Alam 2012.

Study characteristics
Methods	Randomised, double‐blind, placebo‐controlled trial Study type: single‐centre study Location: Bangladesh (Chittagong) Study design: parallel Randomisation: computer random numbers series Allocation concealment: not described Blinding: double‐blind, patients and observer Follow‐up period: 48 hours
Participants	Randomised: 60 (intervention group: 30; control group: 30) Excluded (post‐randomisation): not described Gender (women): 32 (53%) Age (years); mean (standard deviation ‐ SD): intervention group 30.32 (5.83), control group 32.49 (4.69) Baseline VAS score: mean (SD): intervention group 9.32 (0.83), control group 9.17 (1.69) Inclusion criteria: Adult patients (ASA I and II) who developed PDPH after non‐obstetric surgery Exclusion criteria: History of cluster headache, convulsion, cerebrovascular accident, pre‐eclampsia, eclampsia, coagulopathy or previous neurological diseases
Interventions	Intervention group: 100 mg hydrocortisone, diluted in 2 ml, intravenous 8‐hourly for 48 hours Control group: 2 ml of normal saline intravenously (placebo) 8‐hourly for 48 hours Co‐interventions: Conventionally treatment: recumbent positioning, intravenous or oral hydration analgesics with caffeine, stool softeners and soft diet
Outcomes	1. Change in pain severity VAS score after 6, 24 and 48 hours 2. Number of any possible adverse events 3. Number of participants with EBP performed
Notes	Post‐dural puncture headache (PDPH): Quote "The mean of headache intensity was measured in all 60 patients after 1 min in upright position." (page 191) Visual analogue scale (VAS) 10 cm: 0 to 1, no headache; 2 to 4, mild headache; 5 to 7, moderate headache; and 8 to 10, severe headache Sample size calculation: not described
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The investigator reported the use of a computer random number generator
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Quote: "The patients and the single observer were blinded to this study." (Page 191)
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data
Selective reporting (reporting bias)	High risk	The study report fails to include results for a key outcome (PDPH persistence of any severity at follow‐up) that would be expected to have been reported for such a study
Size of study	High risk	Total 60 (intervention group: 30; control group: 30)