Does pain duration and other variables measured at baseline predict re-referral of low back pain patients managed on an evidence-based pathway? A cohort study

OBJECTIVE

To explore the association between baseline pain duration and the likelihood of re-referral of patients with low back pain (LBP) managed on the evidence-based North East of England Regional Back Pain and Radicular Pain Pathway (NERBPP).

STUDY DESIGN

Longitudinal, observational cohort study.

METHODS

In all, 12,509 adults with LBP were identified as having been discharged from the pathway, between May 2015 and December 2019. To quantify any association between baseline pain duration and the likelihood of re-referral, two statistical modelling approaches, were used: logistic regression models for odds ratios and generalised linear models with a binomial link function in order to quantify risk differences.

RESULTS

Twenty-five percent of patients with LBP, who were discharged, re-referred for management over a 4.5-year period. A large difference in pain duration of 2 SD days was statistically associated with re-referral, with an odds ratio of 1.22 (95% CI: 1.03, 1.44) and a risk difference of 3.6% (95% CI: 0.6, 6.6). Nevertheless, the predictive value of an individual's pain duration was found to be weak for re-referral. Higher baseline disability [odds ratio of 1.40 (95% CI: 1.07, 1.83)] and a younger age at baseline [odds ratio of 0.73 (95% CI 0.61, 0.86)] were also associated with an increased risk of re-referral.

CONCLUSIONS

Baseline pain duration, disability and younger age are statistically associated with re-referral onto the NERBPP. However, the value of these variables for predicting an individual's risk of re-referral is weak. CONTRIBUTION OF PAPER.

The Association of Pain with Incident Falls in People with Chronic Obstructive Pulmonary Disease: Evidence from the English Longitudinal Study of Ageing

People with chronic obstructive pulmonary disease (COPD) have a higher prevalence of pain and a greater risk of falls than their healthy peers. As pain has been associated with an increased risk of falls in older adults, this study investigated the association between pain and falls in people with COPD compared to healthy controls. Data from the English Longitudinal Study of Ageing were used to establish an association between pain and falls when modelled with a generalised ordinal logistic regression and adjusted for sex, age, wealth, and education (complete case analysis only; n = 806 COPD, n = 3898 healthy controls). The odds were then converted to the predicted probabilities of falling. The predicted probability of falling for people with COPD was greater across all pain categories than for healthy controls; for COPD with (predicted probability % [95%CI]), no pain was 20% [17 to 25], with mild pain was 28% [18 to 38], with moderate pain was 28% [22 to 34] with severe pain was 39% [30 to 47] and for healthy controls with no pain was 17% [16 to 18], mild pain 22% [18 to 27], moderate pain 25% [20 to 29] and severe pain 27% [20 to 35]. The probability of falling increased across pain categories in individuals with COPD, with the most severe pain category at a nearly 40% probability of falling, indicating a potential interaction between COPD and pain.

Exploring the origin of pain subclassification, with emphasis on low back pain: a scoping review

OBJECTIVE

This scoping review aimed to explore the different working definitions for the duration of acute, subacute, and chronic pain, with emphasis on low back pain, and to establish where these definitions originated and the rationale provided for the time frames used.

INTRODUCTION

From a global perspective, low back pain is a major social and economic problem. One of the most commonly used methods to stratify and manage low back pain is the traditional duration-based classification (acute, subacute, and chronic). Where these time points lie to differentiate these transitions continues to be debated within the scientific community, which may engender a degree of heterogeneity in study findings. Therefore, applying these findings to clinical practice may be somewhat challenging. This review encapsulates the historical origins of the different duration categories to provide an understanding of how these variations were derived.

INCLUSION CRITERIA

Studies that included participants with low back pain were the focus of this review. Sources that included children or other specific pain pathologies, such as cancer pain, were excluded. The main concept of interest was that the publication proposed an original definition of the duration of acute, subacute, or chronic low back pain. All study designs were included provided they gave a rationale for the duration that they used.

METHODS

The following databases were searched: MEDLINE, Embase, CINAHL, and PsycINFO, from the inception of each database until September 18, 2019. This review was limited to studies published in English. Two independent reviewers screened the retrieved articles against the eligibility criteria. Additional studies were searched from the reference lists of studies to find the original source. Some original sources overlapped with general pain duration literature. This led to a deviation from the scoping review protocol, which originally intended to focus on definitions of low back pain duration only. Data extraction was undertaken using a charting table developed specifically for the review objectives. The findings were presented using narrative synthesis.

RESULTS

Nineteen records were included in this review, and comprised three book chapters, four review articles, four articles that arose following pain expert group discussions, seven primary research studies, and a spinal guideline. Data were extracted from the included studies and categorized into four themes based on the origin of the classification of the duration. The themes included i) work/employment setting, ii) empirical studies, iii) expert reasoning, and iv) pathophysiological explanation.

CONCLUSIONS

This scoping review compiled the existing literature on the working definitions of the duration of acute, subacute, and chronic low back pain and found a wide variation. These ranged from seven days, 14 days, and seven weeks for the acute and subacute transition points, and seven weeks to three years for chronic low back pain. The duration definitions specifically referring to the general pain literature focused on three and/or six months for the transition to chronic. Better integration of reasoning between the identified themes could facilitate the establishment of more ideal duration definitions in the future. Although inconclusive, the definition most commonly cited, with most consensus, was three months for the transition to chronic low back pain.

Long-term improvements following a residential combined physical and psychological programme for chronic low back pain

OBJECTIVES

Evaluate the outcomes and explore experiences of patients undergoing a residential combined physical and psychological programme (CPPP) for chronic low back pain.

DESIGN

A longitudinal observational cohort design, with a parallel qualitative design using semistructured interviews.

SETTING

Residential, multimodal rehabilitation.

PARTICIPANTS

136 adults (62 male/74 female) referred to the CPPP, 100 (44 male/56 female) of whom completed the programme, during the term of the study. Ten (2 male/8 female) participated in the qualitative evaluation.

INTERVENTION

A 3-week residential CPPP.

OUTCOME MEASURES

Primary outcome measures were the STarT Back screening tool score; pain intensity-11-point Numerical Rating Scale; function-Oswestry Disability Index (ODI); health status/quality of life-EQ-5D-5L EuroQol five-Dimension-five level; anxiety-Generalised Anxiety Disorder-7; depression-Patient Health Questionnaire-9. Secondary outcome measures were the Global Subjective Outcome Scale; National Health Service Friends and Family Test;.

RESULTS

At discharge, 6 and 12 months follow ups, there were improvements from baseline that were greater than minimum clinically important differences in each of the outcomes (with the sole exception of ODI at discharge). At 12 months, the majority of people considered themselves a lot better (57%) and were extremely likely (86%) to recommend the programme to a friend. The qualitative data showed praise for the residential nature of the intervention and the opportunities for interaction with peers and peer support. There were testimonies of improvements in understanding of pain and how to manage it better. Some participants said they had reduced, or stopped, medication they had been taking to manage their pain.

CONCLUSIONS

Participants improved, and maintained long term, beyond minimum clinically important differences on a wide range of outcomes. Participants reported an enhanced ability to self-manage their back pain and support for the residential setting.

Does Duration of Pain at Baseline Influence Longer-term Clinical Outcomes of Low Back Pain Patients Managed on an Evidence-Based Pathway?

STUDY DESIGN

Nonrandomized longitudinal observational study.

OBJECTIVE

The aim of this study was to evaluate the association between baseline pain duration and medium-to-long term clinical outcomes, in low back pain (LBP) patients enrolled on the North East of England Regional Back Pain and Radicular Pain Pathway (NERBPP).

SUMMARY OF BACKGROUND DATA

The NERBPP is based upon National Institute for Health and Care Excellence (NICE) guidelines. These guidelines no longer differentiate management of LBP patients based on pain duration. Medium-to-long term data from the NERBPP is lacking.

METHODS

Between May 2015 and December 2019, 786 and 552 LBP patients from the NERBPP returned 6-month and 12-month follow-up outcome measures, respectively. Outcomes included pain (Numerical rating scale), function (Oswestry Disability Index) and quality-of-life (EuroQol five-dimension, five-level questionnaire), analyzed using a series of covariate-adjusted models. Patients were categorized into four groups based upon baseline pain duration: <3 months, ≥3 to <6 months, ≥6 months to <12 months, ≥12 months.

RESULTS

Patients with <3 months duration demonstrated clinically important improvements on all outcomes, at both follow-ups. The improvements in outcomes from this group were larger than those in the ≥12 month's duration group (P < 0.05), these group differences in change, in some cases surpassed our threshold for clinical relevance. Functional improvements in those with ≥12 month's duration were not clinically relevant at either follow-up. All patients, regardless of baseline pain duration, reported similar levels of readiness to self-manage at the 12-month follow-up.

CONCLUSION

Baseline pain duration would appear to be of clinical importance. Patients with shorter baseline pain duration demonstrated better outcomes. Those with ≥12 month's duration of pain may need additional support during their management to achieve clinically relevant functional improvements in the medium-to-long term. These findings raise questions about the decision by NICE to move away from duration of pain to differentiate management of LBP patients.Level of Evidence: 3.

The association between baseline persistent pain and weight change in patients attending a specialist weight management service

OBJECTIVE

To quantify the influence of baseline pain levels on weight change at one-year follow-up in patients attending a National Health Service specialist weight management programme.

METHODS

We compared one-year follow-up weight (body mass) change between patient sub-groups of none-to-mild, moderate, and severe pain at baseline. A mean sub-group difference in weight change of ≥5kg was considered clinically relevant.

RESULTS

Of the 141 complete cases, n = 43 (30.5%) reported none-to-mild pain, n = 44 (31.2%) reported moderate pain, and n = 54 (38.3%) reported severe pain. Covariate-adjusted mean weight loss (95%CI) was similar for those with none-to-mild (8.1kg (4.2 to 12.0kg)) and moderate pain (8.3kg (4.9 to 11.7kg). The mean weight loss of 3.0kg (-0.4 to 6.4kg) for the severe pain group was 5.1kg (-0.6 to 10.7, p = 0.08) lower than the none-to-mild pain group and 5.3kg (0.4 to 10.2kg, p = 0.03) lower than the moderate pain group.

CONCLUSIONS

Patients with severe pain upon entry to a specialist weight management service in England achieve a smaller mean weight loss at one-year follow-up than those with none-to-moderate pain. The magnitude of the difference in mean weight loss was clinically relevant, highlighting the importance of addressing severe persistent pain in obese patients undertaking weight management programmes.

The association between displacement of sedentary time and chronic musculoskeletal pain: an isotemporal substitution analysis

OBJECTIVES

Physical activity is an effective intervention for the prevention and management of chronic musculoskeletal pain (CMP). However, there is a lack of research to inform the intensity of physical activity that should be recommended. The aim of this study was to investigate the association between substituting 10minutes of sedentary time with either 10minutes of light physical activity (LPA) or moderate-to-vigorous physical activity (MVPA) and the CMP prevalence ratio.

DESIGN

Secondary Analysis (November 2015) of data from the Health Survey for England (2008).

PARTICIPANTS

2313 adults (≥16years).

MAIN OUTCOME MEASURES

Sedentary time, LPA and MVPA were measured using accelerometry. We used isotemporal models to quantify the prevalence ratio for CMP of replacing 10minutes of sedentary time with 10minutes of LPA or MVPA.

RESULTS

The prevalence of CMP in this sample was 17%. The unadjusted prevalence ratio was 0.99 (95% CI: 0.97 to 1.01) for LPA and 0.76 (0.70 to 0.84) for MVPA. The fully adjusted prevalence ratio was 1.01 (95% CI: 0.99 to 1.02) for LPA and 0.89 (0.82 to 0.96) for MVPA.

CONCLUSIONS

Substituting 10minutes of sedentary time with an equivalent period of LPA was not associated with a reduction in the prevalence ratio for CMP, whereas the equivalent replacement with MVPA showed a small protective relationship. Regarding CMP prevalence, physical activity intensity appears to be important, with MVPA rather than LPA showing a protective relationship. Prospective studies are needed to investigate causality.

Displacing Sedentary Time: Association with Cardiovascular Disease Prevalence

PURPOSE

Isotemporal substitution analysis offers new insights for public health but has only recently been applied to sedentary behavior research. We aimed to quantify associations between the substitution of 10 min of sedentary behavior with 10 min of light physical activity (LPA) or moderate-to-vigorous physical activity (MVPA) and the prevalence of cardiovascular disease (CVD). Age was also explored as a potential effect modifier.

METHODS

We completed a secondary analysis of data from 1477 adults from the Health Survey for England (2008). Sedentary time, LPA, and MVPA were measured using accelerometry. We applied isotemporal models to quantify the relationship with CVD prevalence of replacing 10 min of sedentary time with equivalent amounts of LPA or MVPA. Prevalence risk ratios (RR) with 95% confidence intervals (CI) are presented, adjusted for covariates. The role of age as an effect modifier was explored via age-MVPA and age-LPA interactions. CVD was defined as per the International Classification of Diseases.

RESULTS

The prevalence of CVD was 24%. The RR was 0.97 (95% CI, 0.96-0.99) for LPA and 0.88 (0.81-0.96) for MVPA. Substitution of approximately 50 min of LPA would be required for an association equivalent to 10 min of MVPA. The beneficial association of MVPA was attenuated with age, with a decrease in the relative risk reduction of approximately 7% per decade.

CONCLUSIONS

Isotemporal substitution of sedentary time with LPA was associated with a trivial relative risk reduction for CVD, whereas the equivalent replacement with MVPA had a small beneficial relationship. With respect to CVD prevalence, MVPA might become decreasingly important in older individuals. Prospective studies are needed to investigate causality.