Through the Freedom of Information Act, The Center for Investigative Reporting received two data sets from the Department of Veterans Affairs: one showing the number of opiate prescriptions issued by the VA and the other the number of patients served at every VA hospital and clinic. The data covered the years since 9/11, from 2001 through 2012.

Using the unique regional and facility identifiers in the data, we combined the data and associated it with a map of facility locations from the VA. The IDs allowed us to group hospitals and clinics by system. We also created a map of the VA’s regional boundaries using a map of all U.S. counties, which became the backbone of our interactive map

Although the prescription data came as calendar year totals while the patient data was aggregated by fiscal year, we were able to adjust the fiscal year patient counts to approximate the calendar year. This allowed us to calculate the rate of opiate prescriptions to patients served, making it possible to compare facilities of varying sizes and identify the hospitals and clinics with the highest rates of opiate prescriptions by year, by drug and over time.

In a small handful of cases, patient data was recorded by the VA in a way that likely overstates the number of patients served in a particular hospital system. We have noted this on our map with an asterisk. A few hospital systems also appear to prescribe far fewer opiates than expected, given rates across the country in similar locations, which might indicate that the VA data is missing some information from those areas.

The results of our analysis can be explored through our interactive map

Stephen K. Doig, Knight Chair in Journalism at Arizona State University, contributed to the analysis.

Agustin Armendariz

Agustín Armendariz is an investigative reporter specializing in data analysis for The Center for Investigative Reporting. He previously worked at the San Diego Union-Tribune where he was a database specialist on the watchdog reporting team. While there, he delved into city finances, redevelopment projects and foreclosures. He earned his masters in journalism from American University in Washington, D.C. Agustin worked at the Center for Public Integrity and was a contributor to the publication "The Buying of the President" (2004) which was a New York Times bestseller.