Nourbakhsh 2008.

Methods	RCT; randomisation by having participants draw a card out of a set of cards marked ‘Group A’ or ‘Group B’
Participants	Participants were involved in heavy or repetitive arm movements as part of their job or during recreational activities. Chronic lateral epicondylitis; n = 18
Interventions	Low‐frequency electrical stimulation on trigger points; n = 10 Placebo: n = 8   Six sessions in two to three weeks; six months of follow‐up
Outcomes	Pain (NRS), functional status (Q)
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Draw a card from a set of cards"
Allocation concealment (selection bias)	High risk	Treating therapist did the random assignment
Blinding of participants?	Low risk	Participant was blinded
Blinding of caregivers?	High risk	Therapists were not blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Measuring therapists were blinded to participants' group assignment, and participant blinded for participant‐reported outcomes
Incomplete outcome data (attrition bias) All outcomes ‐ <20% drop‐outs?	Low risk	Two dropouts not described, but dropout rate does not exceed 20%
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis performed?	Low risk	Yes for post‐test measurement, not for six‐month follow‐up
Selective reporting (reporting bias)	Unclear risk	No protocol
Similarity of baseline characteristics?	High risk	Groups not similar in all outcome measures (e.g. grip strength); demographic features (e.g. age range, duration of symptoms)
Co‐interventions avoided?	Low risk	"Subjects did not receive any other form of treatment"
Compliance acceptable ?	Low risk	All participants received six treatment sessions over a two‐ to three‐week period
Timing outcome assessment comparable?	Low risk	Timing comparable