OHA data are derived from the nearly 36 million annual coded hospital encounters in Ohio. The data, which are updated quarterly, is sorted  by gender, race and age range of the patient along with marketplace totals and county level per-capita rates. Data after 2016 includes additional detail on the demographics within the regional marketplaces.

The release of per-capita rates by county, as well as by market area, is intended to assist health policy makers, funders and local collaboratives in their work. The data do not reflect overdoses that did not present for care at a hospital or overdoses that occurred among Ohio residents who were cared for at hospitals outside the state.

This data set is encounter-level and does not reflect individual patients. OHA worked with third-party experts to assure data in the release protects patient privacy. For the initial release of the data in 2018,  OHA analyzed annual data from 2008-2016 and then began quarterly analyses.