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Lifestyle interventions for knee pain in overweight and obese adults aged ≥45: economic evaluation of randomised controlled trial

BMJ 2009; 339 doi: (Published 19 August 2009) Cite this as: BMJ 2009;339:b2273
  1. Garry R Barton, senior lecturer in health economics1,
  2. Tracey H Sach, senior lecturer in health economics123,
  3. Claire Jenkinson, research associate2,
  4. Michael Doherty, professor of rheumatology4,
  5. Anthony J Avery, professor of primary care2,
  6. Kenneth R Muir, professor of epidemiology2
  1. 1Health Economics Group, School of Medicine, Health Policy and Practice, University of East Anglia, Norwich NR4 7TJ
  2. 2School of Community Health Sciences, University of Nottingham, Nottingham NG7 2RD
  3. 3School of Pharmacy, University of East Anglia, Norwich
  4. 4Academic Rheumatology, University of Nottingham, Nottingham
  1. Correspondence to: T Sach, School of Pharmacy, University of East Anglia, Norwich NR4 7TJ T.Sach{at}
  • Accepted 12 December 2008


Objective To estimate the cost effectiveness of four different lifestyle interventions for knee pain.

Design Cost utility analysis of randomised controlled trial.

Setting Five general practices in the United Kingdom.

Participants 389 adults aged ≥45 with self reported knee pain and body mass index (BMI) ≥28.

Interventions Dietary intervention plus quadriceps strengthening exercises, dietary intervention, quadriceps strengthening exercises, and leaflet provision. Participants received home visits over a two year period.

Main outcome measure Incremental cost per quality adjusted life year (QALY) gained over two years from a health service perspective.

Results Advice leaflet was associated with a mean change in cost of −£31, and a mean QALY gain of 0.085. Both strengthening exercises and dietary intervention were more effective (0.090 and 0.133 mean QALY gain, respectively) but were not cost effective. Dietary intervention plus strengthening exercises had a mean cost of £647 and a mean QALY gain of 0.147 and was estimated to have an incremental cost of £10 469 per QALY gain (relative to leaflet provision), and a 23.1% probability of being cost effective at a £20 000/QALY threshold.

Conclusion Dietary intervention plus strengthening exercises was estimated to be cost effective for individuals with knee pain, but with a large level of uncertainty.

Trial registration ISRCTN93206785.


  • Contributors: KRM was principal investigator. All authors contributed towards the development of the economic evaluation protocol. GRB and THS analysed the economic data, wrote the original draft, and are guarantors. All authors commented on the draft and the interpretation of the findings.

  • Funding: The study was funded by the UK Arthritis Research Campaign (ARC) (grant No 13550). ARC had no role in study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication.

  • Competing interests: None declared.

  • Ethical approval: This study was approved by the Nottingham research ethics committee (REC Q1090219); all participants gave informed consent.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: and

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