Lifetime Disability-adjusted Life Year assessment of indolent systemic mastocytosis.

Background: Indolent Systemic Mastocytosis (ISM) is a rare disease associated with numerous and diverse symptoms that significantly impact patients' overall health, psychological, emotional, and professional well-being, ultimately affecting their quality of life.

Objective: We aim to estimate the Disability-adjusted Life Year (DALY) of ISM to assess the burden for patients and society.

Methods: We used prospective and retrospective data on symptoms and quality of life from an ISM population recruited at the French expert center CEREMAST, to estimate Disability Weight allowing DALY calculation. An agent-based model was developed to more accurately assess the DALY of ISM over lifetime.

Results: Prospective data were available for 168 ISM patients. A wide variety of symptoms were assessed, with 12.7 (±5.9) symptoms per patient and huge impact on the quality of life. However, the emotional dimension and the impact on social life were also affected. Finally, we estimated the DALY per patient to be between 4.56 and 8.79, representing 89 to 168 per 100,000 inhabitants. The DALY of ISM is comparable to that of lymphoma, leukemia, and psoriasis.

Conclusion: This is the first study to focus on the DALY of ISM. Despite the differences in disease characteristics (such as prevalence, mortality, and age at diagnosis), DALY allows for the ranking of conditions and provides a better understanding of the disease burden. These data may help research prioritization by offering valuable information to healthcare policymakers.