Experience with central venous access devices (CVADs) in the Canadian hemophilia primary prophylaxis study (CHPS).

INTRODUCTION: Haemophilia A treatment with factor VIII concentrates requires frequent venipunctures; a central venous access device (CVAD) may be required to facilitate reliable venous access, especially in young children. While CVADs provide reliable venous access, complications such as infection and thrombosis may occur. AIM: The aim of this study was to assess CVAD use in the Canadian Hemophilia Primary Prophylaxis Study (CHPS), a single-arm, multi-centre prospective study whereby factor use is tailored to individual prophylactic need. METHODS: Participants received a tailored, escalating dose, prophylaxis regimen of increasing frequency of FVIII infusions: step-1: 50 IU kg(-1) once weekly; step-2: 30 IU kg(-1) twice weekly; and step-3: 25 IU kg(-1) on alternate days, according to their level of bleeding. CVAD insertion was at the discretion of the local health care team. Details regarding CVAD use during this protocol were analysed. RESULTS: Fifty six boys were enrolled, 21 required 25 CVADs due to difficult venous access. CVADs were inserted at a median age of 1.3 years (range: 0.6-2.1) and were removed at a median age of 8.7 years (range 6.3-11.8). Six participants experienced non-life threatening CVAD-complications, the most frequent being device malfunction requiring CVAD replacement (n = 4). Two boys were shown to have CVAD-associated thrombosis detected on routine imaging; one required removal due to infusion difficulties and the other was asymptomatic and did not require device removal. No CVAD-related infections were documented. CONCLUSION: Our study shows that the CHPS tailored prophylaxis regimen is associated with a decreased requirement for CVADs and with few device-related complications.

Musculoskeletal health of subjects with hemophilia A treated with tailored prophylaxis: Canadian Hemophilia Primary Prophylaxis (CHPS) Study.

BACKGROUND: Full-dose prophylaxis is very effective at minimizing joint damage but is costly. Tailored prophylaxis has been proposed as a way of reducing costs while still protecting joints. OBJECTIVE: To report detailed findings in index joints of 56 subjects with severe hemophilia A entered into the Canadian Hemophilia Prophylaxis Study, and treated with tailored prophylaxis, after 13 years. METHODS: Boys with severe hemophilia A (< 2% factor) and normal joints were enrolled between the ages of 1 and 2.5 years. Initial treatment consisted of once-weekly factor infusions, with the frequency escalating in a stepwise fashion when breakthrough bleeding occurred. During the first 5 years, subjects were examined every 3 months using the modified Colorado Physical Evaluation (PE) scale; subsequently, every 6 months. The Childhood Health Assessment Questionnaire (CHAQ) was administered at each visit. RESULTS: Median age at study entry was 19 months (range 12-30 months); median follow-up was 92 months (range 2-156). The median PE score was 2, 3 and 3 at ages 3, 6 and 10 years. Persistent findings were related to swelling, muscle atrophy and loss of range of motion. The median score for each of these items (for the six index joints) was 0 at ages 3, 6 and 10 years. The median overall CHAQ score was 0 at ages 3, 6 and 10 years, indicating excellent function. CONCLUSIONS: Canadian boys treated with tailored primary prophylaxis exhibit minimal joint change on physical examination and minimal functional disability.

Magnetic resonance imaging and joint outcomes in boys with severe hemophilia A treated with tailored primary prophylaxis in Canada.

BACKGROUND/OBJECTIVES: Tailored primary prophylaxis (TPP) is a reduced-intensity treatment program for hemophiliacs with the goal of preventing arthropathy. Our primary aim was to evaluate the joint outcomes of treated subjects using magnetic resonance imaging (MRI) and physical examination as outcome measures. METHODS: Ankles, elbows and knees (index joints) of 24 subjects (median [range] age at start of therapy, 1.6 [1-2.5] years) with severe hemophilia A enrolled in the Canadian Hemophilia Primary Prophylaxis Study (CHPS) were examined by MRI at a median age of 8.8 years (range 6.2-11.5 years). Subjects were treated with TPP using a recombinant factor VIII concentrate, starting once weekly and escalating in frequency and dose according to frequency of bleeding. RESULTS: Osteochondral changes (cartilage loss/subchondral bone damage) were detected in 9% (13/140) of the index joints and 50% (12/24) of study subjects. Osteochondral changes were restricted to joints with a history of clinically reported joint bleeding. Soft tissue changes were detected in 31% (20/65) of index joints with no history of clinically reported bleeding (ankles 75% (12/16); elbows 19% (6/32); and knees 12% (2/17)). In these apparently 'bleed free' index joints hemosiderin deposition was detected by MRI in 26% (17/65) of joints (ankles 63% (10/16); elbows 16% (5/32), and knees 12% (2/17)). CONCLUSION: TPP did not completely avoid the development of MRI-detected structural joint changes in hemophilic boys in this prospective study. A longer period of follow-up is required for assessment of the longitudinal course of these early changes in hemophilic arthropathy, detected using a sensitive imaging technique (MRI).

Effect of intracranial bleeds on the neurocognitive, academic, behavioural and adaptive functioning of boys with haemophilia.

Brain insults are a risk factor for neuropsychological and academic deficits across several paediatric conditions. However, little is known about the specific effects of intracranial haemorrhage (ICH) in boys with haemophilia. The study compared neurocognitive, academic and socio-emotional/behavioural outcomes of boys with haemophilia with and without a history of ICH. Of 172 consecutive patients seen at a Pediatric Comprehensive Care Hemophila Centre, 18 had a history of ICH. Sixteen boys between the ages of 3 and 17 years were available for study and were matched to controls with haemophilia of the same age and disease severity and on the basis of maternal education. Groups were compared on neuropsychological and academic outcomes. Attention, socio-emotional function and executive skills were compared using data from parent questionnaires. Differences were found in intellectual function, visual-spatial skill, fine motor dexterity and particularly language-related skills, including vocabulary, word reading and applied math problem solving. Despite these group differences, outcomes were within the average range for most boys with ICH. No group differences were found in behavioural and socio-emotional functioning. Although ICH in haemophilia is not benign, it was not associated with significant cognitive and academic consequences for most boys. Early neuropsychological assessment may be indicated when there is a history of ICH. Investigation of age at ICH and quantitative measures of brain in relation to neurocognitive outcomes in larger groups of boys with ICH would be useful.

The use of prophylaxis in 2663 children and adults with haemophilia: results of the 2006 Canadian national haemophilia prophylaxis survey.

Prophylaxis is standard of care for boys with severe haemophilia A. Indications for prophylaxis in adulthood, non-severe haemophilia A, haemophilia B and haemophilia with inhibitors are less well defined. This survey, conducted in 2006, aimed to describe prophylaxis use in patients of all ages and severities with haemophilia A or haemophilia B in Canada. Data on 2663 individuals (2161 haemophilia A; 502 haemophilia B), including 78 inhibitor-positive patients, were returned by 22/25 Canadian haemophilia treatment centres. This represented 98% of the Canadian haemophilia population. Frequency of prophylaxis use, defined as infusion of factor VIII/IX concentrate at least once weekly for >/=45 weeks of the year, was highest in individuals with severe haemophilia A (69%). It was lower in individuals with severe haemophilia B (32%), moderate haemophilia A (18%) or B (5%) and mild haemophilia A (1%) or B (1%). Among individuals with severe haemophilia A, the frequency of prophylaxis use was 84% in children (18 years). Thirteen per cent of inhibitor-positive individuals were receiving prophylaxis with bypassing agents. Comparison with data obtained from a 2002 Canadian survey showed a greater use of prophylaxis in children

Definitions for haemophilia prophylaxis and its outcomes: the Canadian consensus study.

The creation of acceptable standard definitions for terms used in the care and assessment of haemophilia patients has become increasingly important, as a growing number of international clinical studies have been initiated. The Delphi approach has been used in health research to reach consensus in large groups and can be used to develop definitions by using several iterations of surveys eliciting opinions from specialists in the field. Three consecutive surveys were designed based on the Delphi approach and distributed to specialist physicians, nurses and physiotherapists in order to develop definitions for seven haemophilia terms: 'primary prophylaxis', 'secondary prophylaxis', 'target joint', 'joint bleed', 'significant soft-tissue bleed', 'superficial soft-tissue bleed' and 'mucosal bleed'. Suggestions were solicited, compiled into a subsequent survey and fed back to the group to rank-order the importance of each suggested component of the definition. Final definitions were created using the top-ranked suggestions and sent back to the experts for approval. Five of the seven terms were highly endorsed with greater than 90% agreement. Some differences in agreement were found when analysed by profession. Haemophilia terms were successfully defined using the Delphi approach. Further refinement from members of the international haemophilia community will ensure that comprehensive standard definitions can be used in multicentre studies in the future.

Hemophilia joint health score reliability study.

UNLABELLED: Measurement of joint health is critically important when assessing children with haemophilia. Few measures exist; they lack sensitivity to small changes, don't account for normal development and were never formally validated. To address these concerns, the Hemophilia Joint Health Score (HJHS) was developed by modifying existing scores. OBJECTIVE: To test the inter-observer and test-retest reliability of the HJHS. METHODS: Using a fully factorial design, four physiotherapists (from Canada, the United States and Sweden) examined eight boys with severe haemophilia A on two consecutive days using the HJHS. The boys ranged in age from 4-12 years and presented with variable joint damage. Six index joints (elbows, knees and ankles) were assessed on 11 impairment items including swelling, flexion and extension loss and gait. Concordance was measured by the intra-class correlation co-efficient. RESULTS: Reliability of the HJHS was excellent with an inter-observer co-efficient of 0.83 and a test-retest of 0.89. CONCLUSION: This study is the first in a series to assess the psychometric properties of the HJHS, a promising new measure of joint health in boys with haemophilia.

Tailored prophylaxis in severe hemophilia A: interim results from the first 5 years of the Canadian Hemophilia Primary Prophylaxis Study.

BACKGROUND: Prophylactic treatment for severe hemophilia A is likely to be more effective than treatment when bleeding occurs, however, prophylaxis is costly. We studied an inception cohort of 25 boys using a tailored prophylaxis approach to see if clotting factor use could be reduced with acceptable outcomes. METHODS: Ten Canadian centers enrolled subjects in this 5-year study. Children were followed every 3 months at a comprehensive care hemophilia clinic. They were initially treated with once-weekly clotting factor; the frequency was escalated in a stepwise fashion if unacceptable bleeding occurred. Bleeding frequency, target joint development, physiotherapy and radiographic outcomes, as well as resource utilization, were determined prospectively. RESULTS: The median follow-up time was 4.1 years (total 96.9 person-years). The median time to escalate to twice-weekly therapy was 3.42 years (lower 95% confidence limit 2.05 years). Nine subjects developed target joints at a rate of 0.09 per person-year. There was an average of 1.2 joint bleeds per person-year. The cohort consumed on average 3656 IU kg(-1)year(-1) of factor (F) VIII. Ten subjects required central venous catheters (three while on study); no complications of these devices were seen. One subject developed a transient FVIII inhibitor. End-of-study joint examination scores--both clinically and radiographically--were normal or near-normal. CONCLUSIONS: Most boys with severe hemophilia A will probably have little bleeding and good joint function with tailored prophylaxis, while infusing less FVIII than usually required for traditional prophylaxis.

Developing a disease activity tool for systemic-onset juvenile idiopathic arthritis by international consensus using the Delphi approach.

OBJECTIVES: The systemic form of juvenile idiopathic arthritis may present with many diverse symptoms, signs and laboratory abnormalities. Our aim was to elicit and pool items useful for developing a consensus disease activity measure for systemic arthritis in children, using an international pool of respondents. METHODS: We used a Delphi survey process in two steps. First we surveyed 187 paediatric rheumatologists and allied health professionals. We elicited 2607 items that, when combined with previously elicited items from parents/patients, could be pooled into 107 independent items. We then surveyed the paediatric rheumatologists to determine the frequency and importance of the 107 items. RESULTS: Our response rate was 83% to both surveys. We identified 29 items as being the most important and most frequently seen indicators of active disease. The most highly rated of these items were: presence of fever, presence of rash, elevated ESR, elevated CRP, requirement for increasing medications, abnormal physician global evaluation and presence of joints with active arthritis. CONCLUSIONS: Twenty-nine items are thought by medical practitioners to be most relevant in determining disease activity in systemic arthritis. As a next step, the measurement properties of these items will be tested to help develop a disease activity tool.

Health-related quality of life (HRQL) scores reported from parents and their children with chronic illness differed depending on utility elicitation method.

OBJECTIVE: To describe the relationship between health-related quality of life (HRQL) as measured by utility when elicited from parents and their children with chronic illness. STUDY DESIGN AND SETTING: We enrolled families of children admitted for cancer chemotherapy and those attending outpatient rheumatology, hemophilia and bone marrow transplantation clinics. Children in grade 6 or higher were included. The child's HRQL was rated by parent and child using the Standard Gamble (SG), Visual Analogue Scale (VAS), Time Trade-Off (TTO), and Health Utilities Index Mark 2/3 (HUI2 and HUI3). RESULTS: 22 families were included. The mean parent SG was 0.92 +/- 0.09, which was similar to the mean SG elicited from their children of 0.92 +/- 0.10. The parent and child SG were moderately concordant (ICC=0.64, 95% CI=0.30, 0.83; P=.0005). In contrast, TTO scores were not concordant (ICC=0.14, 95% CI=-0.29, 0.53; P=.3), with parents (mean TTO=0.77 +/- 0.31) rating HRQL worse than children (mean TTO=0.92 +/- 0.11; P=.04). Similarly, the mean parent HUI2 of 0.82 +/- 0.22 was lower than the child HUI2 of 0.95 +/- 0.07; P=.02 and HUI2 were not concordant (ICC=0.11, 95% CI=-0.35, 0.53; P=.3) between parents and children. CONCLUSION: Parents and children rate HRQL similarly according to SG, but parents rate HRQL significantly worse using TTO and HUI2.

Validity of a modified standard gamble elicited from parents of a hospital-based cohort of children.

OBJECTIVES: To examine the validity of a modified standard gamble (Mod SG) (nondeath baseline) by comparing these scores to SG (death baseline), time trade off (TTO), visual analog scale (VAS), Health Utilities Index (HUI), and Child Health Questionnaire (CHQ). METHODS: Respondents were parents of in-patients with cancer receiving chemotherapy and parents of children without cancer attending outpatient clinics. Construct validity was determined by comparing a priori hypotheses to actual correlations between measures. Discriminant validity was examined by anticipating that in-patients with cancer would have lower HRQL than outpatients. RESULTS: 85 families were included. Both Mod SG and SG were moderately correlated with TTO (r=0.50 and r=0.49; P<.01 for both). Both Mod SG and SG were moderately correlated with TTO (r=0.47 and r=0.05, P<0.002 for both). CONCLUSION: The Mod SG did not perform better than SG. Two nonoverlapping groups of HRQL measures were demonstrated.

Construct validation of the Health Utilities Index and the Child Health Questionnaire in children undergoing cancer chemotherapy.

The objective of this study was to evaluate the construct validity of two questionnaire-based measures of health-related quality of life (HRQL) in children undergoing cancer chemotherapy: the Health Utilities Index (HUI) and the Child Health Questionnaire (CHQ). Subjects were children hospitalised for chemotherapy. To examine construct validity: (1). a priori expected relations between CHQ concepts and HUI attributes were examined; (2). HUI and CHQ summary scores were compared to visual analogue scale (VAS) scores. Ease of completion was rated using a 5-point categorical scale and completion time was recorded. A total of 36 subjects were included. The maximum score was seen in 15 (47%) of HUI3 assessments. As predicted, CHQ body pain was moderately correlated with HUI3 pain (r=0.51), CHQ physical functioning was moderately correlated with HUI2 mobility (r=0.58) and CHQ mental health was moderately correlated with HUI2 emotion (r=0.53). Only the CHQ psychosocial subscale (and not HUI) was correlated with VAS (r=0.44). The CHQ and the HUI were both easy to use. The HUI questionnaires required less time to complete (mean=3.1, s.d.=1 min) compared with CHQ (mean=13.1, s.d.=3.4 min, P<0.0001). In conclusion, HUI and CHQ demonstrated construct validity in children undergoing cancer chemotherapy. The Health Utilities Index is subject to a ceiling effect whereas CHQ requires more time to complete.

Termination of transcription by nusA gene protein of Escherichia coli.

The nusA gene protein of Escherichia coli and N gene protein of bacteriophage lambda interact in vitro and cooperate in vivo to prevent transcription termination. In vitro the nusA gene protein causes RNA polymerase to pause in the tR2 terminator region of lambda DNA. A completed termination event at tR2 requires both the nusA gene protein and the previously described E. coli termination factor rho. The nusA gene protein is therefore both a transcription termination factor and a protein which couples antitermination factors to the elongating transcription complex.