Lifetime Disability-Adjusted Life-Year Assessment of Indolent Systemic Mastocytosis

Indolent systemic mastocytosis (ISM) is a rare disease associated with numerous and diverse symptoms that significantly affect patients' overall health and psychological, emotional, and professional well-being, ultimately affecting the quality of life.

To estimate the disability-adjusted life-years (DALY) of ISM to assess the burden for patients and society.

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

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

To our knowledge, this is the first study to focus on the DALY of ISM. Despite 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 health care policymakers.