Nabi 2021.

Study characteristics
Methods	Design: parallel Duration: 12 weeks Assessment: baseline, 4 weeks, post‐intervention Country: Iran
Participants	Pain condition: painful diabetic neuropathy Population: adults with type I or type II diabetes and a diagnosis of diabetic peripheral neuropathic pain Minimum pain intensity: ≥ 4 on 0‐10 scale Inclusion criteria Diabetic peripheral neuropathic pain for at least 6 months diagnosed according to the MNSI scale Pain intensity of ≥ 4 on 0‐10 scale Exclusion criteria Hepatic, heart, or renal failure; uncontrolled hypertension; psychological disorders; epilepsy; other neuropathies Total participants randomised: 72 Age in years (mean, SD): 57.71 (7.43) Gender: 29/72 were female Pain duration in months (mean, SD): 22.46 (9.52)
Interventions	TENS n = 30 TENS For 4 weeks, sessions every other day. Then, twice a week for 3 months Duloxetine ‐ 60 mg n = 42 SNRI Fixed dose with forced titration
Outcomes	Pain intensity AEs Withdrawal
Missing data methods	Completer analysis only ‐ 12 participants discontinued treatment due to intolerability and were replaced with new cases.
Funding source	Study was not financially supported
Conflicts of interest	The study authors reported no conflicts of interest.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomised using http://www.graphpad.com/quickcalcs/index.cfm.
Allocation concealment (selection bias)	Unclear risk	Allocation procedures not specified
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unable to be blinded due to the nature of TENS
Blinding of outcome assessment (detection bias) All outcomes	High risk	Self‐reported outcomes from unblinded participants
Incomplete outcome data (attrition bias) All outcomes	High risk	Completer analysis only. 12 participants dropped out, all in the duloxetine arm due to side effects. Participants who dropped out were replaced with new participants, and their data not analysed. Attrition Total: 12/72 (16.7%) TENS: 0/30 (0.0%) Duloxetine 60 mg: 12/42 (28.6%)
Selective reporting (reporting bias)	Low risk	Trial registered prospectively and outcomes match
Other bias	Low risk	No other sources of bias were identified.