adjusted incidence rate ratio [IRR] = 2.04, CI 1.61,2.58). The SCCS estimate for 28-day hospitalization risk following statin discontinuation compared to a 28-day pre-discontinuation control period was much lower than the cohort estimate (IRR = 0.79, CI 0.76, 0.83). Conclusion: A significant proportion of nursing home residents with dementia who use statins when they progress to advanced stage disease discontinue use. Hospitalization outcomes following discontinuation differ depending on method of estimation.