Comparison of QoL-AD and DQoL in elderly with Alzheimer's disease

Abstract

Objective: The Dementia Quality of Life (DQoL) and the Quality of Life in Alzheimer's Disease (QoL-AD) are the two most widely used dementia-specific QoL instruments in the world. We aimed to compare the psychometric properties of these two instruments and identify which is most adapted to use in geriatric consultations.

Methods: To evaluate the psychometric properties of the French language validation of DQoL and QoL-AD, 123 patients aged 65 years and over suffering from AD (Mini Mental State Examination score ≥10) were recruited in seven French hospitals and one Switzerland hospital. The DQoL comprises 29 items, ranked on a five-point Likert scale and measuring five QoL domains: self-esteem, positive affect, negative affect, feeling of belonging and sense of aesthetics. The QoL-AD contains 13 items giving an overall score ranging from 13 to 52 and evaluating the domains of interpersonal relationships, financial difficulties, physical condition, memory, mood and overall health.

Results: Both questionnaires showed adequate reproducibility at 2 weeks interval (intra-class correlation coefficient >0.80), good internal consistency (Cronbach's alpha coefficient >0.70) and good convergent validity with the general health dimension of the Duke Health Profile. The time required to complete the QoL-AD was significantly shorter (p < 0.0001). DQoL had better discriminant capacity (with at least one dimension significant for each subgroup of severity of cognitive decline, dependency, presence of depression or behavioural disorders).

Conclusions: For quick evaluation of QoL during consultations in geriatric care, the QoL-AD is preferable, whereas for the purposes of research and more in-depth evaluation, the DQoL is more suitable.

Keywords:

• QoL-AD
• DQoL
• comparison

Acknowledgements

We are grateful to Dr Charbanou Jochum and Dr Laura Di Pollina (University Hospital, Geneva, Switzerland), Dr Marie-Yvonne George (Saint Charles Hospital, Nancy, France), Pr Francis Guillemin (University Hospital, Nancy, France; University of Lorraine, Faculty of Medicine, EA 4003 Vandoeuvre-lès-Nancy, France; CEC INSERM (CIE6), Vandoeuvre-lès-Nancy, France), Dr Jean-Pierre Aquino (Clinique de la Porte Verte, Versailles, France), 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).

We also thank Fiona Ecarnot for her translation.

Additional information

Funding

This study was supported by 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).