Predel 2013b.

Methods	R, DB, PC, parallel groups 2 g gel applied with fingertips over affected area and massaged in for 1 minute. Treatment for 5 days Assessed at baseline, 2, 3, 5 days
Participants	Uncomplicated neck pain originating from cervical joints and accompanying soft tissues (≥ 12 hours but < 3 months), PI ≥ 50/100 N = 72 M 33, F 39 Mean age 34 years
Interventions	Diclofenac gel (Voltaren Emulgel), 4 x 2 g daily, n = 36 Placebo gel, 4 x 2 g daily, n = 36 Rescue medication: paracetamol up to 2 g daily No concomitant therapies allowed
Outcomes	≥ 50% decrease in PI on movement after 48 hours PGE: 5‐point scale (responder = "good" or "excellent" at 5 days Adverse events Withdrawals
Notes	Oxford Quality Score: R2, DB2, W1. Total = 5/5
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Sponsor "produced randomisation list"
Allocation concealment (selection bias)	Low risk	Automated remote system
Blinding (performance bias and detection bias) All outcomes	Low risk	"identical in packaging, labelling, schedule of administration, appearance and odour"
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing data
Size	High risk	< 50 participants per treatment arm