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.

OBJECTIVES

Forced expiratory volume in 1 second (FEV) is proposed as a marker of healthy ageing and FEV 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 FEV expressions for mortality, hospitalization, and physical and mental decline in adults aged 80 and older.

DESIGN

Population-based, prospective, cohort study.

SETTING

The BELFRAIL study, Belgium.

PARTICIPANTS

A total of 501 community-dwelling adults aged 80 and older (mean age 84.7 years).

MEASUREMENTS

Baseline FEV expressed as percent predicted (FEVPP) and z-score (FEVZ) using the Global Lung Function Initiative 2012 reference values; over lowest sex-specific percentile (FEVQ), and height squared (FEV/Ht) and cubed (FEV/Ht). 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.

RESULTS

Individuals in the lowest quartile of FEV 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 FEVQ and 2.01 [1.47-2.76] for FEV/Ht), first hospitalization (highest hazard ratio 1.63 [1.21-2.16] for FEV/Ht and 1.61[1.20-2.16] for FEV/Ht), mental decline (highest odds ratio 2.80 [1.61-4.89] for FEVQ) and physical decline (only FEV/Ht with odds ratio 1.93 [1.13-3.30]). Based on risk classification improvement measures, FEV/Ht and FEVQ performed better than FEVPP.

CONCLUSION

In a cohort of adults aged 80 and older, FEV expressions that are independent of reference values (FEV/Ht and FEVQ) were better at predicting adverse health outcomes than traditional expressions that depend on reference values, and should be used in further research on FEV and aging.