Kokki 2000.

Methods	Design: parallel‐group (2 arms), open, randomized Country: Finland Multisite: no Needle type design used: pencil point and cutting point Needle diameter used: a 50 mm long 25 G needle was used in children up to 7 years and a 90 mm long 27 G needle for older children Procedure: anaesthesia Number of attempts (1 to 2): 97% Site of the puncture: unknown Training level of those who administered the puncture: unknown Median or paramedian technique: midline approach Type of anaesthetic: hyperbaric bupivacaine 5 mg ml‐1 (MarcainA, Astra, Sodertelje, Sweden) was used at a dose of 0.4 mg kg‐1 in children up to 7 years and at a dose of 0.3 mg kg‐1 in older children Patient position: unknown
Participants	1. 215 patients enrolled (ASA I‐II children, aged 1 to 18 years, undergoing surgery below the umbilicus) Patients randomized to: Pencil point (106) Cutting point (109) 2. 1 patient randomized was excluded from the complication analysis 4. Main characteristics of patients: Median age in years: pencil point group: 9; cutting point group: 8 Number of females/males: pencil point group: 36/70; cutting point group: 40/69 Number of ASA I/II: pencil point group: 82/27; cutting point group: 84/22
Interventions	Pencil point group: Pencan, B‐Braun, Melsungen, Germany, duration: 48 seconds Cutting point group: Yale, Becton‐Dickinson, Madrid, Spain. Duration: 40 seconds Co‐intervention: each child was premedicated with diazepam and fentanyl cream was used at the puncture sites
Outcomes	Outcomes were not classified as primary or secondary Incidence of PDPH Post‐puncture complaints Severity of PDPH Any headache
Notes	Trial registration: not stated Funder: not stated Role of funder: not stated A priori sample size estimation: no Conducted: December 1997 to January 1999 Declared conflicts of interest: no
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The random allocation schedule was generated by a computer and concealed until the patient arrived in the operating theatre (…)" (page 211)
Allocation concealment (selection bias)	Unclear risk	Insufficient information to assess this item as low or high risk
Blinding of participants (performance bias)	Low risk	Quote: "Patients, parents and post‐anaesthesia care unit (PACU) nurses were unaware of the type of needle used. (…)" (page 211)
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote: "using an open‐randomised, parallel‐groups, and prospective design (…)" (page 211)
Incomplete outcome data (attrition bias) All outcomes	Low risk	1 patient was lost to follow‐up
Selective reporting (reporting bias)	Low risk	All patient‐important outcomes were reported
Other bias	Low risk	No other biases were identified