Patients and methods
Acne, IGA, acne, renal impairment
RENAL IMPAIRMENT, RECRUITMENT, SECONDARY, ACNE, ACNE
The Spironolactone for Adult Female Acne (SAFA) trial was a pragmatic, multicentre, participant-led and clinician-blind, superiority, randomised trial with two parallel treatment groups: spironolactone compared with placebo in women aged 18 years and older with facial acne judged to warrant oral antibiotics. The economic evaluation was nested within this trial.Participants were recruited in primary care, secondary care and through advertising (community and social media). Baseline assessment was conducted by a research nurse and/or dermatologist in secondary care clinics to ensure standard clinical assessments, as the investigator’s global assessment (IGA) for acne was an inclusion criterion and an important secondary outcome. Baseline appointments included a pregnancy test, blood test (to exclude renal impairment or raised serum potassium), participant photo to aid recall about changes in acne and contraceptive counselling. The first participant was recruited in June 2019 and the last in August 2021, while follow-up finished February 2022. The SAFA trial is described in more detail in the clinical paper.Participants were randomised 1:1 using online software to either 50 mg/day spironolactone or matched placebo until week 6, increasing to 100 mg/day spironolactone or matched placebo until week-24, assuming treatment was tolerated. Participants were stratified by recruitment centre and baseline acne severity (IGA<3 vs IGA≥3). In both groups participants could continue using topical treatment. Between baseline and week 12, participants were asked not to take oral treatment for acne other than study medication, except for oral contraception taken for over 3 months previously. After 12 weeks, participants in both groups could receive usual care, including oral treatments, such as oral antibiotics, hormonal treatment or isotretinoin. In both groups, participants were followed up face-to-face (or by video call or telephone due to COVID-19) at week 6 and week 12 in secondary care, with primary outcome assessment at week 12, and longer term follow-up by questionnaires at week-24.Although in the clinical trial, spironolactone plus routine topical treatment was compared with placebo plus routine topical treatment, it is most appropriate in economic evaluations to compare an active treatment to current usual care.