Explanatory survival model for nursing home residents- a 9-year retrospective cohort study

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.

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.

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 9-year 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).

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.

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.