Dreiser 2003.

Methods	RCT; double‐blind; double‐dummy randomised, placebo‐controlled, parallel group; multicentre Follow‐up time: 8 days Drugs were randomised according to a random scheme in blocks of 3, provided by pharmaceutical company; the lowest available randomisation number was assigned to the participants at each site when entering the study.
Participants	Population: 372 participants, 187 women, 182 men. Mean age approximately 40 years Setting: 54 clinics of general practitioners in France Inclusion criteria: age 18 to 60 years, with untreated acute low back pain, onset within 2 days, pain ≥ 50 mm on 100‐mm VAS, not due to an associated radiculalgia; not radiating below gluteal fold, pain intermittent or constant, and aggravated by mechanical factors Exclusion criteria: hypersensitivity to diclofenac, ibuprofen, paracetamol, aspirin; current disease status that could interfere with safety or efficacy of study medication; drug or alcohol abuse; anticoagulant therapy or other concomitant treatments; pregnant or nursing; sensory or motor deficits in lower extremities; previous episode of LBP within 3 months; chronic LBP, or an infective, inflammatory, neoplastic, metabolic or structural cause for back pain
Interventions	NSAID (i): diclofenac‐K 12.5 mg, initial dose 2 tablets (25 mg), 7 days flexible dose 1 to 2 tablets every 4 to 6 hours, maximum 6 tablets a day; 8 days (N = 124) NSAID (ii): ibuprofen 200 mg, initial dose 2 tablets (400 mg), 7 days flexible dose 1 to 2 tablets every 4 to 6 hours, maximum 6 tablets a day; 8 days (N = 122) Reference treatment (iii): placebo, initial dose 2 tablets, 7 days flexible dose 1 to 2 tablets every 4 to 6 hours, maximum 6 tablets a day; 8 days (N = 126)
Outcomes	Pain intensity, mean changed score (SD), 100 mm VAS, after 7 days: (i, N = 122) ‐48.4 (26.1); (ii, N = 119) ‐48.8 (24.0); (iii, N = 121) ‐37.5 (26.9); (i) vs (iii) and (ii) vs (iii) significantly lower (P < 0.001) Roland‐Morris Back Pain Questionnaire (0 to 24, no to maximal disability) mean changed score (SD) after 7 days: (i, N = 119) ‐8.6 (5.7); (ii, N = 118) ‐8.1 (5.2); (iii, N = 116) ‐5.7 (5.3); (i) vs (iii), and (ii) vs (iii) significantly lower (P < 0.001) Global improvement: a lot/complete in (i) 53/119 (45%) and (ii) 48/119 (40%) Adverse events: (i) 16 participants (4 withdrew); (ii) 14 participants (4 withdrew); (iii) 20 participants (8 withdrew)
Funding	Study supported by Novartis Consumer Health (developer of diclofenac‐K (Voltaren K))
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Unclear how the study sponsor arranged the sequence generation process
Allocation concealment (selection bias)	Low risk	Adequate: drugs were randomised according to a random scheme in blocks of 3, provided by the study sponsor; the lowest available randomisation number was assigned to the participants at each site when entering the study. Each package of study medication looked equal and was labelled with a randomisation number. Sealed decoding envelopes were supplied to the sites for un‐blinding in case of emergency; all were returned unopened to the study sponsor.
Blinding of participants and personnel (performance bias) All outcomes ‐ participants	Low risk	Blinding was achieved by double‐dummy approach.
Blinding of participants and personnel (performance bias) All outcomes ‐ careproviders	Low risk	Double‐blind, double‐dummy
Blinding of outcome assessment (detection bias) All outcomes ‐ outcome assessors	Low risk	Double‐blind, double‐dummy
Incomplete outcome data (attrition bias) All outcomes ‐ dropouts	Low risk	Low dropout rate: 7% (26/369 withdrew)
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis	Low risk	ITT analysis performed
Selective reporting (reporting bias)	Unclear risk	No study protocol registered
Similarity at baseline characteristics	Low risk	Baseline characteristics similar
Co‐interventions avoided or similar	Unclear risk	Rescue medication consisted of 1 or 2 tablets of paracetamol (500 mg); the use of rescue medication terminated the participation of the participant in the trial. No even distribution among groups.
Compliance acceptable	Low risk	Daily use of study medication was recorded in participant diary, and study medication left at the end of the trial was counted.
Timing outcome assessments similar	Low risk	Timing similar
Other bias	Low risk	None