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Response by Dr Mark Williams on 7 April 2017 at 12:29 PM
Author Response HTA Vol19 Issue 55

We would like to thank the authors of the preceding comment for their views and advice regarding a possible RCT of exercise in adolescent idiopathic scoliosis. In the interests of clarity and to provide some rationale behind the decisions made, we would like to respond to the points raised.

1) “…are planning to test the effects of seas exercises.”

It is not our intention to test the SEAS (Scientific Exercises Approach to Scoliosis) programme, nor any other school of exercise therapy that has been developed to treat scoliosis. We have however used the principles developed by SOSORT and embodied in the SEAS programme as a base from which we designed a scoliosis specific exercise (SSE) programme for the pilot phase of the ACTIvATeS feasibility study [1], and which may go on to be tested as part of a full RCT.

The reasoning behind this is that funding for any trial would come from the UK National Health Service (NHS) and would be to test a specific exercise intervention that, if successful, would be possible to implement in the UK NHS. Therefore, it is not a test of efficacy, rather a test of effectiveness within a particular environment.

Also, very few therapists in the UK treat patients with scoliosis on a regular basis and there is very little NHS provision of any form of conservative therapy (including bracing) apart from routine monitoring. Many of the schools of scoliosis-specific exercise involve intensive bouts of therapy which would not be feasible in the NHS under current conditions. It is also very unlikely that the NHS would fund therapists to travel to Europe to undertake the training that would be required to become experts in any particular methodology, particularly as current reviews suggests that there “is a lack of high quality evidence to recommend the use of SSE for AIS” [2]. Therefore, we had to develop a programme that, whilst incorporating aspects of regimens such as SEAS, was able to be taught to therapists across multiple NHS hospital clinics and within the bounds of normal NHS outpatient therapy practice (with its limitations of contact time, frequency/number of sessions, access to resources etc.). We believe it is not beyond the scope of an experienced musculoskeletal physiotherapist to deliver this type of treatment and we worked with experienced practitioners to develop the exercise programme and training package.

2) “…we cannot fall in the mistake to expect that scoliosis specific exercises will substitute braces.”

The brief from the NHS funders that formed the basis of the pilot RCT was to perform an evaluation of SSE, not bracing or other treatments. Therefore, ACTIvATeS was designed for this purpose. However, bracing was permitted at the discretion of their Consultant surgeon, along with other aspects of routine monitoring and care, and information on its use was collected, i.e. SSE was not a substitute for routine care/bracing but was performed alongside it. Note that relatively small numbers of participants were prescribed braces (18%) which is consistent with the relatively low use of bracing in the UK, even amongst people with larger curves as reported in the survey of current practice that was conducted as part of ACTIvATeS. This is probably due to the evidence again suggesting that there is only low quality evidence for its effectiveness [3] despite the study by Weinstein et al [4].

3) “…Is it ethical to include patients at higher risk of progression with curves' magnitude above 25 Cobb degrees?”

We felt it was important to include all patients (with Cobb angle 10-50^o) as there is no strong evidence to suggest which patient groups (e.g. lower v higher Cobb angles) might benefit most from an SSE programme. In our pilot study, ~80% had curves >25^o and ~38% had curves =40^o, therefore limiting to those below 25^o would make recruiting to any trial very difficult as well as missing out on what is potentially the group most in need. Also, despite being an important factor, curve size alone is not the sole indicator of potential curve progression.

 

Patients were eligible for the ACTIvATeS study if they were not currently being considered for surgery and therefore, the only treatment being received by the majority of participants prior to inclusion in the trial was ‘watchful waiting’, with a small minority also receiving bracing. Treatments such as surgery or bracing were not withheld from study participants if their Consultant felt it was indicated.

 

However, the point raised is a worthy one and it might be worthwhile designing any future RCT to allow analysis of the response to SSE according to curve magnitude, whether that be through sub-grouping or other means. 

4) “…the absence of details about the selection of the physiotherapists and the management of exercises in the feasibility study. To guarantee the quality of a scoliosis specific exercises approach, the exercises plan must be prepared, taught and checked by skilled, experienced and certified in the chosen approach physiotherapists.”

If a SSE programme is to be provided by the NHS, it will most likely be implemented by a wide variety of physiotherapists of varying levels of expertise, experience and familiarity with scoliosis. Therefore, it is important that the therapists who deliver the intervention as part of a trial are of similar background (see earlier comment re: trial of effectiveness and NHS unlikely to fund specialist training). It is important to point out that the exercise programme developed for ACTIvATeS was a specific scoliosis exercise programme incorporating many of the principles and some of the practice of SEAS and other scoliosis-specific programmes. It was not a general exercise regime. This programme was standardised and manualised as described in the HTA report and all the therapists underwent training in its delivery albeit this was of shorter duration than that required for proprietary SEE programmes.

5) “…having as main outcome surgery avoidance.”

The proposed primary outcome for a future trial was the Cobb angle as an indicator of curve progression. Progression to surgery was proposed as a secondary outcome. Surgery avoidance was mentioned as one of the main aims of an SSE programme based on SOSORT guidelines [5]. Demonstrating cost-effectiveness is vital if this type of treatment is to be taken up by the NHS. If it is demonstrated that surgery can be avoided in even a small proportion of patients then the likelihood of the intervention being cost-effective increases and provides justification for providing this type of treatment. Without this type of data, commissioners are unlikely to fund this treatment. The recent study by Monticone [6] reported favourable outcomes for Cobb angle but did not report surgical rates or cost-effectiveness data which is needed by commissioners of treatments.

6) “…there is a significant risk to fail the study and to have a large number of patients loss at follow up due to curve progression, with a significant damage to the power of your study and a threaten to internal validity.”

As with any RCT, confidence in results can be compromised by a high drop-out rate. However, participants experiencing curve progression or going on to receive surgery would not be withdrawn from the trial as these are important outcomes and these patients would be followed up. It may indicate that the intervention being tested is ineffective, but would not constitute a failure of the trial itself.

 

 

7) “The risk of type II error increases because it is expected your intervention will [have] a very small effect and a low efficacy.”

There is the possibility of a future RCT producing a negative result with regard to the effectiveness of the SSE intervention being tested. In order to be confident that this is a true result, the methodology employed will have been carefully designed by experts in trial methodology and have undergone intensive review by the funders in a competitive process. It will then be conducted under the auspices of a UK CRC-registered Clinical Trials Unit with extensive experience in conducting such studies.

 

A future trial would need to be adequately powered to detect a small effect size. The purpose of the feasibility study was to get data on which to base the sample size calculations so that it was large enough to detect an effect. The research team is very experienced in conducting trials of rehabilitation where effect sizes are often quite small, and will make the necessary adjustments and sample size calculations to account for this.

 

Before conducting a RCT, it is the policy of our research group to publish a protocol and intervention description which provides all the details of the intended methodology and the intervention itself along with a rationale. Therefore, if we do pursue a full scale RCT, we believe many of the queries raised by the commentators will be answered by these publications.

 

In conclusion, whilst we welcome all such comments and constructive criticism, it appears that many of the points raised are due to a misunderstanding over the purpose of a trial of SSE within the NHS, with all its limitations and restrictions. If future treatment for scoliosis is to be funded by the NHS, it has to be deliverable in the NHS as well as demonstrate clinical and cost effectiveness. 

 

[1] Williams MA, Heine PJ, Williamson EM, Toye F, Dritsaki M, Petrou S, et al. Active Treatment for Idiopathic Adolescent Scoliosis (ACTIvATeS): a feasibility study. Health Technol Assess 2015; 19 (55).

 

[2] Romano M, Minozzi S, Bettany-Saltikov J, Zaina F, Chockalingam N, Kotwicki T, Maier-Hennes A, Negrini S. Exercises for adolescent idiopathic scoliosis. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD007837. DOI:10.1002/14651858.CD007837.pub2.

 

[3] Negrini S, Minozzi S, Bettany-Saltikov J, Chockalingam N, Grivas TB, Kotwicki T, Maruyama T, Romano M, Zaina F. Braces for idiopathic scoliosis in adolescents. Cochrane Database of Systematic Reviews 2015, Issue 6. Art. No.: CD006850. DOI: 10.1002/14651858.CD006850.pub3.

 

[4] Weinstein SL, Dolan LA, Wright JG, Dobbs MB. Effects of Bracing in Adolescents with Idiopathic Scoliosis. NEJM, 2013, 369 (16): 1512-21.

 

[5] Negrini S, Aulisa AG, Aulisa L, Circo AB, de Mauroy JC, Durmala J, Grivas TB, Knott P, Kotwicki T, Maruyama T, Minozzi S, O’Brien JP, Papadopoulos D, Rigo M, Rivard CH, Romano M, Wynne JH, Villagrasa M, Weiss HR, Zaina F. 2011 SOSORT guidelines: Orthopaedic and Rehabilitation treatment of idiopathic scoliosis during growth. Scoliosis 2012, 7: 3.

 

[6] Monticone M, Ambrosini E, Cazzaniga D, Rocca B, Ferrante S. Active self-correction and task-oriented exercises reduce spinal deformity and improve quality of life in subjects with mild adolescent idiopathic scoliosis. Results of a randomised controlled trial. Eur Spine J. 2014; 23 (6): 1204–14

 

Response by Dr Sabrina Donzelli on 2 March 2017 at 10:27 AM
Letter to journal library for ACTIvATeS RCT feasibilty Study Asset ID 170759

After years of decrease of research in Conservative treatment (1), the birth of the new Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT) gave rise to an increased attention and production of evidence (2–4), and consequently of interest in scoliosis conservative treatment, even in the countries that in the last 20 years shifted to surgical treatment mainly (Northern Europe and US). As specialist with large expertise in conservative treatment we really appreciate this changing attitude towards conservative treatment. This interest strenghtens the request for higher quality evidences by the scientific community.

In this view, a randomized controlled trial such as ACTIvATeS(5) attempting to deepen the efficacy of exercises is really appreciated. We have recently been made aware that the authors are planning to test the effects of seas exercises: as developers and teachers of this technique, whose efficacy has already been shown by a RCT (3,6) we are honored of that choice, but at the same time we want to share with the authors of the present feasibility study some main concerns. Our attempt is to improve the methodology you plan, thus guaranteeing a higher margin of success of your work. Brace showed efficacy in avoiding surgery in subjects with adolescent idiopathic scoliosis according to Weinstein results(7). The study was performed with a rigorous methodology and confirmed what previously shown in other studies. (8,9)

The current international guidelines for conservative treatment (10) recommend the use of braces for curve exceeding the 20 - 25 Cobb degrees with an available level of evidence I. Therefore even though we strongly agree that physiotherapic scoliosis specific exercises (PSSE) are a promising and widely underestimated intervention, we cannot fall in the mistake to expect that scoliosis specific exercises will substitute braces.

We have some concerns with the inclusion criteria you are planning to apply for the ACTvATeS trial. Is it ethical to include patients at higher risk of progression with curves' magnitude above 25 Cobb degrees? According to the Sosort International Guidelines the use of exercises only in these patients can be defined an undertreatment.

In addition PSSEs are typically characterized by small effect size. Another concern is the absence of details about the selection of the physiotherapists and the management of exercises in the feasibility study. To guarantee the quality of a scoliosis specific exercises approach, the exercises plan must be prepared, taught and checked by skilled, experienced and certified in the chosen approach physiotherapists. When these requirements are not met, scoliosis specific exercises are no more therapeutic exercises and become general exercises, with no intended efficacy in treating diseases. Monticone's RCT (3) showed that there is a significant difference between scoliosis specific exercises (his experimental group) and general exercises (his control group).

Including in your study patients at high risk of progression, having them treated by unqualified physiotherapists and having as main outcome surgery avoidance, there is a significant risk to fail the study and to have a large number of patients loss at follow up due to curve progression, with a significant damage to the power of your study and a threaten to internal validity. The risk of type II error increases because it is expected your intervention will a very small effect and a low efficacy.

In conclusion, the ACTvATes feasibility study demonstrates a very good methodology and a good attention to the possible threatens to the trial, but we encourage the authors to consider very carefully the inclusion criteria and the quality of the intervention to be tested which should be more adherent with the current guidelines for scoliosis conservative treatment.

References 1. Negrini S. Approach to scoliosis changed due to causes other than evidence: patients call for conservative (rehabilitation) experts to join in team orthopedic surgeons. Disabil Rehabil. 2008;30(10):731–41.

2. Schreiber S, Parent EC, Hedden DM, Moreau M, Hill D, Lou E. Effect of Schroth exercises on curve characteristics and clinical outcomes in adolescent idiopathic scoliosis: protocol for a multicentre randomised controlled trial. J Physiother. 2014 Dec;60(4):234.

3. Monticone M, Ambrosini E, Cazzaniga D, Rocca B, Ferrante S. Active self-correction and task-oriented exercises reduce spinal deformity and improve quality of life in subjects with mild adolescent idiopathic scoliosis. Results of a randomised controlled trial. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv Spine Res Soc. 2014 Jun;23(6):1204–14.

4. Monticone M, Ambrosini E, Cazzaniga D, Rocca B, Motta L, Cerri C, et al. Adults with idiopathic scoliosis improve disability after motor and cognitive rehabilitation: results of a randomised controlled trial. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv Spine Res Soc. 2016 Mar 25;

5. Williams MA, Heine PJ, Williamson EM, Toye F, Dritsaki M, Petrou S, et al. Active Treatment for Idiopathic Adolescent Scoliosis (ACTIvATeS): a feasibility study. Health Technol Assess Winch Engl. 2015 Jul;19(55):1–242.

6. Negrini S, Bettany-Saltikov J, De Mauroy JC, Durmala J, Grivas TB, Knott P, et al. Letter to the Editor concerning: “Active self-correction and task-oriented exercises reduce spinal deformity and improve quality of life in subjects with mild adolescent idiopathic scoliosis. Results of a randomised controlled trial” by Monticone M, Ambrosini E, Cazzaniga D, Rocca B, Ferrante S (2014). Eur Spine J; DOI:10.1007/s00586-014-3241-y...Eur Spine J. 2014 Jun;23(6):1204-14. Eur Spine J. 2014 Oct;23(10):2218–20.

7. Dolan LA, Wright JG, Weinstein SL. Effects of bracing in adolescents with idiopathic scoliosis. N Engl J Med. 2014 Feb 13;370(7):681.

8. Nachemson AL, Peterson LE. Effectiveness of treatment with a brace in girls who have adolescent idiopathic scoliosis. A prospective, controlled study based on data from the Brace Study of the Scoliosis Research Society. J Bone Joint Surg Am. 1995 Jun;77(6):815–22.

9. Negrini S, Minozzi S, Bettany-Saltikov J, Chockalingam N, Grivas TB, Kotwicki T, et al. Braces for idiopathic scoliosis in adolescents. Cochrane Database Syst Rev. 2015;6:CD006850.

10. Negrini S, Aulisa AG, Aulisa L, Circo AB, de Mauroy JC, Durmala J, et al. 2011 SOSORT guidelines: Orthopaedic and Rehabilitation treatment of idiopathic scoliosis during growth. Scoliosis. 2012;7(1):3.