Frailty and driving status associated with disability: a 24-month follow-up longitudinal study

Objectives To examine the relationship of driving status and frailty with disability in older adults. Design A prospective study. Setting and participants The study included 8533 participants (mean age: 72.0 +/- 6.1 years (range: 60-98 years), women: 54.1%) in a community setting. Measures Driving status and frailty were assessed at baseline. The clinical definition of frailty was used according to the Japanese Cardiovascular Health Study index. Disability was prospectively determined using a record of Japanese long-term care insurance (LTCI). Results During the follow-up period (mean duration: 23.5 months), 58 (0.7%) participants were regarded as moving out of the city, 80 (0.9%) participants had died and 311 (3.6%) participants were certified by LTCI. The proportion of disability was 1.3% among the not-frail group and 5.3% among the frail group. The proportion of disability was 2.5% in participants who were currently driving and 7.5% in those not driving. Based on frailty status and driving, participants were further classified into four groups: not frail and currently driving (n=2945), not frail and not driving (n=642), frail and currently driving (n=3598) and frail and not driving (n=1348). Compared with older adults who are not frail and driving, the combined status of frail and not driving (adjusted HR: 2.28; 95% CI: 1.47 to 3.52) and frail and driving (HR: 1.91; 95% CI: 1.30-2.81) were risk factors for disability. Conclusions Not driving and frail were associated with a risk of disability in community-dwelling older adults.