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. Author manuscript; available in PMC: 2017 Jan 7.
Published in final edited form as: N Engl J Med. 2016 Jun 22;375(1):44–53. doi: 10.1056/NEJMsa1514387

Figure 4. Estimated Difference in Opioid Measures Associated with Number of Types of State Controlled-Substance Laws Added since 2006.

Figure 4

This figure shows adjusted estimates of the association between the number of types of state-level controlled-substance laws added since 2006 and measures of opioid receipt. We estimated marginal effects (the change in the predicted probability of the dependent variable was multiplied by 100 for ease of presentation) on the basis of individual-level logistic regressions of prescription-opioid measures on the time-varying number of types of laws added since 2006 (1, 2, or ≥3; 0 is the reference) in a beneficiary’s state of residence in a given year, controlling for the state of residence, year indicators, and beneficiary characteristics. Variance estimates account for autocorrelation of observations within states over time with the use of Huber–White sandwich estimators. Confidence intervals were estimated with the use of the delta method and were not adjusted for multiple comparisons.