Statistical analyses
vulvodynia, pain
VULVODYNIA
Patient characteristics at baseline were analyzed with Mann–Whitney’s U test and the chi-square test for differences between groups.Chi square test was used to analyze differences between groups regarding clinical treatment after the internet intervention (yes/no). Healthcare utilization due to provoked vulvodynia after internet-based treatment (number of visits) and treatment length (in months) were analyzed with Mann–Whitney’s U test as the data were not normally distributed. Analyses were carried out for the total number of healthcare visits and the number of visits by profession (gynecologist, midwife, physiotherapist, psychologist/counselor) due to a discrepancy in resources at different clinics. Due to the variation in the number of visits to midwives and physiotherapists these variables were categorized into groups (0 visits, 1–3 visits, 4–6 visits, and at least 7 visits) and then analyzed with Mann–Whitney’s U test.Health-related quality of life assessed with EQ5-D-3L was first analyzed for differences between groups at all timepoints using Mann–Whitney’s U test without any imputation. Then, quality-adjusted life-years (QALYs) were calculated by multiplying the individual value for the quality of life index derived from EQ5-D-3L domains by the time (in years) that each participant was part of the studyCosts for treatment were reported in euros. To eliminate differences in price levels between countries, the Purchasing Power Parity for the years 2016–2020 and the mean purchasing power parity over the same period were used as the index for conversion from Swedish kronor to euros, covering the Euro zone as calculated by OECD 36Pain acceptance (CPAQ-R) was used as a measure of clinical improvement. Results from CPAQ-R have previously been published elsewhereIn the cost-effectiveness analysis, it was estimated what additional costs were needed with the treatment in comparison to waiting list for clinical treatment in order to gain one meaningful change in pain acceptance for the patients. The meaningful change in pain acceptance was estimated using RCI, as described above. The ICER was estimated using the equation: