Watson 1992.

Study characteristics
Methods	Design: cross‐over Duration: each cross‐over period lasted 5 weeks Assessment: baseline and post‐cross‐over period Country: Canada
Participants	Pain condition: post‐herpetic neuralgia Population: adults with post‐herpetic neuralgia Minimum pain intensity: pain of at least moderate severity (disagreeable, unpleasant, uncomfortable) for at least one half of the day; no numerical values Inclusion criteria Pos‐therpetic neuralgia of > 3 months' duration Pain of at least moderate severity (disagreeable, unpleasant, uncomfortable) for at least one half of the day Exclusion criteria cardiac disease, seizure disorder, severe depression with voiced suicidal intent requiring urgent management, presence of another significant pain problem, previous brain damage due to head injury, stroke or other causes, alcoholism Total participants randomised: 35 Age in years (median, range): 71 (55‐85) Gender: 17/35were female Pain duration in months (median, range): 14 months (4 months‐7 years)
Interventions	Amitriptyline TCA Flexible titration schedule: start with 12.5 mg/day if > 65 years old or 25 mg/day if < 65 Median dose at week 5: 100 mg/day (range: 37.5‐150 mg) Double‐dummy design due to different colour/shape of amitriptyline and maprotiline Maprotiline TCA Flexible titration schedule: start with 12.5 mg/day if > 65 years old or 25 mg/day if < 65 Median dose at week 5 was 100 mg/day (range: 50‐150 mg) Double‐dummy design due to different colour/shape of amitriptyline and maprotiline
Outcomes	Withdrawal
Missing data methods	Unclear
Funding source	Non‐pharmaceutical: The study was funded by Physicians’ Services Incorporated (PSI) Grant PSI: 88‐17.
Conflicts of interest	NR
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation methods NR
Allocation concealment (selection bias)	Unclear risk	Allocation procedures NR
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, double‐dummy design
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Self‐reported outcomes by blinded participants
Incomplete outcome data (attrition bias) All outcomes	Low risk	Completer analysis but very low dropout Attrition Total: 3/35 (8.6%) Amitriptyline 37.5‐150 mg: 2/35 (5.7%) Maprotiline 50‐150 mg: 1/35 (2.9%)
Selective reporting (reporting bias)	Unclear risk	No protocol or trial registration found. Lots of measures mentioned in the methods have no data given in results, just a sentence description
Other bias	Low risk	No other sources of bias were identified