Quality of life in dementia: Psychometric properties of a French language version of the Dementia Quality of Life questionnaire (DQoL)

Abstract

Aim The aim of this study was to discuss about the Dementia Quality of Life (DQoL) psychometric properties and the contributions stemming from the French language version. Methods To assess the psychometric properties of the French language DQoL transcultural validation, 155 patients with mild to moderate dementia (Mini Mental State Examination score ≥ 10) were recruited in seven French-speaking hospitals. Feasibility and acceptability were assessed by the time required to complete the questionnaire, the rate of refusal to participate, and the rates of abandon or non-response. Internal consistency and test-retest reliability were assessed respectively by Cronbach's alpha coefficient and Intraclass Correlation Coefficient. The discriminant validity was tested by evaluating the influence of severity of cognitive decline, dependence, existence of depression or behavioural troubles, as well as caregiver burden. Results Of the 155 eligible patients, 46 patients (29.7%) failed the screening procedure but completed the questionnaire nonetheless. The remaining 109 patients had an average age of 81 ± 6 years, average Mini Mental State Examination (MMSE) score was 20.8 ± 4.4. No patient refused to participate or abandoned. The French DQoL showed acceptable internal consistency (Cronbach's alpha ranging from 0.70 to 0.87) and good reliability (Intraclass Correlation Coefficient [ICC]: 0.96–1.00). Cognitive status, humour and behavioural troubles had an impact on Quality of Life (QoL), whereas dependence and caregiver burden did not. Psychometric properties did not differ for the group who passed the screening test ( n = 109) and for the whole population ( n = 155). Conclusion The French-language version of DQoL showed comparable psychometric properties to the original version. According to our findings, all patients with mild to moderate dementia can undergo evaluation with the French adaptation of the DQoL. We suggest transforming the screening procedure into a training step.