Prognosis for patients with chronic low back pain: inception cohort studyBMJ 2009; 339 doi: https://doi.org/10.1136/bmj.b3829 (Published 06 October 2009) Cite this as: BMJ 2009;339:b3829
- Luciola da C Menezes Costa, PhD candidate1,
- Christopher G Maher, director of division1,
- James H McAuley, research manager12,
- Mark J Hancock, lecturer2,
- Robert D Herbert, associate professor1,
- Kathryn M Refshauge, professor2,
- Nicholas Henschke, postdoctoral fellow1
- 1George Institute for International Health, University of Sydney
- 2Back Pain Research Group, Faculty of Health Sciences, University of Sydney
- Correspondence to: L da C Menezes Costa, PO Box M201, Missenden Road, NSW 2050, Australia
- Accepted 29 June 2009
Objectives To describe the course of chronic low back pain in an inception cohort and to identify prognostic markers at the onset of chronicity.
Design Inception cohort study with one year follow-up.
Setting Primary care clinics in Sydney, Australia.
Participants The study sample was a subcohort of an inception cohort of 973 consecutive patients presenting to primary care with acute low back pain (<2 weeks’ duration). 406 participants whose pain persisted for three months formed the inception cohort of patients with chronic low back pain.
Main outcome measures Outcomes and putative predictors measured at initial presentation, onset of chronicity (study entry), and follow-up at nine and 12 months. Recovery was determined from measures of pain intensity, disability, and work status. The association between potential prognostic factors and time to recovery was modelled with Cox regression.
Results Completeness of follow-up was 97% of total person time for all outcomes. The cumulative probability of being pain-free was 35% at nine months and 42% at 12 months and for complete recovery was 35% at nine months and 41% at 12 months. Of the 259 participants who had not recovered from pain related disability at entry to the chronic study, 47% had recovered by 12 months. Previous sick leave due to low back pain, high disability levels or high pain intensity at onset of chronicity, low levels of education, greater perceived risk of persistent pain, and being born outside Australia were associated with delayed recovery.
Conclusion More than one third of patients with recent onset, non-radicular chronic low back pain recover within 12 months. The prognosis is less favourable for those who have taken previous sick leave for low back pain, have high disability levels or high pain intensity at onset of chronic low back pain, have lower education, perceive themselves as having a high risk of persistent pain, and were born outside Australia.
We thank Anurina Das for assistance in data collection and Laurent Billot for statistical advice.
Contributors: CGM, KMR, and RDH were the chief investigators on the NHMRC project grant that funded the study. CGM, JHMcA, KMR, and NH trained the recruiting clinicians. JHMcA and NH carried out the follow-up assessments and entered the data. LdaCMC double checked the data. All authors contributed to the study design and the analysis and interpretation of the data and reviewed and approved the final version of the manuscript. CGM is the guarantor.
Funding: This study was supported by a grant from the National Health and Medical Research Council of Australia. The funder had no role in the study design; collection, analysis, and interpretation of data; writing of the report; or decision to submit the article for publication. The National Health and Medical Research Council of Australia funds the research fellowships of CGM, RDH, and NH.
Competing interests: None declared.
Ethical approval: This study was approved by the University of Sydney human research ethics committee.
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