Prevalence, Medicaid use and mortality risk of low FEV1in adults aged 20–35 years old in the USA: evidence from a population-based retrospective cohort study

Abstract

BackgroundThe prevalence, Medicaid use and mortality risk associated with low forced expiratory volume in 1 s (FEV1) 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.MethodsA 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 FEV1group (pre-bronchodilator FEV1%pred <80%) and a normal FEV1group (FEV1%pred ≥80%). Weighted logistic regression analysis was employed to identify the risk factors associated with low FEV1, 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.ResultsA total of 5346 participants aged 20–35 were included in the study, with 329 in the low FEV1group and 5017 in the normal group. The weighted prevalence of low FEV1among 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 FEV1. Over a 15-year follow-up, individuals in the low FEV1group 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).ConclusionsA considerable portion of young adults demonstrated low FEV1levels, 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.