Erika Maude, our Clinic Principal, delivered a scientific presentation to the 2019 SOSORT conference in San Francisco last week.
Watch the video below to see her presentation in full.
Erika Maude: Hello everybody, and thank you for having me along today. This is a continuation of the research that my colleague Jason Black first presented in Lyon two years ago looking at the cost-effectiveness of exercise therapy for adults with scoliosis.
Introduction - Health Economics
Adult patients with idiopathic scoliosis have been shown to present with impaired health-related quality of life. Therefore, in health systems globally, a key objective of treatment is to improve quality of life whilst maintaining cost-effectiveness. The cost-effectiveness of PSSEs [physiotherapeutic scoliosis-specific exercises] has not been researched, and thus conclusions about whether or not they are a viable economic alternative to surgery or bracing for healthcare systems cannot be made.
In the UK, the National Health Service offers spinal fusion surgery as the only treatment for adults with idiopathic scoliosis. They treat about 360 cases per year, each costing £24,853. Under cost-utility analysis, cost-effective analysis estimates the cost of treatment. It is used to inform funding decisions based on the benefit of treatment versus how much it costs. It requires extrapolation of data because it estimates the lifetime benefits of treatment.
Introduction - QALYs
The primary outcome of cost-utility analysis is the cost per quality-adjusted life year, or 'QALY' for short - otherwise known as the incremental cost-effectiveness ratio, which I'll come onto a bit more in a moment. QALYs analyse both the quality and the quantity of life years, where (rather morbidly) 0 equals death and 1 equals perfect health. QALY are accumulative, and thus a 0.2 QALY improvement lasting for 5 years equals 1 QALY for the patient.
The ICER [incremental cost-effectiveness ratio] is calculated as the difference in the expected cost of Intervention A compared to Intervention B divided by the difference in the expected QALYs produced by Intervention A and Intervention B. Generally, it is considered that the interventions costing the UK's National Health Service less than £30,000 per QALY gained are deemed to be cost-effective.
Introduction - EQ-5D
The EQ-5D is the measure preferred by the UK's National Institute of Clinical Excellence [NICE] for comparing cost-effectiveness. It's a descriptive system, and it defines health-related quality of life in terms of five dimensions:
- Usual activities
- Pain and discomfort
- Anxiety and depression
Responses to each of these dimensions are divided into three levels (1st, no problems; 2nd, some to moderate problems; and 3rd, severe to extreme problems), thus generating a total of 243 possible health states. On the left is an example EQ-5D form, which can only be used with licensed permission.
The aim of this study was to explore the cost-effectiveness of physiotherapeutic scoliosis-specific exercises for adult patients with idiopathic scoliosis using an intensive, group-based therapy approach.
183 consecutively-recruited UK-based adult patients (with an average age of 38.5 years at the start of treatment) attending the Scoliosis SOS Clinic in London for intensive ScolioGold treatment filled out the EQ5D5L questionnaire at 5 different time points:
- Before treatment
- After treatment
- 6 months check-up
- 12 months check-up
- 18 months check-up
The EQ-5D results were then converted into QALYs using assumptions about the duration of treatment effect. A linear regression model was then used to statistically analyse the results.
Results - Response Rate
Due to the method of data collection, consecutive nature of patient recruitment, and time limitations imposed by the 3-year EQ5D5L licence, 100% of the participants completed the questionnaire pre-treatment, 91% immediately post-treatment, 68% at their 6-month check-up, with 51% at both 12- and 18-month check-ups.
Results - EQ5D5L Scores
Before treatment, the average EQ-5D score was 0.773, and immediately after treatment, this increased to an average of 0.881. At 6 months, the average was 0.862, and at both 12 and 18 months check-up, the average was maintained at 0.863. All of these changes were statistically significant.
Results - Calculation of QALYs
Although patient scores were statistically much improved at 12 and 18 months post-treatment, due to the fewer number of patients who reached the later time points, reliable data was only available up to 6 months following treatment, and therefore an assumption on the persistence of the treatment effect is required for later time points. To look at both extremes: assuming that the treatment benefit ended after just six months, additional QALYs were 0.045, which means that the ICER would be £90,000 per QALY. However, assuming that the treatment effect continued for 43.8 years (the average life expectancy of the patients in this study), then additional QALYs were 3.899, meaning the ICER would fall to just £1,000 per QALY.
Therefore, to meet NICE's requirements for health economics, the effects of treatment would need to persist for 1.5 years.
In conclusion, EQ-5D results improved with PSSE in adult patients with idiopathic scoliosis. If the treatment effect of the PSSEs persists for only 1.5 years, it is expected to be cost-effective in UK-based adults. Further long-term research is required to start planning for PSSE to become available within national healthcare services; with publication of these results, we hope to highlight that the input of physiotherapy in this patient group should warrant funding.
We are aware that there are several limitations to this study, namely lack of a control group, limited long-term follow-up, and no data on cost savings from exercise therapy.
Thank you for listening.
More Scoliosis Research > About Erika and the Team >