Measurement Error, Minimal Detectable Change, and Minimal Clinically Important Difference of the Short Form-36 Health Survey, Hospital Anxiety and Depression Scale, and Pain Numeric Rating Scale in Patients With Chronic Pain.

In both pain research and clinical practice, patient-reported outcome measures are used to assess dimensions of health. Interpreting these instruments requires understanding their measurement error and what magnitude of change has subjective importance for patients. This study estimated the standard error of measurement, 1-year minimal detectable change, and 1-year minimal clinically important difference (MCID) for the Short Form-36 Health Survey physical component summary and mental component summary, the Hospital Anxiety and Depression Scale subscales for anxiety symptoms and depression symptoms, and the numeric rating scale for past-week average pain intensity. MCIDs for these instruments have not previously been estimated in a large sample of chronic pain patients participating in interdisciplinary pain rehabilitation. Data were drawn from the Swedish Quality Registry for Pain Rehabilitation (n = 8,854 patients). MCID was estimated as average change and change difference based on 3 different anchors. MCID estimates were 2.62 to 4.69 for Short Form-36 Health Survey physical component summary, 4.46 to 6.79 for Short Form-36 Health Survey mental component summary, .895 to 1.48 for numeric rating scale, 1.17 to 2.13 for anxiety symptoms in the Hospital Anxiety and Depression Scale, and 1.48 to 2.54 for depression symptoms in the Hospital Anxiety and Depression Scale. The common assumption of an identical standard error of measurement for pre- and post-treatment measurements was not always applicable. When estimating MCID, researchers should select an estimation method and anchor aligned with the study's context and objectives. PERSPECTIVE: This article presents estimates of MCID and minimal detectable change for several commonly used patient-reported outcome measures among patients with chronic pain. These estimates can help clinicians and researchers to determine when a measured health improvement is subjectively important to the patient and greater than measurement error.

Protocol for identifying and characterising critical physical tasks in the military: Development and validation.

BACKGROUND: When establishing Physical Employment Standards, validity is dependent on the correct identification and characterisation of critical job tasks. OBJECTIVE: To develop and validate a standardised protocol for the identification, characterisation, and documentation of critical physical job tasks in military occupational specialities in the Swedish Armed Forces (SwAF), and propose a definition of critical physical job tasks for use in the SwAF. METHODS: A protocol was drafted with three content domains, including a preliminary definition. Protocol content validity was iteratively assessed in two consecutive stages where ten subject experts rated relevance and simplicity. A consensus panel revised the protocol after each stage. Content validity index (CVI) was calculated as item-CVI (I-CVI) per each feature and as scale average (S-CVI/Ave) per content domain. Acceptable content validity thresholds were 0.78 and 0.90, respectively. RESULTS: The validated protocol consisted of 35 items with an I-CVI≥0.90 and≥0.80 for relevance and simplicity, respectively. The S-CVI/Ave was 0.97 for relevance and 0.98 for simplicity. The protocol was language reviewed, reorganised for easy use, and approved by the consensus panel. The final protocol includes: background and aim of the protocol, the accepted generic and critical physical job task definitions, protocol instructions, subject expert-qualifications, job task source and characteristics. CONCLUSION: A standardised protocol for identification and characterisation of critical job tasks in SwAF military occupational specialties was developed. The protocol content was rated relevant and simple by experts and will be of importance in future work establishing physical requirements in the SwAF.

Compliance with cardiopulmonary resuscitation guidelines in witnessed in-hospital cardiac arrest events and patient outcome on monitored versus non-monitored wards.

BACKGROUND: Adherence to cardiopulmonary resuscitation (CPR) guidelines in treatment of in-hospital cardiac arrest (IHCA) have been associated with favourable patient outcome. The aim of this study was to evaluate if compliance with initial CPR guidelines and patient outcome of witnessed IHCA events were associated with the place of arrest defined as monitored versus non-monitored ward. METHODS: A total of 956 witnessed IHCA events in adult patients at six hospitals during 2018 to 2019, were extracted from the Swedish Registry of Cardiopulmonary Resuscitation. Initial CPR guidelines were: ≤1 min from collapse to alert of the rapid response team, ≤1 min from collapse to start of CPR, ≤3 min from collapse to defibrillation of shockable rhythm. RESULTS: The odds of compliance with guidelines was higher on monitored wards vs non-monitored wards, even after adjustment for factors that could affect staffing and resources. The place of arrest was not a significant factor for sustained return of spontaneous circulation, survival at 30 days, or neurological status at discharge, when adjusting for clinically relevant confounders. Compliance with initial CPR guidelines remained a significant factor for survival to 30 days and favourable neurological outcome at discharge regardless of other confounders. CONCLUSION: Compliance with initial CPR guidelines was higher in witnessed IHCA events on monitored wards than on non-monitored wards, which indicates that healthcare professionals in monitored wards are quicker to recognize a cardiac arrest and initiate treatment. When initial CPR guidelines are followed, the place of arrest does not influence patient outcome.

Incidence and case ascertainment of treated in-hospital cardiac arrest events in a national quality registry - A comparison of reported and non-reported events.

BACKGROUND: Approximately 2500 in-hospital cardiac arrest (IHCA) events are reported annually to the Swedish Registry of Cardiopulmonary Resuscitation (SRCR) with an estimated incidence of 1.7/1000 hospital admissions. The aim of this study was to evaluate the compliance in reporting IHCA events to the SRCR and to compare reported IHCA events with possible non-reported events, and to estimate IHCA incidence. METHODS: Fifteen diagnose codes, eight Classification of Care Measure codes, and two perioperative complication codes were used to find all treated IHCAs in 2018-2019 at six hospitals of varying sizes and resources. All identified IHCA events were cross-checked against the SRCR using personal identity numbers. All non-reported IHCA events were retrospectively reported and compared with the prospectively reported events. RESULTS: A total of 3638 hospital medical records were reviewed and 1109 IHCA events in 999 patients were identified, with 254 of the events not found in the SRCR. The case completeness was 77% (range 55-94%). IHCA incidence was 2.9/1000 hospital admissions and 12.4/1000 admissions to intensive care units. The retrospectively reported events were more often found on monitored wards, involved patients who were younger, had less comorbidity, were often found in shockable rhythm and more often achieved sustained spontaneous circulation, compared with in prospectively reported events. CONCLUSION: IHCA case completeness in the SRCR was 77% and IHCA incidence was 2.9/1000 hospital admissions. The retrospectively reported IHCA events were found in monitored areas where the rapid response team was not alerted, which might have affected regular reporting procedures.

High Self-Reported Levels of Pain 1 Year After a Myocardial Infarction Are Related to Long-Term All-Cause Mortality: A SWEDEHEART Study Including 18 376 Patients.

Background Pain increases the risk for cardiovascular diseases, including myocardial infarction (MI). However, the impact of pain on mortality after MI has not yet been investigated in large studies with long-term follow-up periods. Thus, we aimed to examine various levels of pain severity 1 year after an MI as a potential risk for all-cause mortality. Methods and Results We collected data from 18 376 patients, aged <75 years, who had a registered MI event during the period from 2004 to 2013 and with measurements of potential cardiovascular risk indicators at hospital discharge from the Swedish quality register SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies). Self-reported levels of experienced pain according to EuroQol-5 dimension instrument were recorded in secondary prevention clinics 1 year after hospital discharge. We collected all-cause mortality data up to 8.5 years (median, 3.4 years) after the 1-year visit. The Cox proportional hazard regression was used to estimate hazard ratio (HR) and 95% CI. Moderate pain and extreme pain were reported by 38.2% and 4.5%, respectively, of included patients. There were 1067 deaths. Adjusted HR was 1.35 (95% CI, 1.18-1.55) and 2.06 (95% CI, 1.63-2.60) for moderate and extreme pain, respectively. Pain was a stronger mortality predictor than smoking. Conclusions Pain 1 year after MI is highly prevalent, and its effect on mortality 1 year after MI was found to be more pronounced than smoking. Clinicians managing patients after MI should recognize the need to consider experienced pain when making prognosis or treatment decisions.

Acute exercise as active inference in chronic musculoskeletal pain, effects on gait kinematics and muscular activity in patients and healthy participants: a study protocol for a randomised controlled laboratory trial.

INTRODUCTION: Chronic musculoskeletal pain is a highly prevalent, complex and distressing condition that may negatively affect all domains of life. In view of an active inference framework, and resting on the concept of allostasis, human movement per se becomes a prerequisite for health and well-being while chronic pain becomes a sign of a system unable to attenuate an allostatic load. Previous studies on different subgroups of chronic pain conditions have demonstrated alterations in gait kinematics and muscle activity, indicating shared disturbances in the motor system from long-term allostatic load. We hypothesise that such alterations exist in heterogenous populations with chronic musculoskeletal pain, and that exposure to acute and controlled exercise may attenuate these alterations. Therefore, the main aim of this study is to investigate the acute effects of exercise on gait kinematics and activity of the back and neck muscles during diverse walking conditions in patients with chronic musculoskeletal pain compared with a reference sample consisting of healthy participants. METHODS AND ANALYSIS: This two-sample two-armed parallel randomised controlled laboratory trial will include 40 participants with chronic musculoskeletal pain (>3 months) and 40 healthy participants. Participants will be randomly allocated to either 30 min of aerobic exercise or rest. Primary outcomes are gait kinematics (walking speed, step frequency, stride length, lumbar rotation, gait stability) and muscular activity (spatial and temporal) of the back and neck during diverse walking conditions. Secondary outcomes are variability of gait kinematics and muscle activity and subjective pain ratings assessed regularly during the trial. ETHICS AND DISSEMINATION: The study has been approved by the Regional Ethics Review Board in Uppsala, Sweden (#2018/307). Findings will be disseminated via conference presentations, publications in peer-reviewed journals and engagement with patient support groups and clinicians. TRIAL REGISTRATION NUMBER: NCT03882333.

Evaluation of content validity and feasibility of the eVISualisation of physical activity and pain (eVIS) intervention for patients with chronic pain participating in interdisciplinary pain rehabilitation programs.

BACKGROUND: Chronic pain negatively influences most aspects of life, including aerobic capacity and physical function. The "eVISualisation of physical activity and pain" (eVIS) intervention was developed to facilitate individualized physical activity for treatment in interdisciplinary pain rehabilitation programs (IPRPs). The objective of this study was to evaluate the content validity and feasibility of the eVIS intervention prior to an effectiveness trial. METHODS: In order to determine pre-clinical content validity, experts (n = 10) (patients, caregivers, researchers) participated in three assessment rounds using a Likert-scale survey where relevance, simplicity, and safety were rated, whereafter the intervention was revised. Item-content validity index (I-CVI), average, and overall CVI were used to quantify ratings. To determine content validity and feasibility in the clinical context, experts (n = 8) (patients and physiotherapists) assessed eVIS after a 2-3-week test trial, with the feasibility aspects acceptability, demand, implementation, limited efficacy-testing, and practicality in focus. Additional expert interviews (with physiotherapists, physicians) were conducted on two incomplete areas. RESULTS: The intervention was iteratively revised and refined throughout the study. After three assessment and revision rounds, the I-CVI ratings for relevance, simplicity, and safety ranged between 0.88 and 1.00 (≥0.78) in most items, giving eVIS "excellent" content validity. In the IPRP context, the intervention emerged as valid and feasible. Additional interviews further contributed to its content validity and clinical feasibility. CONCLUSIONS: The proposed domains and features of the eVIS intervention are deemed valid in its content and feasible in the IPRP context. The consecutive step-by-step evaluation process enabled careful intervention development with revisions to be made in close collaboration with stakeholders. Findings implicate a robust base ahead of the forthcoming effectiveness trial.

High- Versus Low-Dose Exercise Therapy for Knee Osteoarthritis : A Randomized Controlled Multicenter Trial.

BACKGROUND: The benefits of exercise in patients with knee osteoarthritis are well documented, but the optimal exercise dose remains unknown. OBJECTIVE: To compare high-dose versus low-dose exercise therapy with regard to knee function, pain, and quality of life (QoL) in patients with long-term symptomatic knee osteoarthritis. DESIGN: A Swedish and Norwegian multicenter randomized controlled superiority trial with multiple follow-ups up to 12 months after the intervention. (ClinicalTrials.gov: NCT02024126). SETTING: Primary health care facilities. PATIENTS: 189 patients with diagnosed knee osteoarthritis and a history of pain and decreased knee function were assigned to high-dose therapy (n = 98; 11 exercises; 70 to 90 minutes) or low-dose therapy (n = 91; 5 exercises; 20 to 30 minutes). INTERVENTION: Patient-tailored exercise programs according to the principles of medical exercise therapy. Global (aerobic), semiglobal (multisegmental), and local (joint-specific) exercises were performed 3 times a week for 12 weeks under supervision of a physiotherapist. MEASUREMENTS: The Knee Injury and Osteoarthritis Outcome Score (KOOS) was measured biweekly during the 3-month intervention period and at 6 and 12 months after the intervention. The primary end point was the mean difference in KOOS scores between groups at the end of the intervention (3 months). Secondary outcomes included pain intensity and QoL. The proportion of patients with minimal clinically important changes in primary and secondary outcomes was compared between groups. RESULTS: Both groups improved over time, but there were no benefits of high-dose therapy in most comparisons. One exception was the KOOS score for function in sports and recreation, where high-dose therapy was superior at the end of treatment and at 6-month follow-up. A small benefit in QoL at 6 and 12 months was also observed. LIMITATION: There was no control group that did not exercise. CONCLUSION: The results do not support the superiority of high-dose exercise over low-dose exercise for most outcomes. However, small benefits with high-dose exercise were found for knee function in sports and recreation and for QoL. PRIMARY FUNDING SOURCE: Swedish Rheumatic Fund.

Attitudes towards cardiopulmonary resuscitation situations and associations with potential influencing factors-A survey among in-hospital healthcare professionals.

INTRODUCTION: Attitudes towards cardiopulmonary resuscitation (CPR) among in-hospital healthcare professionals (HCPs) are poorly understood. The aim of this study was to evaluate attitudes towards CPR situations among in-hospital HCPs and assess associations with potential influencing factors. MATERIALS AND METHODS: A questionnaire was distributed to 3,085 HCPs in 2009 and 2,970 HCPs in 2015-2016. The associations of influencing factors were analyzed using binary logistic regression. RESULTS: In the event of a possible cardiac arrest situation, 61% of the HCPs would feel confident in their CPR knowledge, 86% would know what to do, and 60% would be able to take command if necessary. In the latest real-life CPR situation, 30% had been worried about making mistakes or causing complications, 57% had been stressed, and 27% had been anxious. A short time since the latest real-life CPR performance and a high number of previous real-life CPR performances were associated with lower odds of worrying about making mistakes/causing complications, lower odds of feeling stressed or anxious, and higher odds of feeling calm. Regardless of previous real-life CPR experience, there were differences in attitudes between groups of professions, where physicians showed increased odds of worrying about making mistakes/causing complications and nurses showed increased odds of stress. Working on a non-monitored ward meant increased odds of stress and worrying about making mistakes/causing complications. Twelve months or more having passed since the latest CPR training course was associated with increased odds of anxiety. CONCLUSIONS: Despite HCPs' generally positive attitudes towards performing CPR in the event of a possible cardiac arrest situation, feelings of stress and anxiety were common in real-life CPR situations. Regular CPR training among all HCPs is a key factor to maintain competence and reduce anxiety. The possible effects of attitudes on performing CPR need to be studied further.

The association between short-term, chronic localized and chronic widespread pain and risk for cardiovascular disease in the UK Biobank.

AIMS: The interplay between pain of different chronicity and cardiovascular disease (CVD) is incompletely understood. We aimed to investigate the association between different levels of chronic or nonchronic pain and risk of CVD. METHODS AND RESULTS: Participants in the UK Biobank who reported pain at baseline were divided into three groups according to pain duration and widespreadness. Participants reporting no pain were controls. Multivariable Cox regression was used to investigate the association between pain and incidence of myocardial infarction, heart failure, stroke, cardiovascular mortality, and composite CVD (defined as any of the before-mentioned cardiovascular events). Of 475 171 participants, 189 289 reported no pain, 87 830 reported short-term pain, 191 716 chronic localized pain, and 6336 chronic widespread pain (CWP). During a median of 7.0 years' follow-up, participants with chronic localized pain and CWP had, after adjustment for age, sex, established cardiovascular risk factors, physical activity, anxiety, depression, cancer, chronic inflammatory/painful disease, pain/anti-inflammatory medication, socioeconomic status, a significantly increased risk for composite CVD [hazard ratio (HR) 1.14, confidence interval (CI) 1.08-1.21, P < 0.001; and HR 1.48, CI 1.28-1.73, P < 0.001, respectively] compared with controls, with similar results when using the different specific CVDs as outcomes. Population attributable risk proportion for chronic pain as a risk factor for composite CVD was comparable with that of diabetes (8.6 vs. 7.3%, respectively). CONCLUSION: Chronic pain is associated with an increased risk for myocardial infarction, stroke, heart failure, and cardiovascular death independent of established cardiovascular risk factors, socioeconomic factors, comorbidities and medication. Our study, the largest to date, confirms and extends our understanding of chronic pain as an underestimated cardiovascular risk factor with important public health implications.

Effectiveness of the eVISualisation of physical activity and pain intervention (eVIS) in Swedish Interdisciplinary Pain Rehabilitation Programmes: study protocol for a registry-based randomised controlled clinical trial.

INTRODUCTION: Living with chronic pain often involves negative consequences. Interdisciplinary Pain Rehabilitation Programmes (IPRP) is considered superior to single-treatment measures in patients with chronic pain. Despite this, effects emerge suboptimal and more than 20% of patients deteriorate in patient-reported physical health outcomes after IPRP. A novel e-Health intervention, eVISualisation (eVIS) of physical activity and pain, was systematically developed to facilitate individualisation of physical activity levels. By adding elements of data collection, visualisation and communication of objectively measured physical activity and patient-reported outcomes (pain intensity, interference of pain, pharmaceutical consumption) to existing treatment modalities in IPRP, the IPRP team acquires prerequisites to adapt advice and physical activity prescriptions and to evaluate set activity goals. The overall aim is twofold. First, the aim is to evaluate the feasibility of the subsequent registry-based randomised controlled clinical trial (R-RCT). Second, the aim is to prospectively evaluate the effectiveness of the eVIS-intervention as a supplement to IPRP on our defined primary (physical health) and secondary outcomes. METHODS AND ANALYSIS: In the R-RCT, recruitment of 400 patients with chronic pain will be performed at 15 IPRP units. A random allocation to either IPRP + eVIS or to control group that will receive IPRP only will be performed. Data from the initial 30 participants completing the study period (6 months) will be included in a pilot study, where key feasibility outcomes (recruitment, randomisation, implementation, treatment integrity, data collection procedure, preliminary outcome measures) will be evaluated. Outcome variables will be extracted from the web application Pain And TRaining ON-line (PATRON) and from six national registries. Multivariate statistics and repeated measure analyses will be performed. Quality-adjusted life years and incremental cost-effectiveness ratio will be calculated for cost-effectiveness evaluation. ETHICS/DISSEMINATION: The Swedish Ethics Review Board granted approval (Dnr 2021/02109). Results will be disseminated through peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05009459. Protocol V.1.

Feasibility of high dose medical exercise therapy in patients with long-term symptomatic knee osteoarthritis.

PURPOSE: High repetition high dose medical exercise therapy (MET) is a promising treatment for patients with musculoskeletal pain. However, little is known regarding the feasibility of MET in patients with symptomatic knee osteoarthritis (OA). The aim of this study was to investigate the feasibility of MET in patients with symptomatic knee pain with radiographic verified OA. METHODS: Patients with symptomatic knee osteoarthritis were recruited to a group-based high repetitive high dose MET intervention for 12 weeks in a primary health care setting. Indicators of feasibility included processes (recruitment, program adherence, and exercise compliance), and scientific feasibility (safety and pain evaluated by using the Visual Analogue Scale (VAS)). RESULTS: Out of 31 individuals with symptomatic knee OA, 29 (93%) were included in this study. A total of 26 patients (90%) completed the intervention and 83% reached an attendance rate of ≥30 treatments. No adverse events were reported, and a majority of the patients reported a pain intensity <30 mm (VAS) throughout the intervention period. The results showed a 70% reduction of median pain intensity between baseline (33 mm, IQR: 39), and post-assessment (10 mm, IQR: 25, P = .003). CONCLUSION: These findings support an overall positive feasibility of MET for patients with symptomatic knee OA. The results also demonstrated that achieving a high dose of exercises might be challenging for this population. Thus, individual variations in exercise dose may be a confounding factor when evaluating high dose MET in future clinical studies.

The value of interdisciplinary treatment for sickness absence in chronic pain: A nationwide register-based cohort study.

BACKGROUND: Interdisciplinary treatment (IDT) is an internationally recommended intervention for chronic pain, despite inconclusive evidence of its effects on sickness absence. METHODS: With data from 25,613 patients in Swedish specialist healthcare, we compared sickness absence, in the form of both sick leave and disability pensions, over a 5-year period between patients either allocated to an IDT programme or to other/no interventions (controls). To obtain population-average estimates, a Markov multistate model with theory-based inverse probability weights was used to compute both the proportion of patients on sickness absence and the total sickness absence duration. RESULTS: IDT patients were more likely than controls to receive sickness absence benefits at any given time (baseline: 49% vs. 46%; 5-year follow-up: 36% vs. 35%), and thereby also had a higher total duration, with a mean (95% CI) of 67 (87, 48) more days than controls over the 5-year period. Intriguingly, sick leave was higher in IDT patients (563 [552, 573] vs. 478 [466, 490] days), whereas disability pension was higher in controls (152 [144, 160] vs. 169 [161, 178] days). CONCLUSION: Although sickness absence decreased over the study period in both IDT patients and controls, we found no support for IDT decreasing sickness absence more than other/no interventions in chronic pain patients. SIGNIFICANCE: In this large study of chronic pain patients in specialist healthcare, sickness absence is compared over a 5-year period between patients in an interdisciplinary treatment programme and other/no interventions. Sickness absence decreased over the study period in bothgroups; however, there was no support forthat it decreased more with interdisciplinary treatment than alternative interventions.

Predictors of Sickness Absence in a Clinical Population With Chronic Pain.

Chronic pain-related sickness absence is an enormous socioeconomic burden globally. Optimized interventions are reliant on a lucid understanding of the distribution of social insurance benefits and their predictors. This register-based observational study analyzed data for a 7-year period from a population-representative sample of 44,241 chronic pain patients eligible for interdisciplinary treatment (IDT) at specialist clinics. Sequence analysis was used to describe the sickness absence over the complete period and to separate the patients into subgroups based on their social insurance benefits over the final 2 years. The predictive performance of features from various domains was then explored with machine learning-based modeling in a nested cross-validation procedure. Our results showed that patients on sickness absence increased from 17% 5 years before to 48% at the time of the IDT assessment, and then decreased to 38% at the end of follow-up. Patients were divided into 3 classes characterized by low sickness absence, sick leave, and disability pension, with eight predictors of class membership being identified. Sickness absence history was the strongest predictor of future sickness absence, while other predictors included a 2008 policy, age, confidence in recovery, and geographical location. Information on these features could guide personalized intervention in the specialized healthcare. PERSPECTIVE: This study describes sickness absence in patients who visited a Swedish pain specialist interdisciplinary treatment clinic during the period 2005 to 2016. Predictors of future sickness absence are also identified that should be considered when adapting IDT programs to the patient's needs.

Wrist-Worn Activity Trackers in Laboratory and Free-Living Settings for Patients With Chronic Pain: Criterion Validity Study.

BACKGROUND: Physical activity is evidently a crucial part of the rehabilitation process for patients with chronic pain. Modern wrist-worn activity tracking devices seemingly have a great potential to provide objective feedback and assist in the adoption of healthy physical activity behavior by supplying data of energy expenditure expressed as metabolic equivalent of task units (MET). However, no studies of any wrist-worn activity tracking devices' have examined criterion validity in estimating energy expenditure, heart rate, or step count in patients with chronic pain. OBJECTIVE: The aim was to determine the criterion validity of wrist-worn activity tracking devices for estimations of energy expenditure, heart rate, and step count in a controlled laboratory setting and free-living settings for patients with chronic pain. METHODS: In this combined laboratory and field validation study, energy expenditure, heart rate, and step count were simultaneously estimated by a wrist-worn activity tracker (Fitbit Versa), indirect calorimetry (Jaeger Oxycon Pro), and a research-grade hip-worn accelerometer (ActiGraph GT3X) during treadmill walking at 3 speeds (3.0 km/h, 4.5 km/h, and 6.0 km/h) in the laboratory setting. Energy expenditure and step count were also estimated by the wrist-worn activity tracker in free-living settings for 72 hours. The criterion validity of each measure was determined using intraclass and Spearman correlation, Bland-Altman plots, and mean absolute percentage error. An analysis of variance was used to determine whether there were any significant systematic differences between estimations. RESULTS: A total of 42 patients (age: 25-66 years; male: 10/42, 24%; female: 32/42, 76%), living with chronic pain (duration, in years: mean 9, SD 6.72) were included. At baseline, their mean pain intensity was 3.5 (SD 1.1) out of 6 (Multidimensional Pain Inventory, Swedish version). Results showed that the wrist-worn activity tracking device (Fitbit Versa) systematically overestimated energy expenditure when compared to the criterion standard (Jaeger Oxycon Pro) and the relative criterion standard (ActiGraph GT3X). Poor agreement and poor correlation were shown between Fitbit Versa and both Jaeger Oxycon Pro and ActiGraph GT3X for estimated energy expenditure at all treadmill speeds. Estimations of heart rate demonstrated poor to fair agreement during laboratory-based treadmill walks. For step count, the wrist-worn devices showed fair agreement and fair correlation at most treadmill speeds. In free-living settings; however, the agreement for step count between the wrist-worn device and waist-worn accelerometer was good, and the correlation was excellent. CONCLUSIONS: The wrist-worn device systematically overestimated energy expenditure and showed poor agreement and correlation compared to the criterion standard (Jaeger Oxycon Pro) and the relative criterion standard (ActiGraph GT3X), which needs to be considered when used clinically. Step count measured with a wrist-worn device, however, seemed to be a valid estimation, suggesting that future guidelines could include such variables in this group with chronic pain.

Correction to: Musculoskeletal disorders and their associations with health- and work-related factors: a cross-sectional comparison between Swedish air force personnel and army soldiers.

An amendment to this paper has been published and can be accessed via the original article.