OBJECTIVES:

Measuring quality of life (QoL) in rare diseases could be challenging: small samples, pediatric populations and/or without cognitive ability to answer QoL questionnaires requiring a proxy (third person) to respond. These challenges are identified in the French HTA body guidelines for health economics, but no standard is proposed to tackle them. This study aims to assess the impact of methodology used to estimate utility values on the conclusions of the French health-economic committee (CEESP).

METHODS:

A descriptive review of QoL measures used by manufacturers and their assessments in CEESP opinions published since 2014 in rare diseases.

RESULTS:

26 opinions on rare diseases (target populations varied from 75 to 8830 patients) were analyzed: 14 opinions included both pediatric and adult populations, one pediatric population only.

Among the rejected opinions, 54.5% (n=6) were due to inappropriate method used to measure utilities, noting the importance of adequate QoL assessment. For 5 opinions, CEESP rejected the methodology due to data source: vignette study (n=2), expert opinion (n=1), disease-specific questionnaires (n=2). Vignette studies were rejected because they were not completed by patients themselves.

When the method was considered appropriate by CEESP, it was supported by strong data sources: literature (n=10), clinical trials (n=7) or both (n=3). No differences were noted between adult and pediatric populations and no proxy respondent had to be asked when the data came from clinical trial.

When accepted by CEESP (77%), the average ICER was €824,000/QALY.

CONCLUSIONS:

Despite methodological difficulties for assessing utilities in rare diseases, CEESP guidelines could be implemented in most of the opinions without specific problematics related to QoL measure identified. Thus, anticipating relevant data collection in clinical development plan definitively limits risk of negative opinion.