Variations over time in the effects of age and sex on hospitalization rates before and after admission to a nursing home: A German cohort study

Objectives: We examined hospitalization rates for nursing home residents before and after their entry to the home, stratified by sex and age.

Study design: A cohort study was conducted using data from a large health insurance fund on 127,227 residents aged 65 years and over newly admitted to a nursing home between January 1, 2010, and December 31, 2014.

Main outcome measurements: We assessed hospitalization rates and proportions being hospitalized in 6-month intervals one year before nursing home placement and up to 5 years thereafter. Multiple Poisson regression models were fitted to calculate relative risks (RR).

Results: Mean age was 84.0 years and 74.6% of the cohort were females. Hospitalization rates were 194.4 per 100 person-years (PY) in the 12 months before entry to the nursing home and 120.0 per 100 PY thereafter. Rates were highest immediately before entry in both sexes. The influence of age was most pronounced in the 12-7 months before entry (RR: 2.37 for 65-74 vs. 95+ years) and declined thereafter (1.29-1.38 up to month 24 after entry). In contrast, the influence of sex was greater after entry (RR: 1.13 for males vs. females in the 12-7 months before and 1.23-1.31 up to month 24 after entry).

Conclusions: Hospitalization rates of nursing home residents are much higher in Germany than in other Western countries. We have provided some insight into the influence of age and sex on hospitalization rates, which varied over the period (time before and after entry to the nursing home) analyzed. We urgently recommend that future studies on the hospitalization of residents stratify their analyses by sex, age and period.