Does a Multidisciplinary Pain Management Treatment Improve Sleep Quality in Patients with Chronic Widespread Pain and Sleep Problems? Results from the AMS-Pain Cohort

Background: Poor sleep quality is a significant concern for patients with chronic widespread pain (CWP), impacting their emotional, cognitive, and physical well-being. While there is little specific attention given to the treatment of sleep in such programs, it is possible that its ingredients, such as cognitive behavioral therapy, improving body awareness, relaxation, having a balanced daily routine, and physical activity, have a positive effect on sleep. The objectives of this study are to examine:


Introduction
Sleeping disorders are common among patients with chronic widespread pain (CWP), with a prevalence ranging from 75% to 96% [1,2].Literature suggests that sleeping disorders in patients with chronic pain are related to higher levels of pain and fatigue, problems with cognitive and daily functioning, greater psychosocial distress and catastrophizing [2][3][4][5][6][7][8][9] as well as worse multidisciplinary treatment outcome [10].Patients with CWP report that improving sleep is a high priority, in addition to improving pain and fatigue [11,12].

Multidisciplinary
pain management treatment primarily focuses on learning patients to deal with pain, improving their activities in daily life and decreasing their pain-related disability [13][14][15].While there is little specific attention given to the treatment of sleep in such programs, it is possible that its ingredients, such as cognitive behavioral therapy, improving body awareness, relaxation, having a balanced daily routine, and physical activity, have a positive effect on sleep [16][17][18].There is some indirect evidence to support this idea: a meta-analysis conducted by Wibley, et al., [19] found that sleep disturbance is related to pain intensity via mood, pain helplessness, symptoms of anxiety and depression, negative affect, attention to pain, and fatigue-all of which are important targets of a multidisciplinary pain management treatment.
Several studies have been conducted to examine the effect of pain management treatments on sleep.While a review conducted by Bernardy, et al., [20] and the NICE guideline (2021) [21] found no effects of multidisciplinary treatment on sleep, individual results of studies varied [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25].This can be attributed to the heterogeneity of the patients with chronic pain and the treatments provided, as well as the selection criteria utilized in the reviews.Furthermore, it is not known which patients experience a positive effect on sleep and which do not.Insight into patient baseline characteristics associated with a poor treatment effect on sleep can be used to assign patients to a specific sleep treatment that is more likely to be effective.The aim of this study was to examine with.
1. whether subjective sleep quality improves after a multidisciplinary pain management treatment.2. and to explore predictors of treatment outcome, specifically poor improvement in subjective sleep quality in patients with CWP and sleep problems.

Method Design
The study was conducted within the Amsterdam Pain (AMS-PAIN) Cohort.Baseline and post treatment data of 121 CWP patients who experienced poor sleep quality were used.Prior to the start of the treatment, baseline (T0) measurements were made.The second assessment (T1) was performed directly after treatment.This study was authorized by the ethical review board of the Slotervaart Hospital and Reade in Amsterdam.(METC number P1748).Each cohort member provided their written, informed permission.

Procedures and patients
The AMS-PAIN cohort consists of chronic pain patients whose data has been collected since September 2010 at Reade, an outpatient secondary care center for rheumatology and rehabilitation in Amsterdam, the Netherlands.
To participate in the cohort, patients had to be 18 years of age or older, have at least one chronic pain condition of the musculoskeletal system for at least three months, and have provided informed consent in order to join the cohort.

Exclusion criteria were:
(i) pain resulting from known specific pathology (e.g.ankylosing spondylitis); (ii) ineligible for multidisciplinary pain treatment because of a somatic disorder, social problem and/or psychiatric disorder (e.g.major depression), or because the patient was currently involved in a legal procedure that could impose a conflict of interest, was currently receiving pain treatment elsewhere, or was judged by the rehabilitation physician and/or psychologist not to be motivated for behavior change; and, (iii) insufficient control of the Dutch language to complete questionnaires.
In this study, patients were enrolled one after the other.The recruitment period for this study lasted 18.5 months, from February 2016 to mid-August 2017.

Intervention
The multidisciplinary pain management treatment focused on learning patients to cope with pain and fatigue, improving their daily structure and reducing their painrelated disabilities.The treatment consisted of two consecutive parts.In part one a standard package of treatment was offered and consisted of the following modules:  [28,29].
The clinical, emotional and cognitive factors described below were assessed using validated questionnaires and are widely used in pain research and have been described before by our group [30].

Statistical analyses
Baseline patient characteristics were tabulated as means (SD) or medians (IQR) if data did not show a normal distribution.Using two-tailed paired T-tests (with a significance level of P 0.05), the mean differences between T0 and T1 scores on the outcome measures of multidisciplinary treatment and sleep quality were evaluated.Effect sizes were computed by calculating the within group Cohens d.A value of 0.2 indicates a small effect size, 0.5 indicates a medium effect size, and 0.8 indicates a large effect size.[45] Uni-and multivariable regression analyses were performed to evaluate the predictors of poor improvement in sleep quality (PSQI-total score) after multidisciplinary pain management treatment.The factors were divided into 3 groups: 1. clinical factors: pain (NRS), fatigue (MFI), interference of pain (MPI) and disability (PDI), Assumptions of a normal distribution of residuals and homogeneity of residuals variance were visually inspected on residual plots before the analysis [46].Firstly, the individual relationships between the predictive factors and sleep quality post treatment were examined, using simple regression models.Secondly, a preselection of predictors was done due of the small study size.This method of preselection has been described in a previous study [30].In order to achieve this, the predictive factors were analyzed per group of related variables for both the clinical and cognitive factors, using multiple variable regression models (method enter).To avoid multicollinearity, the bivariate correlation coefficients of all pairs of determinants were calculated.One of the variables was taken out of the model when correlation coefficients r > 0.7 were discovered.The multivariable backward regression model was filled out with the predictive factors found in step 2 (multivariable regression models for each group of predictive factors) that had a P value of less than 0.20.In the final model, a factor was included if its significance was P 0.05.Age and gender were taken into account in all analyses.

Study population
Out of 158 patients, a total of 121 patients were included in this study.Eight patients were excluded from the cohort study because they had a score ≤ 5 on the PSQI, 17 patients did not consent to the use of their data for research purposes and 12 patients were excluded from analyses because they had incomplete data.Baseline characteristics of the participants are shown in (Table 1).Participants were mostly women, middle aged and of Dutch ethnicity; about half of the participants experienced pain for more than 5 years.

Factors predicting a change in sleep quality
The results of the simple and multivariate linear regression analyses are shown in (Table 3).The simple regression models (column 1 of Table 3) show that negative clinical (pain and disability), emotional (psychological distress) and cognitive factors (nature /symptoms and less self-efficacy beliefs) are each individually related to less improvement in sleep quality.
Column 2 of (Table 3) shows the results of the multivariable preselection regression models per group of clinical and cognitive variables (step 2) associated with sleep quality.To avoid collinearity interference of pain (MPI) and depression (BDI) were excluded from multivariable analyses.The variables of the multivariable preselection models with a level of significance of P < 0.2 were entered in the multiple backward regression analyses.

Discussion
The results of this study show that the improvement of sleep quality after multidisciplinary pain management treatment is limited and that the majority of CWP patients with sleep problems still experience a poor quality of sleep after a multidisciplinary pain management treatment.In addition, higher levels of psychological distress and disability were related to less improvement in quality of sleep.The measurements were conducted in a representative sample of chronic widespread pain patients of middle age, with a higher proportion of women than men, and high levels of pain, fatigue, depression, and disability [10,22,47].
The study reveals that as many as 94% of chronic widespread pain patients still experienced poor sleep quality after treatment, even though the various elements of a multidisciplinary pain management treatment, such as improving body awareness and relaxation, learning to cope with pain, establishing a daily routine, and increasing physical activity, can have a positive impact on sleep quality.This suggests that the standard approach to pain management, which does not specifically target sleep, may not be sufficient to improve sleep quality.This approach may not adequately address the complex and multifaceted nature of sleep quality.Conversely, studies in patients with CWP that did target sleep quality (e.g., with sleep education, sleep hygiene and/or cognitive behavioral therapy focusing on specific insomnia) reported a large effect size (d 0.8) in improvement of sleep quality [25,48].As stated by McCrae, et al., [25] cognitive behavioral intervention for sleep and pain appears to be distinct interventions with distinct mechanistic effects.Therefore, a hybrid program aimed at improving both pain management and sleep quality may be worthwhile.A pilot study by Pigeon, et al., [16] showed that a hybrid program is feasible.Further research should be conducted on the effectiveness of such interventions.
Several factors, including higher levels of pain-related disability and psychological distress at baseline, predicted lack of improvement in sleep quality.These findings suggest that coping with pain-related disability and emotional distress may require greater emphasis in treatment, particularly within the context of sleep problems [49].The finding that more concerns about pain at baseline were associated with a better The following methodological issues need to be considered.First, Authors did not include a control group.Therefore, it is not possible to attribute changes in outcome measures to multidisciplinary pain treatment, nor is it possible to distinguish between predictors of a natural course of a disorder and predictors of successful treatment.Controlled, longitudinal studies are needed to further evaluate the effectiveness of rehabilitation on sleep quality.Second, although the predictors were selected based on their relevance for pain rehabilitation in CWP there were still a relatively large number of predictors.Therefore, a statistical preselection was applied.This procedure may have caused some instability of the results.Third, Authors assessed self-reported sleep quality only.A more extensive assessment (i.e., polysomnography and actigraphy) may provide more detailed results.However, in chronic pain or chronic insomnia objective measurements of sleep may not always be a valid outcome measure [50,51].Furthermore, subjective measurements of sleep quality, as reported by the patient, reflect patient experience and are therefore important outcome measures.

Conclusion
In conclusion, after a personalized multidisciplinary pain management treatment the majority of CWP patients with sleep problems still experienced poor sleep quality.To address this, it may be necessary to incorporate specific strategies (e.g., sleep education, sleep hygiene and/or cognitive behavioral therapy for sleep) to improve sleep as part of the multidisciplinary treatment plan.Addressing pain related disability and psychological distress, may also help to improve sleep quality.Further research on the management of sleeping disorders in patients with CWP is urgently needed.
The component scores range from 0 (indicating no difficulty) to 3 (indicating severe difficulty).The sum of the seven components yields one total score.The total score varies from 0=no interference with sleep to 21=severe interference with sleep.A total PSQI score ≥ 6 distinguishes patients of having poor sleep quality, while a PSQI score of ≤ 5 indicates good sleep.The PSQI has been extensively used in numerous chronic pain samples and has proven to have sufficient psychometric qualities

Table 1 :
Baseline characteristics of patients attending multidisciplinary treatment.Legend: N=121 unless otherwise indicated, Values are means (SD) or percentages.SD=standard deviation.AAQ=Acceptance and Action Questionnaire, DGSS=Dutch General Self Efficacy Scale, HADS=Hospital Anxiety Depression scale, IPQ=Illness Perception Questionnaire, PCS=Pain Catastrophizing Scale.

Table 2 :
Change in sleep quality and secondary outcome measurements of multidisciplinary treatment.Legend: Values are means (SD) or percentages.SD=standard deviation.Effect size=Cohen's d.BDI=BeckDepression Index, MFI=Multidimensional Fatigue Index, MPI=Multidimensional Pain Inventory, NRS=Numeric Rating Scale, PDI=Pain Disability Index, PSQI=Pittsburgh Sleep Quality Index (PSQI).

Table 3 :
Relationship between baseline characteristics and sleep quality posttreatment.