Trends in endometriosis interventions: an interrupted time series analysis following the Australian National Action Plan for Endometriosis (NAPE) 2018
Chiemeka C. Chinaka
A , Brenda Gannon A * and Jenny Doust B C
A
B
C
Abstract
This study aimed to highlight trends in the utilisation of selected endometriosis treatments before and after the launch of the National Action Plan for Endometriosis and observe the impact of the action plan on the utilisation of these interventions.
Monthly Medicare and Pharmaceutical Benefits Scheme claims were used to represent the utilisation of laparoscopic resection and nafarelin for endometriosis. Time series analysis using autoregressive integrated moving average models was used to establish the trend in the utilisation of these treatments. An interruption was then applied at the launch of the plan, and a counterfactual prediction was modelled based on the claims made before the interruption. Factual values and counterfactual predictions were compared to evaluate the impact of the plan.
The action plan was associated with an immediate increase of 3.94 Medicare Benefits Schedule claims per month (95% CI −44.61 to 52.50) and an estimated change in slope of 1.30 claims per month (95% confidence interval (CI) −3.80 to 6.30) for laparoscopic resection. Nafarelin dispensing after the launch of the action plan had an immediate increase of 68.30 dispensing claims per month (95% CI −4.34 to 141.03), with a slope change of −2.84 claims per month (95% CI −10.975 to 5.293).
The results suggest that although the action plan was linked with a marked immediate spike in the utilisation of nafarelin, it did not make any difference in the long term. However, it may have contributed to a small but steady increase in the utilisation of laparoscopic resection, used in severe cases of the condition.
Keywords: chronic diseases, endometriosis, healthcare utilisation, health policy, interrupted time series, Medicare data, reproductive health.
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