Physical and mental functioning trajectory classes among older adults and their association with specialized healthcare use.

Background: Sex-specific physical and mental functioning trajectory classification could offer a way of understanding the differences in healthcare use at older age.

Methods: Using latent growth mixture models, sex-specific physical and mental functioning trajectory classes were formed for 1991 participants (mean age 61.5 years) of the Helsinki Birth Cohort Study. Physical and mental functioning were evaluated with the SF-36 survey conducted in clinical examinations in 2001-2004, 2011-2013, and 2017-2018. First and follow-up outpatient visits, emergency visits, and hospital days were extracted from a national register between the first clinical examination and the year 2017. We used regression models to examine the associations between healthcare use and trajectory classes.

Results: Two physical and mental functioning trajectory classes, high and intermediate, were observed for both sexes. The intermediate physical functioning trajectory class was associated with higher utilization rates of all examined specialized healthcare services (fully-adjusted IRRs varying 1.36-1.58; 95% CI = 1.03-1.79, 95% CI = 1.21-2.05) compared to the high trajectory class. Relative to the high trajectory class, the intermediate mental trajectory class was associated with the use of first outpatient visits (fully-adjusted IRRs 1.17, 95% CI = 1.03-1.33 for men, and 1.16, 95% CI = 1.04-1.30 for women). The findings were similar among both sexes.

Conclusions: Compared to the high trajectory class, the intermediate physical functioning trajectory class was associated with greater specialized healthcare use and the intermediate mental trajectory class with first outpatient visits. Public health interventions should be considered to support functioning with aging.