Association of clinical outcome assessments of mobility capacity and incident disability in community-dwelling older adults - a systematic review and meta-analysis

IMPORTANCE The predictive value of common performance-based outcome assessments of mobility capacity on incident disability in activities of daily living in community-dwelling older adults remains uncertain. OBJECTIVE To synthesize all available research on the association between mobility capacity and incident disability in non-disabled older adults. DATA SOURCES MEDLINE, EMBASE and CINAHL databases were searched without any limits or restrictions. STUDY SELECTION Published reports of longitudinal cohort studies that estimated a direct association between baseline mobility capacity, assessed with a standardized outcome assessment, and subsequent development of disability, including initially non-disabled older adults. DATA EXTRACTION AND SYNTHESIS Data extraction was completed by independent pairs of reviewers. The risk of bias was assessed using the Quality in Prognosis Studies (QUIPS) tool. Random-effect models were used to explore the objective. The certainty of evidence was assessed using GRADE. MAIN OUTCOME AND MEASURES The main outcome measures were the pooled relative risks (RR) per one conventional unit per mobility assessment for incident disability in activities of daily living. RESULTS A total of 40 reports were included, evaluating 85,515 and 78,379 participants at baseline and follow-up, respectively (median mean age: 74.6 years). The median disability rate at follow-up was 12.0% (IQR: 5.4%-23.3%). The overall risk of bias was judged as low, moderate and high in 6 (15%), 6 (15%), and 28 (70%) reports, respectively. For usual and fast gait speed, the RR per -0.1 m/s was 1.23 (95% CI: 1.18-1.28; 26,638 participants) and 1.28 (95% CI: 1.19-1.38; 8,161 participants), respectively. Each point decrease in Short Physical Performance Battery score increased the risk of incident disability by 30% (RR = 1.30, 95% CI: 1.23-1.38; 9,183 participants). The RR of incident disability by each second increase in Timed Up and Go test and Chair Rise Test performance was 1.15 (95% CI: 1.09-1.21; 30,426 participants) and 1.07 (95% CI: 1.04-1.10; 9,450 participants), respectively. CONCLUSIONS AND RELEVANCE Among community-dwelling non-disabled older adults, a poor mobility capacity is a potent modifiable risk factor for incident disability. Mobility impairment should be mandated as a quality indicator of health for older people.