Explanatory Survival Model For Nursing Home Residents- A 9-Year Retrospective Cohort Study

Purpose: There is a gap in the literature regarding the analysis of long-term survival and mortality risk factors among disabled and multimorbid institutionalized populations. The study aimed to analyze 9-year survival, investigate mortality factors, and develop an explanatory survival model for nursing home residents. Materials and methods: A retrospective cohort study with a 9-year follow-up (2009-2018) was conducted among 96 residents of a nursing home with Barthel index <= 40. The study was based on baseline measurements performed in 2009, which included results obtained on geriatric scales: Mini Nutritional Assessment Short-Form (MNA-SF) and Abbreviated Mental Test Score (AMTS). Information on demographics, comorbidities, pharmacotherapy, transfers and deaths came from medical records. Kaplan-Meier curves were used to estimate and present survival data. Factors associated with mortality were determined using Cox proportional hazard models. Results: The median survival was 2.9 years. Mortality during the follow-up period was 83%. Kaplan-Meier curves showed that residents with normal nutritional status (p = 0.002) and taking aspirin (p = 0.005) had a better 9year survival. The multivariable Cox regression model revealed that the risk of mortality (Hazard Ratio, HR) increased in older age (HR=1.04), male gender (HR=2.08), with risk of malnutrition (HR=3.91), malnutrition (HR=4.84), and presence of urinary incontinence (HR=2.14). The aspirin use was the strongest protective factor against death (HR=0.40). Conclusion: The aspirin use was associated with better long-term survival for nursing home residents. Factors associated with higher mortality among residents include older age, male gender, poor nutritional status, and urinary incontinence. Brief summary: We are the first to report the beneficial effects of a low-dose of aspirin on the long-term survival of disabled, institutionalized populations with multimorbidity. Furthermore, this study presents an explanatory model of survival for nursing home residents and identifies the long-term mortality risk factors among disabled residents with multimorbidity.