Outcome Assessment in Hemophilia: A Pilot Study on Correlation of Different Instruments.

Abstract

Hemophilia is a rare disease, requiring life-long treatment with expensive clotting factor concentrates. Outcome assessment in hemophilia is important to establish both results of treatment, and compare between strategies. Since the 1980s, hemophilia specific assessment tools were available only for radiological (Pettersson score) and clinical (orthopedic joint score) joint damage. Recently, the HAL (Hemophilia Activities List) was developed to assess functional limitations, and the orthopedic joint score was adapted into the HJHS (hemophilia joint health score) to assess more subtle joint damage.To assess correlation of instruments for outcome assessment, a pilot study was conducted in 22 young adults with hemophilia (15 severe, 5 moderate, 2 mild). Joint damage (Pettersson score, HJHS), physical function (self-reported: HAL, performance-based: Figure 8 test; time taken to walk around two pilons at a distance of 5 meter at maximum speed in a pattern of figure 8), Health Related Quality of Life (SF36), and utility (EQ5D) were measured.Median age was 17.8 years (range 14–30), 15 (68%) patients were treated with early prophylaxis, including all but one patient with severe hemophilia who had recently stopped taking prophylaxis. Overall outcome was good, with median HJHS score of 3.5 (range 0–30; max 140, optimum 0), median HAL score of 100 (range 62–100; max 100= optimum), and median figure 8 test 4.9 sec (range 4.2–7.4). Recent (< 2 years of testing) Pettersson scores were available in only 11 patients (9 with severe, 2 with moderate hemophilia); the median score was 3 (range 0–28, max 78, optimum=0), the median physical component score of the SF36 was 53 (range 24–62), median utility (EQ5D) was 1.0 (range 0.7–1.0, optimum=1.0).Spearman's correlations for EQ5D, and Pearson's correlations for other instruments are shown in the table.StructuralFunctionalQuality of LifeHJHSPetterssonHALFig 8SF 36EQ5DHJHS1Pettersson0.861HAL−0.61−0.261Fig 80.510.51−0.561SF 36−0.73−0.410.81−0.541EQ5D−0.37−0.040.76−0.290.681The HJHS scores showed good correlation with the Pettersson score and the physical component score of the SF36. Correlation with functional outcome assessment was only moderate, while the HAL showed a high correlation with both SF36 and EQ5D. In conclusion, the HJHS is a promising instrument for structural assessment, but functional assessment using the HAL showes higher correlation with Quality of Life and utility. For full assessment of results of treatment and to compare different treatment strategies, functional assessment, in addition to structural assessment, is warranted.