What Is the Personal Impact of Recurrences of Low Back Pain? Subanalysis of an Inception Cohort Study

Recurrence of low back pain: A difficult outcome to predict. Development and validation of a multivariable prediction model for recurrence in patients recently recovered from an episode of non-specific low back pain

BACKGROUND

Recurrence of low back pain (LBP) is common. If clinicians could identify an individual's risk of recurrence, this would enhance clinical decision-making and tailored patient care.

OBJECTIVE/DESIGN

To develop and validate a simple tool to predict the probability of a recurrence of LBP by 3- or 12-months following recovery.

METHODS

Data utilised for the prediction model development came from a prospective inception cohort study of participants (n = 250) recently recovered from LBP, who had sought care from chiropractic or physiotherapy services. The outcome measure was a recurrence of activity-limiting LBP. Candidate predictor variables (e.g., basic demographics, LBP history, levels of physical activity, etc) collected at baseline were considered for inclusion in a multivariable Cox model. The model's performance was tested in a separate validation dataset of participants (n = 261) involved in a randomised controlled trial investigating exercise for the prevention of LBP recurrences.

RESULTS

The final model included the number of previous episodes, total sitting time, and level of education. In the development sample, discrimination was acceptable (Harrell's C-statistic = 0.61, 95% CI, 0.59-0.62), but in the validation sample, discrimination was poor (0.56, 95% CI, 0.54-0.58). Calibration of the model in the validation dataset was acceptable at 3 months but was less precise at 12 months.

CONCLUSION

The developed prediction model, which included number of previous episodes, total sitting time, and level of education, did not perform adequately in the validation sample to recommend its use in clinical practice. Predicting recurrence of LBP in clinical practice remains challenging.

Recurrence of an Episode of Low Back Pain: An Inception Cohort Study in Emergency Departments

OBJECTIVES

To (1) determine the 1-year estimate of recurrence of low back pain (LBP) in a cohort of people presenting to emergency departments who have recently recovered from an episode of acute LBP in a middle-income country, (2) estimate a recurrence of LBP stratified by the STarT Back Screening Tool (SBST), and (3) determine prognostic factors for the recurrence of LBP.

DESIGN

Prospective inception cohort study.

METHODS

We included 238 patients who presented to emergency departments with recent-onset nonspecific LBP in São Paulo, Brazil. The outcome was the recurrence of an episode of LBP, assessed using 2 definitions: (1) 12-month recall alone and (2) pain measurements at follow-up. Prognostic factors were determined by logistic regression.

RESULTS

Within 1 year, the estimated recurrence of an episode of LBP ranged from 35% (79/225 events) (first definition) to 44% (100/226 events) (second definition). When patients were stratified by the SBST, the estimate of recurrence ranged from 29% to 37% (21-27/73 events) for low-risk patients, from 33% to 39% (24-28/72 events) for medium-risk patients, and from 43% to 56% (34-45/80 events) for high-risk patients. Age, perceived risk of persistent LBP, and disability were independent prognostic factors associated with LBP recurrence within 1 year.

CONCLUSION

After recovering from a previous episode of acute LBP, 4 in every 10 patients experienced a recurrence within 1 year. This estimate varied depending on the classification used in the SBST. Within 1 year, age, perceived risk of persistent LBP, and baseline disability were predictors of recurrence. J Orthop Sports Phys Ther 2022;52(7):484-492. Epub: 18 May 2022. doi:10.2519/jospt.2022.10775.

Multimorbidity and co-occurring musculoskeletal pain do not modify the effect of the SELFBACK app on low back pain-related disability

BACKGROUND

SELFBACK, an artificial intelligence (AI)-based app delivering evidence-based tailored self-management support to people with low back pain (LBP), has been shown to reduce LBP-related disability when added to usual care. LBP commonly co-occurs with multimorbidity (≥ 2 long-term conditions) or pain at other musculoskeletal sites, so this study explores if these factors modify the effect of the SELFBACK app or influence outcome trajectories over time.

METHODS

Secondary analysis of a randomized controlled trial with 9-month follow-up. Primary outcome is as follows: LBP-related disability (Roland Morris Disability Questionnaire, RMDQ). Secondary outcomes are as follows: stress/depression/illness perception/self-efficacy/general health/quality of life/physical activity/global perceived effect. We used linear mixed models for continuous outcomes and logistic generalized estimating equation for binary outcomes. Analyses were stratified to assess effect modification, whereas control (n = 229) and intervention (n = 232) groups were pooled in analyses of outcome trajectories.

RESULTS

Baseline multimorbidity and co-occurring musculoskeletal pain sites did not modify the effect of the SELFBACK app. The effect was somewhat stronger in people with multimorbidity than among those with LBP only (difference in RMDQ due to interaction, - 0.9[95 % CI - 2.5 to 0.6]). Participants with a greater number of long-term conditions and more co-occurring musculoskeletal pain had higher levels of baseline disability (RMDQ 11.3 for ≥ 2 long-term conditions vs 9.5 for LBP only; 11.3 for ≥ 4 musculoskeletal pain sites vs 10.2 for ≤ 1 additional musculoskeletal pain site); along with higher baseline scores for stress/depression/illness perception and poorer pain self-efficacy/general health ratings. In the pooled sample, LBP-related disability improved slightly less over time for people with ≥ 2 long-term conditions additional to LBP compared to no multimorbidity and for those with ≥4 co-occurring musculoskeletal pain sites compared to ≤ 1 additional musculoskeletal pain site (difference in mean change at 9 months = 1.5 and 2.2, respectively). All groups reported little improvement in secondary outcomes over time.

CONCLUSIONS

Multimorbidity or co-occurring musculoskeletal pain does not modify the effect of the selfBACK app on LBP-related disability or other secondary outcomes. Although people with these health problems have worse scores both at baseline and 9 months, the AI-based selfBACK app appears to be helpful for those with multimorbidity or co-occurring musculoskeletal pain.

TRIAL REGISTRATION

NCT03798288 . Date of registration: 9 January 2019.

The Danish Chiropractic Low Back Pain Cohort (ChiCo): Description and Summary of an Available Data Source for Research Collaborations

BACKGROUND

Back pain is among the most frequent reasons for care seeking globally. Observational clinical cohorts are useful for understanding why people seek care, the content of that care, and factors related to prognosis. This paper describes the Danish Chiropractic low back pain Cohort (ChiCo) and summarizes the primary characteristics of the population to inform the scientific community of the availability of these data as a resource for collaborative research projects.

METHODS

Adults seeking chiropractic care for a new episode of non-specific back pain were enrolled at the initial visit and followed up after 2, 13, and 52 weeks, with a subpopulation having weekly follow-ups for 1 year. Patient-reported and clinical-reported data were collected in an electronic database using the REDCap software (REDCap Consortium, projectredcap.org). Variables were chosen to measure pre-defined research domains and questions and to capture information across health constructs deemed relevant for additional research. Non-responders at 13 and 52 weeks were contacted by phone to maximize follow-up data and explore differences on core outcomes between responders and non-responders.

RESULTS

A total of 2848 patients (mean age 45 years, 59% men) were included from 10 clinics with 71%, 68% and 64% responding to follow-ups at 2, 13 and 52 weeks, respectively. Most participants (82%) were employed, nearly half reported current LBP for 1-7 days, and 83% had experienced LBP episodes previously. We did not identify indications of serious attrition bias.

CONCLUSION

We have described the aims and procedures for establishing the ChiCo cohort, characteristics of the cohort, and available information about attrition bias. These data have the potential to be linked, at an individual participant level, to the extensive Danish population-based registries that measure diverse health and social characteristics.