Further evidence for the importance of subclinical functional limitation and subclinical disability assessment in gerontology and geriatrics

Objectives. The objectives of this work were to determine the prevalence of self-reported subclinical status for functional limitation and disability at baseline and assess their independent effects on the onset of functional limitation and disability 1-2 years later. Methods. Nine hundred ninety-eight African American men and women 49-65 years old in St. Louis, MO, received comprehensive in-home evaluations at baseline and two annual telephone follow-ups. Outcome measures included walking a half-mile, climbing steps, stooping-crouching-kneeling, lifting or cawing 10 lbs., and doing heavy housework. Results. The baseline prevalence of subclinical status was 26.4% for walking a half-mile, 26.8% for climbing steps, 39.0% for stooping-crouching-kneeling, 29.1% for lifting or carrying 10 lbs., and 22.7% for doing heavy housework. The adjusted odds ratios for the task-specific subclinical status measure at baseline on developing difficulty 1-2 years later were 1.68 (p < .05) for walking a half-mile, 4.46 (p < .001) for climbing steps, 2.48 (p < .001) for stooping-crouching-kneeling, 2.51 (p < .001) for lifting or carrying 10 lbs., and 2.22 (p < .001) for doing heavy housework. Performance tests (tandem stand, chair stands, and preferred gait speed) did not have consistent independent effects on the onset of functional limitation or disability. Conclusions. The subclinical status measures were the main predictors of the onset of difficulty in all tasks and functions 1-2 years later. Interventions to reduce frailty should focus on self-reported subclinical status as an early warning system.