Patterns of physical activity in children with haemophilia

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.

Comparisons of global coagulation potential and bleeding episodes in emicizumab-treated hemophilia A patients and mild hemophilia A patients

Emicizumab reduces bleeding events in patients with severe hemophilia A (HA). The coagulation potential of emicizumab at a clinical dose appears to correspond to about 15 IU/dL of factor VIII activity (FVIII:C), the equivalent of converting from a severe to mild phenotype. However, the clinical and laboratory characteristics of HA patients receiving emicizumab (Emi-PwHA) compared with patients with mild HA (PwMHA) remain to be determined. We reviewed clinical data from Emi-PwHA (n = 63) and PwMHA (n = 15) and evaluated comprehensive coagulation function using Ca²⁺-triggered rotational thromboelastometry (ROTEM) and ellagic acid/tissue factor-triggered clot waveform analysis (modified CWA). The median FVIII:C in PwMHA was 13.0 (IQR 8.5-17.0) IU/dL. Bleeding patterns in both groups were similar and classified into three categories: (1) spontaneous bleeding, post-traumatic, (2) bleeding within 1-2 days, and (3) delayed bleeding after 1-2 weeks. The coagulation potential in Emi-PwHA with and without breakthrough bleeds was comparable. Furthermore, coagulation function in Emi-PwHA was equivalent to PwMHA, although time between treatment and hospitalization for breakthrough bleeds in PwMHA appeared to be longer than those in Emi-PwHA. The coagulation potential and bleeding patterns appeared to be similar in Emi-PwHA and PwMHA, indicating that emicizumab-driven coagulation potential reflected mild HA.

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

Sports and Children with Hemophilia: Current Trends

Hemophilia is a sex-linked recessive disorder characterized by a lack of blood factors necessary for clotting. This review aims to investigate the benefits of sports activities in children with hemophilia in terms of both physical and psychological wellness. Sports activity is necessary for children with hemophilia to preserve joints’ range of motion, reduce joint bleeding, improve muscle mass and strength, enhance proprioception and prevent secondary chronic diseases. In the past, high-impact sports were usually forbidden in children with hemophilia because of their high bleeding risk. Recent studies, however, have shown that prophylaxis therapy can allow a hemophilic child to take part in vigorous activities or high-impact sports. The benefits of sports activity in children with hemophilia are expressed by a better muscular trophism and an improved bone mineral density. Moreover, physical activity has a positive impact on children’s psychosocial well-being. Due to prophylaxis therapy, the quality of life of children with hemophilia is similar to their peers, and this has allowed an improvement in sports participation, including team sports.

Similar sports participation as the general population in Dutch persons with haemophilia; results from a nationwide study

Introduction

Although sports participation is advocated in people with haemophilia (PWH), detailed data concerning sports participation in Dutch PWH is lacking.

Aim

to assess sports participation in Dutch PWH (6‐65 years) compared to the Dutch general population (GP).

Methods

Data from a nationwide, cross‐sectional study in PWH were analysed. Sports participation (type, duration, frequency) was assessed by the Modifiable Activities Questionnaire (MAQ), limitations in activities using the (Paediatric) Haemophilia Activities List ((Ped)HAL). Sports in the two highest categories according to the National Hemophilia Foundation classification were considered high‐risk sports. Groups were compared using Chi‐square testing.

Results

A total of 524 Adult PWH (median age: 45 (IQR: 30–55); 37% severe) and 126 paediatric PWH (median age: 11 (IQR: 8–14); 52% severe) were included. Sports participation was higher in adults (70%) than the GP (58%) and similar to the GP in children (PWH: 68%, GP: 72%). High‐risk sports participation decreased with age in PWH: from 65% (6‐12 years) to 17% (50‐65 years), which was also observed in the GP. Sports participation in children was independent of severity (non‐severe: 67% vs. severe: 65%; P = 0.97), but not in adults (non‐severe: 75%, severe: 62%; P < 0.01). Non‐severe PWH played more high‐risk sports than severe PWH: children at 65% vs. 48% (P = 0.05), adults at 25% vs. 15% (P = 0.07).

Discussion

These results suggest that sports participation in PWH was comparable to the GP. Sports participation was dependent of haemophilia severity in adults. Children were more involved in high‐risk sports than adults. More studies on sports‐related injury‐risk are needed for adequate counselling.

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.

Sports participation and sports injuries in Dutch boys with haemophilia

INTRODUCTION

Sports participation in children with hemophilia is generally considered to be associated with increased injury risk, which is generally considered highest in severe hemophilia.

AIM

To assess sports participation according to age and severity in children with hemophilia and its association with sports injuries.

METHODS

In a retrospective single-center study, sports participation, injuries, and bleeding data from three consecutive annual clinic visits were collected for young patients with hemophilia (PWH, aged 6-18). Sports in categories 2.5 and 3 of 3 according to the National Hemophilia Foundation classification were considered high-risk. Groups were compared using chi-square testing.

RESULTS

105 PWH (median age: 13(IQR 10-14); 53% severe; bleeding rate: 1/y) were identified; three were unable to perform sports and were excluded. The majority of PWH (77%) played sports weekly, of which 80% high-risk sports. Sports participation (median 3.0x/wk), and the proportion of injured PWH was similar in severe (42%) and non-severe (33%) PWH. Sports injuries were rare (65% no injuries in 3 years, median 0/y (IQR 0-1)). Annually, PWH did not report more injuries (15%) than age-matched boys (28%). Sports injuries were not associated with frequency and type of sports.

DISCUSSION

This retrospective study showed high sports participation (including high-risk sports) and low injury rates. Sports participation was similar across severities and injury rates were not higher than among the general population. Injuries were not associated with frequency or type of sports. A prospective study with objective assessment of sports participation and injuries is warranted to confirm these findings and avoid recall bias.

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.

A multicentre, open-label study of emicizumab given every 2 or 4 weeks in children with severe haemophilia A without inhibitors

Introduction

Emicizumab is a recombinant humanized bispecific monoclonal antibody mimicking the cofactor function of activated factor VIII.

Aim

In this multicentre, open‐label study (HOHOEMI), we evaluated the efficacy, safety and pharmacokinetics of emicizumab in Japanese paediatric patients aged <12 years with severe haemophilia A without factor VIII (FVIII) inhibitors.

Methods

Emicizumab was administered subcutaneously, with four loading doses of 3 mg/kg every week followed by maintenance doses of 3 mg/kg every 2 weeks (Q2W) or 6 mg/kg every 4 weeks (Q4W) in 6 and 7 patients, respectively.

Results

All patients completed at least 24 weeks of treatment. Baseline ages ranged from 4 months to 10 years, and all patients had been treated with FVIII prophylaxis prior to enrolment except a 4‐month‐old patient untreated with FVIII previously. In the respective Q2W and Q4W cohorts, 2/6 and 5/7 patients experienced no treated bleeding events, and annualized bleeding rates for treated bleeding events were 1.3 (95% confidence interval [CI], 0.6‐2.9) and 0.7 (95% CI, 0.2‐2.6). All caregivers preferred emicizumab to the patient's previous treatment. Only one related adverse event (injection site reaction) was observed. There were no thromboembolic events or thrombotic microangiopathy. Individual trough plasma concentrations of emicizumab were within the variability observed in preceding adult/adolescent studies. All patients tested negative for anti‐emicizumab antibodies.

Conclusions

Emicizumab administered Q2W or Q4W was efficacious and safe in paediatric patients with severe haemophilia A without inhibitors. This study was registered at http://www.clinicaltrials.jp (JapicCTI‐173710).

Nutritional status of children and adolescents with haemophilia in Basra, Iraq

INTRODUCTION

Patients with haemophilia are at increased risk of being overweight or obese, which in turn may have a profound effect on morbidity and quality of life.

AIMS

To assess the nutritional status of paediatric patients with haemophilia and identify possible risk factors that may adversely affect their nutritional status.

METHODS

A case-control study was performed on 63 haemophilia patients and 135 control subjects aged 5-18 years. For all participants, weight, height and body mass index Z (BMIZ) score were assessed. Physical activity (PA) was assessed using the International Physical Activity Questionnaire and the Children's Physical Activity Questionnaire for participants ≥15 years and 5-14 years old, respectively.

RESULTS

The frequency of overweight and obesity was 36.29% among the control group compared with 23.81% among patients, while thinness was higher in patients with haemophilia (19.05%) compared with 9.63% in the control group, P = .042. Low PA was reported in 22.73% of haemophilia patients aged 5-14 years compared with 2.06% in the control group, P < .001. However, no difference in PA was reported among participants aged ≥15 years. There were no significant differences in the frequency of nutritional problems among patients with respect to age, type of haemophilia, disease severity and hepatitis C seropositivity. Regression analysis revealed a negative association between paternal educational level and high BMIZ in patients ≥15 years, P = .028.

CONCLUSIONS

Paediatric patients seem to have lower BMIZ than the control group. In addition, most of the studied factors were not found to predict either high or low BMIZ among studied patients.

Using Oaxaca Decomposition to Study Socioeconomic Inequity of Physical Activity among Children Aged 10-12 Years: A Study in West of Iran

Background

Low physical activity (PA) is increasing public health problem. The present study aimed to determine socioeconomic inequality in PA among children aged 10-12 years old in Kurdistan, west of Iran in 2015.

Methods

The present cross-sectional study was conducted on 2506 children aged 10-12 in Sanandaj, Iran, in 2015. Data on the children's level of PA were collected using the Modifiable Activity Questionnaire. The concentration index was used to measure inequality and the Oaxaca decomposition to examine the different determinants of the inequality. The data were analyzed in Stata 13 and SPSS 20.

Results

Of the 2506 participants, 40.90% (38.97-42.82) had insufficient PA. Girls had a lower level of PA than boys (odds ratio [OR] = 0.34; 95% confidence intervals [CI]: 0.28-0.41) and it is directly related to maternal education (OR = 1.71; 95% CI: 1.18-2.47), the family's Socioeconomic status (SES) (OR = 2.18; 95% CI: 1.56-3.05), and the place of residence (OR = 1.68; 95% CI: 1.16-2.44). The concentration index for insufficient PA was -0.25 (95 CI: -0.30 to -0.21), revealing an insufficient PA in the group with a low SES. The prevalence of insufficient PA is 51.38% (95% CI: 48.45-54.31) in poor group and 28.40% (95% CI: 22.80-33.99) in the wealthier group. The Oaxaca decomposition showed maternal education and the place of residence was the most important determinants of inequality.

Conclusions

According to the findings, most of the children especially in the poor groups didn't have sufficient PA and socioeconomic factors could have the important role.

Telemedicine and telerehabilitation: current and forthcoming applications in haemophilia

In persons with haemophilia (PWH), the importance of comprehensive disease management to prevent bleeding, joint damage and secondary diseases has been well established. However, because haemophilia is a chronic disease, intervention programmes carried out for prolonged periods of time may create problems of patient adherence. Driven by continuous technological innovation, telemedicine is being increasingly proposed as a way to provide PWH with a range of services designed to improve their health, saving the time and cost involved in going to the treatment centre, and increasing therapeutic adherence. The aim of this article is to identify and discuss the tools available for the management of PWH by means of telemedicine and information technology. Video conferences are helpful to obtain a rapid evaluation at a distance of the occurrence and severity of bleeding episodes by the personnel of the treatment centre. Cell phones and associated applications (apps) help to improve the regular implementation of replacement therapy and monitor any ensuing adverse effect. Portable sensors help to improve lifestyle and to monitor the degree of physical activity through the fulfilment of a given number of daily walking steps and other physical activities. In the context of telerehabilitation, exergames have the potential to improve the musculoskeletal function of PWH by exploiting the recreational features of videogames. Thus, telemedicine and its multiple applications may be useful in the management of haemophilia, especially for patients living far from specialised centres. However, since this is a recent and rapidly evolving field, published studies are few and have, so far, involved only a limited number of cases. Therefore, additional evidence needs to be obtained by means of accrual of cumulative data from multiple centres specialised in haemophilia.

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.

An institutional pilot study to investigate physical activity patterns in boys with haemophilia

INTRODUCTION

Haemophilia is a bleeding disorder characterized by musculoskeletal bleeding. Trauma-induced bleeding into joints and muscles may be associated with participation in physical activities. Recognizing this, persons with haemophilia may limit physical activities to avoid bleeding. The characterization of physical activity profiles (type, intensity, frequency and duration) in children with differing severities of haemophilia has not been well documented. This is required to better understand the relationship between physical activity and bleeding in children with haemophilia.

AIM

This study was a prospective, cross-sectional, observational study to compare the quantity, type and intensity of physical activity as measured by accelerometry in boys with different haemophilia severities.

METHODS

Subjects wore an accelerometer daily for 1 week and completed validated self-report PedHAL and 3DPAR questionnaires. Accelerometer activity levels were classified as sedentary, light, moderate or vigorous.

RESULTS

A total of 66 males were enrolled, 24 had mild/moderate and 42 had severe haemophilia. Subjects average age was 11.52 years (±3.99) and their average BMI was 20.74 kg m(2) (±5.68). Boys with severe haemophilia reported significantly more time per day spent in sedentary activities compared to those with mild/moderate haemophilia. Furthermore, the amount of time engaged in sedentary activities increased with age in those boys with severe haemophilia, whereas the opposite was true in those with mild/moderate haemophilia.

CONCLUSION

We speculate that prophylaxis in children with severe haemophilia permitted them to engage in similar amounts of moderate to vigorous physical activity (MVPA) as children with mild/moderate haemophilia. Increasing sedentary time in the severe cohort with age may be attributed to increasing arthropathy among other psychosocial factors.

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.

Prophylaxis in real life scenarios

Prophylaxis has become the standard mantra of care for those individuals with severe haemophilia A and B. Primary prophylaxis is advocated to prevent the occurrence of symptomatic acute spontaneous haemarthroses and to preserve joint structure and function. Typically, twice or thrice weekly infusions of factor VIII or IX concentrates are integral to this treatment approach. Secondary prophylaxis is initiated after the relentless cycle of progressive joint damage has been triggered by prior haemarthroses and is intended to preserve existing joint health by preventing additional spontaneous bleeding events. Event-driven prophylaxis involves the administration of clotting factor concentrates to prevent acute traumatic bleeds, which are anticipated to occur in association with surgical or physical trauma. This regimen enhances the effectiveness of primary or secondary prophylaxis protocols or on-demand approaches to replacement therapy. Besides the marked reduction in the so-called annual bleed rate, prophylaxis regimens frequently increase personal self-confidence to embark on a more active and physical lifestyle; however, in reality, prophylaxis must be individualized in accordance with bleeding phenotypes, with the unique pharmacokinetic profile of administered replacement clotting factor concentrates, with the specific clinical scenario, and with the degree of intensity anticipated for any physical activity. The introduction of extended half-life replacement products will also influence how these prophylaxis regimens will be accomplished. The following scenarios will discuss how prophylaxis regimens can be implemented to protect the individual from developing spontaneous and activity-induced acute bleeding complications and to maintain an improved quality of life.

Physical activity and health outcomes in persons with haemophilia B

Regular participation in physical activity helps to prevent damage and maintain joint health in persons with haemophilia. This study describes self-reported physical activity participation among a sample of people with haemophilia B in the US and measures its association with health-related quality of life (HRQoL). Data on 135 participants aged 5-64 years were abstracted from Hemophilia Utilization Group Study Part Vb. The International Physical Activity Questionnaire assessed physical activity among participants aged 15-64 years, and the Children's Physical Activity Questionnaire abstracted from the Canadian Community Health Survey was used for participants aged 5-14 years. SF-12 was used to measure HRQoL and the EuroQol (EQ-5D-3L) was used to measure health status for participants older than 18 years of age. PedsQL was used to measure HRQoL in children aged 5-18 years. Sixty-two percent of participants in the 15-64 year-old age cohort reported a high level of physical activity, 29% reported moderate activity and 9% reported low activity. For children aged 5-14 years, 79% reported participating in physical activity for at least 4 days over a typical week. Based on the 2008 Physical Activity Guidelines for Americans, 79% of adults achieved the recommended physical activity level. Multivariable regression models indicated that adults who engaged in a high level of physical activity reported EQ-5D Visual Analogue Scale (VAS) scores that were 11.7 (P = 0.0726) points greater than those who engaged in moderate/low activity, indicating better health outcomes. Among children, no statistically significant differences in health outcomes were found between high and moderate or low activity groups.

Deficits in physical function among young childhood cancer survivors

PURPOSE

Childhood cancer survivors (CCSs) are at risk for physical disability. The aim of this investigation was to characterize and compare physical performance among CCSs and a group of siblings age < 18 years and determine if diagnosis, treatment, and physical activity levels were associated with lower performance scores.

METHODS

CCSs ≥ 5 years from diagnosis and a sibling comparison group were recruited and evaluated for strength, mobility, and fitness. Physical performance measures were compared in regression models between survivors and siblings by diagnosis and among survivors by treatment exposures and physical activity levels.

RESULTS

CCSs (n = 183; mean age ± standard deviation [SD], 13.5 ± 2.5 years; 53% male) scored lower than siblings (n = 147; mean age ± SD, 13.4 ± 2.4 years; 50% male) on lower-extremity strength testing, the timed up-and-go (TUG) test, and the 6-minute walk (6MW) test, despite reporting similar levels and types of habitual physical activity. The lowest scores were prevalent among survivors of CNS tumors and bone and soft tissue sarcomas on strength testing (score ± SD: CNS tumors, 76.5 ± 4.7; sarcoma 67.1 ± 7.2 v siblings, 87.3 ± 2.4 Newton-meters quadricep strength at 90° per second; P = .04 and .01, respectively) and among CNS tumor survivors on the TUG (score ± SD: 5.1 ± 0.1 v siblings, 4.4 ± 0.1 seconds; P < .001) and 6MW tests (score ± SD: 533.3 ± 15.6 v siblings, 594.1 ± 8.3 m; P < .001).

CONCLUSION

CCSs may have underlying physiologic deficits that interfere with function that cannot be completely overcome by participation in regular physical activity. These survivors may need referral for specialized exercise interventions in addition to usual counseling to remain physically active.