What changes when a study excludes opioid fills soon after endometriosis surgery?

The claims study asked when opioid prescriptions were filled

Lamvu and colleagues compared 53,847 women with endometriosis with 107,694 matched controls. They examined opioid fills, recorded dose and overlap with benzodiazepine prescriptions. An opioid fill was recorded for 79.3% of the endometriosis group and 24.2% of controls in the study data.

A short postoperative window tests one explanation

The researchers repeated analyses after excluding opioid prescriptions received during a 30-day postsurgery window and reported similar results. This checks whether prescriptions close to surgery explain the observed patterns. The restriction leaves open other reasons for treatment, including care outside the selected window and pain unrelated to the recorded condition.

A claim cannot identify why a particular dose was taken

In an individual record, align fills with procedures, pain assessments and prescriber notes. Record whether an opioid was actually taken and, if known, when. The study’s sensitivity analysis helps interpret a group comparison, while a case-specific timeline addresses the reason and timing of an individual exposure.

Source paper

Lamvu et al., Obstetrics & Gynecology (2019) · Full text