Physical Function Assessment in Older Hemodialysis Patients

RATIONALE & OBJECTIVE: Physical function is not routinely measured in older adults receiving dialysis. We evaluated the appropriateness of repeated measurements of physical function, including Short Physical Performance Battery (SPPB), handgrip strength, and activities of daily living (ADLs), in older adults receiving dialysis. STUDY DESIGN: Prospective study. SETTING & PARTICIPANTS: 37 community-dwelling adults 65 years and older receiving in-center hemodialysis at 5 dialysis units located in North Carolina. EXPOSURES: SPPB (an assessment of standing balance, chair stands, and gait speed), handgrip strength, and Katz and Lawton ADLs at baseline and subsequent 3-month intervals up to 6 months. OUTCOMES: Completion rate, presence of floor or ceiling effects, and presence of clinically meaningful change in physical function measurements. RESULTS: Of 55 potential participants, we enrolled 37 (67%) older adults receiving hemodialysis. Among 35 enrolled participants who completed baseline assessment in a dialysis unit, mean age was 70.1 (SD, 5) years, 46% (n = 16) were women, 77% (n = 27) were African American, and median time receiving dialysis was 2.7 (IQR, 0.6-5.0) years. There were 3 deaths within the observation period, and study retention at 3 and 6 months was 83% (n = 29) and 74% (n = 26), respectively. Participants tolerated measurements; only 2 participants did not attempt 1 of the performance-based tests at a study visit. Baseline median SPPB score, grip strength, and gait speed were 6 (IQR, 4-9), 55 (IQR, 42-70) kg, and 0.76 (IQR, 0.46-0.86) m/s, respectively. Baseline median for Katz and Lawton ADLs were 6 (IQR, 6-6) and 7 (IQR, 4-8), respectively; ceiling effects were observed for both measures. For some participants, clinically meaningful changes (improvement or decline) in SPPB score, grip strength, and gait speed occurred at each 3-month interval. LIMITATIONS: Limited geographic and ethnic variation. CONCLUSIONS: SPPB, handgrip strength, and gait speed alone are appropriate measures for interval physical function assessment in community-dwelling older adults receiving in-center hemodialysis.