Evaluation of the Quality of Life in the Elderly With Dementia : Validation of a Specific Instrument

With nearly one million cases of dementia in France in 2010, Alzheimer's disease (AD) and related syndromes are a major public health issue. The lake of drug for treatment or preventing AD, health related quality of life (HRQoL) became an essential criterion of evaluation to assess the treatment strategies of patients. Generic HRQoL tools are generally less sensitive for a given disease. That is why other specific tools for AD have been developed. None of them was validated in French. The aim of this study was therefore, after a review of the literature, to achieve a cross-cultural adaptation and psychometric validation of the "Quality of Life in Alzheimer's Disease" (QoL-AD) and "Dementia Quality of Life" (DQoL). These two questionnaires were selected because they were the most popular in English- language literature for this disease.This study concerned a total of 155 patient-caregiver pairs recruited from six French hospitals and a Francophone Swiss center.

Patients had a confirmed diagnosis of AD (mild stage to moderate: Mini Mental State Examination ≥ 10). QoL-AD and DQoL were administered by an interviewer. The caregiver sheet of QoL-AD was self-administered. Cross-cultural adaptation and psychometric validation have been carried out for these two questionnaires. First step: the linguistic adaptation will be performed according to the latest available methodology: that of the " Institute for Work and Health ", as recommended 6 phases. Second step: the psychometric validation will be done after a multicentric study, cross repeated at weekly intervals for the validation phase , with two longitudinal points for the assessment phase of sensitivity to change. Analysis of the results will help define the applicability criteria and psychometric acceptability to know the validity of the adapted instrument that is to say, its content validity , validity of perceived, validity of structure, validity of agreement , its discriminative ability , reliability explored by internal consistency and stability over time. Longitudinal follow-up of patients is expected to also assess the sensitivity to change .