| 1. |
- Donfield, S. M., et al.
(författare)
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Value added: increasing the power to assess treatment outcome in joint haemorrhages
- 2008
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Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 14:2, s. 276-280
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Steen Carlsson, Katarina, et al.
(författare)
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Cost and outcome: comparisons of two alternative bypassing agents for persons with haemophilia A complicated by an inhibitor.
- 2008
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Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 99:6, s. 1060-1067
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Tidskriftsartikel (refereegranskat)abstract
- The development of inhibitory antibodies to factor VIII is a serious complication of haemophilia. Two haemostatic agents with different bypassing mechanisms have been used in the treatment of patients with inhibitors: activated prothrombin complex concentrate (aPCC) and recombinant factor VIIa (rFVIIa). The objective was to compare cost and outcome of aPCC and rFVIIa in the treatment of joint bleeds. The analyses were based on the FENOC (FEIBA NovoSeven Comparative Study) crossover study where 48 patients used aPCC and rFVIIa to treat two joint bleeds. Incremental cost-effectiveness ratios were calculated for three outcome measures and the variation in cost was analyzed using two alternative regression methods. Results were subjected to sensitivity analyses. Key determinants of cost were prescribed dose, bodyweight and treatment in addition to protocol. The cost of aPCC was on average lower than rFVIIa. At all but one time point, patients rated slightly higher (but not statistically significantly) percentages of treatment efficacy and stopping of the bleed by aPCC. The reported reduction in pain from start of treatment up to 48 hours varied considerably among individuals. The different relative prices in the US, Turkey and Sweden mattered, but did not reverse the main results. In conclusion, the cost per episode was significantly lower for aPCC. The large individual-level variation in reduction of pain supports decisions that consider the individual patient's experience and that accept trade-offs between cost and reduction in pain rather than focusing on cost only.
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