Note. Standardized betas are reported. Estimates for the joint effect of age group and each explanatory variable are presented row-wise in the table. Separate models were calculated for each joint effect, while adjusting for the main effects of all the other explanatory variables. The joint effects were estimated within the age groups, not between them. The estimates for each joint effect were calculated by switching the reference categories, meaning that the row-wise values reported are in relation to reference categories within each age group, i.e., 66-year-old men are, for example, the reference category to 66-year-old women. a Reference category. PGCMS: Philadelphia Geriatric Center Morale Scale; IADL: Instrumental Activities of Daily Living; PADL: Personal Activities of Daily Living. , , and .