Standard hemophilia tool may miss joint damage in female patients
Study: Assessment relies entirely on healthy male reference data
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- The Haemophilia Joint Health Score (HJHS) may underestimate joint damage in women with hemophilia.
- This occurs because the tool uses male-specific joint mobility reference values.
- Using female-specific values could improve diagnosis and enable earlier intervention for joint health.
The Haemophilia Joint Health Score (HJHS), a standard tool used to assess joint health in people with bleeding disorders, including hemophilia, may underestimate joint damage, or haemarthropathy, in women and girls, a study suggests.
That’s because the HJHS assesses joint mobility by comparing a person’s joint range of motion (ROM), or how far a joint can bend and straighten, with normal reference values established in healthy males. When researchers used female-specific ROM reference values to calculate the HJHS in a group of women and girls, about half received higher scores, indicating more severe joint damage than previously recognized using male-specific ROM reference values.
“Using available female ROM norms for HJHS calculations would provide a more accurate assessment of haemarthropathy, and provide the opportunity for earlier intervention for females with bleeding disorders, along with improved preservation of joint health and quality of life,” researchers wrote.
The study, “Male Range of Motion Norms in the Haemophilia Joint Health Score Underrepresent the Severity of Joint Damage in Females,” was published in Haemophilia.
Female-specific reference values not included in assessment
People with bleeding disorders, including hemophilia, can experience abnormally prolonged or spontaneous bleeding, particularly into their joints. Over time, these repeated bleeds can cause haemarthropathy, leading to pain, stiffness, reduced mobility, and a lower quality of life.
Clinicians commonly assess haemarthropathy using the HJHS, which evaluates the ankles, knees, and elbows for signs of bleeding-related joint damage. The score considers several measures, including swelling, pain, muscle loss, strength, and mobility. A higher score indicates more severe haemarthropathy.
To assess joint mobility, the HJHS compares a person’s joint ROM with standard reference values. Those reference values, however, were developed from measurements in healthy males and are currently applied to everyone, including females.
“Because healthy females have greater joint mobility (ROM) in most joints, applying male ROM norms may underestimate female joint damage,” the researchers wrote.
Although female-specific ROM reference values have been established, they are not included in the current HJHS scoring manual.
Using female reference values altered final score in 41.1% of exams
To examine how this affects joint health assessments, researchers at the University of Colorado Hemophilia and Thrombosis Center reviewed 448 HJHS examinations performed between 2012 and 2024 in 187 women (mean age of 32) with bleeding disorders enrolled in an observational study. Each HJHS examination represented one clinic visit, meaning some participants underwent more than one assessment during the study period.
The group included women with hemophilia A (24.1%) and hemophilia B (13.4%). Of the 448 HJHS examinations, 402 included complete assessments of all six index joints — both ankles, knees, and elbows — while 46 were partial examinations. Nearly all of the examinations were performed during routine clinic visits when patients were in their normal health state, although 17 (3.8%) were performed at the time of acute joint bleeding.
The researchers then recalculated the ROM subscore of the HJHS using female-specific reference values. They then determined how often those revised ROM values changed the final HJHS scores. Using female reference values altered the final score in 41.1% of HJHS examinations. These changes were most often seen in the ankles, particularly among children ages 4 to 9 years.
These data support the hypothesis that joint damage is not adequately captured in females with bleeding disorders when using male ROM norms to calculate the HJHS.
Among the 402 complete examinations, 33.8% yielded higher overall HJHS scores after applying the female ROM reference values. In other words, using the current male reference values had underestimated the overall severity of joint damage in about one-third of complete joint assessments.
Looking at participants rather than individual clinic visits, about half (49.2%) received a higher HJHS score for at least one joint when female-specific ROM reference values were used.
“This means that for around half of females, haemarthropathy was underestimated when male ROM norms were used,” the researchers wrote.
Overall, using female instead of male ROM reference values increased total HJHS scores by an average of 0.67 points, a statistically significant difference.
To illustrate the impact, the researchers noted that an 8-year-old girl who could point her foot downward by 51 degrees could receive a normal score using the current male ROM reference values, but would instead receive a score indicating mild loss of joint movement if female ROM reference values were used.
“These data support the hypothesis that joint damage is not adequately captured in females with bleeding disorders when using male ROM norms to calculate the HJHS,” the researchers wrote, adding that using female-specific ROM reference values in HJHS calculations could provide a more accurate assessment of joint damage.
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