Fuchs 2004.

Study characteristics
Methods	This study was carried out in a secondary care setting. The blinding within this study was unclear. It was unclear if ITT analysis was carried out This study was conducted in Germany.
Participants	80 participants were recruited: 12 dropped out. Inclusion criteria of the trial Adults Refractory warts Warts on the hands or feet
Interventions	20% 5‐aminolevulinic acid (5‐ALA) + visible light (VIS) + water‐filtered infrared‐A (wIRA) versus Placebo + visible light + wIRA versus 20% 5‐ALA + visible light versus Placebo + visible light There were 1 to 3 therapy cycles every 3 weeks for a total duration of 18 weeks.
Outcomes	Outcomes of the trial Per cent change in wart area at 0, 3, 6, 9, 12, and 18 weeks
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote (page 2): "80 patients were randomised within 10 time blocks of 8 patients to 4 therapy groups purely on sequence of the patients being included in the study." Comment: This was probably done.
Allocation concealment (selection bias)	Low risk	Quote (page 5): "...smallest possible block size which allows no information about the allocation of another patient of the same time block to a therapy group, not even that he or she belongs to a different therapy group." Comment: The method of allocation concealment was unclear, but randomisation was done in blocks, preventing knowledge of allocation. Therefore, this was probably done.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote (page 1): "...prospective randomised controlled blind study." No further information was given in the published trial report other than that the placebo could not be distinguished by inspection nor by smell from the treatment cream. Quote (page 6): "Presence or absence of wIRA can be felt by the treating physician by comparing the radiation, the study was performed single instead of double blind."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote (page 1): "...prospective randomised controlled blind study." No further information was given in the published trial report.
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote (page 9): "Out of the 80 patients, 68 completed the entire study." Comment: The reasons for attrition were given in the trial report (page 8). The dropout rate between the groups was similar.
Selective reporting (reporting bias)	Low risk	All outcomes were reported.