J. Van Der Net

Six-minute Walk Test in Children with Chronic Conditions

Objectives The 6-minute walk test (6MWT) is a frequently used indicator of functional exercise capacity. The goals of this study were to compare the 6-minute walk performance of three paediatric patient groups with that of healthy peers, to assess differences between published reference values and to investigate which anthropometric characteristics best predict 6-minute walk performance. Methods 47 children with haemophilia (mean (SD) age 12.5 (2.9) years), 44 with juvenile idiopathic arthritis (JIA) (mean age 9.3 (2.2) years) and 22 with spina bifida (SB) (mean age 10.3 (3.1) years) were included. Subjects performed a 6MWT, and the distance walked (6MWD) was compared with published reference values. Results The haemophilia, JIA and SB patients achieved 90%–92%, 72%–75% and 60%–62% of predicted walking distances, respectively. There were significant associations between 6MWD and age, height and weight in the haemophilia group and 6MWD and height in the JIA group. None of the anthropometric variables was significantly related to 6MWD in the SB group. All anthropometric variables were strongly correlated with walking distance–body weight product (6Mwork) in all groups. Height explained 24% (haemophilia) and 11% (JIA) of the variance in 6MWD and 84% (haemophilia), 78% (JIA) and 73% (SB) of the variance in 6Mwork. Conclusions Walking distances of children with haemophilia, JIA and SB are significantly reduced compared with healthy references. Walking distance–body weight product seems to be a better outcome measure of the 6MWT compared with distance walked alone. Height is the best predictor of 6MWD and 6Mwork.

Physical fitness, functional ability and quality of life in children with severe haemophilia: a pilot study

Summary.  In the Netherlands comparable levels of sports‐participation between persons with haemophilia and healthy controls have been reported. This raises the question if children with haemophilia under the currently available prophylaxis do reach comparable levels of physical fitness and health‐related quality of life (HRQoL) as their healthy peers. The aim of this study was to investigate the level of physical fitness, functional ability and quality of life and to determine the feasibility to safely test the exercise capacity of boys with severe haemophilia A. Thirteen subjects participated in this study. Physical fitness was determined using the measurement of maximal oxygen uptake (VO2peak) attained during a graded maximal exercise test to volitional exhaustion. Joint health, physical activity levels and health‐related quality of life (Haemo‐Qol) were also measured. Mean VO2peak was 1.86 ± 0.77 L min−1 (Z‐score: −0.39 ± 1.61) which was not significantly different from reference values. Relative VO2peak was 47.42 ± 8.29 mL min−1 kg−1 (Z‐score: −0.52 ±1.43), which did not differ significantly from reference values either. One boy suffered a joint bleeding one day after the test. Haemo‐Qol scores in parents and children ranged from 3.2% to 36.7% (100% reflects poor outcome). Relationship between the child or parent reports of Haemo‐QoL and both absolute and relative VO2peak ranged from R = 0.00 and R = 0.4. Exercise testing in children with severe haemophilia A was a safe procedure. Patients with severe haemophilia A with good joint health and no limitations of activities have comparable physical fitness and physical active lifestyle with healthy peers and good HRQoL.

Correlates of disablement in systemic onset juvenile chronic arthritis : A cross sectional study

The impact of systemic onset JCA on functional outcome was studied in a multidimensional construct. Twenty-one patients were subjected to auxologic evaluation, a laboratory check, pulmonary and cardiac function tests, radiographic evaluation, joint count on tenderness, swelling and function, ADL, health assessment (CHAQ), and psychosocial evaluation. Six of 21 patients had active systemic disease. Restrictive pulmonary function was found in 8/17 patients, 1/21 had pericarditis. Joint impairment was moderate. Functional limitations were mild. Self-esteem was positive. Parental report on functional limitation correlated significantly with joint impairment. Performance of daily activities correlated strongly with perceived competence. Active inflammatory disease did not correlate with joint impairment and functional limitation. Patients with systemic onset JCA develop mild functional limitations, which partially correlate with the more serious impairments. Pulmonary function disorders are a common impairment. Active inflammatory disease might influence functional outcome, but there is no evidence that it influences joint impairment outcome.

Choosing outcome assessment tools in haemophilia care and research: a multidisciplinary perspective

The implementation of early long‐term, regular clotting factor concentrate (CFC) replacement therapy (‘prophylaxis’) has made it possible to offer boys with haemophilia a near normal life. Many different regimens have reported favourable results, but the optimum treatment regimens have not been established and the cost of prophylaxis is very high. Both for optimizing treatment and reimbursement issues, there is a need to provide objective evidence of both short‐ and long‐term results and benefits of prophylactic regimens.

Aerobic capacity and muscle strength in juvenile-onset mixed connective tissue disease (MCTD)

Objectives: To study the aerobic capacity and muscle strength in children and adolescents with mixed connective tissue disease (MCTD). Frequently reported clinical symptoms include joint swelling, muscle weakness, fatigue, decreased stamina/exercise tolerance, and shortness of breath. The exercise capacity of patients with MCTD has not been studied systematically in this detail before. Methods: Eleven children and adolescents diagnosed with MCTD (mean age 15.7 years, range 11.3–19.9 years) were studied. Maximal exercise testing on a cycle ergometer was used to determine the peak oxygen uptake (VO2peak) and a hand-held dynamometer was used to measure muscle strength. Cardiac and pulmonary function tests (ultrasonography, electrocardiography, spirometry) were used to measure cardiac function and obstructive or restrictive respiratory impairment. Complementary data (e.g. disease duration and concurrent symptoms) were collected from a medical chart review. Results: VO2peak was significantly lower in patients with MCTD compared to the VO2peak of healthy subjects (Z-score –1.9, p = 0.008). The strength of the proximal muscles (hip flexors, shoulder abductors, knee extensors) of the patients was significantly lower than in the controls, whereas the strength of the distal muscles (dorsal flexors of the foot and handgrip strength) showed no differences. In eight children, arthritis was observed. No clinically relevant impairment in cardiac or pulmonary function was observed. Conclusions: Aerobic capacity and also proximal muscle strength were significantly impaired in our sample of children and adolescents with MCTD. Because respiratory problems were non-dominant in our patient group, the decreased aerobic capacity and muscle strength were probably caused by musculoskeletal impairments. Further studies in larger multicentre samples are warranted to confirm our findings.

Exploring the ceiling effect of the revised Childhood Health Assessment Questionnaire in a European patient sample

Address: 1University Childrens Hospital, Utrecht, Netherlands, 2Hacattepe University, School of Physical Therapy and rehabilitation, Ankara, Turkey, 3Deptartment of Physiotherapy, Arhus University Hospital, Skejby, Arhus, Denmark, 4Institute of Child Health, Great Ormond Street Childrens Hospital, London, UK, 5Birmingham Childrens Hospital NHS foundation trust, Birmingham, UK, 6Royal Hospital for Sick Children, Glasgow, UK, 7Astrid Lindgren Childrens Hospital, Karolinska University Hospital, Stockholm, Sweden and 8Queen Silvia Childrens Hospital, Goteborg, Sweden * Corresponding author

The Dutch translation of the Childhood Health Assessment Questionnaire: an explorative study of the ceiling effect

Address: 1Department of Pediatric Physical Therapy & Paediatric Exercise Physiology, Het Wilhelmina Kinderziekenhuis, University Childrens Hospital, Utrecht, Utrecht, Netherlands, 2Department of Pediatric Physiotherapy, Sophia Childrens Hospital, Erasmus University, Rotterdam, Zuid-Holland, Netherlands, 3Department of Physiotherapy (HO-Q), Leiden University Medical Centre, Leiden, Zuid-Holland, Netherlands, 4Department Physiotherapy, University Hospital Groningen, Groningen, Groningen, Netherlands and 5Department Paediatric Physiotherapy, University Medical Center Nijmegen St. Radboud, Nijmegen, Gelderland, Netherlands * Corresponding author