There are likely several key explanations, explored in detail elsewhere [
19,
24]. Firstly, many of our current treatments are predicated on a healthcare practitioner's specific diagnosis, based on for example imaging findings or the results of subjective and objective examination, yet these approaches to diagnosis correlate poorly with the patient's symptoms [
19], their onward path or trajectory, or their treatment responsiveness. Secondly, patient heterogeneity in clinical trials means that the average treatment effect masks a wide range of individual responses to any specific treatment, including for example, patients who benefit a great deal along with those who benefit little or not at all [
24]. Thus a compelling argument for our lack of progress in achieving better treatment results is that we have failed to focus on identifying and addressing the factors that really do influence patients' outcomes [
19]. In other words, we have largely failed to match patients with the most appropriate treatment for their individual profile. Identification of clinically relevant subgroups of non-specific LBP patients may be related to causal mechanisms, different prognoses or treatment responsiveness. For example, although psychosocial factors associated with poor prognosis (or yellow flags) have been shown to be important in the development of chronicity and future disability [
25,
26] and most guidelines recommend the assessment of these factors, there have been few easy-to-use tools to help clinicians identify these factors in busy clinical practice and limited guidance about appropriate treatment for patients in whom these factors are identified. Although healthcare professionals often feel they can intuitively identify the patients with LBP who have a poor prognosis, actually these patients are often difficult to spot and professionals make inconsistent risk estimations about LBP patients when using intuition alone [
27]. More individual and accurate estimates of the prognosis of patients are needed so that we might better target the treatments we offer to those who need them [
23]. Several clinical tools exist to aid healthcare professionals in identifying patients either at risk of chronicity or to improve targeting of treatment, summarized in Hill
et al. [
28]. One of the most widely used is the 24-item Örebro Musculoskeletal Pain Screening Questionnaire which is still rather long for use in busy clinical practice. A recently validated tool to identify risk subgroups of LBP patients is the shorter nine item STarT Back Tool [
29] which has been shown to have similar properties to the Örebro instrument but is easier for patients to complete and professionals to score [
28].
A second compelling explanation for the generally poor outcomes seen in usual practice such as primary care settings [
25] is the limited way in which best evidence recommendations have been translated into everyday clinical practice for patients with LBP. For example, we know that early access to advice and information about self-management and some specific treatments such as exercise, manual therapy, acupuncture and cognitive-behavioral interventions are effective, yet most patients in primary care actually receive symptomatic care through advice related to the current episode and medication alone, neither of which has a clear focus on secondary prevention. Another example is return to work advice, where just under a third of healthcare practitioners continue to recommend staying off work to patients for whom guideline recommendations suggest the opposite [
21]. Reasons why adherence to guideline recommendations for work might be less than ideal are unclear, but may be, in part, due to the complex nature of the clinical consultation, in which healthcare professionals such as general practitioners (GPs) want to tailor their decisions according to a patient's individual expectations and demands and thus place higher relative importance on maintaining a good long term relationship with their patient rather than adhering to guideline recommendations. Confronting patients about sickness certification may therefore be seen as a potential threat to the practitioner-patient relationship by some GPs while for others, they may feel they are not best placed to judge whether a LBP patient can return to work safely.