Accelerometer Quantification of Physical Activity and Activity Patterns in Patients with Ankylosing Spondylitis and Population Controls

Higher levels of physical activity are associated with less evasive coping, better physical function and quality of life in patients with axial spondyloarthritis

OBJECTIVE

To evaluate daily physical activity (PA) in relation to psychosocial factors, such as anxiety, depression and different types of coping strategies, as well as patient- and disease-related factors in patients with axial spondyloarthritis (axSpA).

METHODS

Consecutive outpatients from the Groningen Leeuwarden AxSpA (GLAS) cohort completed the modified Short Questionnaire to assess health-enhancing PA (mSQUASH), Hospital Anxiety and Depression Scale (HADS) and Coping with Rheumatic Stressors (CORS) questionnaires, as well as standardized patient- and disease-related assessments. Univariable and multivariable linear regression analyses and comparison of lowest and highest PA tertiles were performed to explore associations between the HADS, CORS, patient- and disease-related factors and PA.

RESULTS

In total, 84 axSpA patients were included; 60% male, mean age 49 (SD ±14) years, median symptom duration 20 (25th-75th percentiles: 12-31) years, mean ASDAS 2.1 (±1.0). Higher PA levels were significantly associated with better scores on patient-reported disease activity (BASDAI), physical function (BASFI) and quality of life (ASQoL). Furthermore, higher levels of PA were associated with less impact of axSpA on wellbeing and lower HADS depression scores. In the multivariable linear regression model, less use of the coping strategy 'decreasing activities' (β: -376.4; p 0.003) and lower BMI (β:-235.5; p: 0.030) were independently associated with higher level of PA. Comparison of patients from the lowest and highest PA tertiles showed results similar to those found in the regression analyses.

CONCLUSION

In this cohort of axSpA patients, higher levels of daily PA were associated with better patient-reported outcomes and lower depression scores. Additionally, the passive coping strategy "decreasing activities" and lifestyle factor BMI were independently associated with PA. Besides anti-inflammatory treatment, coping strategies and lifestyle should be taken into account in the management of individual axSpA patients. Incorporating these aspects into patient education could increase patient awareness and self-efficacy. In the future, longitudinal studies are needed to better understand the complex relationship between patient-, disease- and psychosocial factors associated with daily PA.

Impact of different types of exercise programs on ankylosing spondylitis: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis of controlled studies aimed to assess the efficacy of different types of exercise programs (EP) on ankylosing spondylitis (AS) activity, function and mobility.

METHODS

We searched PubMed/Medline, Cochrane Library and Embase databases for reports of controlled trials of patients with AS published up to May 2022. The studies were classified by intervention into categories defined by the 4 exercise domains established by the American College of Sports Medicine and then adopted by the European League Against Rheumatism: aerobic, muscle strength, flexibility, neuromotor performance.

RESULTS

We found a moderate effect of EP as a whole on BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) (-0.60, 95% CI -0.95, -0.25, p < 0.001), BASFI (Functional) (-0.63, 95% CI -0.84, -0.42, p < 0.0001) and BASMI (Metrology) (-0.52, 95% CI -0.88, -0.15, p < 0.01). The effect of "flexibility + muscle strength" EP was large for BASMI, moderate for BASDAI and BASFI. The effect of "flexibility + muscle strength + aerobic" EP was large for BASFI, moderate for BASDAI.

CONCLUSIONS

EP, regardless of the specific type of exercise, have a moderate effect on AS activity, function and mobility. EP including flexibility and muscle strength exercises may have a large effect, especially for mobility. Programs including aerobic exercise showed significant efficacy for function.IMPLICATIONS FOR REHABILITATIONIn ankylosing spondylitis (AS), any exercise program (EP), regardless of the type of exercises involved, showed a moderate effect on disease activity, function and spinal mobility.In AS, EP combining flexibility and strength exercises showed the largest effect on spinal mobility and should be encouraged.In AS, EP combining flexibility, muscle strength and aerobic exercises may be particularly effective on patient function.

Physical activity assessment with wearable devices in rheumatic diseases: a systematic review and meta-analysis

OBJECTIVES

In the management of rheumatic musculoskeletal disorders (RMDs), regular physical activity (PA) is an important recognized non-pharmacological intervention. This systematic review and meta-analysis aims to evaluate how the use of wearable devices (WDs) impacts physical activity in patients with noninflammatory and inflammatory rheumatic diseases.

METHODS

A comprehensive search of articles was performed in PubMed, Embase, CINAHL and Scopus. A random-effect meta-analysis was carried out on the number of steps and moderate-vigorous physical activity (MVPA). Univariable meta-regression models were computed to assess the possibility that the study characteristics may act as modifiers on the final meta-analysis estimate.

RESULTS

In the analysis, 51 articles were included, with a total of 7488 participants. Twenty-two studies considered MVPA outcome alone, 16 studies considered the number of steps alone, and 13 studies reported information on both outcomes. The recommended PA threshold was reached for MVPA (36.35, 95% CI 29.39, 43.31) but not for daily steps (-1092.60, -1640.42 to -544.77). Studies on patients with fibromyalgia report a higher number (6290, 5198.65-7381.62) of daily steps compared with other RMDs. Patients affected by chronic inflammatory arthropathies seemed to fare better in terms of daily steps than the other categories. Patients of younger age reported a higher overall level of PA than elderly individuals for both the number of steps and MVPA.

CONCLUSION

Physical activity can be lower than the recommended threshold in patients with RMDs when objectively measured using WD. WDs could be a useful and affordable instrument for daily monitoring physical activity in RMDs and may support an increase in activity levels.

PROSPERO TRIAL REGISTRATION

CRD42021227681, https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=227681.

The behavioural epidemiology of sedentary behaviour in inflammatory arthritis: where are we, and where do we need to go?

In the last decade, studies into sedentary behaviour in inflammatory arthritis have raised important questions regarding its role in this condition. Specifically, evidence is needed on whether sedentary behaviour might exacerbate adverse inflammatory arthritis outcomes, and whether reducing sedentary behaviour might offer an effective avenue for self-management in this population. Research exploring these important research questions is still very much in its infancy and lacks the direction and scientific rigour required to inform effective intervention design, delivery and evaluation. Behavioural epidemiology refers to research that aims explicitly to understand and influence health behaviour patterns to prevent disease and improve health. To this end, the Behavioural Epidemiology Framework specifies a focused approach to health behaviour research, which leads to the development of evidence-based interventions directed at specific populations. In this review, we introduce the Behavioural Epidemiology Framework in the context of research into sedentary behaviour in inflammatory arthritis and ask: where are we, and where do we need to go?

Understanding beliefs related to physical activity in people living with axial Spondyloarthritis: a theory-informed qualitative study

Background

People living with axial Spondyloarthrtis (axSpA) have an increased risk of cardiovascular diseases, which can be reduced by regular physical activity (PA) and its subset of cardiorespiratory training (CRT). To fulfil their crucial role in PA promotion, physiotherapists and other health professionals need to understand the beliefs that people living with axSpA possess concerning general PA and CRT. The aim of this study is to explore these behavioural, normative and control beliefs.

Methods

A qualitative descriptive design approach was chosen. Five semi-structured focus group interviews with 24 individuals living with axSpA were performed. Data was analysed using structured thematic qualitative content analysis.

Results

People with axSpA possessed multifaceted behavioural, normative and control beliefs concerning general PA and CRT. Behavioural beliefs revealed a positive attitude towards general PA, with participants mentioning numerous physical, psychological, and social benefits and only few risks. However, the conceptual difference between general PA and CRT, and the relevance of CRT, was unclear to some participants. Normative beliefs were expressed as the beliefs of significant others that influenced their motivation to comply with such beliefs, e.g. spouses, other people living with axSpA, rheumatologists. Regarding control beliefs, general PA and CRT were both mentioned as effective self-management strategies to control the disease. From experience, a high level of self-discipline, as well as technology, were shown to be useful.

Conclusions

General PA is understood to be an important self-management strategy for people with axSpA and most participants build general PA into their daily routines. They believe that general PA beneficially impacts personal health and wellbeing. However, some participants are unaware of the difference between general PA and CRT and the important impact that this difference could have on their health. The consequences of CRT promotion for people living with axSpA should be the subject of further research.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00270-2.

High daily energy expenditure of Tuvan nomadic pastoralists living in an extreme cold environment

Research investigating thermoregulatory energy costs in free-living humans is limited. We determined the total energy expenditure (TEE) of Tuvan pastoralists living in an extreme cold environment and explored the contribution of physical activity and cold-induced thermogenesis. Twelve semi-nomadic pastoralists (47 ± 8 years, 64 ± 8 kg) living under traditional circumstances, in Tuva, south-central Siberia, Russia, were observed during two consecutive 6-day periods in winter. TEE was measured via the doubly labelled water technique. Skin and ambient temperatures, and physical activity were continuously monitored. The outdoor temperature during the observation period was - 27.4 ± 5.4 °C. During the daytime, the participants were exposed to ambient temperatures below 0 °C for 297 ± 131 min/day. The Tuvan pastoralists were more physically active compared to western populations (609 ± 90 min/day of light, moderate, and vigorous physical activity). In addition, TEE was 13.49 ± 1.33 MJ/day (3224 ± 318 kcal/day), which was significantly larger by 17% and 31% than predicted by body mass, and fat-free mass, respectively. Our research suggests the daily cold exposure combined with high levels of physical activity contributed to the elevated TEE. Future research should reconsider the assumption that energy costs due to thermoregulation are negligible in free-living humans.

Wearables for Measuring the Physical Activity and Sedentary Behavior of Patients With Axial Spondyloarthritis: Systematic Review

Background

Axial spondyloarthritis (axSpA) is an inflammatory rheumatic disease associated with chronic back pain and restricted mobility and physical function. Increasing physical activity is a viable strategy for improving the health and quality of life of patients with axSpA. Thus, quantifying physical activity and sedentary behavior in this population is relevant to clinical outcomes and disease management. However, to the best of our knowledge, no systematic review to date has identified and synthesized the available evidence on the use of wearable devices to objectively measure the physical activity or sedentary behavior of patients with axSpA.

Objective

This study aimed to review the literature on the use of wearable activity trackers as outcome measures for physical activity and sedentary behavior in patients with axSpA.

Methods

PubMed, PEDro, and Cochrane electronic databases were searched in July 2021 for relevant original articles, with no limits on publication dates. Studies were included if they were original articles, targeted adults with a diagnosis of axSpA, and reported wearable device–measured physical activity or sedentary behavior among patients with axSpA. Data regarding the study’s characteristics, the sample description, the methods used for measuring physical activity and sedentary behavior (eg, wearable devices, assessment methods, and outcomes), and the main results of the physical activity and sedentary behavior assessments were extracted.

Results

A total of 31 studies were initially identified; 13 (13/31, 42%) met the inclusion criteria, including 819 patients with axSpA. All the studies used accelerometer-based wearable devices to assess physical activity. Of the 13 studies, 4 (4/31, 31%) studies also reported outcomes related to sedentary behavior. Wearable devices were secured on the wrists (3/13 studies, 23%), lower back (3/13, 23%), right hip (3/13, 23%), waist (2/13, 15%), anterior thigh (1/13, 8%), or right arm (1/13, 8%). The methods for reporting physical activity and sedentary behavior were heterogeneous. Approximately 77% (10/13) of studies had a monitoring period of 1 week, including weekend days.

Conclusions

To date, few studies have used wearable devices to quantify the physical activity and sedentary behavior of patients with axSpA. The methodologies and results were heterogeneous, and none of these studies assessed the psychometric properties of these wearables in this specific population. Further investigation in this direction is needed before using wearable device–measured physical activity and sedentary behavior as outcome measures in intervention studies in patients with axSpA.

Trial Registration

PROSPERO CRD42020182398; https://tinyurl.com/ec22jzkt

International Registered Report Identifier (IRRID)

RR2-10.2196/23359

Physical activity is associated with physical and global function in patients with axial spondyloarthritis, independent of disease activity

OBJECTIVES

To investigate whether physical activity is independently associated with physical and global function in patients with axial spondyloarthritis (axSpA), and to analyse the relationship between subtypes of physical activity (work, transport, and recreation) and functional impairment.

METHODS

One-hundred-and-eighty-five patients were included. Physical function was assessed using BASFI, and global function was assessed using the ASAS health index (HI). Physical activity was measured using the Global Physical Activity Questionnaire. Levels of physical activity were categorised as low, moderate or high. The associations between levels of physical activity and the BASFI and ASAS HI scores were analysed using multivariate regression analysis.

RESULTS

Of the 185 patients, 46, 63 and 76 reported low, moderate and high levels of physical activity, respectively. There was a negative correlation between the BASFI and total physical activity. Multivariate linear regression analysis revealed that a high level of physical activity was independently associated with BASFI after adjusting for age, ASDAS. sacroiliitis and syndesmophyte number (ß (95% CI) =-0.88 (-1.49--0.26); p=0.006). One-hundred-and-forty-six had good global functioning (ASAS HI≤5). Multivariate logistic regression analysis revealed that moderate physical activity was independently associated with good global functioning (OR (95% CI) = 2.82 (1.02-7.86); p = 0.047). Recreational activity, but not work- and transport-related activity, showed a significant relationship with ASAS HI scores (ß (95% CI) =-0.55 (-1.02-0.08); p = 0.023).

CONCLUSIONS

Physical activity in those with axSpA is associated independently with physical and global functioning. Among the subtypes of physical activity, recreational activity is related to global functioning.

Causal Relationships Between Total Physical Activity and Ankylosing Spondylitis: A Mendelian Randomization Study

Background

Currently, there is little literature about the association between physical activity (PA) and the risk of ankylosing spondylitis (AS). The present study aimed to understand the causal relationships between PA and AS.

Methods

We performed two-sample Mendelian randomization (MR) using publicly released genome-wide association studies summary statistics to estimate the causal associations of PA with AS risk. The inverse variance weighted (IVW) method was utilized as primary MR analysis. Furthermore, sensitivity, pleiotropy, and heterogeneity analyses were then conducted to assess the robustness of the findings of the present study.

Results

Results of the IVW analysis suggested a protective relationship between accelerometer-based PA and AS (average acceleration, odds ratio [OR] = 0.9995, 95% CI, 0.9988–0.9999, P = 0.014). On the contrary, there was no causal relationship between accelerometer-based PA (acceleration fraction >425 mg; OR = 0.9981, 95% CI = 0.9936–1.0026, P = 0.402) and AS. Furthermore, there was no significant relationship between self-reported vigorous PA and AS (OR = 1.0005, 95% CI = 0.9875–1.0136, P = 0.943), or even between self-reported moderate-to-vigorous PA and AS (OR = 1.0000, 95% CI, 0.9947–1.0052; P = 0.990).

Conclusions

The use of genetic approach in the present study revealed that total physical activity (TPA) has a protective relationship with AS risk. Furthermore, it was evident that vigorous PA or moderate-to-vigorous physical levels are not causally associated with AS. Therefore, the present study evidently supports the hypothesis that enhancing TPA rather than PA intensity is an effective prevention strategy for AS.

Correlates of physical activity in adults with spondyloarthritis and rheumatoid arthritis: a systematic review

Physical activity (PA) is a primary non-pharmacological treatment option for those living with rheumatoid arthritis (RA) and spondyloarthritis (SpA). The aim of this systematic literature review was to summarize and present an updated synthesis of the factors associated with PA in the RA and SpA populations. A tailored search of PubMed (inc. Medline), Web of Science, Embase, APA PsycNET, and Scopus was conducted for research published between 2004 and June 2019. Methodological quality was assessed using The National Institutes of Health (NIH) Quality Assessment Tools for Observational Cohort and Cross-sectional Studies, Case–Control Studies, and Controlled Intervention Studies. Forty RA and eleven SpA articles met the inclusion criteria. Methodological quality was generally fair to good, with two RA studies rated as poor. Correlates are discussed in the sociodemographic, physical, psychological, social, and environmental categories. Environmental factors were not measured in any RA study. In individuals living with RA, consistent positive associations were found between PA and high-density lipoprotein, self-efficacy, and motivation. Consistent negative associations were found for functional disability and fatigue. In individuals with SpA, consistent positive associations were found between PA and quality of life, and consistent negative associations with functional disability. Physical and psychological factors are most consistently related with PA parameters in those living with RA and SpA. Many variables were inconsistently studied and showed indeterminant associations. Studies with prospective designs are needed to further understand the factors associated with PA in these populations, especially in those living with SpA.

Treat-to-target in axial spondyloarthritis - what about physical function and activity?

In patients with axial spondyloarthritis (axSpA), pain, functional and structural impairments, reduced mobility and potential deformity of the axial skeleton are the most prominent health concerns. Limitations in physical function and spinal mobility are caused by both inflammation and structural damage, and therefore restrictions to physical function must be monitored throughout a patient's life. Consequently, the assessment of physical function is recommended as a key domain in the Assessment of Spondyloarthritis International Society-OMERACT Core Outcome Set. However, in comparison with disease activity, physical function seems to be a relatively neglected target of intervention in patients with axSpA, even though physical function is a major contributor to costs and disability in this disease. This Review aims to reacquaint rheumatologists with the targets for physical function, physical activity and performance by giving guidance on determinants of physical function and how physical function can be examined in patients with axSpA.

Comparison of physical activity levels among different sub-types of axial spondyloarthritis patients and healthy controls

OBJECTIVES

The aim was to compare the physical activity levels among radiographic axial spondyloarthritis (axSpA) patients, non-radiographic axSpA patients, and healthy controls and investigating the possible relationships between physical activity level and clinical features.

METHODS

Thirty-four patients with radiographic axSpA (24 male), 33 patients with non-radiographic axSpA (23 male), and 35 age and sex-matched healthy controls (24 male) were included. The patients were assessed with Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Metrology Index, Ankylosing Spondylitis Quality of Life Questionnaire, Hospital Anxiety and Depression Scale, Tampa Scale of Kinesiophobia. Physical activity was measured by using an accelerometer (Actigraph wGT3X-BT).

RESULTS

Physical and disease-related characteristics were comparable between groups (p > .05). Radiographic axSpA patients showed lesser physical activity compared to non-radiographic axSpA patients and healthy controls (p < .05). No difference was detected between non-radiographic axSpA patients and healthy controls (p > .05). Physical activity levels were correlated with different clinical features for each sub-type of axSpA. Decreased spinal mobility is the most correlated disease characteristic with lower physical activity level for both sub-types.

CONCLUSION

It seems that disease sub-type in axSpA may alter the physical activity levels. Increasing physical activity levels might need different approaches for different sub-types of axSpA.

Supervised intensive Exercise strengthen Exercise Health Beliefs in Patients with Axial Spondyloarthritis: A Multicentre Randomized Controlled Trial

OBJECTIVE

To evaluate the effect of a three-month supervised high-intensity exercise program, on exercise health beliefs in patients with Axial Spondyloarthritis.

METHODS

This was secondary analysis of a randomized controlled trial. Participants (ages 23-69 years), were randomized to an exercise group (n=50) or a control group (n=50). The intervention was an individually guided cardiorespiratory and strength exercise program performed two times per week, plus an additional individual exercise session of personal choice. The control group received standard care and instructions to maintain their physical activity level. Exercise health beliefs using the Exercise health beliefs questionnaire (ranges 20-100, 100= best) i.e. barriers, benefits, self-efficacy and exercise impact on arthritis and physical activity were assessed with self-reported questionnaires at baseline, three months and 12 months after inclusion.

RESULTS

The majority, (76%) of the participants in the exercise group followed ≥ 80% of the prescribed exercise protocol. There was a significant effect of the intervention on exercise health beliefs at 3 months (estimated mean group differences 4.0 [95%CI 1.4, 6.6], p=0.003) and the effect persisted at 12 months follow-up (estimated mean group differences 3.8 [95%CI 1.0, 6.6], p=0.008). Participants with higher exercise health beliefs had a higher odds ratio (1.1 [95%CI 1.0, 1.20], p=0.003) for being physically active at 12 months follow-up.

CONCLUSIONS

A supervised high intensity exercise program had beneficial short- and long-term effects on participants' exercise health beliefs. Stronger exercise health beliefs were positively associated with a higher chance to be physically active on a health enhancing level at 12-months follow-up.

A Thorough Examination of Morning Activity Patterns in Adults with Arthritis and Healthy Controls Using Actigraphy Data

Background

Wearable sensors allow researchers to remotely capture digital health data, including physical activity, which may identify digital biomarkers to differentiate healthy and clinical cohorts. To date, research has focused on high-level data (e.g., overall step counts) which may limit our insights to whether people move differently, rather than how they move differently.

Objective

This study therefore aimed to use actigraphy data to thoroughly examine activity patterns during the first hours following waking in arthritis patients (n = 45) and healthy controls (n = 30).

Methods

Participants wore an Actigraph GT9X Link for 28 days. Activity counts were analysed and compared over varying epochs, ranging from 15 min to 4 h, starting with waking in the morning. The sum, and a measure of rate of change of cumulative activity in the period immediately after waking (area under the curve [AUC]) for each time period, was calculated for each participant, each day, and individual and group means were calculated. Two-tailed independent t tests determined differences between the groups.

Results

No differences were seen for summed activity counts across any time period studied. However, differences were noted in the AUC analysis for the discrete measures of relative activity. Specifically, within the first 15, 30, 45, and 60 min following waking, the AUC for activity counts was significantly higher in arthritis patients compared to controls, particularly at the 30 min period (t = -4.24, p = 0.0002). Thus, while both cohorts moved the same amount, the way in which they moved was different.

Conclusion

This study is the first to show that a detailed analysis of actigraphy variables could identify activity pattern changes associated with arthritis, where the high-level daily summaries did not. Results suggest discrete variables derived from raw data may be useful to help identify clinical cohorts and should be explored further to determine if they may be effective clinical biomarkers.

Adequately dosed aerobic physical activity in people with axial spondyloarthritis: associations with physical therapy

INTRODUCTION

This study aimed to compare the engagement in moderate- and vigorous-intensity PA in axSpA patients with and without current physical therapy (PT).

METHODS

In this cross-sectional study, a survey, including current PT treatment (yes/no) and PA, using the 'Short QUestionnaire to ASsess Health-enhancing PA' (SQUASH), was sent to 458 axSpA patients from three Dutch hospitals. From the SQUASH, the proportions meeting aerobic PA recommendations (≥ 150 min/week moderate-, ≥ 75 min/week vigorous-intensity PA or equivalent combination; yes/no) were calculated. To investigate the association between PT treatment and meeting the PA recommendations, odds ratios (OR) with 95% confidence intervals (95% CI) were estimated using logistic regression models, adjusting for sex, age, health status and hospital.

RESULTS

The questionnaire was completed by 200 patients, of whom 68%, 50% and 82% met the moderate-, vigorous- or combined-intensity PA recommendations, respectively. Ninety-nine patients (50%) had PT treatment, and those patients were more likely to meet the moderate- (OR 2.09 [95% CI 1.09-3.99]) or combined-intensity (OR 3.35 [95% CI 1.38-8.13]) PA recommendations, but not the vigorous-intensity PA recommendation (OR 1.53 [95% CI 0.80-2.93]). Aerobic exercise was executed in 19% of individual PT programs.

CONCLUSION

AxSpA patients with PT were more likely to meet the moderate- and combined-intensity PA recommendations, whereas there was no difference in meeting the vigorous-intensity PA recommendation. Irrespective of having PT treatment, recommendations for vigorous-intensity PA are met by only half of the patients. Implementation should thus focus on aerobic PA in patients without PT and on vigorous-intensity PA in PT programs.

How to optimize exercise behavior in axial spondyloarthritis? Results of an intervention mapping study

OBJECTIVE

Many individuals with axial spondyloarthritis (axSpA) do not engage in adequate exercise, despite its proven health benefits. This study aimed to identify the intervention components needed to optimize exercise behavior in people with axSpA.

METHODS

The first three steps of the Intervention Mapping protocol were used: 1) needs assessment; 2) identification of axSpA-specific exercise barriers and facilitators (´determinants'); 3) selection of effective intervention components addressing potentially modifiable determinants. All three steps included scoping reviews and semi-structured interviews with patients (n = 2) and physical therapists (n = 2).

RESULTS

The scoping reviews included 28, 23 and 15 papers, respectively. Step 1 showed that only one third of axSpA patients exercise regularly, demonstrating especially a lack of strengthening and cardiorespiratory exercises. Based on eight determinants identified in Step 2, 10 intervention components were selected in Step 3: education, motivational interviewing, goal setting, action planning, monitoring, feedback, tailoring, guided practice, therapists' training and group exercise encouragement.

CONCLUSION

Using the Intervention Mapping method, 10 intervention components for optimizing exercise behavior in people with axSpA were identified and an intervention with behavior change guidance and a training for health professionals is proposed.

PRACTICE IMPLICATIONS

This study provides a foundation for the development of an axSpA-specific exercise intervention.

Detection of Flares by Decrease in Physical Activity, Collected Using Wearable Activity Trackers in Rheumatoid Arthritis or Axial Spondyloarthritis: An Application of Machine Learning Analyses in Rheumatology

OBJECTIVE

Flares in rheumatoid arthritis (RA) and axial spondyloarthritis (SpA) may influence physical activity. The aim of this study was to assess longitudinally the association between patient-reported flares and activity-tracker-provided steps per minute, using machine learning.

METHODS

This prospective observational study (ActConnect) included patients with definite RA or axial SpA. For a 3-month time period, physical activity was assessed continuously by number of steps/minute, using a consumer grade activity tracker, and flares were self-assessed weekly. Machine-learning techniques were applied to the data set. After intrapatient normalization of the physical activity data, multiclass Bayesian methods were used to calculate sensitivities, specificities, and predictive values of the machine-generated models of physical activity in order to predict patient-reported flares.

RESULTS

Overall, 155 patients (1,339 weekly flare assessments and 224,952 hours of physical activity assessments) were analyzed. The mean ± SD age for patients with RA (n = 82) was 48.9 ± 12.6 years and was 41.2 ± 10.3 years for those with axial SpA (n = 73). The mean ± SD disease duration was 10.5 ± 8.8 years for patients with RA and 10.8 ± 9.1 years for those with axial SpA. Fourteen patients with RA (17.1%) and 41 patients with axial SpA (56.2%) were male. Disease was well-controlled (Disease Activity Score in 28 joints mean ± SD 2.2 ± 1.2; Bath Ankylosing Spondylitis Disease Activity Index score mean ± SD 3.1 ± 2.0), but flares were frequent (22.7% of all weekly assessments). The model generated by machine learning performed well against patient-reported flares (mean sensitivity 96% [95% confidence interval (95% CI) 94-97%], mean specificity 97% [95% CI 96-97%], mean positive predictive value 91% [95% CI 88-96%], and negative predictive value 99% [95% CI 98-100%]). Sensitivity analyses were confirmatory.

CONCLUSION

Although these pilot findings will have to be confirmed, the correct detection of flares by machine-learning processing of activity tracker data provides a framework for future studies of remote-control monitoring of disease activity, with great precision and minimal patient burden.

A systematic review of the association of obesity with the outcomes of inflammatory rheumatic diseases

This was a systematic review of the literature on the association between obesity and the outcome of inflammatory rheumatic diseases. We conducted a literature search using PubMed®, Embase and PsycINFO®. Articles were classified into three categories based on the effects of obesity on the outcomes of inflammatory rheumatic diseases. The subject population, country, type of studies, number of patients, measurement of obesity and outcomes assessed were presented. Quality was appraised using Kmet et al's criteria. 4,331 articles were screened and 60 were relevant to the objective. Obesity had a negative, positive and neutral association with outcomes of inflammatory rheumatic diseases in 38 (63.3%) studies with 57,612 subjects, 11 (18.3%) studies with 3,866 subjects, and 11 (18.3%) studies with 3,834 subjects, respectively. In most studies, the disease population had been diagnosed with rheumatoid arthritis (RA). Tumour necrosis factor-α inhibitors were mostly associated with negative outcomes. More studies examining subjects outside Europe and North America and diseases other than RA are warranted.

Aerobic exercise for axial spondyloarthritis - its effects on disease activity and function as compared to standard physiotherapy: A systematic review and meta-analysis

AIM

To evaluate the impact of an aerobic fitness program on disease activity, defined by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and on C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and the Bath Ankylosing Spondylitis Functional Index (BASFI) in case of axial spondyloarthritis.

METHODS

A systematic review of the literature, following the Prisma recommendations, was performed by two reviewers on the PubMed and Embase databases. Controlled trials assessing the efficacy of aerobic exercises compared to physiotherapy on axial spondyloarthritis disease activity were included. The diagnosis of axial spondyloarthritis was meeting the New York criteria and/or the Assessment in Axial Spondyloarthritis International Working Group criteria. Aerobic fitness was defined as an exercise performed at 50%-90% of the maximal heart rate or between 50% and 80% oxygen consumption (VO₂ ) peak.

RESULTS

Five hundred and twenty abstracts were identified and 93 abstracts were analyzed. Eight studies met the selection criteria and 6 were finally included in this study because of the presence of a control group. Both groups were similar in terms of age, sex ratio, disease duration. Aerobic exercise provided a positive impact on the BASDAI in the intervention group (148 patients) (weighted mean difference [WMD]: -0.52 [95% CI: -0.9 to -0.13]) (I² : 10.3%, P = 0.35). However, when compared to a control group (152 patients), the improvement of BASDAI didn't reach significance (WMD: -0.25 [95% CI: -0.83 to 0.32]) (I² : 0%, P = 0.41). Aerobic exercise did not improve BASFI, CRP or ESR.

CONCLUSION

Aerobic exercise did not provide beneficial effects either on disease activity or on physical function and biological parameters when compared to a control group in axial spondyloarthritis.

Physical Activity Assessment Using an Activity Tracker in Patients with Rheumatoid Arthritis and Axial Spondyloarthritis: Prospective Observational Study

Background

Physical activity can be tracked using mobile devices and is recommended in rheumatoid arthritis (RA) and axial spondyloarthritis (axSpA) management. The World Health Organization (WHO) recommends at least 150 min per week of moderate to vigorous physical activity (MVPA).

Objective

The objectives of this study were to assess and compare physical activity and its patterns in patients with RA and axSpA using an activity tracker and to assess the feasibility of mobile devices in this population.

Methods

This multicentric prospective observational study (ActConnect) included patients who had definite RA or axSpA, and a smartphone. Physical activity was assessed over 3 months using a mobile activity tracker, recording the number of steps per minute. The number of patients reaching the WHO recommendations was calculated. RA and axSpA were compared, using linear mixed models, for number of steps, proportion of morning steps, duration of total activity, and MVPA. Physical activity trajectories were identified using the K-means method, and factors related to the low activity trajectory were explored by logistic regression. Acceptability was assessed by the mean number of days the tracker was worn over the 3 months (ie, adherence), the percentage of wearing time, and by an acceptability questionnaire.

Results

A total of 157 patients (83 RA and 74 axSpA) were analyzed; 36.3% (57/157) patients were males, and their mean age was 46 (standard deviation [SD] 12) years and mean disease duration was 11 (SD 9) years. RA and axSpA patients had similar physical activity levels of 16 (SD 11) and 15 (SD 12) min per day of MVPA (P=.80), respectively. Only 27.4% (43/157) patients reached the recommendations with a mean MVPA of 106 (SD 77) min per week. The following three trajectories were identified with constant activity: low (54.1% [85/157] of patients), moderate (42.7% [67/157] of patients), and high (3.2% [5/157] of patients) levels of MVPA. A higher body mass index was significantly related to less physical activity (odds ratio 1.12, 95% CI 1.11-1.14). The activity trackers were worn during a mean of 79 (SD 17) days over the 90 days follow-up. Overall, patients considered the use of the tracker very acceptable, with a mean score of 8 out 10.

Conclusions

Patients with RA and axSpA performed insufficient physical activity with similar levels in both groups, despite the differences between the 2 diseases. Activity trackers allow longitudinal assessment of physical activity in these patients. The good adherence to this study and the good acceptability of wearing activity trackers confirmed the feasibility of the use of a mobile activity tracker in patients with rheumatic diseases.

Flares assessed weekly in patients with rheumatoid arthritis or axial spondyloarthritis and relationship with physical activity measured using a connected activity tracker: a 3-month study

BACKGROUND

The evolution of rheumatoid arthritis (RA) and axial spondyloarthritis (axSpA) is marked by flares, although their frequency is unclear. Flares may impact physical activity. Activity can be assessed objectively using activity trackers. The objective was to assess longitudinally the frequency of flares and the association between flares and objective physical activity.

METHODS

This prospective observational study (ActConnect) included patients with definite clinician-confirmed RA or axSpA, owning a smartphone. During 3 months, physical activity was assessed continuously by number of steps/day, using an activity tracker, and disease flares were self-assessed weekly using a specific flare question and, if relevant, the duration of the flare. The relationship between flares and physical activity for each week (time point) was assessed by linear mixed models.

RESULTS

In all, 170/178 patients (91 patients with RA and 79 patients with axSpA; 1553 time points) were analysed: mean age was 45.5±12.4 years, mean disease duration was 10.3±8.7 years, 60 (35.3%) were men and 90 (52.9%) received biologics. The disease was well-controlled (mean Disease Activity Score 28: 2.3±1.2; mean Bath Ankylosing Spondylitis Disease Activity Index score: 3.3±2.1). Patients self-reported flares in 28.2%±28.1% of the weekly assessments. Most flares (78.9%±31.4%) lasted ≤3 days. Persistent flares lasting more than 3 days were independently associated with less weekly physical activity (p=0.03), leading to a relative decrease of 12%-21% and an absolute decrease ranging from 836 to 1462 steps/day.

CONCLUSION

Flares were frequent but usually of short duration in these stable patients with RA and axSpA. Persistent flares were related to a moderate decrease in physical activity, confirming objectively the functional impact of patient-reported flares.