Figure 1.

Timeline for evaluation of outcomes associated with high-risk and chronic opioid use.

Exposure determination period: time period from date of new endometriosis diagnosis running out to 12 months after diagnosis, which was used for determination of exposure (opioids vs no opioids). The date of first opioid prescription in the exposure determination period was determined as the index date.

Exposure assessment period: 12 months post-index date used for determination of high-risk and chronic opioid use.

Baseline period: 12 months prior to index date (not including index date) for evaluation of baseline covariates.

Outcome period: 12 months after the end of the exposure assessment period for determination of HCRU and costs.

Patient index identification period: time period for the potential index date of a patient. The period is between 1 January 2010 and 30 September 2016 since a minimum enrollment of 12 month prior to and 24 month post-index date was required for each patient.