Machine learning model for predicting physical activity related bleeding risk in Chinese boys with haemophilia A

BACKGROUND

Physical activity is a crucial part of an active lifestyle for haemophiliac children. However, the fear of bleeds has been identified as barriers to participating physical activity for haemophiliac children even with prophylaxis. Lack of evidence and metrics driven by data is key problem.

OBJECTIVES

We aim to develop machine learning models based on clinical data with multiple potential factors considered to predict risk of physical activity bleeding for haemophilia children with prophylaxis.

METHODS

From this cohort study, we collected information on 98 haemophiliac children with adequate prophylaxis (trough FVIII:C level > 1 %). The involved potential predictor variables include demographic information, treatment information, physical activity, joint evaluation, and pharmacokinetic parameters, etc. We applied CoxPH, Random Survival Forests (RSF) and DeepSurv to construct prediction models for the risk of bleeding during physical activities. All three survival analysis models were internally and externally validated.

RESULTS

A total of 98 patients were enrolled in this study. Their median age was 7.9 (5.5, 10.2) years. The CoxPH, RSF and DeepSurv models' discriminative and calibration abilities were all high, and the RSF model had the best performance (Internal validation: C-index, 0.7648 ± 0.0139; Brier Score, 0.1098 ± 0.0015; External validation: C-index, 0.7260 ± 0.0154; Brier Score, 0.0930 ± 0.0018). The prediction curves demonstrated that the developed RSF model can distinguish the risks well between bleeding and non-bleeding patients, as well as patients with different levels of physical activity. Meanwhile, the feature importance analysis confirmed that physical activity bleeding was deduced by comprehensive effects of various factors, and the importance of different factors on bleeding outcome is discrepant.

CONCLUSIONS

This study revealed from the mechanism that it is necessary to incorporate multiple factors to accurately predict physical activity related bleeding risk. In clinical practice, the designed machine learning models can provide guidance for children with haemophilia A to positively participate in physical activity.

Physical activity in Norwegian teenagers and young adults with haemophilia A compared to general population peers

INTRODUCTION

Limited evidence exists on objectively measured habitual physical activity (PA) of young people with haemophilia (PWH).

AIMS

To compare different outcomes of objective PA between young PWH A and controls using a commercial activity tracker.

METHODS

We enrolled males aged 13-30 years with moderate and severe haemophilia A, without inhibitors on regular prophylaxis. PA was measured with the activity tracker Fitbit Charge 3 for 12 weeks. Control group data was obtained from ≈60,000 Fitbit users, matched on age, sex and measurement period. PA variables [steps, intensities, volume, activity types, exercise frequencies and proportion meeting the World Health Organization's moderate-to-vigorous PA (MVPA) recommendations] were compared between groups descriptively and using Welch's two-sample t-test and two-sample test of proportions.

RESULTS

Forty PWH A were enrolled (mean age 19.5 years, 50% teenagers, 50% adults, three (7.5%) with moderate and 37 (92.5%) with severe haemophilia). Mean daily steps and minutes MVPA were similar between PWH and controls. PWH spent more time in light PA (mean 227 vs. 192 min/day, P = .033) and exercised more frequently (mean 5.6 vs. 3.9 exercise sessions/week, P < .001). Among teenagers, 40% PWH and 8% controls reached MVPA recommendations, compared to 95% and 100% among adults. The most common type of PA was walking.

CONCLUSION

This cohort of young PWH A on prophylactic treatment had PA levels comparable to controls. Still, a considerable proportion of teenagers did not meet the recommended weekly volume of MVPA, and we encourage clinicians to have a particular focus on promoting PA for this group.

An Electronic Patient-Reported Outcome Mobile App for Data Collection in Type A Hemophilia: Design and Usability Study

Background

There is currently limited evidence on the level and intensity of physical activity in individuals with hemophilia A. Mobile technologies can offer a rigorous and reliable alternative to support data collection processes but they are often associated with poor user retention. The lack of longitudinal continuity in their use can be partly attributed to the insufficient consideration of stakeholder inputs in the development process of mobile apps. Several user-centered models have been proposed to guarantee that a thorough knowledge of the end user needs is considered in the development process of mobile apps.

Objective

The aim of this study is to design and validate an electronic patient-reported outcome mobile app that requires sustained active input by individuals during POWER, an observational study that aims at evaluating the relationship between physical activity levels and bleeding in patients with hemophilia A.

Methods

We adopted a user-centered design and engaged several stakeholders in the development and usability testing of this mobile app. During the concept generation and ideation phase, we organized a need-assessment focus group (FG) with patient representatives to elicit specific design requirements for the end users. We then conducted 2 exploratory FGs to seek additional inputs for the app’s improvement and 2 confirmatory FGs to validate the app and test its usability in the field through the mobile health app usability questionnaire.

Results

The findings from the thematic analysis of the need-assessment FG revealed that there was a demand for sense making, for simplification of app functionalities, for maximizing integration, and for minimizing the feeling of external control. Participants involved in the later stages of the design refinement contributed to improving the design further by upgrading the app’s layout and making the experience with the app more efficient through functions such as chatbots and visual feedback on the number of hours a wearable device had been worn, to ensure that the observed data were actually registered. The end users rated the app highly during the quantitative assessment, with an average mobile health app usability questionnaire score of 5.32 (SD 0.66; range 4.44-6.23) and 6.20 (SD 0.43; range 5.72-6.88) out of 7 in the 2 iterative usability testing cycles.

Conclusions

The results of the usability test indicated a high, growing satisfaction with the electronic patient-reported outcome app. The adoption of a thorough user-centered design process using several types of FGs helped maximize the likelihood of sustained retention of the app’s users and made it fit for data collection of relevant outcomes in the observational POWER study. The continuous use of the app and the actual level of engagement will be evaluated during the ongoing trial.

Trial Registration

ClinicalTrials.gov NCT04165135; https://clinicaltrials.gov/ct2/show/NCT04165135

Feasibility, safety and acceptability of select outcome measures in a physiotherapy study protocol for boys with haemophilia

Background

There is a lack of functional performance measures for children and young people with haemophilia (CYPwH) with associated control data from typically developing boys (TDB). The literature advocates development of a core set of outcome measures for different chronic conditions. As medical treatment improves, CYPwH are experiencing better outcomes; therefore, more challenging measures are required to monitor physical performance. Such testing is not performed routinely, due to practical and safety concerns.

Aim

Evaluate the feasibility, safety and acceptability of select outcome measures as part of a study protocol testing CYPwH; including myometry, 10 metre incremental shuttle walk test (10-m ISWT), iSTEP (an incremental step test, with data from TDB), and 1 week of accelerometry-wear at home.

Methods

Sixty-six boys aged 6–15 years with mild, moderate or severe haemophilia A or B (including inhibitors) attending routine clinics at Great Ormond Street Hospital were approached to participate. Descriptive statistics and content analysis were used to assess outcomes of feasibility, safety and acceptability, which included recruitment/retention rates, protocol completion within routine appointment timeframes, performance testing without serious adverse events/reactions (SAE/SARs), and acceptability to CYPwH of high-level performance measures.

Results

Outcomes were met: 43 boys completed testing at clinic review (Jan–Nov 2018) within a 10-month timeframe, retention was 95% at completion of protocol and no SAE/SARs were reported throughout testing.

Conclusion

Feasibility, safety and acceptability of the study protocol have been established in this population. Both high-level performance tests, iSTEP and 10-m ISWT, were an acceptable addition to boys’ routine clinic appointments and could be safe, acceptable choices of outcome measure as part of a core set of tests for CYPwH. Further investigation of the psychometric properties for the iSTEP is now justified, in order for it to be used as a standardised, validated, reliable outcome measure in clinical or research settings.

Trial registration

Retrospectively registered on September 3, 2019, on ClinicalTrials.gov (ID: NCT04076306).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00831-1.

A systematic review of physical activity in people with haemophilia and its relationship with bleeding phenotype and treatment regimen

INTRODUCTION

Although the measurement of physical activity (PA) amongst people with haemophilia (PWH) has become increasingly widespread in recent years, the relationship between PA and bleeding phenotype remains poorly understood. In addition, the influence of various treatment regimens on this relationship has not been defined.

AIM

This review aimed to systematically assess the data that are available regarding PA levels amongst PWH, as well as the relationship between PA and bleeding.

METHODS

A systematic search of the online databases EMBASE, Cochrane, MEDLINE Ovid, CINAHL and Web of Science was conducted by two independent reviewers. Quality assessment was undertaken using the AXIS Critical Appraisal Tool for Cross-sectional Studies and the STROBE checklist.

RESULTS

Of 1902 sources identified overall, 36 articles were included. Low-to-moderate transparency of reporting and various sources of bias were identified. PA levels varied amongst heterogeneous samples of PWH. The relationship between PA and bleeds was inconclusive, although there was evidence that improvements in treatment over recent decades have appeared to enable PWH to become more physically active.

CONCLUSION

Based upon the limited available evidence, the relationship between PA and bleeding phenotype in PWH remains unclear. However, with the development of improved prophylaxis treatment regimens in recent years, there is evidence that PA levels have increased, especially amongst people with severe haemophilia. The use of validated outcome measures of PA and more robust reporting of bleeds and treatment regimen are warranted in future research, especially in a rapidly evolving era of new treatments for PWH.

Movement behaviour patterns in adults with haemophilia

Background:

Joint bleeds are the hallmark of haemophilia, and can lead to disabling haemophilic arthropathy. Consequently, the movement behaviour of adults with haemophilia differs from that of healthy adults. It seems unlikely that a single outcome is able to reflect all relevant information regarding movement behaviour. The aim of the current study was to identify patterns of movement behaviour within persons with haemophilia (PWH) and compare clinical characteristics between patterns of movement behaviour.

Methods:

A total of 105 PWH [70% severe haemophilia; median age 43 years (30.0–54.0)] were included in the study. Hierarchical cluster analysis was used to identify patterns of movement behaviour. Clustering variables included seven parameters of movement behaviour: sitting, standing, walking, biking, running, frequency of active bouts and length of active bouts. Clinical characteristics included age, severity of haemophilia, joint health, physical functioning and pain. Clinical characteristics were compared between identified clusters by Kruskall–Wallis test. Movement behaviour was assessed with the Activ8 accelerometer, joint health was assessed on the Haemophilia Joint Health Score, physical functioning on the Haemophilia Activity List and the 40 m self-paced walk test and pain on the Numerical Pain Rating Score.

Results:

Cluster analysis identified three clusters, which were defined as: ‘sedentary’ (57%), ‘bikers and runners’ (22%) and ‘walkers’ (20%). The ‘bikers and runners’ showed better joint health and experienced fewer limitations in activities than the ‘walkers’ and the ‘sedentary’. The ‘walkers’ perceived fewer limitations in activities than the ‘sedentary’, with comparable joint health. We did not identify differences in pain, walking speed and age between the clusters.

Conclusions:

We identified three patterns of movement behaviour. The majority of PWH was identified as sedentary, whereas less sitting and regular walking during the day seemed to be more beneficial.

Physical Activity Monitoring and Acceptance of a Commercial Activity Tracker in Adult Patients with Haemophilia

Physical activity (PA) is highly beneficial for people with haemophilia (PWH), however, studies that objectively monitor the PA in this population are scarce. This study aimed to monitor the daily PA and analyse its evolution over time in a cohort of PWH using a commercial activity tracker. In addition, this work analyses the relationship between PA levels, demographics, and joint health status, as well as the acceptance and adherence to the activity tracker. Twenty-six PWH were asked to wear a Fitbit Charge HR for 13 weeks. According to the steps/day in the first week, data were divided into two groups: Active Group (AG; ≥10,000 steps/day) and Non-Active Group (NAG; <10,000 steps/day). Correlations between PA and patient characteristics were studied using the Pearson coefficient. Participants' user experience was analysed with a questionnaire. The 10,000 steps/day was reached by 57.7% of participants, with 12,603 (1525) and 7495 (1626) being the mean steps/day of the AG and NAG, respectively. In general, no significant variations (p > 0.05) in PA levels or adherence to wristband were produced. Only the correlation between very active minutes and arthropathy was significant (r = -0.40, p = 0.045). Results of the questionnaire showed a high level of satisfaction. In summary, PWH are able to comply with the PA recommendations, and the Fitbit wristband is a valid tool for a continuous and long-term monitoring of PA. However, by itself, the use of a wristband is not enough motivation to increase PA levels.

Screen time among Spanish university students with disabilities: a self-organizing maps analysis

BACKGROUND

Screen time can play a significant role in the health and quality of life of people with disabilities. However, there is a lack of studies on this issue among people with disabilities, and even fewer in the university setting. Thus, the aim of our study was to explore the relationships between screen time, disability grade, body mass index (BMI), physical activity and sociodemographic variables (gender and socioeconomic status) in university students with different disabilities.

METHODS

A cross-sectional study was conducted on a sample of 1091 students with disabilities from 55 Spanish universities. Instruments used for data gathering were the Adolescent Sedentary Activity Questionnaire (ASAQ) and the International Physical Activity Questionnaire-Short Form (IPAQ-SF). A Self-Organizing Maps (SOM) analysis was carried out to explore the relationships between the variables under study.

RESULTS

Participants reported high values in overall screen time (5.45 h per day/week), with computers being the media most used (2.45 h per day/week). The SOM analysis showed slightly higher screen time values in women than men. People with a high disability grade spent less screen time than those with lower disability grade. Contradictory results exist when a group of men with the highest BMI had the highest screen time and the lowest physical activity (PA) while women with low BMI show the highest screen time and PA.

CONCLUSIONS

Gender and disability grade played a moderating role in screen time among people with disabilities while BMI and PA do not play such a role.

Sports participation and physical activity in adult Dutch and Swedish patients with severe haemophilia: A comparison between intermediate- and high-dose prophylaxis

Introduction

Differences in treatment and outcome have been reported for persons with haemophilia (PWH) on intermediate‐dose (Dutch) and high‐dose (Swedish) prophylaxis, but the potential influence of sports participation has not been considered.

Aim

To compare sports participation and clinical outcome between adult Dutch and Swedish PWH.

Methods

Self‐reported sports participation (type and frequency per week), physical functioning (SF‐36_PF: 100‐0), joint status (HJHS: 0‐144), perceived limitations (HAL_sum: 100‐0) and physical activity (IPAQ) were recorded. Sports were classified according to National Haemophilia Foundation classification (5 categories, highest two were classified as high‐risk sports). Sports participation and clinical outcome were compared according to country and age (18‐22, 23‐29, 30‐40 years) using non‐parametric tests and Spearman correlations (rho).

Results

Seventy‐one adult PWH (NL: 43, SWE: 28) completed sports questionnaires (mean age: 26 years). All participants engaged in sports, including 59.2% in high‐risk sports (33.9% twice weekly). Dutch PWH showed a significant age‐related decline in (high‐risk) sports participation (7x/wk in PWH 18‐22 years to 2x/wk in PWH 30‐40 years, P < 0.05), joint health (HJHS: median 2‐15.5, P < 0.01) and physical functioning (SF‐36_PF: median 100 to 77.5, P < 0.01), while Swedish did not. Sports participation was not associated with bleeding (Spearman's rho = −0.119).

Conclusion

All participants reported sports participation, including 59.2% in high‐risk sports. Dutch PWH treated with intermediate‐dose prophylaxis showed an age‐related decline in sports participation, joint status and physical functioning, whereas Swedish PWH on high‐dose prophylaxis did not. Sports participation was not associated with bleeding.

Recent advances in musculoskeletal physiotherapy for haemophilia

Physiotherapy is directed towards the movement needs and potential of individuals, providing treatment and rehabilitation to develop, maintain and restore maximum movement and functional ability throughout the lifespan. Recent systematic reviews and randomized controlled trials have extended evidence for the clinical efficacy of physiotherapy interventions and rehabilitation for people with haemophilia. This narrative review synthesizes recent evidence to discuss; differentiating musculoskeletal bleeding and haemophilic arthropathy, efficacy of physiotherapy and rehabilitation for acute musculoskeletal bleeding and arthropathy, as well as monitoring musculoskeletal health. Whilst robust evidence is emerging, there is a need for more well designed randomized clinical studies with larger numbers and homogeneity of participants and collaboration of all researchers and clinicians to identify a core set of outcome measures that can be used to monitor musculoskeletal health.

Movement behaviour in adults with haemophilia compared to healthy adults

BACKGROUND

Limited research has been published regarding movement behaviour of adult persons with haemophilia (PWH). It is hypothesized that avoidance of activities and more sedentary behaviour cause poorer physical functioning.

AIM

To determine differences in movement behaviour between PWH and healthy adults.

METHODS

Movement behaviour was measured with an accelerometer distinguishing between; lying/non-wear, sitting, standing, walking, running and cycling. Time spent on activities was compared between PWH and healthy adults, using absolute time spent on activities and activities as percentage of wear time.

RESULTS

One hundred and five PWH (32 mild/moderate with a mean age of 42.8 ± 15.1, severe 42.1 ± 13.6) and 98 healthy adults (mean age 41.9 ± 15.5) showed that adults with severe haemophilia sit and stand more than healthy adults (4.5 [CI 0.6-8.4] and 4.2 [CI 1.8-6.6] h/wk, respectively) and walk and run less (3.4 [CI 1.4-5.3] hours and 33.6 [CI 19.0-41.7] min/wk, respectively). Patients with mild/moderate haemophilia stand more than healthy adults (3.3 [CI 0.1-6.4] h/wk). Differences in sitting between severe haemophilia and healthy adults and differences in standing between mild/moderate haemophilia and healthy adults disappeared when using activities as percentage of wear time.

CONCLUSION

Movement behaviour of adults with severe haemophilia differs from healthy adults, mainly due to less walking and less running. No differences were found in other activities and postures or the distribution of movement behaviour over the day. No significant differences were found between adults with mild/moderate haemophilia and healthy adults.

Physical activity and sedentary behavior following pediatric burns - a preliminary investigation using objective activity monitoring

Background

Adequate levels of regular physical activity (PA) are crucial for health and well-being. Pediatric burn injuries can have major physiological consequences in both the short and long term. The question is whether these consequences affect post burn PA levels. This study therefore aimed to describe PA and sedentary behavior (SB) in children and adolescents 1–5 years after burn injury.

Methods

Daily PA and SB were monitored in 20 children and adolescents (12 boys and 8 girls, aged 6–17 years, with burns covering 10–37% of total body surface area, 1–5 years post burn) for 1 week using the ActiGraph GTX3+ accelerometer. Activity counts were categorized into SB, light PA, moderate PA, vigorous PA, moderate-to-vigorous PA (MVPA), and total PA. Outcomes were compared with non-burned reference values and PA levels recommended by the World Health Organization (WHO).

Results

The participants spent about 5.1 h per day on total PA and 7.4 h on SB. Most of the active time (~ 83%) was categorized as light PA. Thirty-five percent of the group, especially the young boys, spent on average ≥ 60 min on MVPA per day. The boys, although with large interindividual differences, spent more time on MVPA than the girls (p < .005). Older age was associated with less PA time, while more time was spent sedentary. No trends were found indicating an effect of burn characteristics, time post burn, or length of hospital stay, and no differences were found with non-burned peers.

Conclusion

Duration and intensity of PA and SB in children and adolescents 1–5 years after burn injury were similar to non-burned peers. However, only 35% of the group met the WHO physical activity recommendation. Given the increased long term risk for physical conditions following pediatric burns, physical activity should be encouraged in this vulnerable population.

Trial registration

The study is registered in the National Academic Research and Collaborations Information System of the Netherlands (OND1348800).

Electronic supplementary material

The online version of this article (10.1186/s13102-018-0093-5) contains supplementary material, which is available to authorized users.

Physical activity in individuals with haemophilia and experience with recombinant factor VIII Fc fusion protein and recombinant factor IX Fc fusion protein for the treatment of active patients: a literature review and case reports

The World Federation of Hemophilia and the National Hemophilia Foundation encourage people with haemophilia (PWH) to participate in routine physical activity. The benefits of physical activity for PWH include improvements in joint, bone, and muscle health. Accordingly, a number of studies suggest that levels of physical activity among PWH are similar to those of their healthy peers, especially among individuals who began prophylaxis at an early age (≤3 years). Importantly, several studies found either no increased risk or only a transient increase in risk of bleeding with more intensive physical activity compared with less intensive physical activity. Data on optimal prophylaxis regimens for PWH who participate in physical/sporting activities; however, remain sparse. Long-acting recombinant factor VIII Fc fusion protein (rFVIIIFc) and recombinant factor IX Fc fusion protein (rFIXFc) demonstrated efficacy for the prevention and treatment of bleeding episodes in Phase 3 clinical trials of participants with haemophilia A and B, respectively, with most individuals able to maintain or increase their physical activities. This manuscript reviews the current literature that describes physical activity in PWH. Additionally, case studies are presented to provide supplemental information to clinicians illustrating the use of rFVIIIFc and rFIXFc in physically active patients with haemophilia A and B, respectively. These case reports demonstrate that it is possible for patients to be physically active and maintain good control of their haemophilia with extended interval prophylactic dosing using rFVIIIFc or rFIXFc.

Strategies to encourage physical activity in patients with hemophilia to improve quality of life

Hemophilia is a bleeding disorder caused by a congenital abnormality of blood coagulation. Until the mid-1970s, patients with hemophilia (PWH) were advised to refrain from physical activity (PA) because of a perceived increased risk of bleeding. Since then, PA, which is recognized as being essential for health maintenance, is now recommended by the World Federation of Hemophilia. Moreover, a number of studies reported that PA can improve treatment efficacy and prevent bleeding in PWH. Physical assessment and intervention in PA are currently used in clinical practice. However, the necessity of PA is not emphasized, and many PWH generally have low- to- no PA. Therefore, a behavior change approach to encourage patient motivation is becoming ever more important. In this article, we review articles addressing PA in PWH and discuss strategies to encourage PA through a behavior change approach by focusing on factors relevant to hemophilia, such as benefits and bleeding risk of PA, risk management of bleeding, PA characteristics, and difficulty with exercise adherence. The trust relationship between clinicians and patients, a transtheoretical model of behavior change, and motivation theory as approaches to promote PA are introduced. Finally, we review a case report of the clinical success of a behavior change approach to promote PA. Many PWH find it difficult to continue PA because of aging, fear of bleeding, insufficient recognition of PA benefits, and psychological problems. Therefore, it is essential and important to perform prophylaxis with PWH and to heighten their understanding of the benefits and risks of PA, before initiating the exercise regimen. For those patients who find it difficult to participate in PA, it is necessary to plan individual-based behavior change approach and encourage self-efficacy.

Does Sedentary Behavior Predict Academic Performance in Adolescents or the Other Way Round? A Longitudinal Path Analysis

This study examined whether adolescents' time spent on sedentary behaviors (academic, technological-based and social-based activities) was a better predictor of academic performance than the reverse. A cohort of 755 adolescents participated in a three-year period study. Structural Equation Modeling techniques were used to test plausible causal hypotheses. Four competing models were analyzed to determine which model best fitted the data. The Best Model was separately tested by gender. The Best Model showed that academic performance was a better predictor of sedentary behaviors than the other way round. It also indicated that students who obtained excellent academic results were more likely to succeed academically three years later. Moreover, adolescents who spent more time in the three different types of sedentary behaviors were more likely to engage longer in those sedentary behaviors after the three-year period. The better the adolescents performed academically, the less time they devoted to social-based activities and more to academic activities. An inverse relationship emerged between time dedicated to technological-based activities and academic sedentary activities. A moderating auto-regressive effect by gender indicated that boys were more likely to spend more time on technological-based activities three years later than girls. To conclude, previous academic performance predicts better sedentary behaviors three years later than the reverse. The positive longitudinal auto-regressive effects on the four variables under study reinforce the 'success breeds success' hypothesis, with academic performance and social-based activities emerging as the strongest ones. Technological-based activities showed a moderating effect by gender and a negative longitudinal association with academic activities that supports a displacement hypothesis. Other longitudinal and covariate effects reflect the complex relationships among sedentary behaviors and academic performance and the need to explore these relationships in depth. Theoretical and practical implications for school health are outlined.

Screen media usage, sleep time and academic performance in adolescents: clustering a self-organizing maps analysis

Screen media usage, sleep time and socio-demographic features are related to adolescents' academic performance, but interrelations are little explored. This paper describes these interrelations and behavioral profiles clustered in low and high academic performance. A nationally representative sample of 3,095 Spanish adolescents, aged 12 to 18, was surveyed on 15 variables linked to the purpose of the study. A Self-Organizing Maps analysis established non-linear interrelationships among these variables and identified behavior patterns in subsequent cluster analyses. Topological interrelationships established from the 15 emerging maps indicated that boys used more passive videogames and computers for playing than girls, who tended to use mobile phones to communicate with others. Adolescents with the highest academic performance were the youngest. They slept more and spent less time using sedentary screen media when compared to those with the lowest performance, and they also showed topological relationships with higher socioeconomic status adolescents. Cluster 1 grouped boys who spent more than 5.5 hours daily using sedentary screen media. Their academic performance was low and they slept an average of 8 hours daily. Cluster 2 gathered girls with an excellent academic performance, who slept nearly 9 hours per day, and devoted less time daily to sedentary screen media. Academic performance was directly related to sleep time and socioeconomic status, but inversely related to overall sedentary screen media usage. Profiles from the two clusters were strongly differentiated by gender, age, sedentary screen media usage, sleep time and academic achievement. Girls with the highest academic results had a medium socioeconomic status in Cluster 2. Findings may contribute to establishing recommendations about the timing and duration of screen media usage in adolescents and appropriate sleep time needed to successfully meet the demands of school academics and to improve interventions targeting to affect behavioral change.

Outcome measures monitoring physical function in children with haemophilia: a systematic review

Our objective was to provide a synthesis of measurement properties for performance-based outcome measures used to evaluate physical function in children with haemophilia. A systematic review of articles published in English using Medline, PEDro, Cinahl and The Cochrane Library electronic databases was conducted. Studies were included if a performance-based method, clinical evaluation or measurement tool was used to record an aspect of physical function in patients with haemophilia aged ≤ 18 years. Recording of self-perceived or patient-reported physical performance, abstracts, unpublished reports, case series reports and studies where the outcome measure was not documented or cross-referenced was excluded. Description of outcome measures, patient characteristics, measurement properties for construct validity, internal consistency, repeatability, responsiveness and feasibility was extracted. Data synthesis of 41 studies evaluating 14 measures is reported. None of the outcome measures demonstrated the requirements for all the measurement properties. Data on validity and test-retest repeatability were most lacking together with studies of sufficient size. Measurement of walking and muscle strength demonstrated good repeatability and discriminative properties; however, correlation with other measures of musculoskeletal impairment requires investigation. The Haemophilia Joint Health Score demonstrated acceptable construct validity, internal consistency and repeatability, but the ability to discriminate changes in physical function is still to be determined. Rigorous evaluation of the measurement properties of performance-based outcome measures used to monitor physical function of children with haemophilia in larger collaborative studies is required.