Study protocol

Differences across health care systems in outcome and cost-utility of surgical and conservative treatment of chronic low back pain: a study protocol

Markus Melloh^1,2 , Christoph Röder¹ , Achim Elfering³ , Jean-Claude Theis² , Urs Müller¹ , Lukas P Staub¹ , Emin Aghayev¹ , Thomas Zweig¹ , Thomas Barz⁴ , Thomas Kohlmann⁵ , Simon Wieser⁶ , Peter Jüni⁷ and Marcel Zwahlen⁷

¹  MEM Research Center for Orthopaedic Surgery, University of Berne, Stauffacherstrasse 78, 3014 Berne, Switzerland

²  Section of Orthopaedic Surgery, Department of Medical and Surgical Sciences, Dunedin School of Medicine, University of Otago, Private Bag 1921, Dunedin, New Zealand

³  Department for Work and Organizational Psychology, Institute for Psychology, University of Berne, Muesmattstrasse 45, 3000 Berne 9, Switzerland

⁴  Department of Orthopaedic Surgery, Asklepius Klinikum Uckermark, Auguststrasse 23, 16303 Schwedt/Oder, Germany

⁵  Department of Methods in Community Medicine, Institute for Community Medicine, University of Greifswald, Walther-Rathenau-Strasse 48, 17487 Greifswald, Germany

⁶  Institute of Health Economics, Zurich University of Applied Sciences, Im Park, St. Georgenstrasse 70, Postfach 958, 8401 Winterthur, Switzerland

⁷  Research Support Unit, Institute of Social and Preventive Medicine (ISPM), University of Berne, Finkenhubelweg 11, 3012 Berne, Switzerland

author email corresponding author email

BMC Musculoskeletal Disorders 2008, 9:81doi:10.1186/1471-2474-9-81

Published:	6 June 2008

Abstract

Background

There is little evidence on differences across health care systems in choice and outcome of the treatment of chronic low back pain (CLBP) with spinal surgery and conservative treatment as the main options. At least six randomised controlled trials comparing these two options have been performed; they show conflicting results without clear-cut evidence for superior effectiveness of any of the evaluated interventions and could not address whether treatment effect varied across patient subgroups. Cost-utility analyses display inconsistent results when comparing surgical and conservative treatment of CLBP. Due to its higher feasibility, we chose to conduct a prospective observational cohort study.

Methods

This study aims to examine if

1. Differences across health care systems result in different treatment outcomes of surgical and conservative treatment of CLBP

2. Patient characteristics (work-related, psychological factors, etc.) and co-interventions (physiotherapy, cognitive behavioural therapy, return-to-work programs, etc.) modify the outcome of treatment for CLBP

3. Cost-utility in terms of quality-adjusted life years differs between surgical and conservative treatment of CLBP.

This study will recruit 1000 patients from orthopaedic spine units, rehabilitation centres, and pain clinics in Switzerland and New Zealand. Effectiveness will be measured by the Oswestry Disability Index (ODI) at baseline and after six months. The change in ODI will be the primary endpoint of this study.

Multiple linear regression models will be used, with the change in ODI from baseline to six months as the dependent variable and the type of health care system, type of treatment, patient characteristics, and co-interventions as independent variables. Interactions will be incorporated between type of treatment and different co-interventions and patient characteristics. Cost-utility will be measured with an index based on EQol-5D in combination with cost data.

Conclusion

This study will provide evidence if differences across health care systems in the outcome of treatment of CLBP exist. It will classify patients with CLBP into different clinical subgroups and help to identify specific target groups who might benefit from specific surgical or conservative interventions. Furthermore, cost-utility differences will be identified for different groups of patients with CLBP. Main results of this study should be replicated in future studies on CLBP.