Prematurity as a predictor of childhood asthma among low-income children

PURPOSE: The purpose of this study was to evaluate the association among birth weight, prematurity, and the prevalence of asthma later in childhood and to assess the degree to which this association may differ between black and white children. METHODS: Michigan Medicaid claims data from 2001 through 2003 were analyzed to determine asthma prevalence for 150,204 children between ages 5 and 18 years. Asthma cases were identified using Healthcare Effectiveness Data and Information Set persistent asthma criteria and included children having claims for any of the following services within a calendar year: at least one inpatient or one emergency department (ED) claim with an asthma primary diagnosis; at least four asthma medication-dispensing events; or at least four outpatient visits with an asthma diagnosis, and at least two asthma medication-dispensing events. Birth weight and gestational age from birth certificate data were matched with Medicaid files to determine size-for-gestational-age criteria. RESULTS: Overall, 8.3% of children had persistent asthma; black children had slightly higher asthma prevalence (8.6%) than white children (7.8%; odds ratio [OR] = 1.11, 95% confidence interval [CI]: 1.07-1.15). Children born very preterm (<= 32 weeks) had higher prevalence of childhood asthma (11.7%) compared with term births (8.0%; OR = 1.51, 95% CI: 1.40-1.63). However, no significant differences were observed in odds of asthma between black and white children born very preterm, preterm. (33-36 weeks), or small for gestational age (SGA). CONCLUSIONS: Regardless of race, children born very preterm had an increased risk of childhood asthma. Although overall asthma prevalence is higher among black children enrolled in Medicaid compared with their white counterparts, these differences were attenuated when prematurity or SGA status were taken into account.