Zoppi 1995.

Methods	Randomized, double‐blind, parallel group trial of 7 days duration.
Participants	Adults with radiographic OA of the knee. Mean age 56 years. 62% female.
Interventions	Acetaminophen 1000 mg po tid versus placebo.
Outcomes	Pain, functional assessments, patient global assessments, number of awakenings during the night.
Notes	This study was identified only through the meta‐analysis published by Zhang et al, 2004.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear