The influence of sleep disorders on the quality of life in patients with chronic low back pain

Associations between lifestyle-related risk factors and back pain: a systematic review and meta-analysis of Mendelian randomization studies

BACKGROUND

Mendelian randomization (MR) studies have an advantage over conventional observational studies when studying the causal effect of lifestyle-related risk factors on back pain. However, given the heterogeneous design of existing MR studies on back pain, the reported causal estimates of these effects remain equivocal, thus obscuring the true extent of the biological effects of back pain lifestyle-risk factors.

PURPOSE

The purpose of this study was to conduct a systematic review with multiple meta-analyses on the associations between various lifestyle factors and low back pain.

METHODS

We conducted a PRISMA systematic review and specifically included MR studies to investigate the associations between lifestyle factors-specifically, BMI, insomnia, smoking, alcohol consumption, and leisure sedentary behavior-and various back pain outcomes. Each meta-analysis synthesized data from three or more studies to assess the causal impact of these exposures on distinct back pain outcomes, including chronic pain, disability, and pain severity. Quality of studies was assessed according to STROBE-MR guidelines.

RESULTS

A total of 1576 studies were evaluated and 20 were included. Overall, the studies included were of high quality and had a low risk of bias. Our meta-analysis demonstrates the positive causal effect of BMI (OR IVW-random effects models: 1.18 [1.08-1.30]), insomnia(OR IVW-random effects models: 1.38 [1.10-1.74]), smoking(OR IVW-fixed effects models: 1.30 [1.23-1.36]), alcohol consumption(OR IVW-fixed effects models: 1.31 [1.21-1.42]) and leisure sedentary behaviors(OR IVW-random effects models: 1.52 [1.02-2.25]) on back pain.

CONCLUSION

In light of the disparate designs and causal effect estimates presented in numerous MR studies, our meta-analysis establishes a compelling argument that lifestyle-related risk factors such as BMI, insomnia, smoking, alcohol consumption, and leisure sedentary behaviors genuinely contribute to the biological development of back pain.

Effects of sleep quality on pain, cognitive factors, central sensitization, and quality of life in patients with chronic low back pain

BACKGROUND

Sleep quality in patients with chronic low back pain (CLBP) may affect quality of life (QoL), possibly due to worsening pain, central sensitization (CS), and cognitive factors. However, causal relationship among the factors has not been confirmed yet.

OBJECTIVE

The purpose of this study was to test the hypothesis that sleep quality in patients with CLBP is attributable to pain, cognitive factors, and CS, and influences QoL, by structural covariance analysis.

METHODS

This is a cross-sectional study. Participants were recruited from six health care facilities and 101 patients with CLBP were included. Structural covariance analysis assessed the fit of data to the model using goodness of fit index (GFI), adjusted goodness of fit index (AGFI), comparative fit index (CFI), and mean squared approximation error (RMSEA).

RESULTS

The structural covariance analysis showed that the goodness-of-fit indices were high (GFI = 0.993, AGFI = 0.964, CFI = 1.00, RMSEA < 0.01). Sleep quality was not directly influenced by QoL but rather by CS and cognitive factors.

CONCLUSION

This study suggests that sleep quality in patients with CLBP is indirectly mediated through multiple pathways, including cognitive factors and CS, which may influence QoL.

Patient enablement and health-related quality of life for patients with chronic back and knee pain: a cross-sectional study in primary care

BACKGROUND

Chronic back and knee pain impairs health- related quality of life (HRQoL) and patient enablement can improve HRQoL.

AIM

To determine whether enablement was a moderator of the effect of chronic back and knee pain on HRQoL.

DESIGN AND SETTING

A cross-sectional study of Chinese patients with chronic back and knee problems in public primary care clinics in Hong Kong.

METHOD

Each participant completed the Chinese Patient Enablement Instrument-2 (PEI-2), the Chinese Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Pain Rating Scale (PRS). Multivariable regression examined the effects of PRS score and PEI-2 score on WOMAC total score. A moderation regression model and simple slope analysis were used to evaluate whether the interaction between enablement (PEI-2) and pain (PRS) had a significant effect on HRQoL (WOMAC).

RESULTS

Valid patient-reported outcome data from 1306 participants were analysed. PRS score was associated with WOMAC total score (β = 0.326, P<0.001), whereas PEI-2 score was associated inversely with WOMAC total score (β = -0.260, P<0.001) and PRS score. The effect of the interaction between PRS and PEI-2 (PRS × PEI-2) scores on WOMAC total score was significant (β = -0.191, P<0.001) suggesting PEI-2 was a moderator. Simple slope analyses showed that the relationship between PRS and WOMAC was stronger for participants with a low level of PEI-2 (gradient 3.056) than for those with a high level of PEI-2 (gradient 1.746).

CONCLUSION

Patient enablement moderated the impact of pain on HRQoL. A higher level of enablement can lessen impairment in HRQoL associated with chronic back and knee pain.

Effects of Footbath on Postoperative Pain and Sleep Quality in Patients With Lumbar Degenerative Disc Disease: A Randomized Controlled Study

ABSTRACT

BACKGROUND: Pain management and good sleep are essential for patients after surgical procedures. This study aimed to evaluate the effects of footbath on postoperative pain severity and sleep quality levels of patients who have undergone degenerative lumbar spine surgery. METHODS: Sixty patients were randomly assigned to the footbath intervention group or the control group. The intervention was a 20-minute footbath in 42°C water before patients fell asleep on the evening of the surgery day. On the morning of the surgery day and the morning of postoperative day, the patient's pain severity and sleep quality scores were obtained using the visual analog scale and the Visual Analog Sleep Scale. RESULTS: There was no significant difference between the pain severity scores of the study groups (P > .05). The sleep quality level of the intervention group was statistically significantly higher than that of the control group (P < .05). CONCLUSION: Consequently, a footbath is effective in increasing sleep quality levels of patients who have undergone degenerative lumbar spine surgery. It may be used as a simple and practical nonpharmacological nursing strategy for improving patients' sleep quality.

Health-related quality of life among spondyloarthritis and chronic low back pain patients: results from a nationwide population-based survey

PURPOSE

Both spondyloarthritis and chronic low back pain (CLBP) significantly impact health-related quality of life (HRQoL). It is important to clarify whether these disorders have different impacts on the several domains of HRQoL as different mechanisms may necessitate different treatment interventions. Moreover, the factors associated with HRQoL can inform more targeted group interventions to promote HRQoL.

METHODS

We used data from EpiReumaPt, a population-based survey conducted from September 2011 to December 2013. HRQoL was assessed with EuroQoL-5-Dimensions (EQ-5D). Spondyloarthritis was diagnosed by expert opinion (rheumatologist) and predefined criteria. CLBP was diagnosed if low back pain was present on the day of the interview and persisted for > 90 days. Univariable and multivariable linear regression analyses compared HRQoL among subjects with spondyloarthritis, CLBP, and no rheumatic diseases. Multivariable linear regression analyses evaluated HRQoL factors in spondyloarthritis and CLBP subjects.

RESULTS

We included 92 spondyloarthritis patients, 1376 CLBP patients, and 679 subjects without rheumatic diseases. HRQoL was similarly affected in spondyloarthritis and CLBP (ß =  - 0.03, 95% CI [- 0.08; 0.03]) in all EQ5D dimensions. A much lower HRQoL was found in spondyloarthritis and CLBP patients compared with subjects without rheumatic diseases (ß =  - 0.14, 95% CI [- 0.19; - 0.10]; ß =  - 0.12, 95% CI [- 0.14; - 0.09], respectively). In spondyloarthritis subjects, multimorbidity and active disease were associated with worse HRQoL (ß =  - 0.18; 95% CI [- 0.24; 0.03]; ß =  - 0.13; 95% CI [- 0.29; - 0.05], respectively), and regular physical exercise was associated with better HRQoL (ß = 0.18; 95% CI [0.10; 0.30]). In CLBP subjects, multimorbidity (β =  - 0.11; 95% CI [- 0.14; - 0.08]), obesity (β =  - 0.04; 95% CI [- 0.08; - 0.01]), and low back pain intensity (β =  - 0.02; 95% CI [- 0.03; - 0.02]) were associated with worse HRQoL, and regular physical exercise (β = 0.08; 95% CI [0.05; 0.11]) was significantly associated with better HRQoL.

CONCLUSION

Spondyloarthritis and CLBP subjects reported similar levels of impairment in the mental, physical, and social domains of HRQoL. Future health plans should address modifiable factors associated with HRQoL in these conditions to achieve better outcomes.

Influence of Disease Acceptance on the Quality of Life of Patients with Ankylosing Spondylitis - Single Centre Study

Introduction

Ankylosing spondylitis (AS) is a chronic, progressive disease, often with multiple complications, with periods of exacerbation and remission. The onset of the disease usually affects people under 30 years of age. The disease impairs physical, psychological, and social functioning, leading to disability. Therefore, patients with AS face the challenge of adapting to life with the condition and deteriorating quality of life (QoL).

Objective

This study aimed to assess the impact of disease acceptance on quality of life in patients with AS.

Material and Methods

The study was conducted in the Department of Rheumatology and Internal Diseases of the University Hospital in Wrocław among 110 patients (67 men and 43 women) with the diagnosis of AS, aged 20-89 years (M=48.44 years, SD±12.55). The study used the Acceptance of Illness Scale (AIS), the WHOQoL-BREF Quality of Life Scale, and a self-constructed questionnaire of clinical and sociodemographic data.

Results

Respondents rated the quality of life as good and moderate (M = 3.49 points, SD=±0.84). The mean AIS score was 27.44 (SD=±8.67). AIS scores are positively correlated with all QoL domains and perception of quality of life and health (p<0.001). The strongest correlation was in the physical domain (r=0.71), while the weakest correlation was observed in the social domain (r=0.329). AIS and QoL measures showed significant relationships with selected sociodemographic data (eg, gender, age, education, and occupational activity) and correlated with selected disease data (eg, type of treatment used, duration of disease, or comorbidities).

Conclusion

AIS in patients with AS condition correlated positively with their QoL in all domains. Both disease acceptance and quality of life are influenced by specific sociodemographic and disease-related data. Prevention of complications and the type of treatment for AS (primarily biological treatment) can be essential in improving patients' quality of life.

Prevalence and extent of low back pain and low back-related disability in non-care-seeking working-age adults

OBJECTIVE

To explore the prevalence and extent of low back pain (LBP) and low back-related disability in working-age adults not seeking care.

METHODS

A convenience sample of 101 working-age adults not seeking care for LBP completed the Oswestry Disability Index (ODI) and Roland-Morris Disability Questionnaire (RMDQ) as measures of disability and completed questionnaires that collected information on various demographic and health-related variables. Those reporting current LBP also completed a Numeric Pain Rating Scale (NPRS). Prevalence was assessed based on a dichotomization of whether any disability or pain was reported and also as a continuous variable to assess the extent of pain and disability present for each participant.

RESULTS

Of the 101 participants, 72.3% reported some level of disability (ODI mean = 7.91%, RMDQ mean = 2.63) and 46.5% reported some level of pain (NRPS mean = 3.68). Previous care-seeking for LBP was associated with increased odds of reporting disability (ODI odds ratio [OR] 7.91, 95% confidence interval [CI], 2.43 to 31.18; RMDQ OR 2.69, 95% CI, 1.05 to 7.24), as was reporting any current LBP (ODI OR 9.45, 95% CI, 3.15 to 33.21; RMDQ OR 7.03, 95% CI, 2.82 to 18.89). No other demographic or health-related variables were associated with the presence or extent of pain or disability.

CONCLUSION

Many non-care-seeking individuals reported some level of LBP and/or disability, suggesting that some level of pain and disability may be considered normal, acceptable, or manageable. One-third of individuals with no pain reported some disability.

Sleep Characteristics in Dogs; Effect on Caregiver-Reported Problem Behaviours

Simple Summary

Sleep duration and quality can be difficult to assess. Clinicians working in the field of veterinary behavioural medicine with dogs showing problem behaviours currently have little evidence-based literature to guide recommendations on assessment of sleep or treatment options if sleep is deemed poor. This study aims to broaden the level of knowledge regarding canine sleep durations and characteristics and begin research into the relationship between behavioural responses and the duration and quality of sleep. A questionnaire was used to capture information regarding canine sleep characteristics and caregiver perceptions of the severity of problem behaviours shown by this cohort. Responses regarding 1330 dogs were received and assessed. Dogs shown to sleep less than 6 h whilst their caregivers are in bed showed a greater caregiver-reported severity of problem behaviours. Dogs more easily disturbed from sleep at times their caregiver was out of bed, showed increased reported severity of problem behaviours. Whilst it is not possible to determine an optimal canine sleep duration, sufficient evidence is presented to argue that addressing problem behaviours by recommending increased activity may not be appropriate when it results in deprivation in relation to species-specific sleep requirements.

Abstract

Optimal sleep duration and quality is difficult to define. There are strong arguments for a relationship between sleep, in particular REM sleep, and emotional health and behaviour in a variety of species. This study aims to broaden the level of knowledge regarding canine sleep durations and characteristics and begin research into the relationship between behavioural responses and the duration and quality of sleep. A caregiver questionnaire was used to capture information regarding the duration and characteristics of canine sleep, how easily this cohort of dogs were disturbed from sleep, and caregiver perceptions of the severity of problem behaviours shown by this cohort (n = 1330). A quadratic relationship between canine sleep duration whilst a caregiver is in bed and severity of problem behaviour is shown, with less than 8 h sleep and more than 10 h sleep correlating with increased severity of problem behaviours in this cohort. Dogs which were more easily disturbed from sleep at times their caregiver was out of bed, showed increased reported severity of problem behaviours. Whilst it is not possible to determine an optimal canine sleep duration, sufficient evidence is presented to argue that problem behaviour should not be remedied by sleep deprivation.

Differences and Correlations of Anxiety, Sleep Quality, and Pressure-Pain Threshold between Patients with Chronic Low Back Pain and Asymptomatic People

Background. Chronic low back pain (CLBP) is a clinically common and expensive disease. Patients frequently take sick leaves because of pain and dysfunction, and their unpleasant life and work experiences cause psychological depression and anxiety and affect their quality of life. Sleep disturbance is a common problem among patients with low back pain (LBP) with more than 50% complaining about poor sleep quality. This study aimed to explore the correlations between anxiety, sleep quality, and pressure-pain threshold (PPT) and their differences between patients with CLBP and asymptomatic people. Methods. Forty patients with CLBP and 40 asymptomatic people were recruited. Relevant data, including State-Trait Anxiety Inventory, Pittsburgh Sleep Quality Index, and PPT, were individually and independently collected by blinded physiotherapists with a practicing certificate and then statistically analyzed. An independent sample t-test was used to determine the intergroup differences between patients with CLBP and asymptomatic populations. Pearson correlation coefficient was employed for correlation analysis. Results. The CLBP group had significantly higher anxiety scores (41.64 ± 9.88 vs. 36.69 ± 8.31; t = −2.496, $p=0.015$ ) than the asymptomatic group. A significant difference was found in the total score of the Pittsburgh Sleep Quality Index (6.41 ± 2.43 vs. 5.09 ± 2.18; t = −2.628, $p=0.010$ ) but not in the trait anxiety (44.00 ± 7.83 vs. 42.67 ± 9.51; t = −0.695, $p=0.489$ ) of the two groups. State−Trait Anxiety Inventory showed a low to moderate negative correlation with PPT. No remarkable correlation was observed between Pittsburgh Sleep Quality Index and PPT. Conclusions. Patients with CLBP showed considerably worse state anxiety and sleep quality than asymptomatic people; however, no substantial difference in PPT was found between the two groups. The results suggest that in clinical practice, the focus should include pain and related social and psychological factors. CLBP treatment could be considered from multiple perspectives and disciplines.This trial is registered with Chinese Clinical Trial Registry (Trial registration: ChiCTR-TRC-13003701).

Profile of individuals with low back pain and factors defining chronicity of pain: a population-based study in Ethiopia

Purpose

Low back pain (LBP) is the most prevalent public health problem globally, second only to headaches in the ranking of painful disorders that affect human beings. However, evidence about the profile of LBP patients is lacking in low-income countries for appropriate management approaches. This study examined the profile of individuals with LBP and factors defining chronicity of pain in Ethiopia.

Methods

A population-based cross-sectional study design was used to collect data from 1812 adults (≥ 18 years) with LBP at present. Data were collected by interviewing the study participants using an instrument developed and validated in the same study population. The instrument includes socio-demographic information, health behaviours/lifestyle habits, beliefs about pain, and pain and general health-related characteristics of the participants. Data analysis was performed using R version 3.5.1. Both unconditional and conditional logistic regression models were fitted and Odds Ratio (OR) with 95% confidence intervals (95% CIs) were computed to identify factors significantly associated with chronicity of pain at p ≤ 0.05 significance level.

Results

Negative beliefs about pain, a varying degree of pain interference with daily and social activities, complaining of pain in other anatomical sites other than the low back region, general health status rated as not excellent, depressive symptomology, and sleeping problems/insomnia were common within the profile of individuals with LBP. Age, educational level, residential setting, beliefs about pain, and depressive symptomology were found to have a statistically significant association with chronicity of pain.

Conclusions

This study provides an overview of the profile of individuals with LBP and factors defining chronicity of pain, assisting clinicians to design appropriate management strategies to improve patients' outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11136-022-03148-5.

Determinants of quality of life in individuals with chronic low back pain: a systematic review

OBJECTIVE

Chronic low back pain (CLBP) is a prominent medical condition that can affect an individual at some point in their life time which could lead to poor quality of life (QOL). Low back pain has affected approximately 577 million individuals globally by 2017. The aim of the current systematic review is to synthesise the existing evidence on the factors influencing the QOL in individuals with CLBP and to identify strategies to improve their QOL.

METHOD

PubMed, ScienceDirect, PsychNet and Google Scholar were used to extract studies reporting quantitative relationships between QOL and its possible determinants in individuals having CLBP and the intervention strategies to improve QOL.

RESULTS

10,851 studies were initially identified and twenty-six studies which met the inclusion criteria were selected for the review. 21 studies reported relationship between QOL and potential determinants and five studies assessed the influence of interventions on QOL. Determinants were classified as kinesiophobia, fear avoidance belief, or pain belief; occupation-related factors; pain and disability; activity; personal factors including age, gender, employment status; and other psychological factors including anxiety, quality of sleep, and health locus of control. Intervention strategies including MBSR, Pilates method and Back School Programme improved QOL in individuals with CLBP.

CONCLUSION

Psychosocial factors as well as the physical status of the individual contributed to the QOL in individuals having CLBP.

Association of insomnia and daytime sleepiness with low back pain: A bidirectional mendelian randomization analysis

Purpose: Observational research has indicated the presence of a causal relationship between sleep disturbances and low back pain (LBP). However, the link may have been biased by confounding factors. The purpose of this study was to examine the potential causal association of insomnia and daytime sleepiness with LBP by using mendelian randomization (MR). Methods: Genome-wide association study (GWAS) summary statistics of insomnia were obtained from a large-scale GWAS meta-analysis (n = 1,331,010; individuals from UK Biobank and 23andMe) or UK Biobank alone (n = 453,379). The summary statistics of daytime sleepiness were from UK Biobank (n = 452,071) and LBP were provided by the FinnGen Release 6 (210,645 individuals with 16,356 LBP cases and 194,289 controls) or UK Biobank (5,423 cases versus 355,771 controls). Linkage disequilibrium score (LDSC) regression and bidirectional MR analysis was employed to estimate genetic correlation and causal relationship. In the MR analysis, the inverse variance weighted method (IVW) was utilized as the main analysis procedure, while MR-Egger, Weighted median and Robust adjusted profile score (RAPS) were utilized for supplementary analyses. Results: LDSC analysis showed that LBP were significantly genetically correlated with insomnia (rg = 0.57, p = 2.26e-25) and daytime sleepiness (rg = 0.18, p = 0.001). The MR analysis revealed that genetically predicted insomnia was significantly associated with an increased risk of LBP (OR = 1.250, 95% CI: 1.186-1.318; p = 1.69e-16). However, the reverse causality was not confirmed. No evidence was identified supporting causality of daytime sleepiness and LBP. Conclusion: This study demonstrates a putative causal link of insomnia on LBP and a null causal effect of LBP on insomnia. Furthermore, a causal link between daytime sleepiness and LBP were not reported. This finding may stimulate new strategies for patient management in clinical practice, benefiting public health.

Pain, Sleep, and Health-Related Quality of Life after Multidisciplinary Intervention for Chronic Pain

Multidisciplinary pain-management programs have the potential to decrease pain intensity, improve health-related quality of life (HRQOL), and increase sleep quality. In this longitudinal prospective cohort study, the aim was to investigate the long-term effects of multidisciplinary pain rehabilitation interventions in Iceland. More precisely, we (a) explored and described how individuals with chronic pain evaluated their pain severity, sleep, and HRQOL at pre-treatment and at one-year follow-up and (b) examined what predicted the participants' one-year follow-up HRQOL. Seventy-nine patients aged 20-68 years, most of whom were women (85%), responded. The participants scored their pain lower at one-year follow-up (p < 0.001). According to their response, most of them had disrupted sleep, mainly because of pain. One year after the treatment, more participants slept through the night (p = 0.004), and their HRQOL increased. Higher pre-treatment mental component summary (MCS) scores and having pursued higher education predicted higher MCS scores at one-year follow-up, and higher pre-treatment physical component summary (PCS) scores predicted higher PCS scores at one-year follow-up. Sleep problems, being a woman, and having children younger than 18 years of age predicted lower MCS scores at one-year follow-up. These findings are suggestive that patients should be examined with respect to their mental status, and it could be beneficial if they received some professional support after completing the intervention.

The Association between Sleep and Chronic Spinal Pain: A Systematic Review from the Last Decade

Chronic spinal pain, including both neck and low back pain, is a common disabling disorder in which sleep problems are frequently reported as a comorbidity. The complex processes of both sleep and chronic pain seem to have overlapping mechanisms, which may explain their often established bidirectional relationship. This systematic review aims to investigate the assumed association between sleep and chronic spinal pain by providing an overview of the literature from the last decade. Eligible studies were obtained by searching four databases (PubMed, Embase, Web of Science, and PsycARTICLES). Articles were found relevant if they included a human adult population and investigated the possible association between sleep parameters and chronic spinal pain. Only studies published after January 2009 were included, as this review aimed to provide an update of a previous literature overview on this topic. The quality of the studies was assessed by risk of bias and level of evidence. A total of twenty-seven studies (6 cohort, 5 case-control, and 16 cross-sectional studies) were included in this systematic review. The methodological quality of these studies was low to moderate. The majority of studies reported weak to moderate evidence for an association between sleep parameters and chronic spinal pain, with more severe pain accompanied by more disturbed sleep. Addressing frequently reported sleep problems in chronic spinal pain patients therefore appears to be a necessary complement to pain management to achieve optimal treatment outcomes.

Sleepiness, sleep deprivation, quality of life, mental symptoms and perception of academic environment in medical students

BACKGROUND

It has been previously shown that a high percentage of medical students have sleep problems that interfere with academic performance and mental health.

METHODS

To study the impact of sleep quality, daytime somnolence, and sleep deprivation on medical students, we analyzed data from a multicenter study with medical students in Brazil (22 medical schools, 1350 randomized medical students). We applied questionnaires of daytime sleepiness, quality of sleep, quality of life, anxiety and depression symptoms and perception of educational environment.

RESULTS

37.8% of medical students presented mild values of daytime sleepiness (Epworth Sleepiness Scale - ESS) and 8.7% presented moderate/severe values. The percentage of female medical students that presented ESS values high or very high was significantly greater than male medical students (p <  0.05). Students with lower ESS scores presented significantly greater scores of quality of life and perception of educational environment and lower scores of depression and anxiety symptoms, and these relationships showed a dose-effect pattern. Medical students reporting more sleep deprivation showed significantly greater odds ratios of presenting anxiety and depression symptoms and lower odds of good quality of life or perception of educational environment.

CONCLUSIONS

There is a significant association between sleep deprivation and daytime sleepiness with the perception of quality of life and educational environment in medical students.

Health-related quality of life and its determinants in patients with chronic low back pain at a tertiary hospital in Cameroon: a cross-sectional study

OBJECTIVE

To evaluate health-related quality of life (HRQoL) and its determinants in chronic low back pain (CLBP) patients in Cameroon.

DESIGN

Observational cross-sectional study.

SETTING

Tertiary hospital.

PARTICIPANTS

There were 150 eligible adults with low back pain of at least 12 weeks who provided informed consent. Of these, 136 with complete questionnaires were analysed.

OUTCOMES

HRQoL was measured using the WHO Quality of Life questionnaire (WHOQOL-BREF). Outcome measures included its four domain (physical health, psychological, social relationships and environmental) scores and two independent scores for overall quality of life (OQOL) and general health satisfaction (GH).

RESULTS

Participants had a median age of 52 years, and median pain duration of 33 (IQR: 69) months. The median OQOL score was 50 (IQR: 25). After multivariable adjustment, tertiary education (β=11.43, 95% CI 3.12 to 19.75), age (β=0.49, 95% CI 0.12 to 0.87) and being a student (β=23.07, 95% CI 0.28 to 45.86) contributed to better OQOL. Age (β=0.57, 95% CI 0.10 to 1.04) and physical-type employment (β=-14.57, 95% CI -25.83 to -3.31) affected GH. Smoking (β=-20.49, 95% CI -35.49 to -5.48) and radiological anomalies (β=-7.57, 95% CI -14.64 to -0.49) affected the physical health domain, while disability (β=-0.67, 95% CI -1.14 to -0.20) and duration of pain (β=-0.13, 95% CI -0.20 to -0.05) affected the psychological domain. Income (β=14.94, 95% CI 4.06 to 25.81) affected the social domain, while education (β=9.96, 95% CI 1.41 to 18.50) and disability (β=-0.75, 95% CI -1.26 to -0.24) affected the environmental domain.

CONCLUSIONS

Our findings suggest that CLBP affects HRQoL and multiple socioeconomic and clinical factors influence its impact on different domains of HRQoL. Multipronged management programmes, especially those that reduce disability, could improve HRQoL in patients with CLBP.

Functional linear modeling of activity data shows analgesic-mediated improved sleep in dogs with spontaneous osteoarthritis pain

In humans, pain due to osteoarthritis has been demonstrated to be associated with insomnia and sleep disturbances that affect perception of pain, productivity, and quality of life. Dogs, which develop spontaneous osteoarthritis and represent an increasingly used model for human osteoarthritis, would be expected to show similar sleep disturbances. Further, these sleep disturbances should be mitigated by analgesic therapy. Previous efforts to quantify sleep in osteoarthritic dogs using accelerometry have not demonstrated a beneficial effect of analgesic therapy; this is despite owner-reported improvements in dogs' sleep quality. However, analytic techniques for time-series accelerometry data have advanced with the development of functional linear modeling. Our aim was to apply functional linear modeling to accelerometry data from osteoarthritic dogs participating in a cross-over non-steroidal anti-inflammatory (meloxicam) drug trial. Significant differences in activity patterns were seen dogs receiving drug (meloxicam) vs. placebo, suggestive of improved nighttime resting (sleep) and increased daytime activity. These results align with owner-reported outcome assessments of sleep quality and further support dogs as an important translational model with benefits for both veterinary and human health.