We found 26 economic evaluations conducted alongside randomised controlled trials that investigated the cost-effectiveness of guideline-endorsed treatments for non-specific LBP. There were inconsistent findings regarding the cost-effectiveness of advice, but studies generally showed that interdisciplinary rehabilitation, exercise, acupuncture, spinal manipulation and cognitive-behavioural therapy were relatively cost-effective for people with sub-acute or chronic LBP. Results from single studies suggested that massage alone was unlikely to be cost-effective, and that the cost-effectiveness of spinal manipulation for acute LBP was unclear. No studies investigated the cost-effectiveness of medication, yoga or relaxation as treatments for LBP.
The eight studies which investigated advice did not yield consistent or conclusive evidence about its relative cost-effectiveness. Interestingly, these studies also reported inconsistencies in the effectiveness of advice compared to other treatments. In contrast, the American clinical guideline made a strong recommendation for advice to stay active based on moderate-quality evidence [3
]. Other guidelines also recommend advice to stay active [5
]. One reason for the difference between our findings and guideline recommendations may be that in the guidelines, the recommendations were based on evidence from systematic reviews which compared advice to stay active with bed rest, which is considered potentially harmful for this population [47
]. The studies included in this review compared advice to a variety of treatment alternatives, but not bed rest.
We did not pool the results in the studies that compared advice, and interdisciplinary rehabilitation, exercise, acupuncture, spinal manipulation and cognitive-behavioural therapy for sub-acute or chronic LBP, as may occur in a systematic review of treatment effectiveness. This is due to the heterogeneity in study treatments, as well as differences in economic perspectives and settings. The underlying assumption for pooling in a systematic review of treatment effectiveness is that results obtained in one country are generalisable to a similar population in a different setting or country. Whilst it seems reasonable to assume that individuals or groups are likely to react in the same way to a particular intervention, no matter where they live, comparing economic data across different settings or countries is not as straightforward due to differences in the structure and organization of healthcare systems. For example, in some countries patients may have direct access to medical specialists or other healthcare providers while in other countries patients need a referral from a primary care physician. Access to some care providers may be limited in some countries where this care is not provided by a public healthcare system or is not reimbursed by an insurance scheme. Cost data may also be sensitive to the funding and reimbursement arrangements in a particular healthcare system. However, despite this complexity, there are emerging guidelines on the transferability of economic evaluations [48
We used the NICE threshold to provide an indication of the cost-effectiveness of treatment, because the NICE threshold is commonly available. However, it should be noted that there is no consensus about the maximum costs per QALY gained that would be acceptable, and recent evidence indicates that the cost-effectiveness threshold may vary depending upon the severity and the prevalence of the disease. We used the treatments endorsed by the American College of Physicians and the American Pain Society as guideline-endorsed treatments, because at the time of study conception the American guideline was one of the most recent guidelines. A recent review shows that treatments endorsed by the American guideline are in line with other guidelines [5
]. The only area of contention is in the use of spinal manipulation where, unlike the American guideline, some countries do not recommend spinal manipulation for LBP. Interestingly, our systematic review considers evidence purely from a cost-effectiveness perspective and shows some evidence of cost-effectiveness when using spinal manipulation in sub-acute to chronic pain.
There were some methodological issues which limit the interpretation of our findings. These include the incomplete identification and measurement of costs, which reduces the rigour of the results. Three studies had follow-up periods that are likely to be too short to fully appreciate the economic consequences for the chronic population under investigation [44
]. Based on recent large cohort studies on the prognosis of acute [51
] and chronic [52
] LBP, we recommend a follow-up period of at least 3 months for acute LBP and at least 12 months for chronic LBP. In addition, to help readers assess the extent to which the results of studies are applicable to different healthcare systems, we recommend that economic evaluations report unit costs as well as reporting a breakdown of costs and resource utilization. Eleven of the 26 included studies provided a table of unit costs [21
Considering the evidence regarding both relative effectiveness and cost-effectiveness when making treatment recommendations means that the endorsed treatments are both beneficial to patients and efficient in terms of healthcare resources. The small number or lack of economic evaluations for some guideline-endorsed treatments means well-conducted economic evaluations are required to strengthen the evidence-base of treatments for LBP. However, evidence to date indicates that guideline-endorsed treatments such as interdisciplinary rehabilitation, exercise, acupuncture, spinal manipulation and cognitive-behavioural therapy for sub-acute or chronic LBP are cost-effective. Although advice to stay active is endorsed in the guideline, and evidence regarding its cost-effectiveness compared to other interventions is inconsistent. In addition, there is little or no high-level evidence about other guideline-endorsed treatments: medication, spinal manipulation for acute LBP, and massage, yoga or relaxation for chronic LBP.