Can screening instruments accurately determine poor outcome risk in adults with recent onset low back pain? A systematic review and meta-analysis

Karran et al. BMC Medicine (2017) 15:13 DOI 10.1186/s12916-016-0774-4 RESEARCH ARTICLE Open Access Can screening instruments accurately determine poor outcome risk in adults with recent onset low back pain? A systematic review and meta-analysis Emma L. Karran1, James H. McAuley2,4, Adrian C. Traeger2,4, Susan L. Hillier1, Luzia Grabherr1, Leslie N. Russek3 and G. Lorimer Moseley1,2* Abstract Background: Delivering efficient and effective healthcare is crucial for a condition as burdensome as low back pain (LBP). Stratified care strategies may be worthwhile, but rely on early and accurate patient screening using a valid and reliable instrument. The purpose of this study was to evaluate the performance of LBP screening instruments for determining risk of poor outcome in adults with LBP of less than 3 months duration. Methods: Medline, Embase, CINAHL, PsycINFO, PEDro, Web of Science, SciVerse SCOPUS, and Cochrane Central Register of Controlled Trials were searched from June 2014 to March 2016. Prospective cohort studies involving patients with acute and subacute LBP were included. Studies administered a prognostic screening instrument at inception and reported outcomes at least 12 weeks after screening. Two independent reviewers extracted relevant data using a standardised spreadsheet. We defined poor outcome for pain to be ≥ 3 on an 11-point numeric rating scale and poor outcome for disability to be scores of ≥ 30% disabled (on the study authors' chosen disability outcome measure). Results: We identified 18 eligible studies investigating seven instruments. Five studies investigated the STarT Back Tool: performance for discriminating pain outcomes at follow-up was ‘non-informative’ (pooled AUC = 0.59 (0.55–0.63), n = 1153) and ‘acceptable’ for discriminating disability outcomes (pooled AUC = 0.74 (0.66–0.82), n = 821). Seven studies investigated the Orebro Musculoskeletal Pain Screening Questionnaire: performance was ‘poor’ for discriminating pain outcomes (pooled AUC = 0.69 (0.62–0.76), n = 360), ‘acceptable’ for disability outcomes (pooled AUC = 0.75 (0.69–0.82), n = 512), and ‘excellent’ for absenteeism outcomes (pooled AUC = 0.83 (0.75–0.90), n = 243). Two studies investigated the Vermont Disability Prediction Questionnaire and four further instruments were investigated in single studies only. Conclusions: LBP screening instruments administered in primary care perform poorly at assigning higher risk scores to individuals who develop chronic pain than to those who do not. Risks of a poor disability outcome and prolonged absenteeism are likely to be estimated with greater accuracy. It is important that clinicians who use screening tools to obtain prognostic information consider the potential for misclassification of patient risk and its consequences for care decisions based on screening. However, it needs to be acknowledged that the outcomes on which we evaluated these screening instruments in some cases had a different threshold, outcome, and time period than those they were designed to predict. (Continued on next page) * Correspondence: 1 Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, South Australia 5001, Australia 2 Neuroscience Research Australia, Barker Street, Randwick, Sydney, New South Wales 2031, Australia Full list of author information is available at the end of the article © The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Karran et al. BMC Medicine (2017) 15:13 Page 2 of 15 (Continued from previous page) Systematic review registration: PROSPERO international prospective register of systematic reviews registration number CRD42015015778. Keywords: Low back pain, Screening, Prognosis, Risk, Predictive validity Background A current trend in health service delivery towards the provision of stratified models of care [1–3] offers potential to optimise treatment benefits, reduce harms and maximise healthcare efficiency. Stratified approaches aim to match patients to the most appropriate care pathways on the basis of their presentation. A common approach bases stratification on patients’ prognostic profile, which requires early, accurate screening using a valid and reliable instrument. By so doing, care decisions aim to offer treatment to those who need it most and avoid over-treatment of those who need it least. Better matching of patients to care is particularly important for a condition as burdensome as low back pain (LBP) [4, 5]. The prognosis of chronic LBP – when symptoms persist beyond 3 months – is poor [6]. This warrants a focus on the potential for intervention to be appropriately targeted prior to the development of chronic pain. Improved understanding of factors associated with chronic LBP [7–10] has led to the development of selfreport questionnaires containing multiple variables known to have prognostic relevance. These prognostic screening instruments (PSIs; also referred to as predictive tools) assess certain characteristics of an individual’s pain experience (including pain intensity and functional impairment) and certain psychosocial factors (e.g. beliefs, catastrophisation, anxiety and depression). These prognostic variables have been shown to be associated with specific outcome measures and time frames [11]. PSIs are widely recommended to inform the management of LBP [12–15], with updated international guidelines encouraging the use of risk stratification to guide care decisions. A possible consequence of these broad recommendations is that PSIs are likely to be used for purposes other than the specific purpose for which they were intended and in varied clinical settings. These factors may impact instrument performance, with implications for care decisions based on screening. As the use of PSIs to inform care delivery becomes more widely adopted, it is important to further consider the uncertainty that surrounds their accuracy [16, 17]. We investigate how PSIs perform (individually and generally) when administered for the purpose of predicting the likely course of LBP. The aim of this review was to determine how well LBP PSIs discriminate between patients who develop a poor outcome and those who do not in adults with LBP of less than 3 months duration. Methods This systematic review is reported in accordance with the statement for Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) [18] (see Additional file 1). Regi (...truncated)