Author Contributions: Mr Wilkens had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Wilkens, Scheel, Grundnes, Hellum, Storheim.
Acquisition of data: Wilkens, Storheim.
Analysis and interpretation of data: Wilkens, Scheel, Grundnes, Hellum, Storheim.
Drafting of the manuscript: Wilkens, Scheel, Hellum, Storheim.
Critical revision of the manuscript for important intellectual content: Wilkens, Scheel, Grundnes, Hellum, Storheim.
Statistical analysis: Wilkens.
Obtained funding: Wilkens, Scheel, Grundnes, Storheim.
Administrative, technical, or material support: Wilkens, Storheim.
Study supervision: Wilkens, Scheel, Grundnes, Hellum, Storheim.
Financial Disclosures: None reported.
Funding/Support: The study was supported by grants from the EXTRA funds from the Norwegian Foundation for Health and Rehabilitation through the Norwegian Low Back Pain Association, Norwegian Chiropractic Associations Research Fund, and Wilhelmsens Research Fund. The study medications (glucosamine and placebo) were produced by and purchased from Pharma Nord. Pharma Nord was chosen as the study agent supplier after all companies with marketing approvals in Norway were asked if they wanted to contribute with their product to the trial.
Role of the Sponsor: The Norwegian Foundation for Health and Rehabilitation, the Norwegian Low Back Pain Association, Norwegian Chiropractic Associations Research Fund, and Wilhelmsens Research Fund had no role in design or conduct of the study, collection or analysis of the data, or preparation of the manuscript. Pharma Nord had no involvement in conducting the study, or publishing results from the study.
Additional Contributions: We thank the patients who participated in the trial, the support form Oslo University Hospital Ulleval, and the referring health personnel. We would also like to thank Leiv Sandvik, PhD (professor in biostatistics, Oslo University Hospital), for statistical advice, and Irene Syse, BSN (Oslo University Hospital), for data monitoring, for which they received no compensation. Additionally, we would like to thank Lucy Hyatt, PhD, for critically editing the manuscript, for which she received £275.