Validity of Birth Certificate and Hospital Discharge Data Reporting of Labor Induction.

PURPOSE: To examine the concordance of labor induction measures derived from birth certificate and hospital discharge data with each other and with maternal report.

METHODS: Birth certificate data were linked with hospital discharge data and structured interviews of 2,851 mothers conducted 1 month after first childbirth. Those who reported that a doctor or nurse tried to cause their labor to begin, and were not in labor before that event, were classified as undergoing labor induction. The mothers were aged 18 to 35 years at study entry and delivered at 78 hospitals (76 in Pennsylvania and 2 out of state) from 2009 to 2011.

RESULTS: The labor induction rate was 34.3% measured by maternal report, 29.4% by birth certificate data, and 26.2% by hospital discharge data. More than one-third of the women who reported labor induction were not reported as having been induced in the birth certificate data (33.6%), with similar results for the hospital discharge data (36.5%). The rate of underreporting of labor induction in the birth certificate data was higher for inductions occurring before 39 weeks of gestation (43.9%) than for inductions at 39 weeks or later (29.9%; p < .0001). Agreement between birth certificate and hospital discharge data was relatively low (kappa = 0.56), as was agreement between maternal report and birth certificate data (kappa = 0.58), and maternal report and hospital discharge data (kappa = 0.60).

CONCLUSIONS: Both the birth certificate and hospital discharge data exhibit relatively poor agreement with maternal report of labor induction and seem to miss a substantial portion of labor inductions.