Brief report: Assessing the risk of reporting bias in a RCT for adolescent mothers

Abstract

Introduction: Most adolescent sexual and reproductive health studies rely solely upon self-report surveys to assess key variables such as pregnancy and sexually transmitted infections (STIs). The current study investigated the risk of reporting bias that may result from using such surveys to measure outcomes in randomized controlled trials (RCTs).

Methods: As part of an RCT of a multicomponent intervention to delay repeat pregnancy among adolescent mothers, we compared survey data on repeat pregnancy with birth records from a state's vital statistics system. The survey assessed contraceptive use, pregnancy status, and future pregnancy intentions. The sample consisted of American adolescents ages 18 and 19 years who were at least 28 weeks pregnant or less than nine weeks postpartum.

Results: For 14 of 331 study participants (4 percent), we found a birth record in the vital statistics system for a mother who reported not having gotten pregnant on the survey. We found no evidence of underreporting for the other survey respondents. The rate of underreporting was similar for the intervention and control groups.

Conclusions: A low rate of underreporting for repeat pregnancy in adolescent mothers was found in the present sample.

Trial registration: ClinicalTrials.gov NCT01456793.

Keywords: Adolescent; Bias; Birth certificate; Pregnancy; Randomized trial; Survey; Underreporting.