Identifying Treatment Effect Modifiers in the STarT Back Trial: A Secondary Analysis

Treatment Effect Modifiers for Return-to-Work in Patients With Musculoskeletal Disorders

Investigating how individual characteristics modify treatment effects can improve understanding, interpretation, and translation of trial findings. The purpose of this secondary analysis was to identify treatment effect modifiers of the MI-NAV trial, a 3 arm, parallel randomized controlled trial which compared motivational interviewing and stratified vocational advice intervention in addition to usual case management (UC), to UC alone. This study included (n = 514) participants with musculoskeletal disorders on sick leave for at least 50% of their contracted work hours for at least 7 consecutive weeks with the Norwegian Labour and Welfare Administration. Sickness absence days was the primary outcome, measured from baseline assessment date until the 6-month follow-up. Potential treatment effect modifiers, identified a priori and informed by expert consultation and literature, were evaluated using linear regression models and statistical interaction tests. For motivational interviewing versus UC, age (mean difference [MD] -.7, 95% confidence interval [CI] -1.5 to .2; P = .13) and self-perceived health status (MD -.3, 95% CI -.7 to .1; P = .19) were identified as potential effect modifiers (P ≤ .2). For stratified vocational advice intervention versus UC, analgesic medication use (MD -26.2, 95% CI -45.7 to -6.7; P = .009) was identified as a treatment effect modifier (P ≤ .05). These findings may assist in more targeted treatment adaptation and translation as well as the planning of future clinical trials. PERSPECTIVE: This secondary analysis of the MI-NAV trial found that analgesic medication use, age, and self-perceived health may modify the effect of 2 vocational interventions on reducing sickness absence in people with musculoskeletal disorders.

Validation of the Keele STarT MSK Tool for Patients With Musculoskeletal Pain in United States-based Outpatient Physical Therapy Settings

The STarT MSK tool was developed to enable risk stratification of patients with common musculoskeletal (MSK) pain conditions and help identify individuals who may require more targeted interventions or closer monitoring in primary care settings, however, its validity in U.S.-based outpatient physical therapy settings has not been investigated. The 10-item Keele STarT MSK risk stratification tool was tested for construct (convergent and discriminant) and predictive validity using a multicenter, prospective cohort study design. Participants (n = 141) receiving physical therapy for MSK pain of the back, neck, shoulder, hip, knee, or multisite regions completed intake questionnaires including the Keele STarT MSK tool, Functional Comorbidity Index (FCI), Optimal Screening for Prediction of Referral and Outcome Review-of-Systems and Optimal Screening for Prediction of Referral and Outcome Yellow Flag tools. Pain intensity, pain interference, and health-related quality of life (Medical Outcomes Study 8-item Short-Form Health Survey (SF-8) physical [PCS] and mental [MCS] component summary scores) were measured at 2- and 6-month follow-up. Participants were classified as STarT MSK tool low (44%), medium (39%), and high (17%) risk. Follow-up rates were 70.2% (2 months) and 49.6% (6 months). For convergent validity, fair relationships were observed between the STarT MSK tool and FCI and SF-8 MCS (r = .35-.37) while moderate-to-good relationships (r = .51-.72) were observed for 7 other clinical measures. For discriminant validity, STarT MSK tool risk-dependent relationships were observed for Optimal Screening for Prediction of Referral and Outcome Review-of-Systems, Optimal Screening for Prediction of Referral and Outcome Yellow Flag, pain interference, and SF-8 PCS (low < medium < high; P < .01) and FCI, pain intensity, and SF-8 MCS (low < medium-or-high; P < .01). For predictive validity, intake STarT MSK tool scores explained additional variability in pain intensity (11.2%, 20.0%), pain interference (7.5%, 14.1%), and SF-8 PCS (8.2%, 12.8%) scores at 2 and 6 months, respectively. This study contributes to the existing literature by providing additional evidence of STarT MSK tool cross-sectional construct validity and longitudinal predictive validity. PERSPECTIVE: This study presents STarT MSK risk stratification tool validity findings from a U.S. outpatient physical therapy sample. The STarT MSK tool has the potential to help physical therapists identify individuals presenting with the most common MSK pain conditions who may require more targeted interventions or closer monitoring.

Machine learning-based identification of determinants for rehabilitation success and future healthcare use prevention in patients with high-grade, chronic, nonspecific low back pain: an individual data 7-year follow-up analysis on 154,167 individuals

ABSTRACT

To individually prescribe rehabilitation contents, it is of importance to know and quantify factors for rehabilitation success and the risk for a future healthcare use. The objective of our multivariable prediction model was to determine factors of rehabilitation success and the risk for a future healthcare use in patients with high-grade, chronic low back pain. We included members of the German pension fund who participated from 2012 to 2019 in multimodal medical rehabilitation with physical and psychological treatment strategies because of low back pain (ICD10:M54.5). Candidate prognostic factors for rehabilitation success and for a future healthcare use were identified using Gradient Boosting Machines and Random Forest algorithms in the R-package caret on a 70% training and a 30% test set. We analysed data from 154,167 patients; 8015 with a second medical rehabilitation measure and 5161 who retired because of low back pain within the study period. The root-mean-square errors ranged between 494 (recurrent rehabilitation) and 523 (retirement) days ( R2 = 0.183-0.229), whereas the prediction accuracy ranged between 81.9% for the prediction of the rehabilitation outcome, and 94.8% for the future healthcare use prediction model. Many modifiable prognostic factors (such as duration of the rehabilitation [inverted u-shaped], type of the rehabilitation, and aftercare measure), nonmodifiable prognostic factors (such as sex and age), and disease-specific factors (such as sick leave days before the rehabilitation [linear positive] together with the pain grades) for rehabilitation success were identified. Inpatient medical rehabilitation programmes (3 weeks) may be more effective in preventing a second rehabilitation measure and/or early retirement because of low back pain compared with outpatient rehabilitation programs. Subsequent implementation of additional exercise programmes, cognitive behavioural aftercare treatment, and following scheduled aftercare are likely to be beneficial.

Potential effect modifiers for treatment with chiropractic manipulation versus sham manipulation for recurrent headaches in children aged 7-14 years: development of and results from a secondary analysis of a randomised clinical trial

BACKGROUND

A recent randomized controlled trial (RCT) investigating the effect of chiropractic manipulation in 199 children aged 7-14 years with recurrent headaches demonstrated a significant reduction of number of days with headache and a better global perceived effect (GPE) in the chiropractic manipulation group compared to a sham manipulation group. However, potential modifiers for the effectiveness of chiropractic manipulation of children with recurrent headaches have never been identified. The present study is a secondary analysis of data from that RCT and will investigate potential effect modifiers for the benefit of chiropractic manipulation for children with headache.

METHODS

Sixteen potential effect modifiers were identified from the literature and a summary index was prespecified based on clinical experience. Relevant variables were extracted from baseline questionnaires, and outcomes were obtained by means of short text messages. The modifying effect of the candidate variables was assessed by fitting interaction models to the data of the RCT. In addition, an attempt to define a new summary index was made.

RESULTS

The prespecified index showed no modifying effect. Four single variables demonstrated a treatment effect difference of more than 1 day with headache per week between the lower and the upper end of the spectrum: intensity of headache (p = 0.122), Frequency of headache (p = 0.031), sleep duration (p = 0.243), and Socioeconomic status (p = 0.082). Five variables had a treatment effect difference of more than 0.7 points on the GPE scale between the lower and the upper end of the spectrum: Frequency of headache (p = 0.056), Sport activity (p = 0.110), Sleep duration (p = 0.080), History of neck pain (p = 0.011), and Headache in the family (0.050). A new summary index could be constructed giving highest weight to History of neck pain and Headache in the family and Frequency of headache. The index suggests a difference of about 1 point in GPE between low and high values of the index.

CONCLUSION

Chiropractic manipulation offers a moderate benefit for a broad spectrum of children. However, it cannot be excluded that specific headache characteristics, family factors, or a history of neck pain may modify the effect. This question must be addressed in future studies.

TRIAL REGISTRATION

ClinicalTrials.gov (Albers et al in Curr Pain Headache Rep 19:3-4, 2015), identifier NCT02684916, registered 02/18/2016-retrospectively registered.

Interaction analyses: Enhancing understanding of chronic low back pain

BACKGROUND

Chronic low back pain (CLBP) is complex. Statistical examination of influences of exposures (e.g. characteristics) upon outcomes (e.g. pain) facilitates understanding of complexity and personalized care. Psychological factors may be associated with higher disability following exercise in CLBP. Examining interactions of psychological variables with exercise on disability might further understanding of CLBP.

OBJECTIVES

Secondary analysis of data from a CLBP cohort evaluating interactions between psychological variables and exercise on disability.

DESIGN

Longitudinal cohort study.

METHOD

Variables from a published prognostic model for disability: disability (baseline/one-year follow-up), psychological principal component scores (principal component score two (PC2) - Fear-avoidance beliefs, pain catastrophizing, pain self-efficacy; principal component score three (PC3) - thought suppression, behavioral endurance), exercise (during follow-up), forward-bending time, punishing significant other responses. Differences between exercisers and non-exercisers were assessed using Chi-Squared/Mann-Whitney tests. Multivariable linear regression models for follow-up disability included a term examining interaction between principal component scores and exercise.

RESULTS

Exercisers had significantly different scores for PC2 (p = .02) and PC3 (p = .03), lower baseline (p = .005) and follow-up pain intensity (p < .001), follow-up disability (p < .001) and faster forward-bend times (p = .014). There was no significant interaction between exercise and PC2 (p = .92) or PC3 (p = .75).

CONCLUSIONS

This study showed no interaction between psychological factors and exercise on disability at follow-up. These findings suggest that the disability outcome of people with CLBP who undertake exercise as an intervention does not differ from those who do not undertake exercise, irrespective of their baseline psychological status.

Treatment effect modifiers for individuals with acute low back pain: secondary analysis of the TARGET trial

ABSTRACT

Treatment effect modifiers identify patient characteristics associated with treatment responses. The purpose of this secondary analysis was to identify potential treatment effect modifiers for disability from the TARGET trial that compared usual care (control) with usual care + psychologically informed physical therapy (PIPT). The sample consisted of a STarT Back tool identified high-risk patients with acute low back pain that completed Oswestry Disability Index (ODI) data at index visit and 6 months later (n = 1250). Candidate treatment effect modifiers were identified a priori and informed by the literature. Linear mixed models tested for treatment effect modification through tests of statistical interaction. All statistical interactions ( P ≤ 0.20) were stratified by modifier to inspect for specific effects ( P ≤ 0.05). Smoking was identified as a potential effect modifier (treatment * smoking interaction, P = 0.08). In participants who were smokers, the effect of PIPT was (ODI = 5.5; 95% CI: 0.6-10.4; P = 0.03) compared with usual care. In participants who were nonsmokers, the effect of PIPT was (ODI = 1.5; 95% CI: -1.4 to 4.4; P = 0.31) compared with usual care. Pain medication was also identified as a potential effect modifier (treatment × pain medication interaction, P = 0.10). In participants prescribed ≥3 pain medications, the effect of PIPT was (ODI = 7.1; 95% CI: -0.1 to 14.2; P = 0.05) compared with usual care. The PIPT effect for participants prescribed no pain medication was (ODI = 3.5; 95% CI: -0.4 to 7.4; P = 0.08) and for participants prescribed 1 to 2 pain medications was (ODI = 0.6; 95% CI: -2.5 to 3.7; P = 0.70) when compared with usual care. These findings may be used for generating hypotheses and planning future clinical trials investigating the effectiveness of tailored application of PIPT.

Patients' and physiotherapists' perspectives on implementing a tailored stratified treatment approach for low back pain in Nigeria: a qualitative study

BACKGROUND

Stratified care has the potential to be efficient in addressing the physical and psychosocial components of low back pain (LBP) and optimise treatment outcomes essential in low-income countries. This study aimed to investigate the perceptions of physiotherapists and patients in Nigeria towards stratified care for the treatment of LBP, exploring barriers and enablers to implementation.

METHODS

A qualitative design with semistructured individual telephone interviews for physiotherapists and patients with LBP comprising research evidence and information on stratified care was adopted. Preceding the interviews, patients completed the Subgroups for Targeted Treatment tool. The interviews were recorded, transcribed and analysed following grounded theory methodology.

RESULTS

Twelve physiotherapists and 13 patients with LBP participated in the study (11 female, mean age 42.8 (SD 11.47) years). Seven key categories emerged: recognising the need for change, acceptance of innovation, resistance to change, adapting practice, patient's learning journey, trusting the therapist and needing conviction. Physiotherapists perceived stratified care to be a familiar approach based on their background training. The prevalent treatment tradition and the patient expectations were seen as major barriers to implementation of stratified care by the physiotherapists. Patients see themselves as more informed than therapists realise, yet they need conviction through communication and education to cooperate with their therapist using this approach. Viable facilitators were also identified as patients' trust in the physiotherapist and adaptations in terms of training and modification of the approach to enhance its use.

CONCLUSION

Key barriers identified are the patients' treatment expectations and physiotherapists' adherence to the tradition of practice. Physiotherapists might facilitate implementation of the stratified care by communication, hierarchical implementation and utilisation of patients' trust. Possibilities to develop a consensus on key strategies to overcome barriers and on utilisation of facilitators should be tested in future research.

Do recommended interventions widen or narrow inequalities in musculoskeletal health? An equity-focussed systematic review of differential effectiveness

Background

It is unclear whether seven interventions recommended by Public Health England for preventing and managing common musculoskeletal conditions reduce or widen health inequalities in adults with musculoskeletal conditions.

Methods

We used citation searches of Web of Science (date of ‘parent publication’ for each intervention to April 2021) to identify original research articles reporting subgroup or moderator analyses of intervention effects by social stratifiers defined using the PROGRESS-Plus frameworks. Randomized controlled trials, controlled before-after studies, interrupted time series, systematic reviews presenting subgroup/stratified analyses or meta-regressions, individual participant data meta-analyses and modelling studies were eligible. Two reviewers independently assessed the credibility of effect moderation claims using Instrument to assess the Credibility of Effect Moderation Analyses. A narrative approach to synthesis was used (PROSPERO registration number: CRD42019140018).

Results

Of 1480 potentially relevant studies, seven eligible analyses of single trials and five meta-analyses were included. Among these, we found eight claims of potential differential effectiveness according to social characteristics, but none that were judged to have high credibility.

Conclusions

In the absence of highly credible evidence of differential effectiveness in different social groups, and given ongoing national implementation, equity concerns may be best served by investing in monitoring and action aimed at ensuring fair access to these interventions.

When Treating Coexisting Low Back Pain and Hip Impairments, Focus on the Back: Adding Specific Hip Treatment Does Not Yield Additional Benefits-A Randomized Controlled Trial

OBJECTIVE

To determine whether adding hip treatment to usual care for low back pain (LBP) improved disability and pain in individuals with LBP and a concurrent hip impairment.

DESIGN

Randomized controlled trial.

METHODS

Seventy-six participants (age, 18 years or older; Oswestry Disability Index, 20% or greater; numeric pain-rating scale, 2 or more points) with LBP and a concurrent hip impairment were randomly assigned to a group that received treatment to the lumbar spine only (LBO group) (n = 39) or to one that received both lumbar spine and hip treatments (LBH group) (n = 37). The individual treating clinicians decided which specific low back treatments to administer to the LBO group. Treatments aimed at the hip (LBH group) included manual therapy, exercise, and education, selected by the therapist from a predetermined set of treatments. Primary outcomes were disability and pain, measured by the Oswestry Disability Index and the numeric pain-rating scale, respectively, at baseline, 2 weeks, discharge, 6 months, and 12 months. The secondary outcomes were fear-avoidance beliefs (work and physical activity subscales of the Fear-Avoidance Beliefs Questionnaire), global rating of change, the Patient Acceptable Symptom State, and physical activity level. We used mixed-model 2-by-3 analyses of variance to examine group-by-time interaction effects (intention-to-treat analysis).

RESULTS

Data were available for 68 patients at discharge (LBH group, n = 33; LBO group, n = 35) and 48 at 12 months (n = 24 for both groups). There were no between-group differences in disability at discharge (-5.0; 95% confidence interval [CI]: -10.9, 0.89; P = .09), 12 months (-1.0; 95% CI: -4.44, 2.35; P = .54), and all other time points. There were no between-group differences in pain at discharge (-0.2; 95% CI: -1.03, 0.53; P = .53), 12 months (0.1; 95% CI: -0.53, 0.72; P = .76), and all other time points. There were no between-group differences in secondary outcomes, except for higher Fear-Avoidance Beliefs Questionnaire (work subscale) scores in the LBH group at 2 weeks (-3.35; 95% CI: -6.58, -0.11; P = .04) and discharge (-3.45; 95% CI: - 6.30, -0.61; P = .02).

CONCLUSION

Adding treatments aimed at the hip to usual low back physical therapy did not provide additional short- or long-term benefits in reducing disability and pain in individuals with LBP and a concurrent hip impairment. Clinicians may not need to include hip treatments to achieve reductions in low back disability and pain in individuals with LBP and a concurrent hip impairment. J Orthop Sports Phys Ther 2021;51(12):581-601. Epub 16 Nov 2021. 2021. doi:10.2519/jospt.2021.10593.

Barriers to Building More Effective Treatments: Negative Interactions Amongst Smoking Intervention Components

Meaningfully improved mental and behavioral health treatment is an unrealized dream. Across three factorial experiments, inferential tests in prior studies showed a pattern of negative interactions suggesting that better clinical outcomes are obtained when participants receive fewer rather than more intervention components. Further, relatively few significant main effects were found in these experiments. Modeling suggested that negative interactions amongst components may account for these patterns. This paper evaluates factors that may contribute to such declining benefit: increased attentional or effort burden; components that produce their effects via the same capacity limited mechanisms, making their effects subadditive; and a tipping point phenomenon in which those near a hypothesized "tipping point" for change will benefit markedly from weak intervention while those far from the tipping point will benefit little from even strong intervention. New research should explore factors that cause negative interactions amongst components and constrain the development of more effective treatments.

Moderators of the Effect of Spinal Manipulative Therapy on Pain Relief and Function in Patients with Chronic Low Back Pain: An Individual Participant Data Meta-analysis

STUDY DESIGN

Individual participant data (IPD) meta-analysis.

OBJECTIVE

The aim of this study was to identify which participant characteristics moderate the effect of spinal manipulative therapy (SMT) on pain and functioning in chronic LBP.

SUMMARY OF BACKGROUND

The effects of SMT are comparable to other interventions recommended in guidelines for chronic low back pain (LBP); however, it is unclear which patients are more likely to benefit from SMT compared to other therapies.

METHODS

IPD were requested from randomized controlled trials (RCTs) examining the effect of SMT in adults with chronic LBP for pain and function compared to various other therapies (stratified by comparison). Potential patient moderators (n = 23) were a priori based on their clinical relevance. We investigated each moderator using a one-stage approach with IPD and investigated this interaction with the intervention for each time point (1, 3, 6, and 12 months).

RESULTS

We received IPD from 21 of 46 RCTs (n = 4223). The majority (12 RCTs, n = 2249) compared SMT to recommended interventions. The duration of LBP, baseline pain (confirmatory), smoking, and previous exposure to SMT (exploratory) had a small moderating effect across outcomes and follow-up points; these estimates did not represent minimally relevant differences in effects; for example, patients with <1 year of LBP demonstrated more positive point estimates for SMT versus recommended therapy for the outcome pain (mean differences ranged from 4.97 (95% confidence interval, CI: -3.20 to 13.13) at 3 months, 10.76 (95% CI: 1.06 to 20.47) at 6 months to 5.26 (95% CI: -2.92 to 13.44) at 12 months in patients with over a year LBP. No other moderators demonstrated a consistent pattern across time and outcomes. Few moderator analyses were conducted for the other comparisons because of too few data.

CONCLUSION

We did not identify any moderators that enable clinicians to identify which patients are likely to benefit more from SMT compared to other treatments.Level of Evidence: 2.

Which Chronic Low Back Pain Patients Respond Favorably to Yoga, Physical Therapy, and a Self-care Book? Responder Analyses from a Randomized Controlled Trial

PURPOSE

To identify baseline characteristics of adults with chronic low back pain (cLBP) that predict response (i.e., a clinically important improvement) and/or modify treatment effect across three nonpharmacologic interventions.

DESIGN

Secondary analysis of a randomized controlled trial.

SETTING

Academic safety net hospital and seven federally qualified community health centers.

SUBJECTS

Adults with cLBP (N = 299).

METHODS

We report patient characteristics that were predictors of response and/or modified treatment effect across three 12-week treatments: yoga, physical therapy [PT], and a self-care book. Using preselected characteristics, we used logistic regression to identify predictors of "response," defined as a ≥30% improvement in the Roland Morris Disability Questionnaire. Then, using "response" as our outcome, we identified baseline characteristics that were treatment effect modifiers by testing for statistical interaction (P < 0.05) across two comparisons: 1) yoga-or-PT vs self-care and 2) yoga vs PT.

RESULTS

Overall, 39% (116/299) of participants were responders, with more responders in the yoga-or-PT group (42%) than the self-care (23%) group. There was no difference in proportion responding to yoga (48%) vs PT (37%, odds ratio [OR] = 1.5, 95% confidence interval = 0.88 - 2.6). Predictors of response included having more than a high school education, a higher income, employment, few depressive symptoms, lower perceived stress, few work-related fear avoidance beliefs, high pain self-efficacy, and being a nonsmoker. Effect modifiers included use of pain medication and fear avoidance beliefs related to physical activity (both P = 0.02 for interaction). When comparing yoga or PT with self-care, a greater proportion were responders among those using pain meds (OR = 5.3), which differed from those not taking pain meds (OR = 0.94) at baseline. We also found greater treatment response among those with lower (OR = 7.0), but not high (OR = 1.3), fear avoidance beliefs around physical activity.

CONCLUSIONS

Our findings revealed important subgroups for whom referral to yoga or PT may improve cLBP outcomes.

Participant characteristics are poorly reported in exercise trials in tendinopathy: A systematic review

OBJECTIVE

To evaluate the reporting of eligibility criteria and baseline participant characteristics in randomised controlled trials investigating the effects of exercise interventions in tendinopathy.

METHODS

Randomised controlled trials investigating the effects of exercise therapy compared to a non-exercising intervention in upper and lower limb tendinopathy were included. Data extraction was categorised into the following domains: participant demographics, tendinopathy descriptors, general health, participant recruitment and eligibility criteria.

RESULTS

The review included the following tendinopathies: Achilles (n = 9), gluteal (n = 2), lateral elbow tendinopathy (n = 15), patellar (n = 3) plantar (n = 3), and rotator cuff (n = 13). Age, sex, duration of symptoms and symptom severity were commonly reported across the review, while prior history of tendinopathy was poorly reported (6/45). Variables such as physical activity level (17/45), sleep (0/45), psychological factors (2/45), medication at baseline (8/45), co morbid health complaints (10/45) and sociodemographic factors (11/45) were poorly reported across the included studies. Substantial variation existed between studies in the specific eligibility criteria used.

CONCLUSION

The findings of this systematic review demonstrate that participant characteristics are poorly reported in exercise trials in tendinopathy. To improve effectiveness of exercise interventions in tendinopathy, improved reporting of participant characteristics may allow better comparisons and targeted interventions for specific subgroups.

The strength of association between psychological factors and clinical outcome in tendinopathy: A systematic review

Objective

Tendinopathy is often a disabling, and persistent musculoskeletal disorder. Psychological factors appear to play a role in the perpetuation of symptoms and influence recovery in musculoskeletal pain. To date, the impact of psychological factors on clinical outcome in tendinopathy remains unclear. Therefore, the purpose of this systematic review was to investigate the strength of association between psychological factors and clinical outcome in tendinopathy.

Methods

A systematic review of the literature and qualitative synthesis of published trials was conducted. Electronic searches of ovid MEDLINE, ovid EMBASE, PsychINFO, CINAHL and Cochrane Library was undertaken from their inception to June 2020. Eligibility criteria included RCT’s and studies of observational design incorporating measurements of psychological factors and pain, disability and physical functional outcomes in people with tendinopathy. Risk of Bias was assessed by two authors using a modified version of the Newcastle Ottawa Scale. High or low certainty evidence was examined using the GRADE criteria.

Results

Ten studies of observational design (6-cross sectional and 4 prospective studies), involving a sample of 719 participants with tendinopathy were included. Risk of bias for the included studies ranged from 12/21 to 21/21. Cross-sectional studies of low to very low level of certainty evidence revealed significant weak to moderate strength of association (r = 0.24 to 0.53) between psychological factors and clinical outcomes. Prospective baseline data of very low certainty evidence showed weak strength of association between psychological factors and clinical outcome. However, prospective studies were inconsistent in showing a predictive relationship between baseline psychological factors on long-term outcome. Cross sectional studies report similar strengths of association between psychological factors and clinical outcomes in tendinopathy to those found in other musculoskeletal conditions.

Conclusion

The overall body of the evidence after applying the GRADE criteria was low to very low certainty evidence, due to risk of bias, imprecision and indirectness found across included studies. Future, high quality longitudinal cohort studies are required to investigate the predictive value of baseline psychological factors on long-term clinical outcome.

Efficacy and acceptability of pharmacological and non-pharmacological interventions for non-specific chronic low back pain: a protocol for a systematic review and network meta-analysis

BACKGROUND

Despite the enormous financial and humanistic burden of chronic low back pain (CLBP), there is little consensus on what constitutes the best treatment options from a multitude of competing interventions. The objective of this network meta-analysis (NMA) is to determine the relative efficacy and acceptability of primary care treatments for non-specific CLBP, with the overarching aim of providing a comprehensive evidence base for informing treatment decisions.

METHODS

We will perform a systematic search to identify randomised controlled trials of interventions endorsed in primary care guidelines for the treatment of non-specific CLBP in adults. Information sources searched will include major bibliographic databases (MEDLINE, Embase, CENTRAL, CINAHL, PsycINFO and LILACS) and clinical trial registries. Our primary outcomes will be patient-reported pain ratings and treatment acceptability (all-cause discontinuation), and secondary outcomes will be functional ability, quality of life and patient/physician ratings of overall improvement. A hierarchical Bayesian class-based NMA will be performed to determine the relative effects of different classes of pharmacological (NSAIDs, opioids, paracetamol, anti-depressants, muscle relaxants) and non-pharmacological (exercise, patient education, manual therapies, psychological therapy, multidisciplinary approaches, massage, acupuncture, mindfulness) interventions and individual treatments within a class (e.g. NSAIDs: diclofenac, ibuprofen, naproxen). We will conduct risk of bias assessments and threshold analysis to assess the robustness of the findings to potential bias. We will compute the effect of different interventions relative to placebo/no treatment for both short- and long-term efficacy and acceptability.

DISCUSSION

While many factors are important in selecting an appropriate intervention for an individual patient, evidence for the analgesic effects and acceptability of a treatment are key factors in guiding this selection. Thus, this NMA will provide an important source of evidence to inform treatment decisions and future clinical guidelines.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registry number: CRD42019138115.

Family History Influences the Effectiveness of Home Exercise in Older People With Chronic Low Back Pain: A Secondary Analysis of a Randomized Controlled Trial

OBJECTIVE

To investigate whether a family history of low back pain (LBP) influences patient outcomes and treatment effects following home exercises in older people with chronic LBP.

DESIGN

Secondary analysis of a randomized controlled trial.

SETTING

Local community.

PARTICIPANTS

People older than 55 years with chronic LBP (N=60).

INTERVENTIONS

Participants in the intervention group completed video game exercises for 60 minutes 3 times per week for 8 weeks. Participants in the control group were instructed to maintain their usual levels of activity and care seeking behaviors.

MAIN OUTCOMES MEASURES

Participants indicated whether any of their immediate family members had a history of "any" LBP or "activity-limiting" LBP at baseline. We collected self-reported measures of pain, function, pain self-efficacy, care seeking, physical activity, disability, fear of movement and/or reinjury, and falls efficacy at baseline, 8 weeks, 3 months, and 6 months. We performed regression analyses to determine whether a family history of LBP predicted patient outcomes and moderated the effects of home exercise.

RESULTS

Participants with a family history of any LBP were less likely to be highly active than those without a family history (odds ratio, 0.08; 95% CI, 0.01-0.42; P=.003). Home-based video game exercises led to improvements in function in those without a family history of activity-limiting LBP (β=1.78; 95% CI, 0.56-3.00; P=.006) but not in those with a family history (β=-0.17; 95% CI, -2.56 to 2.21; P=.880) (interaction P=.049). A family history of LBP did not influence the remaining patient outcomes or treatment effects.

CONCLUSIONS

A family history of LBP appears to negatively influence physical activity levels in older people with chronic LBP. Further, home-based video game exercises appear to be beneficial for older people with chronic LBP that do not have a family history of LBP.

Framework for improving outcome prediction for acute to chronic low back pain transitions

Clinical practice guidelines and the Federal Pain Research Strategy (United States) have recently highlighted research priorities to lessen the public health impact of low back pain (LBP). It may be necessary to improve existing predictive approaches to meet these research priorities for the transition from acute to chronic LBP. In this article, we first present a mapping review of previous studies investigating this transition and, from the characterization of the mapping review, present a predictive framework that accounts for limitations in the identified studies. Potential advantages of implementing this predictive framework are further considered. These advantages include (1) leveraging routinely collected health care data to improve prediction of the development of chronic LBP and (2) facilitating use of advanced analytical approaches that may improve prediction accuracy. Furthermore, successful implementation of this predictive framework in the electronic health record would allow for widespread testing of accuracy resulting in validated clinical decision aids for predicting chronic LBP development.

Potential treatment effect modifiers for manipulative therapy for children complaining of spinal pain.Secondary analyses of a randomised controlled trial

Background

In children, spinal pain is transitory for most, but up to 20% experience recurrent and bothersome complaints. It is generally acknowledged that interventions may be more effective for subgroups of those affected with low back pain. In this secondary analysis of data from a randomized clinical trial, we tested whether five indicators of a potential increased need for treatment might act as effect modifiers for manipulative therapy in the treatment of spinal pain in children. We hypothesized that the most severely affected children would benefit more from manipulative therapy.

Method

This study was a secondary analysis of data from a randomised controlled trial comparing advice, exercises and soft tissue treatment with and without the addition of manipulative therapy in 238 Danish school children aged 9-15 years complaining of spinal pain. A text message system (SMS) and clinical examinations were used for data collection (February 2012 to April 2014).Five pre-specified potential effect modifiers were explored: Number of weeks with spinal pain 6 months prior to inclusion, number of weeks with co-occurring musculoskeletal pain 6 months prior to inclusion, expectations of the clinical course, pain intensity, and quality of life.Outcomes were number of recurrences of spinal pain, number of weeks with pain, length of episodes, global perceived effect, and change in pain intensity. To explore potential effect modification, various types of regression models were used depending on the type of outcome, including interaction tests.

Results

We found that children with long duration of spinal pain or co-occurring musculoskeletal pain prior to inclusion as well as low quality of life at baseline tended to benefit from manipulative therapy over non-manipulative therapy, whereas the opposite was seen for children reporting high intensity of pain. However, most results were statistically insignificant.

Conclusions

This secondary analysis indicates that children more effected by certain baseline characteristics, but not pain intensity, have a greater chance to benefit from treatment that include manipulative therapy. However, these analyses were both secondary and underpowered, and therefore merely exploratory. The results underline the need for a careful choice of inclusion criteria in future investigations of manipulative therapy in children.

Trial registration

NCT01504698; results.

Individual recovery expectations and prognosis of outcomes in non-specific low back pain: prognostic factor review

BACKGROUND

Low back pain is costly and disabling. Prognostic factor evidence can help healthcare providers and patients understand likely prognosis, inform the development of prediction models to identify subgroups, and may inform new treatment strategies. Recent studies have suggested that people who have poor expectations for recovery experience more back pain disability, but study results have differed.

OBJECTIVES

To synthesise evidence on the association between recovery expectations and disability outcomes in adults with low back pain, and explore sources of heterogeneity.

SEARCH METHODS

The search strategy included broad and focused electronic searches of MEDLINE, Embase, CINAHL, and PsycINFO to 12 March 2019, reference list searches of relevant reviews and included studies, and citation searches of relevant expectation measurement tools.

SELECTION CRITERIA

We included low back pain prognosis studies from any setting assessing general, self-efficacy, and treatment expectations (measured dichotomously and continuously on a 0 - 10 scale), and their association with work participation, clinically important recovery, functional limitations, or pain intensity outcomes at short (3 months), medium (6 months), long (12 months), and very long (> 16 months) follow-up.

DATA COLLECTION AND ANALYSIS

We extracted study characteristics and all reported estimates of unadjusted and adjusted associations between expectations and related outcomes. Two review authors independently assessed risks of bias using the Quality in Prognosis Studies (QUIPS) tool. We conducted narrative syntheses and meta-analyses when appropriate unadjusted or adjusted estimates were available. Two review authors independently graded and reported the overall quality of evidence.

MAIN RESULTS

We screened 4635 unique citations to include 60 studies (30,530 participants). Thirty-five studies were conducted in Europe, 21 in North America, and four in Australia. Study populations were mostly chronic (37%), from healthcare (62%) or occupational settings (26%). General expectation was the most common type of recovery expectation measured (70%); 16 studies measured more than one type of expectation. Usable data for syntheses were available for 52 studies (87% of studies; 28,885 participants). We found moderate-quality evidence that positive recovery expectations are strongly associated with better work participation (narrative synthesis: 21 studies; meta-analysis: 12 studies, 4777 participants: odds ratio (OR) 2.43, 95% confidence interval (CI) 1.64 to 3.62), and low-quality evidence for clinically important recovery outcomes (narrative synthesis: 12 studies; meta-analysis: 5 studies, 1820 participants: OR 1.89, 95% CI 1.49 to 2.41), both at follow-up times closest to 12 months, using adjusted data. The association of recovery expectations with other outcomes of interest, including functional limitations (narrative synthesis: 10 studies; meta-analysis: 3 studies, 1435 participants: OR 1.40, 95% CI 0.85 to 2.31) and pain intensity (narrative synthesis: 9 studies; meta-analysis: 3 studies, 1555 participants: OR 1.15, 95% CI 1.08 to 1.23) outcomes at follow-up times closest to 12 months using adjusted data, is less certain, achieving very low- and low-quality evidence, respectively. No studies reported statistically significant or clinically important negative associations between recovery expectations and any low back pain outcome.

AUTHORS' CONCLUSIONS

We found that individual recovery expectations are probably strongly associated with future work participation (moderate-quality evidence) and may be associated with clinically important recovery outcomes (low-quality evidence). The association of recovery expectations with other outcomes of interest is less certain. Our findings suggest that recovery expectations should be considered in future studies, to improve prognosis and management of low back pain.

Treatment monitoring as a component of psychologically informed physical therapy: A case series of patients at high risk for persistent low back pain related disability

BACKGROUND

Psychologically Informed Physical Therapy (PIPT) aims to identify individuals at high risk for transitioning to chronicity and merge impairment-focused physical therapy with cognitive behavioral therapy principles. Treatment monitoring is an important part of PIPT and involves identifying changes in clinical measures to inform clinical decision making.

OBJECTIVES

The purpose of this case series is to describe treatment monitoring using psychological and physical impairment measures for patients identified as 'high-risk' for persistent low back pain (LBP) related disability.

DESIGN

Secondary analysis of patients (n = 23) identified as 'high-risk' using the STarT Back Tool and enrolled in two-phased, sequential study that evaluated feasibility and generated preliminary PIPT treatment effects for 4-week clinical outcomes.

METHOD

Physical therapists (n = 5) used psychological [Fear-Avoidance Beliefs Questionnaire (FABQ-PA, FABQ-W), Tampa Scale for Kinesiophobia (TSK-11), Pain Catastrophizing Scale (PCS) and Fear of Daily Activities Questionnaire (FDAQ)] and the Physical Impairment Index (PII) measures for PIPT treatment monitoring. Clinical outcome measures [Numerical Pain Rating Scale (NPRS), Oswestry Disability Index (ODI)] were administered at intake and 4-weeks later. Linear regression models evaluated independent contribution of intake and 4-week changes in psychological measures and PII scores as predictors of 4-week NPRS and ODI scores.

RESULTS

FABQ-PA and PCS changes provided largest contributions to prediction of 4-week ODI scores. Treatment monitoring measures did not explain additional variability in 4-week NPRS scores after baseline scores were considered.

CONCLUSIONS

For patients at high risk for persistent LBP psychological measures consistently performed better as treatment monitoring variables compared to physical impairment measures. Treatment monitoring for PIPT with psychological measures provides opportunities to refine prediction of disability outcomes. Findings from this exploratory case series should be interpreted with caution based on its small sample size and lack of statistical power which prohibits definitive conclusions to be made on any of the treatment monitoring measures.

The use of STarT back screening tool to predict functional disability outcomes in patients receiving physical therapy for low back pain

BACKGROUND CONTEXT

The STarT Back Screening Tool (SBST) categorizes risk of future disability in patients with low back pain (LBP). Previous studies evaluating the use of SBST in physical therapy (PT) populations do not reflect the ethnic and socioeconomic diversity occurring in clinical practice and lack statistical power to evaluate factors associated with outcomes within each SBST risk category.

PURPOSE

The purpose of this study is to further refine SBST risk categorization for predicting improvements in functional disability with attention toward patient level factors that might guide SBST use in routine outpatient physical therapy practice.

STUDY DESIGN/SETTING

This was a retrospective cohort study that took place within a large academic, tertiary-care health system.

PATIENT SAMPLE

The study cohort consisted of 1,169 patients with LBP who completed a course of outpatient physical therapy from June 1, 2014 to May 31, 2015 and who completed the patient-reported SBST and modified low back pain disability questionnaire (MDQ) questionnaires as part of standard of care.

OUTCOME MEASURES

Improvement in functional disability defined as decrease in 10 or more points in the MDQ.

METHODS

Multivariable logistic regression was performed to evaluate independent predictors of improvement after PT, which included SBST risk category, baseline MDQ, a two-way interaction term between SBST category and baseline MDQ, prior level of function (independent vs. required assistance), demographic characteristics, number of completed PT visits, and duration of PT episode of care. In exploratory analyses, additional two-way interaction terms between SBST category and the significant predictors were added to the regression model.

RESULTS

Mean age of patients in the study cohort was 55.1 years (SD 16.1); 657 (56.2%) were female, 117 (10.0%) were black race, 127 (10.9%) had Medicaid insurance, and 353 (30.2%) had previously received PT for back pain. In all, 35.8% (n=419) patients categorized as low risk SBST category, 40.7% (n=476) medium risk SBST category, and 23.4% (n=274) high risk SBST category. There was an interaction between baseline MDQ and SBST risk category and improvement with PT. For all three SBST categories, higher baseline MDQ was associated with higher probability of improvement, but the effect was less pronounced as SBST risk category increased. Additional factors independently associated with reduced odds of improvement after PT included black race (odds ratio [OR] 0.44, 95% confidence interval [CI] 0.28-0.72), Medicaid insurance (OR=0.58, 95% CI 0.36-0.95), and prior PT (OR=0.48, 95% CI 0.34-0.67). In exploratory analyses, there was a significant interaction between insurance type and SBST risk category in predicting functional improvement after PT. Patients with Medicare and Medicaid insurance had similar rates of improvement in low and high risk SBST categories but different rates of improvement in the medium risk categories.

CONCLUSIONS

The SBST tool predicts outcomes of PT in a cohort of patients receiving outpatient PT for LBP. The odds of improvement varied according to baseline disability and SBST risk status. Race, insurance type, and history of previous PT influenced prediction independent of SBST risk status. Incorporating these variables and the interaction between SBST and baseline disability in outcome models has the potential to refine prediction of outcomes after PT.

The Impact of Inadequate Health Literacy in a Population with Musculoskeletal Pain

Musculoskeletal conditions are a major cause of ill health and disability. Inadequate health literacy may partly explain why musculoskeletal self-management programs are not effective for some patients. This study prospectively evaluated the impact of patients' health literacy level on their musculoskeletal pain and physical function (PF) following usual primary care. Primary care patients (N = 4,720) who had consulted for musculoskeletal pain were mailed a baseline questionnaire; responders were sent a 6-month follow-up questionnaire. The measure of health literacy used was the single-item Literary Screener at baseline, and the outcomes were PF and pain intensity at the 6-months follow-up. Analysis was conducted by linear regression. The number of patients who responded was 1,890 (40%); 17.3% (95% CI [15.6%–19%]) of them had inadequate health literacy. Inadequate health literacy was associated with older age (p < .05), lower education, mental health, and comorbidities (all p < .001), but not by gender (p = .642). At the 6-month follow-up stage, patients with inadequate health literacy had lower PF (mean difference −12.2; 95% CI [−16.7, −7.6]) and higher pain intensity (mean difference 1; 95% CI [0.6, 1.4]), which was adjusted for age, gender, education, mental health, and comorbidities. Differences in PF and particularly pain scores between patients with inadequate and adequate health literacy increased over 6 months. Future studies should develop interventions that better support patients who have musculoskeletal pain with inadequate health literacy to successfully manage their pain. [HLRP: Health Literacy Research and Practice. 2018;2(4):e214–e220.]

The heterogeneous effect of short-term transfers for improving ART adherence among HIV-infected Tanzanian adults

A recently concluded randomized study in Tanzania found that short-term conditional cash and food transfers significantly improved HIV-infected patients’ possession of antiretroviral therapy (ART) and reduced patient loss to follow-up (LTFU) (McCoy, S. I., Njau, P. F., Fahey, C., Kapologwe, N., Kadiyala, S., Jewell, N. P., & Padian, N. S. (2017). Cash vs. food assistance to improve adherence to antiretroviral therapy among HIV-infected adults in Tanzania. AIDS, 31(6), 815–825. doi:10.1097/QAD.0000000000001406 ). We examined whether these transfers had differential effects within population subgroups. In the parent study, 805 individuals were randomized to one of three study arms: standard-of-care (SOC) HIV services, food assistance, or cash transfer. We compared achievement of the medication possession ratio (MPR) ≥ 95% at 6 and 12 months and patient LTFU at 12 months between those receiving the SOC and those receiving food or cash (combined). Using a threshold value of p < 0.20 to signal potential effect measure modifiers (EMM), we compared intervention effects, expressed as risk differences (RD), within subgroups characterized by: sex, age, wealth, and time elapsed between HIV diagnosis and ART initiation. Short-term transfers improved 6 and 12-month MPR ≥ 95% and reduced 12-month LTFU in most subgroups. Study results revealed wealth and time elapsed between HIV diagnosis and ART initiation as potential EMMs, with greater effects for 6-month MPR ≥ 95% in the poorest patients (RD: 32, 95% CI: (9, 55)) compared to those wealthier (RD: 16, 95% CI: (5, 27); p = 0.18) and in newly diagnosed individuals (<90 days elapsed since diagnosis) (RD: 25, 95% CI: (13, 36)) compared to those with ≥90 days (RD: 0.3, 95% CI (−17, 18); p = 0.02), patterns which were sustained at 12 months. Results suggest that food and cash transfers may have stronger beneficial effects on ART adherence in the poorest patients. We also provide preliminary data suggesting that targeting interventions at patients more recently diagnosed with HIV may be worthwhile. Larger and longer-term assessments of transfer programs for the improvement of ART adherence and their potential heterogeneity by sub-population are warranted.

Advancing practice for back pain through stratified care (STarT Back)

BACKGROUND

Low back pain (LBP) is common, however research comparing the effectiveness of different treatments over the last two decades conclude either no or small differences in the average effects of different treatments. One suggestion to explain this is that patients are not all the same and important subgroups exist that might require different treatment approaches. Stratified care for LBP involves identifying subgroups of patients and then delivering appropriate matched treatments. Research has shown that stratified care for LBP in primary care can improve clinical outcomes, reduce costs and increase the efficiency of health-care delivery in the UK. The challenge now is to replicate and evaluate this approach in other countries health care systems and to support services to implement it in routine clinical care.

RESULTS

The STarT Back approach to stratified care has been tested in the National Health Service, within the UK, it reduces unnecessary overtreatment in patients who have a good prognosis (those at low risk) yet increases the likelihood of appropriate healthcare and associated improved outcomes for those who are at risk of persistent disabling pain. The approach is cost-effective in the UK healthcare setting and has been recommended in recent guidelines and implemented as part of new LBP clinical pathways of care. This approach has subsequently generated international interest, a replication study is currently underway in Denmark, however, some lessons have already been learnt. There are potential obstacles to implementing stratified care in low-and-middle-income settings and in other high-income settings outside of the UK, however, implementation science literature can inform the development of innovations and efforts to support implementation of stratified care.

CONCLUSIONS

The STarT Back approach to stratified care for LBP is a promising method to advance practice that has demonstrated clinical and cost effectiveness in the UK. Over time, further evidence for both the effectiveness and the adaptations needed to test and implement the STarT Back stratified care approach in other countries is needed.

Advancing Psychologically Informed Practice for Patients With Persistent Musculoskeletal Pain: Promise, Pitfalls, and Solutions

There has been growing interest in psychologically oriented pain management over the past 3 to 4 decades, including a 2011 description of psychologically informed practice (PIP) for low back pain. PIP requires a broader focus than traditional biomechanical and pathology-based approaches that have been traditionally used to manage musculoskeletal pain. A major focus of PIP is addressing the behavioral aspects of pain (ie, peoples' responses to pain) by identifying individual expectations, beliefs, and feelings as prognostic factors for clinical and occupational outcomes indicating progression to chronicity. Since 2011, the interest in PIP seems to be growing, as evidenced by its use in large trials, inclusion in scientific conferences, increasing evidence base, and expansion to other musculoskeletal pain conditions. Primary care physicians and physical therapists have delivered PIP as part of a stratified care approach involving screening and targeting of treatment for people at high risk for continued pain-associated disability. Furthermore, PIP is consistent with recent national priorities emphasizing nonpharmacological pain management options. In this perspective, PIP techniques that range in complexity are described, considerations for implementation in clinical practice are offered, and future directions that will advance the understanding of PIP are outlined.

A systematic review of psychological correlates of HIV testing intention

Undiagnosed HIV infection is associated with onward HIV transmission and delays in accessing HIV care and treatment. As a significant proportion of HIV tests are self-initiated, it is important to assess correlates of the intention to test for HIV. Psychological correlates of HIV testing intention are more likely to be the feasible target of interventions than structural determinants. A systematic review of psychological correlates of HIV testing intention was conducted. Twenty studies were included in the review, covering a range of populations and geographical regions. The most commonly assessed variables were HIV risk perception and HIV knowledge rather than HIV test-specific psychological factors. There was evidence that HIV risk perception and pro-testing attitudes were consistently associated with HIV testing intention across a number of studies. There is a need for longitudinal designs, including experimental studies, allowing for more confident casual inferences to be made. Theoretical, research and practice implications are outlined.

The STarT back tool in chiropractic practice: a narrative review

Background

The Keele STarT Back Tool was designed for primary care medical physicians in the UK to determine the risk for persistent disabling pain in patients with musculoskeletal pain and to tailor treatments accordingly. In medical and physical therapy settings, STarT Back Tool’s tailored care plans improved patients’ low back pain outcomes and lowered costs.

Objective

Review studies using the STarT Back Tool in chiropractic patient populations.

Methods

PubMed, The Cochrane Library, Index to Chiropractic Literature, and Science Direct databases were searched. Articles written in English, published in peer-reviewed journals, that studied the STarT Back Tool in patients seeking chiropractic care were included.

Results

Seven articles were selected based on inclusion and exclusion criteria. The STarT Back Tool was feasibly incorporated into 19 chiropractic clinics in Denmark. Total STarT Back 5-item score correlated moderately with total Bournemouth Questionnaire score. Two studies reported that the STarT Back Tool’s predictive ability was poor, while another reported that the tool predicted outcomes in patients scoring in the medium and high risk categories who completed the STarT Back 2 days after their initial visit. A study examining Danish chiropractic, medical and physical therapy settings revealed that only baseline episode duration affected STarT Back’s prognostic ability across all care settings. The tool predicted pain and disability in chiropractic patients whose episode duration was at least 2 weeks, but not in patients with an episode duration <2 weeks.

Conclusion

While the STarT Back Tool can be incorporated into chiropractic settings and correlates with some elements of the Bournemouth Questionnaire, its prognostic ability is sometimes limited by the shorter low back pain episodes with which chiropractic patients often present. It may be a better predictor in patients whose episode duration is at least 2 weeks. Studies examining outcomes of stratified care in chiropractic patients are needed.