793 - Do Preterm Birth (PTB) Subtypes Modify the Association Between PTB and Attention-Deficit/Hyperactivity Disorder?

Publication Number: 793.4418

Darios Getahun, Department of Research & Evaluation, Kaiser Permanente Southern California; Department of Health Systems Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA, United States; Yinka Oyelese, Beth Israel Deaconess Medical Center, Boston, Boston, MA, United States; Nehaa Khadka, Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, United States; Vicki Chiu, Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, United States; Fagen Xie, Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, United States; Theresa M. Im, Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, United States; Iris Smith, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA, United States; Morgan Peltier, Hackensack Meridian School of Medicine, Neptune, NJ, United States

Background: Preterm birth (PTB) is the leading cause of infant morbidity and mortality, but the extent to which PTB subtypes correlate with attention-deficit/hyperactivity disorder (ADHD) in the offspring and whether child characteristics modify the PTB subtypes-specific association are unclear.

Objective: This study aimed to examine if the association between PTB and ADHD is modified by PTB subtypes and the child’s characteristics.

Design/Methods: A retrospective cohort study of singleton live-born children aged 3-12 years in the Kaiser Permanente Southern California healthcare system between 01/01/2010-12/31/2019 (n=229,860), was performed. Preterm labor evaluation records extracted from electronic health records using natural language processing were used to categorize PTB subtypes (spontaneous [sPTB] and iatrogenic [iPTB]). Validated ICD-9/10-CM codes were used to ascertain the outcome of interest. Incidence rates and adjusted hazard ratios (aHR) were estimated to quantify the magnitude of associations.

Results: Preterm-born children were more likely to be diagnosed with ADHD than term-born children (7.60 vs. 5.49/1000 person-years, aHR=1.28, confidence interval [CI]: 1.19-1.38) (Table). The aHRs (95% CI) for the associations between sPTB and iPTB with ADHD were 1.33 (1.22-1.44) and 1.13 (0.98-1.31), respectively. The incidence of ADHD increases with decreasing gestational age for both sPTB and iPTB children and is higher among non-Hispanic white children than among members of other racial/ethnic groups at each PTB subtype. Although boys were 3-times more likely than girls to be diagnosed with ADHD, sPTB (not iPTB) appeared to affect the risk for both sexes similarly.

Conclusion(s): The findings suggest that sPTB (not iPTB) is associated with an increased risk of ADHD risk. Risk varies by child’s race/ethnicity and sex, which need to be taken into consideration when developing targeted surveillance and interventions.

Table. Association Between Preterm Status and Attention-Deficit/Hyperactivity Disorder (ADHD) Incidence and Risk
Abbreviations: IR, incidence rates per 1000 person-years; HR, hazard ratio; PTB, preterm birth; sPTB, spontaneous preterm birth; iPTB, iatrogenic preterm birth
†Adjustments were made for maternal age, median household income, parity, prenatal care, smoking and/or illicit drug use during pregnancy, child’s sex, child’s race/ethnicity, and maternal comorbidities (type I/II diabetes and gestational diabetes).