Hodgson 2000.

Methods	Randomization: yes Participant blinding: yes Provider blinding: no Assessor blinding: yes Dropouts: 0
Participants	Country: USA ASA: I and II Gender: men and women Mean age: lido: 49 (SD 12); pro: 49 (SD 12) years Procedures: arthroscopy Ambulatory surgery: yes Surgical positioning: supine Number of participants: 70
Interventions	Drug 1: 5% lido, hyperbaric, fixed dose (1 mL) Drug 2: 5% pro, hyperbaric, fixed dose (2 mL) Needle: 24 and 25 G, pencil‐point
Outcomes	TNS at 1 day
Notes	Follow‐up duration: 3 days Follow‐up method: telephone contact TNS therapy: unclear TNS resolution: 48 hours
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "randomization was accomplished by random selection of blank, closed envelopes assigned by a computer‐generated scheme to lidocaine or procaine by a numerical code which remained unbroken until data collection and assessment of all patients was complete."
Allocation concealment (selection bias)	Low risk	Quote: "randomization was accomplished by random selection of blank, closed envelopes assigned by a computer‐generated scheme to lidocaine or procaine by a numerical code which remained unbroken until data collection and assessment of all patients was complete."
Participant blinding (performance bias and detection bias)	Low risk	Quote: "the patient remained blinded to the study drug."
Provider blinding (performance bias)	High risk	Quote: "…side effects…were managed intraoperatively by the managing anesthesia team, which was not blinded to the spinal drug."
Assessor blinding (detection bias)	Low risk	Quote: "patients were contacted…by a single anesthesiologist blinded to the agent that the patient had received."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Randomized 70 participants, results reported on 70 participants.
Selective reporting (reporting bias)	Unclear risk	Study protocol not available.