Table 2 Appraisal of the internal validity of the QALY-endpoint in six cost-utility studies in the HTA on dementia drugs [56]
From: Quality of Life as an outcome in Alzheimer's disease and other dementias- obstacles and goals
Product assessed (study) | Internal validity | Comment on generation of QALYs |
|---|---|---|
Donepezil [58] | Unacceptable | Based on the Index of Health Related Quality of Life (IHQL) which was not validated for valuing cognitive impairment, and no rationale was given for the IHQL values used |
Donepezil [59] | Unclear or unknown | Not stated |
Rivastigmine [60] | Unacceptable | Based on the IHQL (see above) |
Unclear or unknown | Derived from [63] (pre – full time care at 0.60, full time care at 0.34) | |
Memantine [64] | Unclear or unknown/unacceptable | Insufficient detail found in the study |