It is time for using adequate assessment and new designs to improve the effectiveness of treatment in chronic musculoskeletal pain

Chronic pain in European society is highly prevalent (19%), causing many personal as well as societal problems (1). Complaints of the spine and other parts of the musculoskeletal system are the most common. Besides pain-relieving drugs, many patients suffering from musculoskeletal pain are being referred to primary care physiotherapists. However, many of these patients cannot be sufficiently treated and develop/maintain chronic pain and disability, such as loss of personal relevant activities and experiencing problems with participation such as work. But what treatment should be provided to whom? To answer this question, we still need more clear theories that explain the development and maintenance of chronic musculoskeletal pain and its associated disability. For the assessment of a patient, the WHO International Classification of Functioning, Disability and Health (ICF) provides a nice framework (2). Assessment of all aspects of function, activity and participation, and personal and environmental factors, should be done properly. Next, especially in the cases in which no resolvable/treatable function disorder can be diagnosed, one should focus on improving the level of activities and participation in close collaboration with the patient. It is the patient who has to take responsibility for changing his/her situation and we, as professionals, should coach the patient, while providing the best evidence-based care. Nevertheless, in daily practice, many types of treatment are still provided without a proper cause. For example, we still state that patients with musculoskeletal pain are physically deconditioned without even testing this properly, or knowing that many patients, despite having pain for an extensive period, have no reduced physical fitness (3). Next we provide training that is not even fulfilling physiological training principles (4). Likewise, we also provide all kinds of movement pattern-improving treatments without having a valid classification system for diagnosing such problems, or which might even be contra productive, as such movement pattern changes might even be protective as a reaction to the pain experience (5). Likewise, 
we are using many types of cognitive–behavioral treatment modalities – we still don't know who 
benefits most from what type of treatment – or sometimes even combining types of CBT that might also be contra productive, for example gradually increasing activities by using operant principles on a time contingent basis and teaching the patient to rebalance activity–rest using a pain-contingent approach.

Results of randomized, controlled trials (RCTs) in which multidisciplinary treatments are being studied show only low to moderate effect sizes and at least half of the patients do not even show a clinically relevant improvement of personal relevant activities and participation (6). It should be mentioned that many trials do not even use personal relevant outcome measures. But why are the results so moderate? Shouldn't we first perform an adequate assessment of each patient on the basis of his/her goals and a hierarchy of factors that maintain the chronicity of disability to decide what treatment modalities should be provided? I do think that is what we commonly do in clinical practice, but it is difficult to study within an RCT design (7). By applying newer techniques using sophisticated statistical analyses, such as randomization testing in single case design (SCD) studies (8), we can make significant progress. This type of study really resembles our daily clinical 
practice, and by multiple sampling of each patient provides much data to ensure sufficient power to test whether the hypothesis that the selected treatment modality works can be confirmed or rejected. Unfortunately, most journals, and especially communities involved in meta-analysis such as the Cochrane collaboration, still view this type of study as being of low quality. I do think it is time to change this view. Another important topic of intervention studies is the description of the content of the treatment and the check as to whether the provided treatment is similar to the treatment protocol, the so-called process evaluation. Many studies still only briefly discuss the content and treatment rationale (underlying theory) and hardly ever present data on the process evaluation. Regrettably, an extensive description of the diagnostic process, selection of treatment and content of treatment is rarely published, although more recently some journals do (Rehabilitation in Practice-issue of Clinical Rehabilitation, open access journals publishing design articles). So I urgently call upon all of us working in the field of physiotherapy and pain management to set up studies using the multiple sampling SCD studies and neatly describe the assessment, content of treatment and outcome of all your patients. Another way to move forward, and increase our knowledge on how and for whom treatments seem (not) to work, is to do more qualitative research by interviewing patients and therapists. Again, the challenge is to get more editorial boards of peer-reviewed journals interested in publishing such important and challenging studies.