Relationship between peak expiratory flow and incidence of frailty, deaths and falls among nursing home residents: Results of the SENIOR cohort

Objective: To correlate peak expiratory flow (PEF) with the incidence of frailty, deaths and falls among nursing home residents. Methods: This is a 1-year longitudinal analysis performed on the clinical data of the SENIOR cohort. PEF, measured by peak flow meter, was considered as low when the observed value was <= 80% of the theoretical value. Physical capacity was evaluated using Short Physical Performance Battery, balance and gait using Tinetti test and muscle strength using a dynamometer. The incidence of frailty was defined as the transition from a robust or prefrail status to a frail status following Fried's criteria. Deaths and falls were also collected. Results: Among 646 subjects included at baseline (83.2 +/- 9 years and 72.1% women), 297 (45.7%) displayed a low PEF. In this subgroup, physical capacity (p-values from 0.01 to < 0.001), muscle strength (p < 0.001), balance and gait score (p < 0.001) were significantly lower compared to subjects displaying normal PEF. Subjects who became frail after one year displayed a lower % of the theoretical PEF value compared to those that did not (88.52 +/- 45.06 vs 102.78 +/- 50.29, respectively, p = 0.03). After adjustment for potential confounding variables (calf circumference, Tinetti test, SPPB test and handgrip strength), PEF was no longer associated with the occurrence of frailty. There was no association between PEF and mortality and falls. Conclusion: In a nursing home setting, PEF is not an independent factor associated with the incidence of frailty, deaths and falls.