Longitudinal characterization of course types of functional limitations

Longitudinal data have provided evidence on factors that increase the risk of incidence of functional limitations. However, little insight exists in course types of functional limitations other than simple incidence or recovery.

This contribution examines the variety of course types across the first three cycles of the Longitudinal Aging Study Amsterdam (n = 3107, initial ages 55 - 85 years, 6-year period covered). Using cluster analysis, course types were determined among both the survivors and the deceased. Multinomial analyses were performed to determine the predictive ability of baseline physical and mental chronic conditions for each course type.

Eight course types were distinguished: (1) stable not limited (53%) (2) stable mild (8%) (3) stable severe (3%) (4) gradual increase (4%) (5) delayed increase (5%) (6) not limited, died t3 (8%) (7) increase t1-t2, died t3 (4%) (8) died t2 (15%). Socio-demographic and chronic conditions differentially predicted the course types. Arthritis was predictive mainly of course types not ending in death, cancer of course types ending in death. The other physical and mental conditions were predictive of both.

These longitudinal data show the usefulness of distinguishing between course types of functional limitations beyond incidence and recovery.