Exercise referral schemes may be cost-effective, but we don’t have enough good evidence yet

Exercising

In Exercise Referral Schemes (ERS), primary care patients who are sedentary or are likely to benefit from physical activity are referred by a primary care professional to a third party provider for a tailored exercise programme.

Are the benefits of these exercise schemes worth the costs?

Methods

Coins and tape measureThis was an economic evaluation using a cost-utility model.  The study was entirely a secondary analysis based on evidence from a range of different sources.

  1. Data on costs of ERS were estimated from observational studies
  2. Quality of life was expressed as Quality-Adjusted Life Years (QALYs)
  3. Data on the effectiveness of ERS were taken from an HTA from 2011 of exercise interventions [2] and  NICE review in 2006 that reported on coronary heart disease (CHD), stroke and colon cancer benefits from increased exercise.

Results

The overall estimate was that ERS were cost-effective, with an incremental cost-effectiveness ratio of £20,876 per QALY gained.

Put another way, for every 100,000 patients referred to an exercise service, the researchers  expected about 3,900 to become physically active.  This would prevent 51 cases of CHD, 16 strokes and 86 cases of diabetes.  Overall, the population would gain around 800 QALYs.

The cost would be around £22 million to the healthcare provider and £12 million to participants.

Sensitivity analysis showed that this model was very sensitive to all of the baseline assumptions, ranging from £679 per QALY in a best-case scenario to being dominated by usual care in a worst case scenario.

The researchers concluded:

Our analysis suggests that ERS results in only a marginal benefit in terms of QALYs at a modest cost, hence the favourable ICER. It should be noted though, that the QALY gain is based on relatively poor quality evidence on the effectiveness of ERS.

Comments

  • A woman exercising in a gym

    There isn’t enough good evidence in this model to tell whether ERS are truly cost-effective

    The abstract of this paper is a thing of beauty.  If all abstracts were like this, I’d be out of a job.

  • Except of course that the abstract doesn’t look at the underlying assumptions of the paper.  These are taken from data from surveys and other primary observational studies as well as from experimental studies.  They include some less-than-systematic assessments of  the likelihood of ERS leading to more exercise and subsequently to health benefits.
  • In quickly reviewing this underlying literature, we can say that the assumption of 3.9% of participants becoming physically active as a result of the ERS is at the conservative end of the spectrum.  However, this is in no way a systematically-derived figure.  Much of the evidence cited is very old and we would expect the true values to differ from those used in the model.
  • The evidence of effectiveness was marginal, and could be subject to change as more studies are done in this area.
  • In this case, we need to look at the sensitivity analysis.  This showed that cost-effectiveness was very sensitive to the  clinical effectiveness of the ERS.  For example, the 95% confidence range around estimates of effectiveness included the possibility that ERS could be more costly and less effective than usual care.
  • The model assumed that all health outcomes occur separately from one another, when in reality, a lot of people would have more than one outcome.  This might artificially inflate our estimate of the number of people who would benefit from the exercise scheme.
  • It is good that they include the costs to participants as this is often neglected by systems-centric economic analyses.
  • In summary, this is a good analysis of sub-optimal evidence.  Hopefully this model will be kept updated as new evidence emerges.

References

  1. Trueman P, Anokye NK. Applying economic evaluation to public health interventions: the case of interventions to promote physical activity. J Public Health (Oxf). 2013 March; 35(1): 32–39.
  2. Pavey TG, Anokye N, Taylor AH et al.IHR HTA programme. The clinical effectiveness and cost-effectiveness of exercise referral schemes: a systematic review and economic evaluation. Health Technology Assessment 2011; Vol. 15: No. 44.
  3. NICE. Modelling the cost effectiveness of physical activity interventions.  NICE 2006.