Burden of illness in hereditary periodic fevers: a multinational observational patient diary study.

This study aimed to characterise the burden of illness of patients with inadequately controlled hereditary periodic fevers (HPFs), during and outside of flares. It was focused on the burden to the patients and also considered the wider impact on their caregivers and families. The target population was patients or caregivers of patients with clinically/genetically confirmed colchicine resistant FMF (crFMF), mevalonate kinase deficiency/hyperimmunoglobinaemia D with periodic fever syndrome (MKD/HIDS) or TRAPS, who were expected to flare at least once in a 6-month period based on patient history. Disease burden was captured during and between flares using an electronic diary (e-diary) with questions on patient functioning, emotional/social well-being and pain, using validated instruments. HPF-related symptoms such as fever, joint, muscle or bone pain and tiredness and fatigue were reported by patients both during and outside of a flare. The SF-10 Health Survey (SF-10v2) (paediatric patients) and SF-12 Health Survey (SF-12v2) (adult patients) showed that flares negatively impacted patients' psychosocial and physical health. Negative effect of on-flare status on health utility index score assessed by the Short-Form Six-Dimension (SF-6D) was significant only for crFMF patients. Furthermore, the Sheehan Disability Score (SDSv3) showing the on-flare status resulted in significant functional impairment in all 3 disease cohorts through assessment of impact on work/school, social and family life. crFMF, MKD/HIDS and TRAPS negatively affected the quality of life (QoL) of adult and paediatric patients, including their physical, mental, psychosocial health, and social functioning. There remains, however, a high number of unmet needs for these patients to reduce their disease burden.