Study concept and design: Leidenius, Tasmuth, Kalso.
Acquisition of data: Leidenius, Tasmuth, Kalso.
Analysis and interpretation of data: Meretoja, Leidenius, Tasmuth, Sipilä, Kalso.
Drafting of the manuscript: Meretoja, Leidenius, Kalso.
Critical revision of the manuscript for important intellectual content: Meretoja, Leidenius, Tasmuth, Sipilä, Kalso.
Statistical analysis: Meretoja.
Obtained funding: Meretoja, Kalso.
Administrative, technical, or material support: Tasmuth, Kalso.
Study supervision: Kalso.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Kalso reported serving as a consultant to Pharmaleads and Orion Pharma; receiving payment for lectures from Pfizer, Mundipharma, Jansen-Cilag, Merck Sharp Dohme, Gruenental, and Orion Pharma; holding patents with Orion Pharma and Licentia (formerly the University of Helsinki patent office); receiving payment for the development of educational presentations from Jansen-Cilag and Gruenenthal; and owning stock in Orion Pharma.
Funding/Support: This work was supported by grants from the Academy of Finland and Helsinki and Uusimaa Hospital District and by funding from the Orion-Pharmos Research Foundation and the Emil Aaltonen Foundation.
Role of the Sponsor: The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: We also thank Eija R. Ruoppa, RN, and Minna Kaiponen, RN (Department of Anaesthesia, Intensive care Medicine, Emergency Medicine and Pain Medicine, Helsinki University Central Hospital), and the nurses, physicians, and physiotherapists who participated in the treatment and recruitment of the patients. We are grateful to the patients who participated in this study and diligently returned several questionnaires. The persons named were not compensated for study assistance beyond their salaries.