Assessing the accuracy of the death certificate injury at work box for identifying fatal occupational injuries in Michigan.

Background: Death certificates contain a box labeled "Injury at Work" which is to be marked "Yes" for all fatal occupational injuries. The accuracy of this box in Michigan is not fully characterized.

Methods: The accuracy of the Injury at Work box on the Michigan death certificate was compared to deaths identified from 2001 through 2016 by the Michigan Fatality Assessment and Control Evaluation multi-source surveillance system. The sensitivity was calculated across this time period, while specificity and positive and negative predictive values were derived for 2011-2016. Univariate and multivariate regression were used to examine differences in the sensitivity over time and across demographic variables, industry, and the type of death.

Results: We found a sensitivity for the Injury at Work box of 73.1% among 2156 deaths. The sensitivity showed a significant declining trend over the 17 years, from 79.8% to 63.1%. Sensitivity varied significantly across incident type (aircraft, animal-related, drug overdose, motor vehicle, and suicides having particularly lower sensitivities, and electrocutions, falls, and machine-related incidents having higher sensitivities), and industry sector (construction, manufacturing, public safety, transportation, and trade sectors having higher sensitivities, and agriculture and services sectors showing lower sensitivities). Across nearly all categories the sensitivity was significantly below 1.

Conclusions: The Injury at Work box on the Michigan death certificate was often incorrectly completed and has become less accurate with time, though the degree of this inaccuracy varies by the industry of the victim and the type of incident.