Health care service utilization and drug overdose death: A national nested case-control registry study.

Background and objectives: More knowledge is needed to identify and reach those at overdose risk with preventive measures. We examined past 12-month health service utilization, identified the most frequently utilized service, explored this utilization in more detail, and examined correlates of overdose death.

Methods: A population-based nested case-control registry study including all drug overdose deaths (1 January 2010 to 31 December 2018) in Norway through the Cause of Death Registry (n = 2388). The year-, age- and gender-matched controls included through a population registry (n = 21,465). Data cross-linked with population and patient registries. Multivariable conditional logistic regression analyses estimated the likelihood of overdose death.

Results: The cases (vs. controls) attended a higher median number of services (3 vs. 1). The General Practitioner (GP) was the most utilized service. The majority (55.7%) of cases had 11-50 encounters, while the majority (60.7%) of the controls had 1-5 encounters. No high school diploma, no employment, urban living, social welfare benefits/disability pension, single-person household, recent incarceration, multiple health service utilization and frequent GP encounters, as well psychological and certain physical diagnoses were correlates of overdose death among the GP attenders.

Discussion and conclusions: The cases had utilized more services than the controls and the GP was the most frequently utilized service. In addition to low socioeconomic status, psychological and certain physical diagnoses were correlates of overdose death.

Scientific significance: This is the first national case-control registry study to document the high utilization of multiple primary and secondary health care services before drug overdose death, as well as reasons for attendance and correlates of overdose death.