Predicting a clinically important outcome in patients with low back pain following McKenzie therapy or spinal manipulation: a stratified analysis in a randomized controlled trial

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.

Predictors of failure to achieve minimal clinical important difference for pain and disability after mechanical diagnosis and therapy (MDT)-based multimodal rehabilitation for neck pain: a retrospective analysis of 4998 patients

PURPOSE

To determine predictors of failure to achieve minimal clinical important difference (MCID) for pain and disability at discharge after mechanical diagnosis and therapy (MDT)-based multimodal rehabilitation for neck pain (NP).

METHODS

Pre- and post-treatment numerical pain rating scale (NPRS) and neck disability index (NDI) in patients with mechanical NP were analysed in this retrospective study. Multivariate analysis was performed to investigate the effect of covariates such as age, gender, lifestyle, body mass index, presentation, diabetes, osteoporosis, response to repeated movement testing, treatment sessions, compliance rate, and pre-treatment NPRS and NDI scores on failure to achieve MCID of ≥ 30% for NPRS and NDI scores post-treatment.

RESULTS

In the 4998 patients analysed for this study, 7% and 14.5% of patients failed to achieve MCID for NPRS and NDI scores, respectively, at the end of treatment. Age > 70 years, diabetes, osteoporosis, partial or non-response to repeated movements, lesser treatment sessions, and lower compliance rate were associated with increased risk for failure to achieve MCID for NPRS and NDI scores. A higher pre-treatment NDI score was associated with failure to achieve MCID for NPRS score, whereas lower pre-treatment NPRS and NDI scores were associated with failure to achieve MCID for NDI score.

CONCLUSION

Although MDT-based multimodal rehabilitation helped to achieve significant reduction in pain and disability in mechanical NP, several baseline risk factors were associated with failure to achieve MCID for pain and disability after treatment. Identifying and modifying these factors as part of rehabilitation treatment may help to achieve better outcomes in mechanical NP.

The effect of ambient temperature on in-hospital mortality: a study in Nanjing, China

To reduce the inpatient mortality and improve the quality of hospital management, we explore the relationship between temperatures and in-hospital mortality in a large sample across 10 years in Nanjing, Jiangsu. We collected 10 years’ data on patient deaths from a large research hospital. Distributed lag non-linear model (DLNM) was used to find the association between daily mean temperatures and in-hospital mortality. A total of 6160 in-hospital deaths were documented. Overall, peak RR appeared at 8 °C, with the range of 1 to 20 °C having a significantly high mortality risk. In the elderly (age ≥ 65 years), peak RR appeared at 5 °C, with range − 3 to 21 °C having a significantly high mortality risk. In males, peak RR appeared at 8 °C, with the range 0 to 24 °C having a significantly high mortality risk. Moderate cold (define as 2.5th percentile of daily mean temperatures to the MT), not extreme temperatures (≤ 2.5th percentile or ≥ 97.5th percentile of daily mean temperatures), increased the risk of death in hospital patients, especially in elderly and male in-hospital patients.

How Does the Measurement of Disability in Low Back Pain Map Unto the International Classification of Functioning, Disability and Health?: A Scoping Review of the Manual Medicine Literature

ABSTRACT

The objective of this study was to catalog items from instruments used to measure functioning, disability, and contextual factors in patients with low back pain treated with manual medicine (manipulation and mobilization) according to the International Classification of Functioning, Disability and Health. This catalog will be used to inform the development of an International Classification of Functioning, Disability and Health-based assessment schedule for low back pain patients treated with manual medicine. In this scoping review, we systematically searched MEDLINE, Embase, PsycINFO, and CINAHL. We identified instruments (questionnaires, clinical tests, single questions) used to measure functioning, disability, and contextual factors, extracted the relevant items, and then linked these items to the International Classification of Functioning, Disability and Health. We included 95 articles and identified 1510 meaningful concepts. All but 70 items were linked to the International Classification of Functioning, Disability and Health. Of the concepts linked to the International Classification of Functioning, Disability and Health, body functions accounted for 34.7%, body structures accounted for 0%, activities and participation accounted for 41%, environmental factors accounted for 3.6%, and personal factors accounted for 16%. Most items used to measure functioning and disability in low back pain patient treated with manual medicine focus on body functions, as well as activities and participation. The lack of measures that address environmental factors warrants further investigation.

Artificial intelligence to improve back pain outcomes and lessons learnt from clinical classification approaches: three systematic reviews

Artificial intelligence and machine learning (AI/ML) could enhance the ability to detect patterns of clinical characteristics in low-back pain (LBP) and guide treatment. We conducted three systematic reviews to address the following aims: (a) review the status of AI/ML research in LBP, (b) compare its status to that of two established LBP classification systems (STarT Back, McKenzie). AI/ML in LBP is in its infancy: 45 of 48 studies assessed sample sizes <1000 people, 19 of 48 studies used ≤5 parameters in models, 13 of 48 studies applied multiple models and attained high accuracy, 25 of 48 studies assessed the binary classification of LBP versus no-LBP only. Beyond the 48 studies using AI/ML for LBP classification, no studies examined use of AI/ML in prognosis prediction of specific sub-groups, and AI/ML techniques are yet to be implemented in guiding LBP treatment. In contrast, the STarT Back tool has been assessed for internal consistency, test-retest reliability, validity, pain and disability prognosis, and influence on pain and disability treatment outcomes. McKenzie has been assessed for inter- and intra-tester reliability, prognosis, and impact on pain and disability outcomes relative to other treatments. For AI/ML methods to contribute to the refinement of LBP (sub-)classification and guide treatment allocation, large data sets containing known and exploratory clinical features should be examined. There is also a need to establish reliability, validity, and prognostic capacity of AI/ML techniques in LBP as well as its ability to inform treatment allocation for improved patient outcomes and/or reduced healthcare costs.

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.

Which specific modes of exercise training are most effective for treating low back pain? Network meta-analysis

Objective

Examine the effectiveness of specific modes of exercise training in non-specific chronic low back pain (NSCLBP).

Design

Network meta-analysis (NMA).

Data sources

MEDLINE, CINAHL, SPORTDiscus, EMBASE, CENTRAL.

Eligibility criteria

Exercise training randomised controlled/clinical trials in adults with NSCLBP.

Results

Among 9543 records, 89 studies (patients=5578) were eligible for qualitative synthesis and 70 (pain), 63 (physical function), 16 (mental health) and 4 (trunk muscle strength) for NMA. The NMA consistency model revealed that the following exercise training modalities had the highest probability (surface under the cumulative ranking (SUCRA)) of being best when compared with true control: Pilates for pain (SUCRA=100%; pooled standardised mean difference (95% CI): −1.86 (–2.54 to –1.19)), resistance (SUCRA=80%; −1.14 (–1.71 to –0.56)) and stabilisation/motor control (SUCRA=80%; −1.13 (–1.53 to –0.74)) for physical function and resistance (SUCRA=80%; −1.26 (–2.10 to –0.41)) and aerobic (SUCRA=80%; −1.18 (–2.20 to –0.15)) for mental health. True control was most likely (SUCRA≤10%) to be the worst treatment for all outcomes, followed by therapist hands-off control for pain (SUCRA=10%; 0.09 (–0.71 to 0.89)) and physical function (SUCRA=20%; −0.31 (–0.94 to 0.32)) and therapist hands-on control for mental health (SUCRA=20%; −0.31 (–1.31 to 0.70)). Stretching and McKenzie exercise effect sizes did not differ to true control for pain or function (p>0.095; SUCRA<40%). NMA was not possible for trunk muscle endurance or analgesic medication. The quality of the synthesised evidence was low according to Grading of Recommendations Assessment, Development and Evaluation criteria.

Summary/conclusion

There is low quality evidence that Pilates, stabilisation/motor control, resistance training and aerobic exercise training are the most effective treatments, pending outcome of interest, for adults with NSCLBP. Exercise training may also be more effective than therapist hands-on treatment. Heterogeneity among studies and the fact that there are few studies with low risk of bias are both limitations.

Centralization and directional preference: An updated systematic review with synthesis of previous evidence

BACKGROUND

Centralization and directional preference are common management and prognostic factors in spinal symptoms.

OBJECTIVE

To update the previous systematic review.

DESIGN

Systematic review to synthesis multiple aspects of centralization and directional preference.

METHOD

Contemporary search was made of multiple databases using relevant search terms. Abstracts and titles were filtered by two authors; relevant articles were independently reviewed by two authors for content, data extraction, and quality.

RESULTS

Forty-three additional relevant articles were found. The quality of the studies, using PEDro for randomized controlled trials, was moderate or high in six out of ten RCTs; moderate or high in six out of 12 cohort studies. Prevalence of centralization was 40%, the same as the previous review. Directional preference without Centralization was 26%; thus Centralization and directional preference combined was 66%, which was very similar to the previous review. Neither clinical response was recorded in about a third of patients. Centralization and directional preference were confirmed as key positive prognostic factors, certainly in patients with low back pain, but limited evidence for patients with neck pain. There was no evidence that these might be important treatment effect modifiers. One study evaluated reliability, and found generally poor levels, despite training.

CONCLUSIONS

Centralization and directional preference are worthwhile indicators of prognosis, and should be routinely examined for even in patients with chronic low back pain. But they do not occur in all patients with spinal problems, and there was no evidence that they were treatment effect modifiers.

The impact of pragmatic vs. prescriptive study designs on the outcomes of low back and neck pain when using mobilization or manipulation techniques: a systematic review and meta-analysis

Objective

The purpose of this systematic review and meta-analysis was to examine the impact of pragmatic versus prescriptive study designs on the outcomes of low back and neck pain when using mobilization or manipulation techniques.

Methods

This study design was a systematic review and meta-analysis, which was performed according to the PRISMA guidelines. A search of MEDLINE and CINAHL complete databases was performed. Article titles and abstracts were reviewed to identify studies comparing mobilization and manipulation in low back or neck pain that met eligibility criteria. Validity of studies was examined using the Cochrane Risk of Bias tool. Data analysis was performed using RevMan 5.3. Forest plots were constructed after data were analyzed to determine effect sizes.

Results

Thirteen studies with a total of 1313 participants were included in the systematic review, and 12 studies with 977 participants in the meta-analysis. For most time-points prescriptive studies found manipulation to be superior to mobilization for both pain and disability. At no time-point did pragmatic designs find a difference between mobilization and manipulation for either pain or disability.

Discussion

When a pragmatic design was used, representing actual clinical practice, patients improved with both techniques with no difference between mobilization and manipulation. When clinicians were prescribed techniques, not representing true clinical practice, manipulation showed better outcomes than mobilization for pain and disability.

Level of Evidence

1a.

McKenzie Method of Mechanical Diagnosis and Therapy was slightly more effective than placebo for pain, but not for disability, in patients with chronic non-specific low back pain: a randomised placebo controlled trial with short and longer term follow-up

Background

The McKenzie Method of Mechanical Diagnosis and Therapy (MDT) is one of the exercise approaches recommended by low back pain (LBP) guidelines. We investigated the efficacy of MDT compared with placebo in patients with chronic LBP.

Methods

This was a prospectively registered, two-arm randomised placebo controlled trial, with a blinded assessor. A total of 148 patients seeking care for chronic LBP were randomly allocated to either MDT (n=74) or placebo (n=74). Patients from both groups received 10 treatment sessions over 5 weeks. Patients from both groups also received an educational booklet. Clinical outcomes were obtained at the end of treatment (5 weeks) and 3, 6 and 12 months after randomisation. Primary outcomes were pain intensity and disability at the end of treatment (5 weeks). We also conducted a subgroup analysis to identify potential treatment effect modifiers that could predict a better response to MDT treatment.

Results

The MDT group had greater improvements in pain intensity at the end of treatment (mean difference (MD) −1.00, 95% CI −2.09 to −0.01) but not for disability (MD −0.84, 95% CI −2.62 to 0.93). We did not detect between-group differences for any secondary outcomes, nor were any treatment effect modifiers identified. Patients did not report any adverse events.

Conclusion

We found a small and likely not clinically relevant difference in pain intensity favouring the MDT method immediately at the end of 5 weeks of treatment but not for disability. No other difference was found for any of the primary or secondary outcomes at any follow-up times.

Trial registration number

ClinicalTrials.gov (NCT02123394)

EVALUATION AND TREATMENT OF A PATIENT DIAGNOSED WITH ADHESIVE CAPSULITIS CLASSIFIED AS A DERANGEMENT USING THE MCKENZIE METHOD: A CASE REPORT

BACKGROUND/PURPOSE

The McKenzie Method of mechanical diagnosis and therapy (MDT) is supported in the literature as a valid and reliable approach to the management of spine injuries. It can also be applied to the peripheral joints, but has not been explored through research to the same extent. This method sub-classifies an injury based on tissue response to mechanical loading and repeated motion testing, with directional preferences identified in the exam used to guide treatment. The purpose of this case report is to demonstrate the assessment, intervention, and clinical outcomes of a subject classified as having a shoulder derangement syndrome using MDT methodology.

CASE DESCRIPTION

The subject was a 52-year-old female with a four-week history of insidious onset left shoulder pain, referred to physical therapy with a medical diagnosis of adhesive capsulitis. She presented with pain (4-7/10 on the visual analog scale [VAS]) and decreased shoulder range of motion that limited her activities of daily living and work capabilities (Upper Extremity Functional Index (UEFI) score: 55/80). Active and passive ranges of motion (A/PROM) were limited in all planes. Repeated motion testing was performed, with an immediate reduction in pain and increased shoulder motion in all planes following repeated shoulder extension. As a result, her MDT classification was determined to be derangement syndrome. Treatment involved specific exercises, primarily repeated motions, identified as symptom alleviating during the evaluation process.

OUTCOMES

The subject demonstrated significant improvements in the UEFI (66/80), VAS (0-2/10), and ROM within six visits over eight weeks. At the conclusion of treatment, A/PROM was observed to be equal to the R shoulder without pain.

DISCUSSION

This subject demonstrated improved symptoms and functional abilities following evaluation and treatment using MDT methodology. While a cause-effect relationship cannot be determined with a single case, MDT methodology may be a useful approach to the examination, and potentially management, of patients with shoulder pain. This method offers a patient specific approach to treating the shoulder, particularly when the pathoanatomic structure affected is unclear.

LEVEL OF EVIDENCE

4.

Classification of patients with low back-related leg pain: a systematic review

BACKGROUND

The identification of clinically relevant subgroups of low back pain (LBP) is considered the number one LBP research priority in primary care. One subgroup of LBP patients are those with back related leg pain. Leg pain frequently accompanies LBP and is associated with increased levels of disability and higher health costs than simple low back pain. Distinguishing between different types of low back-related leg pain (LBLP) is important for clinical management and research applications, but there is currently no clear agreement on how to define and identify LBLP due to nerve root involvement. The aim of this systematic review was to identify, describe and appraise papers that classify or subgroup populations with LBLP, and summarise how leg pain due to nerve root involvement is described and diagnosed in the various systems.

METHODS

The search strategy involved nine electronic databases including Medline and Embase, reference lists of eligible studies and relevant reviews. Selected papers were appraised independently by two reviewers using a standardised scoring tool.

RESULTS

Of 13,358 initial potential eligible citations, 50 relevant papers were identified that reported on 22 classification systems. Papers were grouped according to purpose and criteria of the classification systems. Five themes emerged: (i) clinical features (ii) pathoanatomy (iii) treatment-based approach (iv) screening tools and prediction rules and (v) pain mechanisms. Three of the twenty two systems focused specifically on LBLP populations. Systems that scored highest following quality appraisal were ones where authors generally included statistical methods to develop their classifications, and supporting work had been published on the systems' validity, reliability and generalisability. There was lack of consistency in how LBLP due to nerve root involvement was described and diagnosed within the systems.

CONCLUSION

Numerous classification systems exist that include patients with leg pain, a minority of them focus specifically on distinguishing between different presentations of leg pain. Further work is needed to identify clinically meaningful subgroups of LBLP patients, ideally based on large primary care cohort populations and using recommended methods for classification system development.

Identifying Patients With Chronic Low Back Pain Who Respond Best to Mechanical Diagnosis and Therapy: Secondary Analysis of a Randomized Controlled Trial

BACKGROUND

"Mechanical Diagnosis and Therapy" (MDT) (also known as the McKenzie method), like other interventions for low back pain (LBP), has been found to have small effects for people with LBP. It is possible that a group of patients respond best to MDT and have larger effects. Identification of patients who respond best to MDT compared with other interventions would be an important finding.

OBJECTIVE

The purpose of the study was to investigate whether baseline characteristics of patients with chronic LBP, already classified as derangement syndrome, can identify those who respond better to MDT compared with Back School.

METHODS

This study was a secondary analysis of data from a previous trial comparing MDT with Back School in 148 patients with chronic LBP. Only patients classified at baseline assessment as being in the directional preference group (n=140) were included. The effect modifiers tested were: clear centralization versus directional preference only, baseline pain location, baseline pain intensity, and age. The primary outcome measures for this study were pain intensity and disability at the end of treatment (1 month). Treatment effect modification was evaluated by assessing the group versus predictor interaction terms from linear regression models. Interactions ≥1.0 for pain and ≥3 for disability were considered clinically important.

RESULTS

Being older met our criteria for being a potentially important effect modifier; however, the effect occurred in the opposite direction to our hypothesis. Older people had 1.27 points more benefit in pain reduction from MDT (compared with Back School) than younger participants after 1 month of treatment.

LIMITATIONS

The sample (n=140) was powered to detect the main effects of treatment but not to detect the interactions of the potential treatment effect modifiers.

CONCLUSIONS

The results of the study suggest older age may be an important factor that can be considered as a treatment effect modifier for patients with chronic LBP receiving MDT. As the main trial was not powered for the investigation of subgroups, the results of this secondary analysis have to be interpreted cautiously, and replication is needed.