The relatively old age our study cohort could suggest a population with some degree of left-censoring, particularly for patients with the greatest severity of OUD. Also, we could not study non-European-Americans, whose genetic diversity tends to be highest, and the mean age of the cohort suggests that we cannot necessarily generalize to younger populations. Lastly, our data is from a single medical system with suboptimal sample size, which limits statistical power. The non-significant correlation we observed between our study and Polimanti’s results could be due to our sample size.
