The association between apathy, decline in physical performance, and falls in older persons

Background Symptoms of apathy are common in older persons. Negative effects on physical performance and fall risk are plausible, considering the pathophysiology of apathy. However, literature is scarce. Aim To longitudinally assess the association between apathy and (1) decline of physical performance and (2) the number of falls in older community-dwelling persons. Methods The ‘B vitamins for the PRevention Of Osteoporotic Fractures’ study provided data on 2919 older persons over a period of 2 years. Apathy was assessed using the Geriatric Depression Scale 3. A physical performance score (PPS) was calculated using three performance tests. Falls were registered prospectively. We calculated adjusted odds ratios (ORs), Incidence Rate Ratios (IRRs), and their 95% confidence intervals. Effect modification by age and gender was investigated. We also investigated mediation by baseline PPS for the association between apathy and the number of falls. Results Apathy and decline of PPS were independently associated. After stratification, the effect only remained in men. Age was an effect modifier; higher ORs for decreasing age. Apathy was also independently associated with the number of falls. After stratification, women had higher IRRs than men. Age modified the association in the opposite direction: higher IRRs for increasing age. Baseline PPS was a mediator in the association. Conclusion The impact of apathy on physical performance and fall incidents varied with age and gender. Potentially, in older individuals with apathy, fall risk is preceded by a decline in physical performance. In clinical practice, identifying apathy in older persons might be useful to target mobility preserving interventions.