The Patient-Specific Functional Scale (PSFS) appears to be a reliable tool to measure functional musculoskeletal changes in patients with hemophilia, according to a prospective observational study recently published in Haemophilia.

Musculoskeletal damage due to recurrent bleeding is the most common cause of morbidity in patients with hemophilia. Preventing complications such as hemophilic arthropathy is one of the main objectives of therapy. Therefore, there is a need for objective and easy-to-use tools to aid in the assessment of functional musculoskeletal changes. 

The PSFS is a clinical questionnaire that has already been validated for functional assessment in pathologies such as chronic neck pain and total knee arthroplasty. It offers advantages like easy applicability and pre- and post-treatment scores that allow clinicians to evaluate treatment effectiveness.

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The test involves listing 5 activities that a patient considers difficult due to their condition and rating the difficulty of each task on a scale from 1 to 11, with lower values being associated with more difficulty. 

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The authors aimed to assess the validity of the PSFS by comparing it to the Hemophilia Activity List, a validated tool for functionality assessment in patients with hemophilia. The study included 28 participants diagnosed with hemophilia A or B. Exclusion criteria included a history of joint bleeding in the last 30 days, cognitive impairments, and surgery in the previous 3 months. 

All patients included in the study completed both scales over the telephone, repeating the process 1 week later. The researchers measured reliability through the standard error of measurement (SEM), smallest detectable change, and internal correlation coefficient (ICC). Both scales were correlated through scatter plots and the Pearson product-moment r correlation coefficient.

An important degree of correlation was found between the results obtained by both assessment tools according to the scatter plot regression line, while the Pearson product-moment correlation coefficient revealed a moderate correlation. Both the SEM and ICC values demonstrated the reliability of the PSFS.

“PSFS could become a new tool for clinicians to assess functional musculoskeletal changes in this group of patients, in a simple and fast way,” the authors concluded.


Chimeno‐Hernández A, Alberola‐Zorrilla P, Sánchez‐Zuriaga D. Validation of the patients‐specific functional scale in patients with haemophilia. Haemophilia. Published online August 3, 2022. doi:10.1111/hae.14640