Herbal decoctions for dysmenorrhea under universal health coverage pilot project: Evidence from a nationwide claims database in the Republic of Korea

Abstract

Background: Despite its high prevalence, dysmenorrhea is an underestimated gynecological disorder. To enhance the service coverage, the Pilot Project for Expanding National Health Insurance (NHI) Coverage to Herbal Decoctions (HDs) was implemented in the Republic of Korea from November 2020. This study aimed to assess the effectiveness and safety of HDs for dysmenorrhea at a nationwide level. Additionally, its impact on accessibility was explored.

Methods: This retrospective observational study used claims data from the pilot project (November 1, 2020, to April 28, 2024). A linear mixed-effects model was used to estimate symptom improvement during the HD exposure period. Time series data decomposition and structural change points detection were performed using NHI statistics on dysmenorrhea patient counts for those who received medical services between 2014 and 2023.

Results: Among 39,574 participants, a descriptive analysis of 7016 suggested a tendency to receive HD treatment for moderate-to-severe symptoms. Effectiveness analysis demonstrated that HD significantly reduced symptom severity over time (β = -0.072, p < 0.001). Adverse events were reported by 0.58 % of the patients, mostly involving gastrointestinal symptoms. Following the initiation of the pilot project, a significant increase in the number of patients with dysmenorrhea receiving traditional Korean medicine (TKM) services was observed.

Conclusion: The nationwide pilot project showed clinical effectiveness and a manageable safety profile of HDs for dysmenorrhea. The universal health coverage initiative appeared to have improved the accessibility of TKM services for managing dysmenorrhea. Further robust research utilizing nationwide real-world data is required to validate these findings.

Keywords: Dysmenorrhea; Herbal medicine; Universal health coverage.

Fig. 1

Recording criteria for symptom severity and definition of exposure period in the first phase of the pilot project. *Abbreviations: d, Days; Rx, Prescription course. X indicates the day of herbal decoction prescription. The black line represents the prescription days per cycle. The red line indicates the last course of prescription, while the red X marks the last day of herbal decoction prescription, which corresponds to the last recorded symptom severity. The exposure period (blue dashed line) represents the total number of days of herbal decoction prescriptions before the last recorded symptom severity.

Fig. 2

Flow diagram of subjects selection.

Fig. 3

Prediction of symptom severity changes based on the linear mixed-effects model (LMM). The squares represent the mean symptom severities for each exposure period, while the black vertical lines indicate the standard deviation. The red solid line shows the predicted symptom severity based on Model 3, which incorporates the exposure period, age, secondary dysmenorrhea, and interaction terms in the linear mixed-effects model. The x-axis represents the exposure period in 10-day intervals, with values outside the 0 to 100-day range omitted for clarity.

Fig. 4

10-year medical service utilization changes based on time series decomposition: (a) Traditional Korean medicine services, (b) Conventional medicine services. The black solid line represents N944 (primary dysmenorrhea), the blue solid line represents N945 (secondary dysmenorrhea), and the red solid line represents N946 (unspecified dysmenorrhea). In the time-series plot of patients per 100,000 population (monthly), the black, blue, and red dashed vertical lines indicate the structural break points for the patient count trends of N944, N945, and N946, respectively.