[Skip to Content]
[Skip to Content Landing]
The Pediatric Forum
July 2012

School-Based Health Center Use and High School Dropout Rates

Author Affiliations

Author Affiliation: Department of Statistics, University of Washington, Seattle.

Arch Pediatr Adolesc Med. 2012;166(7):675-677. doi:10.1001/archpediatrics.2012.550

In a recent article in the Archives, Kerns et al1 found that high school students of an urban public school district who occasionally used school-based health centers (SBHCs) had a roughly 33% lower dropout rate than non-SBHC users.

The apparent association between lower dropout rates and SBHC visits might have been exaggerated by their methods, which seem to have introduced time-dependent (or “immortal time”) bias. This bias, apparently common in clinical studies, arises from modeling a time-dependent treatment in a hazards regression as a fixed baseline covariate instead of as a time-varying covariate.2 In this case, Kerns et al ignored the timing of SBHC visits, modeling the treatment as a fixed covariate representing the frequency of the subject's SBHC visits, averaged over his or her entire high school career.

First Page Preview View Large
First page PDF preview
First page PDF preview