Community-level variation in diagnostic testing in infants hospitalized for poor weight gain

Infants with poor weight gain (PWG) are frequently hospitalized for evaluation and management. Diagnostic testing during hospitalization varies and may reflect practice variation and bias.

To determine if diagnostic testing among infants hospitalized for PWG differed by community characteristics, as measured by the childhood opportunity index (COI).

We conducted a retrospective cross-sectional study of children, ages 2 weeks-11 months, hospitalized with PWG at 43 children's hospitals in the Pediatric Health Information Systems database between 2017 and 2022. COI, measured at the zip-code level, was categorized into nationally normed quintiles. Logistic regression models estimated adjusted associations between COI and diagnostic testing, accounting for confounders defined a priori and clustering by hospital.

Compared to infants from very high COI communities, those from very low COI communities were more likely to receive screening tests like CBC (64.2% vs. 54.2%, adjusted odds ratio [aOR] 1.22, 95% confidence interval [CI] 1.10, 1.35). In contrast, infants from very low COI communities were less likely to have diagnostic testing directed toward investigation of potentially specific medical etiologies, including upper gastrointestinal series (10.3% vs. 12.8%, aOR 0.67, 95% CI 0.56, 0.81). However, they were more likely to receive urine toxicology screening (1.5% vs. 0.6%, aOR 2.4, 95% CI 1.39, 4.14), suggestive of suspected neglect.

This national study demonstrates community-level variation in the diagnostic evaluation of infants hospitalized for PWG. While differences in psychosocial factors and healthcare access may contribute, these findings underscore the need to address potential bias in the care of infants with PWG.