This study examined the independent contributions of depression and cognitive impairment to WS in a bi-ethnic cohort of adults aged 65-80 years.
Using a holistic approach to PTE, we examined two common conditions in aging and their influence on mobility.
Data were collected from 703 participants (366 Mexican Americans, 337 European Americans) in the San Antonio Longitudinal Study of Aging (SALSA), a community-based study of the disablement process.
WS was assessed at participants’ usual and comfortable pace over a 50-foot (5.24 meters) distance and calculated as the mean of 2 trials. Depression was assessed using the 30-item Geriatric Depression Scale (GDS); a score >10 was considered probable depression. Cognition was assessed using the Mini-Mental State Examination (MMSE); a score 24 was considered mild cognitive impairment (MCI).
Multivariable regression was performed to examine the independent association of probable depression and MCI with WS.
Applying the SALSA disablement process model, covariates included demographics (age, sex, ethnicity, education, income), anthropometrics (height, BMI), chronic diseases (diabetes, angina, MI, HTN, stroke, arthritis, COPD), and musculoskeletal (upper- and lower-leg pain, upper- and lower-extremity strength and ROM), cardiopulmonary (FEV1, LVH), and neurosensory (near, far vision) impairments.
Mean age was 69.6±3.4, with 57% females. Education, income, and height were higher in EAs, while BMI was lower (p.001). EAs had faster WS than MAs (1.29±.24 m/s vs.1.17±.27 m/s; p.001).
Age, diabetes, stroke, and upper-leg pain were significantly and negatively associated with WS (p.05). Lower-extremity (LE) strength and ROM, FEV1, and education were significantly and positively associated with WS (p.05).
Probable depression and MCI had significant, negative associations with WS (p.05), independent of covariates. Strength of the relationship with WS for probable depression (b= -.093) and MCI (b=-.089) was very similar to that for stroke (b=-.100) and diabetes (b=-.096).
In addition to key musculoskeletal and pulmonary targets in physical therapy, probable depression and MCI have a significant, independent negative association with WS.
Our findings support the recommendation that WS be a vital sign in physical therapist practice and incorporated into geriatric PTE.
The PTE for older adults should be based on a holistic approach that includes measures of mobility (WS) and mentation (probable depression, cognitive impairment). Modifiable factors can influence multiple aspects of physical therapist intervention.
Depression
Cognitive impairment