A Longitudinal Assessment of Endometriosis Patients Prescribed Cannabis‐Based Medicinal Products: A Case Series From the UK Medical Cannabis Registry

Background Although there is growing evidence supporting the use of cannabis‐based medicinal products (CBMPs) for the management of chronic pain, there is a paucity of data on their effect on endometriosis‐associated chronic pain. Aims This study aimed to perform an analysis of pain‐specific and general health‐related quality of life (HRQoL) outcomes for patients with endometriosis‐associated chronic pain treated with CBMPs. Materials and Methods Primary outcomes included changes in patient‐reported outcome measures (PrOMs) from baseline to 1, 3, 6, 12 and 18 months. A repeated measures ANOVA was applied to assess changes in PrOMs at 1 to 18 months from baseline. Secondary outcomes included incidence and frequency of adverse events (AEs). Results Sixty‐three patients met inclusion criteria. Initiation of CBMPs was associated with improvements in all pain‐specific PrOMs from baseline to 18 months ( p < 0.050). EQ‐5D‐5L index value showed improvements between baseline and all months ( p < 0.050). Anxiety and sleep quality PrOMs showed improvements from baseline to 18 months ( p < 0.050). Minimal clinically significant differences (11%–37%), moderately important improvements (5%–22%) and substantial improvements (0%–11%) were observed in the Brief Pain Inventory (BPI) and pain severity visual analogue scale. Sixty‐two adverse events were reported by 16 (25.40%) participants. Conclusions This study observed an association between CBMP treatment and improvements in pain and HRQoL in patients with endometriosis. Causality cannot be inferred due to the nature of this observational study; however, these findings provide complementary evidence for the development of randomised controlled trials to assess the efficacy of CBMPs for endometriosis‐associated chronic pain.