Recently, I received this comment from a reader:
Edzard-‘I see you do not understand much of trial design’ is true BUT I wager that you are in the same boat when it comes to a design of a trial for LBP treatment: not only you but many other therapists. There are too many variables in the treatment relationship that would allow genuine , valid criticism of any design. If I have to pick one book of the several listed elsewhere I choose Gregory Grieve’s ‘Common Vertebral Joint Problems’. Get it, read it, think about it and with sufficient luck you may come to realize that your warranted prejudices against many unconventional ‘medical’ treatments should not be of the same strength when it comes to judging the physical therapy of some spinal problems as described in the book.
And a chiro added:
EE: I see that you do not understand much of trial design
Perhaps it’s Ernst who doesnt understand how to research back pain.
“The identification of patient subgroups that respond best to specific interventions has been set as a key priority in LBP research for the past 2 decades.2,7 In parallel, surveys of clinicians managing LBP show that there are strong views against generic treatment and an expectation that treatment should be individualized to the patient.6,22.”
Journal of Orthopaedic & Sports Physical Therapy
Published Online:January 31, 2017Volume47Issue2Pages44-48
Do I need to explain why the Grieve book (yes, I have it and yes, I read it) is not a substitute for evidence that an intervention or technique is effective? No, I didn’t think so. This needs to come from a decent clinical trial.
And how would one design a trial of LBP (low back pain) that would be a meaningful first step and account for the “many variables in the treatment relationship”?
How about proceeding as follows (the steps are not necessarily in that order):
- Study the previously published literature.
- Talk to other experts.
- Recruit a research team that covers all the expertise you need (and don’t have yourself).
- Formulate your research question. Mine would be IS THERAPY XY MORE EFFECTIVE THAN USUAL CARE FOR CHRONIC LBP? I know LBP is but a vague symptom. This does, however, not necessarily matter (see below).
- Define primary and secondary outcome measures, e.g. pain, QoL, function, as well as the validated methods with which they will be quantified.
- Clarify the method you employ for monitoring adverse effects.
- Do a small pilot study.
- Involve a statistician.
- Calculate the required sample size of your study.
- Consider going multi-center with your trial if you are short of patients.
- Define chronic LBP as closely as you can. If there is evidence that a certain type of patient responds better to the therapy xy than others, that might be considered in the definition of the type of LBP.
- List all inclusion and exclusion criteria.
- Make sure you include randomization in the design.
- Randomization should be to groups A and B. Group A receives treatment xy, while group B receives usual care.
- Write down what A and B should and should not entail.
- Make sure you include blinding of the outcome assessors and data evaluators.
- Define how frequently the treatments should be administered and for how long.
- Make sure all therapists employed in the study are of a high standard and define the criteria of this standard.
- Train all therapists of both groups such that they provide treatments that are as uniform as possible.
- Work out a reasonable statistical plan for evaluating the results.
- Write all this down in a protocol.
Such a trial design does not need patient or therapist blinding nor does it require a placebo. The information it would provide is, of course, limited in several ways. Yet it would be a rigorous test of the research question.
If the results of the study are positive, one might consider thinking of an adequate sham treatment to match therapy xy and of other ways of firming up the evidence.
As LBP is not a disease but a symptom, the study does not aim to include patients that all are equal in all aspects of their condition. If some patients turn out to respond better than others, one can later check whether they have identifiable characteristics. Subsequently, one would need to do a trial to test whether the assumption is true.
Therapy xy is complex and needs to be tailored to the characteristics of each patient? That is not necessarily an unsolvable problem. Within limits, it is possible to allow each therapist the freedom to chose the approach he/she thinks is optimal. If the freedom needed is considerable, this might change the research question to something like ‘IS THAT TYPE OF THERAPIST MORE EFFECTIVE THAN THOSE EMPLOYING USUAL CARE FOR CHRONIC LBP?’
My trial would obviously not answer all the open questions. Yet it would be a reasonable start for evaluating a therapy that has not yet been submitted to clinical trials. Subsequent trials could build on its results.
I am sure that I have forgotten lots of details. If they come up in discussion, I can try to incorporate them into the study design.