FIGURE 2.

Copositivity analysis – methamphetamine positive versus negative population OR. Notes: OR were calculated for logistic regression models of fentanyl, heroin, and other opioids. OR estimates represent the odds of being positive for the response drug in the methamphetamine-positive population divided by the odds in the methamphetamine-negative population. Higher OR values represent higher copositivity values. OR was calculated for the total US population and each individual US census division for each year of the study. Solid circles represent OR significantly higher than 1 based on a Tukey corrected P value (P < 0.05). Open circles represent OR not significantly higher than 1 (n.s.). n.s. indicates not significant; OR, odds ratios.