Pregnant? Validity of the pregnancy checkbox on death certificates in four states, and characteristics associated with pregnancy checkbox errors

BACKGROUND: Maternal mortality rates in the United States appear to be increasing. One potential reason may be increased identification of maternal deaths after the addition of a pregnancy checkbox to the death certificate. In 2016, 4 state health departments (Georgia, Louisiana, Michigan, and Ohio) implemented a pregnancy checkbox quality assurance pilot, with technical assistance provided by the Centers for Disease Control and Prevention. The pilot aimed to improve accuracy of the pregnancy checkbox on death certificates and resultant state maternal mortality estimates. OBJECTIVE: To estimate the validity of the pregnancy checkbox on the death certificate, and to describe characteristics associated with errors using 2016 data from a 4-state quality assurance pilot. MATERIALS AND METHODS: Potential pregnancy-associated deaths were identified by linking death certificates with birth or fetal death certificates from within 1 year preceding death or by pregnancy checkbox status. Death certificates that indicated that the decedent was pregnant within 1 year of death via the pregnancy checkbox, but that did not link to a birth or fetal death certificate, were referred for active follow-up to confirm pregnancy status by either death certifier confirmation or medical record review. Descriptive statistics and 95% confidence intervals were used to examine the distributions of demographic characteristics by pregnancy confirmation category (confirmed pregnant, confirmed not pregnant, and unable to confirm). We compared the proportion confirmed pregnant and confirmed not pregnant within age, race/ethnicity, pregnancy checkbox category, and certifier type categories using a Wald test of proportions. Binomial and Poisson regression models were used to estimate prevalence ratios for having an incorrect pregnancy checkbox (false positive, false negative) by age group, race/ethnicity, pregnancy checkbox category, and certifier type. RESULTS: Among 467 potential pregnancy-associated deaths, 335 (72%) were confirmed pregnant via linkage to a birth or fetal death certificate, certifier confirmation, or review of medical records. A total of 97 women (21%) were confirmed not pregnant (false positives) and 35 (7%) were unable to be confirmed. Women confirmed pregnant were significantly younger than women confirmed not pregnant (P < .001). Deaths certified by coroners and medical examiners were more likely to be confirmed pregnant than confirmed not pregnant (P = .04). The association between decedent age category and false-positive status followed a dose-response relationship (P < .001), with increasing prevalence ratios for each increase in age category. Death certificates of non-Hispanic black women were more likely to be false positive, compared with non-Hispanic white women (prevalence ratio, 1.41; 95% confidence interval, 1.01, 1.96). The sensitivity of the pregnancy checkbox among these 4 states in 2016 was 62% and the positive predictive value was 68%. CONCLUSION: We provide a multi-state analysis of the validity of the pregnancy checkbox and highlight a need for more accurate reporting of pregnancy status on death certificates. States and other jurisdictions may increase the accuracy of their data used to calculate maternal mortality rates by implementing quality assurance processes.