Assessing state level variation in signature authority and cause of death accuracy, 2005-2017

This study utilized a convergent mixed-methods design to examine whether variation in death certificate certifier type predicts the accuracy of cause of death reporting in the US. We analyzed the content of state statutes, amendments, and policies concerning cause of death signature authority in 2005-2017 to create the Cause of Death Signature Authority (CoDSA) database. After merging the CoDSA data with 2005-2017 National Vital Statistics System Multiple Cause of Death Mortality files for adults with cerebral palsy (CP) (N = 29,996), we employed logistic regression models to determine the likelihood that different certifier groups made one particular type of death certification error - inaccurately reporting CP as the underlying cause of death (UCOD). The content analysis provided evidence of significant liberalization of cause of death signature authority, with 23 states expanding signature authority to include physician extenders. Logistic regression analysis revealed differences in UCOD accuracy based on certifier type. Compared to medical examiners, the likelihood of CP being reported as the UCOD, was: 41% higher (CI 1.12, 1.78) for coroners; 25% higher (1.05, 1.49) for mixed-system death investigators; 24% higher (1.08, 1.42) for physicians; and 16% higher (1.00, 1.34) for physician extenders. Inaccuracies limit public health efforts aimed at improving the health and longevity for disadvantaged populations, such as people with CP. Poor performance among cause of death certifiers may indicate systemic problems with death certification that should be addressed with more robust training for all professional groups with signature authority.