Max 1992

Methods	Randomised, double‐blind, cross‐over study After clinical assessment, 2 x 6 weeks of desipramine or amitriptyline. Dose titrated to maximum tolerated over 4 weeks, then stable for 2 weeks. No washout between treatment periods
Participants	Painful diabetic neuropathy for at least 3 months; stable glycaemic control Exclusions: other more severe pain; severe depression; postural hypotension; vascular disease; nephropathy; medical contra‐indication N = 54 (38 completed) M 33; F 21 Median age 58 years (range 20 ‐ 84)
Interventions	Desipramine 12.5 mg ‐ 150 mg daily Amitriptyline 12.5 mg ‐ 150 mg daily
Outcomes	PGPR at end of treatment period: 6‐point categorical scale, from complete to worse Daily PI diary, using 13 descriptors. Converted into numerical scores and weekly means calculated
Notes	Oxford Quality Score: R = 1; DB = 1; W = 0. Total = 2/5
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Details of randomisation method not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Details of blinding not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Details of blinding not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	Completer analysis reported. Claims ITT analysis "similar". Withdrawals > 10% (but evenly distributed between groups)
Size	High risk	< 50 participants evaluated per treatment arm (54 randomised, but only 38 completers)