Background
Perceived physical fatigability is highly prevalent in older adults and associated with mobility decline and other health consequences. We examined the prognostic value of perceived physical fatigability as an independent predictor of risk of death among older adults.
Methods
Participants (N = 2,906), mean age 73.5 [SD, 10.4] years, 54.2% women, 99.7% white enrolled in the Long Life Family Study were assessed at Visit 2 (2014-2017) with 2.7 [SD, 1.0] years follow-up. The Pittsburgh Fatigability Scale (PFS), a 10-item, self-administered validated questionnaire (score range 0-50, higher=greater fatigability) measured perceived physical fatigability at Visit 2. Deaths post-Visit 2 through December 31, 2019 were identified by: family members notifying field centers, reporting during another family member’s annual phone follow-up, an obituary, or Civil Registration System (Denmark). We censored all other participants at their last contact. Cox proportional hazard models predicted mortality by fatigability severity, adjusted for family relatedness and other covariates.
Results
Age-adjusted PFS Physical scores were higher for those who died (19.1 [SE, 0.8]) compared to alive (12.2, [SE, 0.4]) overall, as well as across age strata (P<.001), except for those 60-69 years (P=.79). Participants with the most severe fatigability (PFS Physical scores ≥25) were over twice as likely to die (HR, 2.33 [95% CI, 1.65 to 3.28]) compared to those with less severe fatigability (PFS Physical scores <25) after adjustment.
Conclusions
This work underscores the utility of the PFS as a novel patient-reported prognostic indicator of phenotypic aging that captures both overt and underlying disease burden that predicts death.