Introduction

Aromatic l-amino acid decarboxylase deficiency (AADCd) is an rare neurological condition, requiring 24-hour care. The EQ-5D is increasingly being used to evaluate caregiver health-related quality of life (HRQoL), but it is unclear whether it adequately captures the full impact of caring for an individual with AADCd. This study compared caregiver HRQoL as evaluated by the EQ-5D and qualitative interviews.

Methods

Qualitative interviews were conducted with caregivers of individuals with AADCd in Europe and the US. An interview guide with open-ended questions was used to elicit information on the impact of caring for an individual with AADCd. Interviews were conducted by telephone, were recorded and transcribed. Participants completed the EQ-5D prior to their interview, rating their mobility, self-care, usual activities, pain/discomfort and anxiety/depression from 1=no problems to 5=unable. Mixed methods analyses were used to compare the EQ-5D scores with the interview data.

Results

Twelve caregivers completed an interview and the EQ-5D. There was concordance for the mobility and self-care dimensions, with 100% reporting no problems on the EQ-5D and no participants reporting difficulties with these in the interviews. There was general concordance for pain/discomfort and anxiety/depression, but two participants who reported no pain/discomfort on the EQ-5D described some physical pain in the interview, and two who reported no anxiety/depression on the EQ-5D described anxiety or poor mental wellbeing in the interview. For usual activities, 75% reported no problems on the EQ-5D, but all described substantial limitations during the interviews (e.g. difficulties with household tasks, socialising and travel).

Conclusions

The EQ-5D may not adequately capture the HRQoL of caregivers of individuals with AADCd, particularly with regard to usual activities. This highlights a potential problem of using the EQ-5D to evaluate caregiver burden in rare paediatric diseases, where caregivers’ perceptions of ‘usual activities’ are far removed from that of the general population.