Transcultural adaptation and psychometric validation of a French-language version of the QoL-AD

Abstract

Objectives: The aim of this study was to assess the psychometric properties and the transcultural adaptation into French of the quality-of-life in Alzheimer's disease (QoL-AD).

Methods: A total of 120 patient-proxy pairs were recruited in six French hospitals and one French-speaking Swiss hospital to take part in the study. The patients presented mild to moderate AD (MMSE ≥ 10). The QoL-AD was administered by an interviewer for patients and was self-administered for caregiver proxies. Thus, the psychometric validation enabled the study of feasibility, acceptability, reliability and convergent and discriminant validity of the instrument.

Results: The French version of the QoL-AD showed good internal consistency (Cronbach's α coefficient ≥ 0.70) and good reliability (Intra-class correlation > 0.80) at a 2-week interval, for patient and caregiver questionnaires. Convergent validity, as indicated by correlation between the QoL-AD (disease-specific instrument) and the dimensions of the Duke Health Profile (generic instrument), was also good for eight dimensions in the Duke profile (p < 0.05). Discriminant validity showed a significant difference for depression (p = 0.0025) and did not show significant difference for two groups of dementia (p = 0.11).

Conclusion: There is now a validated French version of the QoL-AD available, following transcultural adaptation according to international recommendations, which possesses good psychometric qualities.

Keywords:

• quality of life
• Alzheimer's disease
• QoL-AD
• psychometric validation
• French version

Acknowledgements

We would like to thank R. Logsdon, PhD, for allowing us to make the transcultural adaptation of the QoL-AD into French and for her agreement for the final version. We also thank Angela Verdier, for her translation and for her pertinent comments. We are grateful to Dr Charbanou Jochum (University Hospital, Geneva, Switzerland), Dr Marie-Yvonne George (Saint Charles Hospital, Nancy, France), Pr Pierre Pfitzenmeyer and Dr Olivier Rouaud (University Hospital, Dijon, France), Dr Etienne Ravenel (Genibois Hospital Association, Joeuf, France), Dr Annie Parent (General Hospital, Epernay, France), Dr Michèle Collart (General Hospital, Troyes, France) and Dr Marie-Paule Poncelet Gochart (General Hospital, Sedan, France). This study was supported by grants from the Hospital Clinical Research Program of the French Ministry of Health (PHRC 2004), the Mederic Alzheimer Foundation and the National Institute of Health and Medical Research (INSERM).