Kaur 2011.

Methods	Randomised, double‐blind, cross‐over clinical trial comparing amitriptyline and duloxetine in painful diabetic neuropathy
Participants	86 participants ‐ 65 randomised to treatment in 1st arm, 58 of whom completed both arms People of either sex with type 2 diabetes, aged between 18 and 75 years, who were on stable glucose‐lowering medications during the preceding month and who had painful diabetic neuropathy for at least 1 month were considered for the study. The study enrolled people who had a pain score of > 50%, as assessed by visual analogue scale (VAS). Painful diabetic neuropathy was confirmed by 1) medical history, 2) a diabetic neuropathy symptom (DNS) score of > 1 point (7), 3) a Diabetic Neuropathy Examination (DNE) score of > 3 points (8), 4) a modified neuropathy symptom score (mNSS) (9,10), and 5) increased thresholds on the vibration perception test and monofilament test
Interventions	Amitiyptyline 10, 25 or 50 mg once daily at night or duloxetine, 20, 40 or 60 mg once daily at night Intervention only 6 weeks before 2 week washout and cross‐over to alternate arm. Participants commenced on lowest dose and then increased every 2 weeks to next dose if required by treating physician; thus potentially only 2 weeks on maximum dose. 48% of amitriptyline and 65% of duloxetine participants reached the highest dose of drug. 17% vs 5% of the participants preferred higher dose duloxetine to amitriptyline
Outcomes	Primary outcome Patient's global assessment of efficacy by VAS (0 to 100) Secondary outcomes Short form McGill pain questionnaire (11) 11‐point Likert scale for pain (0 to 10) DNE score DNS score mNSS Hamilton Depression Rating Scale (HAMD) change in sleep pattern (increased, unchanged or decreased) Patient global impression of change
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomised (computer generated randomisation of blocks of 4)
Allocation concealment (selection bias)	Unclear risk	An independent person unrelated to the study carried out blinding and randomisation. Two separate companies provided medicines, so it is not clear that they were identical in appearance
Blinding (performance bias and detection bias) All outcomes	Low risk	Blinded. Single physician assessment. "success of blinding was assessed by the accuracy of the physicians prediction at the end of the study" (34% correctly identified only)
Incomplete outcome data (attrition bias) All outcomes	Low risk	No concerns
Selective reporting (reporting bias)	High risk	The primary end point of the study was the reduction in the median pain score from baseline, (patient’s global assessment of efficacy by VAS (0 to 100 points)). Secondary end points included the assessment of pain by the short‐form McGill Pain Questionnaire (11); an 11‐point Likert scale for pain (0 = no pain and 10 = excruciating pain); change in sleep pattern (increased, unchanged, or decreased); overall improvement by DNE score, DNS score, mNSS, and the 24‐point HAMD; and patient self evaluation of overall change on the basis of a 7‐point Patient Global Impression of Change (PGIC) scale not reported in analysis.
Other bias	High risk	Significant (but similar) carryover into period 2 despite 2 weeks' washout