Effectiveness of treatments for acute and sub-acute mechanical non-specific low back pain: Protocol for a systematic review and network meta-analysis

Background: Non-specific low back pain (LBP) is the leading cause of disability worldwide. Acute LBP usually has a good prognosis, with rapid improvement within the first 6 weeks. However, the majority of patients develop chronic LBP and suffer from recurrences. For clinical management, a plethora of treatments is currently available but evidence of the most effective options is lacking. The objective of this study will be to identify the most effective interventions to relieve pain and reduce disability in acute and sub-acute non-specific LBP. Methods/design: We will search electronic databases (MEDLINE, Embase, CENTRAL) from inception onwards. The eligible population will be individuals with non-specific LBP older than 18 years, both males and females, who experience pain less than 6 weeks (acute) or between 6 and 12 weeks (subacute). Eligible interventions and comparators will include all conservative rehabilitation or pharmacological treatments provided by any health professional; the only eligible study design will be a randomized controlled trial. The primary outcomes will be pain intensity and back-specific functional status. Secondary outcomes will be any adverse events. Studies published in languages other than English will also potentially be included. Two reviewers will independently screen the titles and abstracts retrieved from a literature search, as well as potentially relevant full-text articles. General characteristics, potential effect modifiers, and outcome data will be extracted from the included studies, and the risk of bias will be appraised. Conflicts at all levels of screening and abstraction will be resolved through team discussions. After describing the results of the review, if appropriate, a random effects meta-analysis and network meta-analysis will be conducted in a frequentist setting, assuming equal heterogeneity across all treatment comparisons and accounting for correlations induced by multi-arm studies using a multivariate normal model. Discussion: Our systematic review will address the uncertainties in the use of pharmacological or non-pharmacological treatments, and their relative efficacy, for acute and subacute LBP. These findings will be useful for patients, healthcare providers, and policymakers. Systematic review registration: PROSPERO CRD42018102527