Driving exposure (driving distance and trips taken), driving cessation, crashes, citations, and poor driving ability are all factors that can have significant implications for safety and health among older adults, and so identifying measures associated with these is important for preventing negative driving outcomes. In current aging research, only one well-validated and reliable physical functioning battery (the Short Physical Performance Battery [SPPB]) is being used consistently, although there are multiple stand-alone measures that are regularly employed, including the Timed Up and Go Test (TUG) and the Rapid Pace Walk (RPW). This systematic review assesses the evidence in the research literature on the association between three well-validated lower extremity physical functioning measures (SPPB, TUG, and the RPW) with driving outcomes in older adults. Studies published between 1994 and 2015 that included the SPPB, the TUG, or the RPW as a measure of physical functioning, included a driving-related outcome, and were conducted in adults aged 50 years and older were identified through a comprehensive search of bibliographic databases and were reviewed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Thirteen studies involving 5,313 older adults met all of the inclusion criteria. Of them, three included the SPPB, two included the TUG, and eight included the RPW. Lower SPPB scores were associated with reduced driving exposure and increased cessation in all three studies. Specifically, average frequency of trips per week made by driving a car decreased from 5.1 for older adults with high SPPB scores (10-12) to 2.5 for those with intermediate SPPB scores (7-9) and to 1.0 for those with low SPPB scores (<7), (ANOVA, p<.001, Davis et al., 2011); and the odds of driving cessation increased progressively with lower SPPB scores (adjusted odds ratio (OR) for each point reduction in SPPB scores 1.16, 95% confidence interval (CI) 1.05-1.28, Sims et al., 2007; adjusted HR 1.35, 95% CI 0.81—2.26 for intermediate SPPB scores (7-9) and 2.20, 95% CI 1.32-3.68 for low SPPB scores (4-6), relative to high SPPB scores (10-12), Gill et al., 2012). TUG was not associated with an increased rate of negative driving outcomes (cessation, ability, crashes, and citations) in either of the two studies. Poorer RPW scores were associated with decreased driving ability in two studies (moderate correlation between RPW (higher score is worse) and driving ability (Global Rating Score — lower score is worse), r=-.454, p<.001, Stav et al., 2008; adjusted OR for each one-unit increase in RPW completion time 1.45, 95% CI 1.05-2.00, Classen et al., 2013) and with reduced driving exposure in one study (relative risk ratio (RR) of low mileage drivers compared to high mileage drivers 1.30, 95% CI 1.08-1.55, Langford et al., 2013) but was not associated with decreased driving ability, increased crashes, increased citations, or increased cessation in the remaining five studies. Lower SPPB scores are associated with reduced driving exposure and increased cessation, poorer RPW scores are associated with decreased driving ability in some studies and reduced driving exposure in one study, and TUG scores are not associated with any driving outcomes. The TUG measure does not appear to be a useful measure of physical functioning for the driving outcomes that were included here, although the studies were limited. The RPW may be useful in studies related to driving ability and exposure. More driving studies should consider using the SPPB to determine if there is an association between SPPB scores and driving outcomes that have not been studied with this battery, and the SPPB may be useful as a risk factor assessment for identifying individuals at risk of reducing their driving exposure and driving cessation. (Author/publisher)
Samenvatting