Biesbroeck 1995.

Methods	Double blind double dummy parallel design study, eight weeks four week titration to max tolerated dose of amitriptyline then four week stable dose Randomisation method not stated Inclusion criteria: age 21 to 85 years, duration of symptoms at least four months
Participants	Painful diabetic neuropathy of three to five years. 235 participants (212 final number). Age range 21 to 85 years. Baseline pain score in amitriptyline group VAS 64.5 and in capsaicin cream group VAS 61.7
Interventions	Amitriptyline dose escalation from 25 mg to 125 mg daily orally + active placebo in first two weeks (methyl nicotinate). Capsaicin cream topically 4 x daily + active placebo (benzatropine dose escalation from 0.25 mg to 1.25 mg, and for first two weeks diazepam 2 mg to 6 mg
Outcomes	Pain patients reported. 6‐item global improvement, VAS, pain relief by VAS (from no relief to complete relief) At least better on amitriptyline 79/108 (complete response 11, much better 35, better 33, no change 23, worse 5, much worse 1), on capsaicin cream 75/104 (complete response 8, much better 31, better 36, no change 23, worse 4, much worse 2) VAS decreased on amitriptyline 29.1 (+/‐ 3.0), on capsaicin cream 26.1 (+/‐ 2.9) Pain relief on amitriptyline 57.0 (+/‐ 3.6) and on capsaicin cream 55.1 (+/‐3.5) Sleep improved on amitriptyline in 64/108 patients and on capsaicin cream in 59/104 patients
Notes	Dropouts: 9/117 on amitriptyline, 14/118 on capsaicin cream Reason for withdrawal not stated QS = 4 (R2, DB1, W1)
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear