Abstract
BACKGROUND: The prevalence, Medicaid use and mortality risk associated with low forced expiratory volume in 1 s (FEV(1)) among young adults aged 20-35 years are not well understood, despite its potential implications for the development of chronic pulmonary disease and overall prognosis. METHODS: A retrospective cohort study was conducted among young adults aged 20-35 years old, using data from the National Health and Nutrition Examination Survey, National Death Index and Centers for Medicare & Medicaid Services. Participants were categorised into a low FEV(1) group (pre-bronchodilator FEV(1)%pred <80%) and a normal FEV(1) group (FEV(1)%pred ≥80%). Weighted logistic regression analysis was employed to identify the risk factors associated with low FEV(1), while Cox proportional hazard models were used to calculate the hazard ratio (HR) for Medicaid use and the all-cause mortality between the two groups. RESULTS: A total of 5346 participants aged 20-35 were included in the study, with 329 in the low FEV(1) group and 5017 in the normal group. The weighted prevalence of low FEV(1) among young adults was 7.1% (95% CI 6.0 to 8.2). Low body mass index (OR=3.06, 95% CI 1.79 to 5.24), doctor-diagnosed asthma (OR=2.25, 1.28 to 3.93), and wheezing or whistling (OR=1.57, 1.06 to 2.33) were identified as independent risk factors for low FEV(1). Over a 15-year follow-up, individuals in the low FEV(1) group exhibited a higher likelihood of Medicaid use compared with those in the normal group (HR=1.73, 1.07 to 2.79). However, there was no statistically significant increase in the risk of all-cause mortality over a 30-year follow-up period (HR=1.48, 1.00 to 2.19). CONCLUSIONS: A considerable portion of young adults demonstrated low FEV(1) levels, a characteristic that was associated with a higher risk of Medicaid use over a long-term follow-up, yet not linked to an augmented risk of all-cause mortality.