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. Author manuscript; available in PMC: 2018 Aug 7.
Published in final edited form as: Am J Prev Med. 2018 Mar 26;54(5):611–619. doi: 10.1016/j.amepre.2018.01.040

Appendix Table D.2.

Regression Coefficients From Supplemental Sensitivity Models Using 2010–2014 ACS Estimates

Model 3 Model 4
Variable Est. (SE) p-value Est. (SE) p-value
Economic environment
Economic distress index 12.55 (1.60) <0.001 9.62 (1.47) <0.001
Housing distress
Vacant housing units, % 0.87 (1.20) 0.468 2.79 (1.11) 0.012
Rent >30% of household income, % 2.51 (1.11) 0.024 3.31 (1.08) 0.002
Labor market dependence
Non-specialized (ref) 0.00 0.00
Services 4.99 (2.65) 0.060 3.95 (2.36) 0.094
Public sector –9.27 (2.56) <0.001 –7.37 (2.29) 0.001
Manufacturing –3.69 (1.89) 0.050 –3.33 (1.68) 0.048
Mining 13.09 (4.05) 0.001 12.77 (3.69) 0.001
Farming –9.74 (3.71) 0.010 –4.02 (3.24) 0.215
Social environment
Family distress index 7.14 (1.35) <0.001 8.73 (1.22) <0.001
Residents living in different county 5 years ago, % –1.86 (1.05) 0.077 –2.87 (0.95) 0.003
Social capital
Religious establishments per 10,000 population
Bottom 25th percentile (ref) 0.00 0.00
25th–50th percentile –3.47 (2.13) 0.104 –2.06 (1.94) 0.288
50th–75th percentile –7.92 (2.46) 0.001 –6.33 (2.27) 0.005
Top 25th percentile –8.79 (2.93) 0.003 –6.08 (2.70) 0.024
Nonprofit organizations per 10,000 population
Bottom 25th percentile (ref) 0.00 0.00
25th–50th percentile –0.24 (2.21) 0.912 –2.18 (1.98) 0.272
50th–75th percentile –0.62 (2.82) 0.826 –4.29 (2.52) 0.089
Top 25th percentile –0.25 (3.86) 0.949 –5.86 (3.35) 0.080
Membership associations per 10,000 population
Bottom 25th percentile (ref) 0.00 0.00
25th–50th percentile 1.21 (2.02) 0.548 1.44 (1.82) 0.430
50th–75th percentile 3.44 (2.30) 0.135 3.69 (2.15) 0.087
Top 25th percentile 6.25 (2.74) 0.023 8.39 (2.61) 0.001
Sports establishments per 10,000 population
Bottom 25th percentile (ref) 0.00 0.00
25th–50th percentile 3.18 (2.06) 0.122 2.10 (1.82) 0.248
50th–75th percentile 3.04 (2.22) 0.172 1.65 (2.03) 0.415
Top 25th percentile –1.14 (2.59) 0.661 –3.08 (2.41) 0.203
Healthcare environment
Physicians per 10,000 population 2.07 (0.87) 0.017 2.26 (0.79) 0.004
Primary healthcare professional shortage area –2.57 (1.53) 0.093 –2.26 (1.45) 0.120
Mental healthcare professional shortage area 0.49 (1.87) 0.793 1.84 (1.72) 0.283
Population characteristics
Nonmetro county –10.46 (1.92) <0.001 –9.58 (1.76) <0.001
Age >65 years, % 6.12 (1.20) <0.001 6.48 (1.10) <0.001
Military veterans, % 2.23 (0.92) 0.015 2.60 (0.81) 0.001
Black population, %
Bottom 25th percentile (ref) 0.00 0.00
25th–50th percentile 4.41 (2.09) 0.035 5.69 (2.00) 0.004
50th–75th percentile 0.72 (2.63) 0.784 3.13 (2.38) 0.188
Top 25th percentile –15.06 (3.57) <0.001 –11.64 (3.20) <0.001
Hispanic population, %
Bottom 25th percentile (ref) 0.00 0.00
25th–50th percentile 2.92 (2.18) 0.181 2.26 (2.10) 0.282
50th–75th percentile 3.15 (2.56) 0.217 2.03 (2.42) 0.401
Top 25th percentile –1.04 (3.26) 0.749 –3.70 (3.07) 0.228
American Indian population, %
Bottom 25th percentile (ref) 0.00 0.00
25th–50th percentile –1.09 (1.93) 0.573 0.88 (1.79) 0.624
50th–75th percentile 1.73 (2.18) 0.428 2.60 (2.05) 0.204
Top 25th percentile 6.69 (2.67) 0.012 7.12 (2.56) 0.005
Spatial autocorrelation parameter 0.524 (0.027) <0.001 0.630 (0.03) <0.001
N 3,106 2,484

Notes: Boldface indicates statistical significance (p<0.05). All models control for state fixed effects. Model 3 is the same as Model 1 (N=3,106), but uses temporally proximate/overlapping demographic, economic distress, housing distress, and family distress variables from the American Community Survey 5-year estimates (2010–2014). These estimates represent more current conditions, whereas Model 1 is based on county conditions from 2000. The direction and significance (p<0.05) of coefficients are generally consistent between Model 1 and Model 3, and when there are differences in significance, it is usually because the p-value was between 0.05 and 0.10, thereby failing to meet the conventional p<0.05 threshold. There was one important difference that reflects the importance of current economic conditions on drug mortality rates. The magnitude of the economic distress coefficient is nearly twice as large in Model 3 compared to Model 1, suggesting that economic conditions from 2000, while important, may be underestimating the true impact of economic distress on county mortality rates. Importantly, this differences could also be the result of reverse causality bias; high rates of substance abuse could lead to increases in poverty, unemployment, and disability rates, for example. The only other major difference is that counties in the top quartile of membership associations had a significantly higher average AAMR than counties in the bottom quartile in this model. It is unclear why substituting economic, demographic, and family predictors from 2000 with those from 2010–2014 would result in this change. T-tests showed that counties in the top quartile of non-profit associations had lower average economic distress in both 2000 and 2010–2014, higher average percentages of vacant housing units, lower average rental stress, lower average family distress, and higher average percent aged >65 years in both 2000 and 2010–2014. The only difference between these two time periods was that percent veterans in 2000 was higher in counties in the top quartile of non-profit associations, but percent veteran in 2010–2014 was significantly lower in counties in the top quartile of nonprofit organizations than in the other 75% of counties. Model 4 is the same as Model 3, but does not use multiple imputation. This model is conducted only on complete cases (i.e., counties with at least ten drug-related deaths, N=2,484) and uses the 2010–2014 ACS estimates. Again, model results are consistent with the exception that vacant housing units is positive and significant in Model 4. This is because counties with suppressed mortality rates had a significantly higher average percentage of vacant housing units in 2010–2014 than counties without suppressed mortality rates. Excluding these counties from the analysis overestimates the relationship between vacant housing units and drug mortality rates.

Est., Estimate; AAMR, Age-Adjusted Mortality Rate