Babej‐Dolle 1994.

Methods	RCT; observer‐blind, multicentrer study Follow‐up time: 1 to 2 days (depending on amount of injections)
Participants	Population: 260 participants, 126 women, 134 men Setting: 16 medical offices of GPs throughout Germany, May 1990 to December 1990 Inclusion criteria: age 18 years or older; lumbago or sciatic pain Exclusion criteria: hypersensitivity to drugs or drug‐related malfunction of liver or kidney, polyneuropathy, previous disk surgery or vertebral fractures, psychiatric disease, alcohol and drug abuse, pregnancy or lactation. No use of other analgesics, spasmolytics, or NSAIDs besides study medication.
Interventions	NSAIDs (i): dipyrone IM, 5 mL (= 2.5 g), once daily, 1 to 2 injections, 1 to 2 days (N = 88) NSAIDs (ii): diclofenac IM, 3 mL (= 75 mg), once daily, 1 to 2 injections, 1 to 2 days (N = 86) Reference treatment (iii): placebo, 5 mL isotonic saline, once daily, 1 to 2 injections, 1 to 2 days (N = 86)
Outcomes	Mean (SD) pain intensity (VAS) at baseline and after 6 hours: (i) 80.2 (15.4), 33.4 (25.5); (ii) 79.2 (14.5), 41.7 (25.9); (iii) 78.2 (14.8), 54.8 (25.3). (i) significantly better than (ii) and (iii) No. (%) of participants recovered after 2 days (characterising their general well‐being as 'very well'): (i) 27 (32%); (ii) 10 (12%); (iii) 7 (9%) Adverse events: (i) 4 participants (1 withdrew), (ii) 1 participant, (iii) 2 participants
Funding	The study was funded by Hoechst AG, developer of Dipyrone
Notes	Some participants with sciatic pain, not clear how many, although 22 were pretreated because of this; no subgroup analysis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation using a random number generator
Allocation concealment (selection bias)	Low risk	Drugs were randomised, pre‐packed and provided by pharmaceutical company in individualised participant's kits, which were assigned by the investigator according to the participant's order of entry to the study.
Blinding of participants and personnel (performance bias) All outcomes ‐ participants	Low risk	There was no possibility of using matched preparations, therefore, treatments were given observer‐blind to three parallel groups of outpatients.
Blinding of participants and personnel (performance bias) All outcomes ‐ careproviders	Low risk	There was no possibility of using matched preparations, but the preparation of the injection and the injection itself were carried out by two different persons.
Blinding of outcome assessment (detection bias) All outcomes ‐ outcome assessors	Low risk	Treatments were given observer‐blind to three parallel groups of outpatients; and assessments were performed by someone from the investigational staff who was unaware of the drug administered.
Incomplete outcome data (attrition bias) All outcomes ‐ dropouts	Low risk	Low dropout rate (14/260 = 5.4%)
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis	Low risk	ITT analysis performed
Selective reporting (reporting bias)	Unclear risk	No study protocol
Similarity at baseline characteristics	Low risk	Baseline characteristics similar; 22 participants with sciatic complaints were pre‐treated with NSAIDs, they had an even distribution among the 3 groups: (i) 7 participants, (ii) 9 participants, (iii) 6 participants
Co‐interventions avoided or similar	Low risk	Sciatic pain was pre‐treated in 22 participants (mostly with diclofenac, piroxicam, or ibuprofen). Besides the study medication, no other analgesics, spasmolytics, or anti‐inflammatory drugs were allowed.
Compliance acceptable	Low risk	Compliance acceptable
Timing outcome assessments similar	High risk	Similar timing of outcome assessments, but if a participant was pain‐free, there was no second injection. Maximum follow‐up was set on 24 hours after the last injection. This implies some participants had 24 hours of follow‐up and others 48 hours.
Other bias	Low risk	None