Rehman 2015.

Methods	RCT
Participants	Included: 45 unmarried participants (primary dysmenorrhoea) between the ages of 15 to 25 years with regular menstrual cycles that lasted from 21 to 35 days with 2 to 6 days of flow, with moderate to severe dysmenorrhoea Excluded: women with pelvic pathology, irregular cycles, systemic illness, married women, allergic to NSAIDs and mild dysmenorrhoea, with a thyroid profile (to exclude systemic illnesses), taking any drug that could influence the study outcomes (such as NSAIDs and oral contraceptive pills) Age: mean rhubarb group = 18.87 years, mefenamic acid group = 17.73 years Source: women with primary dysmenorrhoea Location: India
Interventions	Group 1: rhubarb was finely powdered and filled in 500 mg capsules (N = 30); each capsule contained ˜420 mg of the powdered drug. Participants took 3 capsules of rhubarb twice a day, began treatment 2 days before the menstruation, and continued until the first 3 days of menstruation for 3 consecutive cycles Group 2: mefenamic acid (250 mg) (N = 15) was powdered and filled in capsules similar to the test drug Control group patients took capsules of mefenamic acid 3 times a day after meals for the same protocol
Outcomes	Primary Change in severity (pain severity was assessed by VAS (scale 10 cm), severity of dysmenorrhoea was assessed by verbal multi‐dimensional scoring system (VMSS) (0 to 3; 0 = painless, 3 =severe)); duration of menstrual pain from baseline to last follow‐up (pain duration was graded as: grade 0 = no pain, grade 1 = pain persisted for < 12 hours, grade 2 = 12 to 24 hours, and grade 3 = > 24 hours). Secondary Overall improvement in dysmenorrhoea (measured by change in associated symptoms at baseline and after 3‐cycle intervention (such as fatigue, nausea, vomiting, headache, and anorexia; scale 0 to 3; 0 = painless, 3 = severe); improvement in quality of life (QoL) (measured by the American Chronic Pain Association, graded from 0 to 10; 0 = non‐functioning and 10 = normal QoL); adverse reactions or events (serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase, blood urea, serum creatinine, and serum uric acid at baseline and after 3 cycles of treatment). All participants were requested to report any adverse effect during the trial, such as gastric upset, diarrhoea and constipation, and any change in the menstrual cycle during the trial.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“Patients were randomised into 2:1 ration by simple randomizations (lottery method) to receive either rhubarb (i.e. experimental group, n=30) or mefenamic acid (control group, n=15).”
Allocation concealment (selection bias)	High risk	“Investigator assigned the participants to interventions but the participants were not aware about the treatment.” “the participants were blinded to the treatment allocation.” Comment: the investigator knew in advance what intervention a particular participant would have.
Blinding (performance bias and detection bias) All outcomes	Low risk	“This was a single‐blind trial. The appearances of the experimental and control drug capsules were identical, and no aroma was detected from either”.
Incomplete outcome data (attrition bias) All outcomes	Low risk	“45 were randomised into experimental and control groups. Three patients in the control group did not come for last follow up; information regarding lost to follow up was not obtained. The final analysis was conducted on 45 patients” Comment: an intention to treat analysis was applied
Selective reporting (reporting bias)	Unclear risk	“In the rhubarb group, six (20%) patients were given the history of side effects out of which two patients complained bloating and four patients diarrhoea for the last two days of last cycle. As diarrhoea and bloating were mild and were not so much troubling, so the trial continued. No other side effects such as heart burn, abdominal pain and vomiting were reported by patients.” Comment: it is unclear whether or not data on adverse effects was collected systematically in both groups.
Other bias	Low risk	Comment: we did not identify any other potential sources of bias.