Appendix Table B.1.

Data Sources and Variables Used in Regression Analysis of Variation in Drug-related Mortality Rates

	Data sources for main analysis	Data sources for sensitivity analysis
Population below the poverty line, age 25–54 years, %	1	2
Civilian non-institutionalized population unemployed or not in labor force, age 25–54 years, %	1	2
Civilian non-institutionalized population with a work disability, age 21–64 years, %	1	2
Population with <4-year college degree, age >25 years, %	1	2
Households with supplemental security income, %	1	2
Households with public assistance income, %	1	2
Population without health insurance, age 18–64 years, %	7a	2
Gini coefficient of income inequality	1	2
Vacant housing units, %	1	2
Renter-occupied housing units with rent >30% of household income, %	1	2
Economic/employment dependence typology	3	3
Persons separated/divorced, age >15, %	1	2
Families with children headed by single parent, %	1	2
Religious establishments per 10,000 population	4	5
Nonprofit organizations per 10,000 population	4	5
Membership (civic, business, labor, political, professional) associations per 10,000 population	4	5
Sports (bowling, golf, sports, fitness) establishments per 10,000 population	4	5
Residents living in different county 5 years earlier, %	1	2
Physicians per 10,000 population, 2000b	6	6
County designated as a primary healthcare professional shortage areab	6	6
County designated as a mental healthcare professional shortage areab	6	6
Metropolitan status (metropolitan vs nonmetropolitan)	3	4
Population age >65 years, %	1	2
Veterans or currently in armed forces, %	1	2c
Black population, %	1	2
Hispanic population, %	1	2
American Indian population, %	1	2

^aHealth insurance estimates are from 2008. County-level health insurance rates for 2000 are unavailable. American Community Survey (ACS) health insurance rates first became available in the 2010–2014 ACS release. Insurance rates prior to 2010–2014 are available only from the Small Area Health Insurance Estimates (SAHIE). SAHIE estimates for 2005 and 2006 are based on the Current Population Survey (CPS) and have wide margins of error, making them unreliable for national county-level analyses. SAHIE estimates for 2008 and later are based on restricted ACS data and provide estimates that are more consistent with the 2010–2014 estimates produced by the ACS than with estimates produced from CPS data.

^bCounties are designated as primary and/or mental health professional shortage areas based on a formula derived by the Health Resources & Services Administration that considers multiple factors, including the population-to-provider ratio and travel time to the nearest source of care outside of the county. Ideally, I would have included indicators that capture the pre-2006 supply of healthcare professionals and facilities in the area of mental health and substance abuse services, but those data are not available nationally at the county level. The Area Health Resource File (AHRF) captures county-level measures for specific types of healthcare providers (e.g., psychiatrists, psychologists, social workers, occupational, physical, and recreational therapists), but prior to the 2013–2014 AHRF release, counties with missing values on any measures were designated with values of 0, thereby making those measures unreliable (users are unable to identify which counties are missing vs. which counties truly have values of 0 on these measures). For more information, see User Documentation for the County Area Health Resource File 2015–2016 release, page 148. (https://datawarehouse.hrsa.gov/data/datadownload.aspx#MainContent_ctl00_gvDD_lbl_dd_topic_ttl_0).

^cThe variable available in the 2010–2014 ACS measures percent veterans only, not percent currently in armed forces. Therefore, coefficients from the 2000 and 2010–2014 models are not comparable for this variable.