Bleeding-related hospitalization in patients with von Willebrand disease and the impact of prophylaxis: Results from national registers in Sweden compared with normal controls and participants in the von Willebrand Disease Prophylaxis Network.

INTRODUCTION: Patients suffering from von Willebrand disease (VWD) have a variety of bleeding symptoms and require both outpatient care for treatment and, in more severe cases, hospitalization. AIM: To investigate the impact of having VWD on frequency of hospitalization compared to a control group and to evaluate whether regular replacement therapy (prophylaxis) is associated with reduction in the number of hospitalizations. METHODS: Linkage of national population-based registries was used in the Congenital Bleeding Disorders study in Sweden (CBDS). Data were from the von Willebrand Disease Prophylaxis Network (VWD PN). RESULTS: The national registries contained 2790 subjects with a diagnosis of VWD between 1987 and 2009. A total of 13 920 age- and gender-matched controls were identified. There were 2.0 times (range 1.5-2.5) as many inpatient hospitalizations among subjects with VWD compared to controls. The most common causes of hospitalization were gastrointestinal (GI) bleeding (n = 232 as primary diagnosis), menorrhagia (n = 198) and epistaxis (n = 192). Outpatient visits per year were also twice as common among those with VWD. From the VWD PN, 105 subjects were included (VWD type 3, 52.4%; type2A, 22.9%; type 1, 12.4% and other types, 3.9%). A total of 122 hospitalizations due to bleeding episodes, dominated by GI bleeds, were analysed. Significantly fewer hospitalizations occurred after initiation of prophylaxis (75 prior to and 45 after, P = .006). CONCLUSION: Our study indicates that subjects with VWD have a considerably higher consumption of healthcare resources compared to controls and that initiation of prophylaxis may reduce the number of hospitalizations due to bleeding.

Prophylaxis in severe forms of von Willebrand's disease: results from the von Willebrand Disease Prophylaxis Network (VWD PN).

The bleeding patterns of severe von Willebrand's disease (VWD) adversely affect quality of life, and may be life threatening. There is a presumed role for prophylaxis with VWF-containing concentrates, but data are scarce. The von Willebrand Disease Prophylaxis Network (VWD PN) was formed to investigate the role of prophylaxis in clinically severe VWD that is not responsive to other treatment(s).Using a retrospective design, the effect of prophylaxis was studied. Availability of records to document, or reliably assess, the type and frequency of bleeding episodes prior to, and after, the initiation of prophylaxis was required. Annualized bleeding rates were calculated for the period prior to prophylaxis, during prophylaxis and by primary bleeding indication defined as the site accounting for more than half of all bleeding symptoms. The Wilcoxon signed-rank test of differences in the medians was used. Sixty-one subjects from 20 centres in 10 countries were enrolled. Data for 59 were used in the analysis. The median age at onset of prophylaxis was 22.4 years. Type 3 VWD accounted for the largest number (N = 34, 57.6%). Differences in bleeding rates within individuals during compared with before prophylaxis were significant for the total group (P < 0.0001), and for those with primary bleeding indications of epistaxis (P = 0.0005), joint bleeding (P = 0.002) and GI bleeding (P = 0.001). The effect of prophylaxis was similar among those age < 18 years and those ≥ 18. One person developed an inhibitor during treatment. We conclude that prophylactic treatment of VWD is efficacious.

Value added: increasing the power to assess treatment outcome in joint haemorrhages.

Subject reports of efficacy of treatment of haemophilia-related joint bleeding are by definition subjective, yet are often the primary outcome in studies comparing therapies. Verbal descriptors such as effective, partially effective, poorly effective, not effective are treated as dichotomous or categorical variables in analyses, lowering the statistical power relative to that which might be achieved with a continuous variable. The aims of this study were to examine reports of pain recorded on a 100-mm visual analogue scale (VAS) during the course of joint bleeding; determine whether pain varied by treatment period among pairs reporting discordant outcomes on a verbal scale (one product effective, the other not effective); test whether the two products under study were equivalent with respect to VAS scores; and evaluate their relationship to verbal reports of efficacy. Data from the international, prospective, randomized, crossover FEIBA NovoSeven Comparative study of two bypassing agents used for treatment of 96 bleeding episodes in 48 participants were examined. VAS scores were associated with verbal descriptors of efficacy at every time point, and were equivalent between treatment periods. There were differences in mean scores at time points at which participants rated one treatment effective, the other not effective. As a continuous variable, the VAS score may have more power than a dichotomous variable and when used with verbal descriptions of efficacy can improve the overall accuracy of assessment. This report highlights an important consideration in the selection of outcome measurement that can be generalized to other haemophilia treatment research.