Adedoyin 2005.

Methods	Randomised controlled trial 3‐arm parallel group design Trial duration: 4 weeks Power calculation reported
Participants	51 patients randomised 46 patients with knee OA reported at baseline Study joints: 46 knees Number of females: 28 of 46 (61%) Average age: 55 years Average BMI: 28 kg/m2
Interventions	Comparison 1 Experimental intervention: TENS and exercise twice per week Control intervention: exercise, twice per week Comparison 2 Experimental intervention: interferential current stimulation and exercise, twice per week Control intervention: exercise, twice per week Duration of treatment period: 4 weeks Analgesics not allowed, patients confirmed not to take analgesics TENS Device: Endomed 5921D Self‐administered: no Waveform: not reported Pulse width: 200 ms Pulse frequency: 80 Hz Amplitude: above sensory threshold, strong but comfortable Duration of stimulation per session: 20 minutes Electrodes: 2 electrodes 8 x 6 cm Placement: Each side of affected knee joint, aligned longitudinally along length of limb Interferential Current Stimulation Device: Endomed 5921D (2 pole) Waveform: interferential Pulse width: not applicable Pulse frequency: 80 Hz (beat) Amplitude: above sensory threshold: strong but comfortable, strong tingling sensation without muscle contraction Duration of stimulation per session: 20 minutes Electrodes: 2 electrodes 8 x 6 cm Placement: each side of affected knee joint, aligned longitudinally along length of limb
Outcomes	Extracted pain outcome: pain on activities other than walking after 4 weeks, described as "Pain recorded while standing (10‐point pain rating scale with 0 “no pain”, 5 “moderate pain” and 10 “worst pain imaginable”)" Extracted function outcome: WOMAC global scale after 4 weeks (Likert) No primary outcome reported
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	No information provided
Allocation concealment?	Unclear risk	No information provided
Free of selective reporting?	Unclear risk	Trial protocol not accessible, methods section not explicit about pre‐specified outcomes
Adequate blinding of patients?	High risk	No sham intervention
Incomplete outcome reporting: intention‐to‐treat analysis performed? Pain	High risk	15 out of 15 (100%) in TENS group, 16 out of 19 (84%) in interferential current stimulation group, 15 out of 17 (88%) in control group analysed
Incomplete outcome reporting: intention‐to‐treat analysis performed? Function	High risk	See above
Funding by commercial organisation avoided?	Unclear risk	No information provided
Funding by non‐profit organisation?	Unclear risk	No information provided