Predictive Value of Different Expressions of Forced Expiratory Volume in 1 Second (FEV1) for Adverse Outcomes in a Cohort of Adults Aged 80 and Older

Abstract

ObjectivesForced expiratory volume in 1 second (FEV1) is proposed as a marker of healthy ageing and FEV1 expressions that are independent of reference values have been reported to be better at predicting mortality in older adults. We assess and compare the predictive value of different FEV1 expressions for mortality, hospitalization, and physical and mental decline in adults aged 80 and older. DesignPopulation-based, prospective, cohort study. SettingThe BELFRAIL study, Belgium. ParticipantsA total of 501 community-dwelling adults aged 80 and older (mean age 84.7 years). MeasurementsBaseline FEV1 expressed as percent predicted (FEV1PP) and z-score (FEV1Z) using the Global Lung Function Initiative 2012 reference values; over lowest sex-specific percentile (FEV1Q), and height squared (FEV1/Ht2) and cubed (FEV1/Ht3). Mortality data until 5.1 ± 0.2 years from baseline; hospitalization data until 3.0 ± 0.25 years. Activities of daily living, battery of physical performance tests, Mini-Mental State Examination, and 15-item Geriatric Depression Scale at baseline and after 1.7 ± 0.2 years. ResultsIndividuals in the lowest quartile of FEV1 expressions had higher adjusted risk than the rest of study population for all-cause mortality (highest hazard ratio 2.05 [95% Confidence Interval 1.50–2.80] for FEV1Q and 2.01 [1.47–2.76] for FEV1/Ht3), first hospitalization (highest hazard ratio 1.63 [1.21–2.16] for FEV1/Ht2 and 1.61[1.20–2.16] for FEV1/Ht3), mental decline (highest odds ratio 2.80 [1.61–4.89] for FEV1Q) and physical decline (only FEV1/Ht3 with odds ratio 1.93 [1.13–3.30]). Based on risk classification improvement measures, FEV1/Ht3 and FEV1Q performed better than FEV1PP. ConclusionIn a cohort of adults aged 80 and older, FEV1 expressions that are independent of reference values (FEV1/Ht3 and FEV1Q) were better at predicting adverse health outcomes than traditional expressions that depend on reference values, and should be used in further research on FEV1 and aging.