Including carer health-related quality of life in NICE health technology assessments in the United Kingdom

The impact of health technologies may extend beyond the patient and affect the health of people in their network, like their informal carers. The National Institute for Health and Care Excellence (NICE) methods guide explicitly allows the inclusion of health-related quality of life (HRQoL) effects on carers in economic evaluations when these effects are substantial, but the proportion of NICE appraisals that includes carer HRQoL remains small. This paper discusses when inclusion of carer HRQoL is justified, how inclusion can be substantiated, and how carer HRQoL can be measured and included in health economic models. Inclusion of HRQoL in economic evaluations can best be substantiated by data collected in (carers for) patients eligible for receiving the intervention. To facilitate combining patient and carer utilities on the benefit side of economic evaluations, using EQ-5D to measure impacts on carers seems the most successful strategy in the UK context. Alternatives to primary data collection of EQ-5D include vignette studies, using existing values, and mapping algorithms. Carer HRQoL was most often incorporated in economic models in NICE appraisals by employing (dis)utilities as a function of the patient's health state or disease severity. For consistency and comparability, economic evaluations including carer HRQoL should present analyses with and without carer HRQoL.