Dementia disorders are associated with poor quality of life of patients. Generic tools have been shown to hardly capture main aspects of these conditions. The aim was to validate the Spanish version of the two dementia-specific health-related quality of life scales that make up the DEMQOL system: DEMQOL and DEMQOL-Proxy.

One-hundred-nineteen subjects with dementia according to DSM-III-R/DSM-IV, and their caregivers from six centers participated in the study. The following patient-reported information was obtained by interview: demographics, subjective perception of health, comorbidity, depressive symptoms (GDS-15), functional ability (Barthel Index), and generic (WHOQOL-BREF) and dementia-specific (DEMQOL) health-related quality of life. Proxy-reported information about the patient's quality of life was obtained by interview of a family caregiver using the DEMQOL-Proxy.

The Spanish version of DEMQOL showed good psychometric properties. Acceptability was good, with 5% missing information. Internal consistency (Cronbach alpha=0.85) and test-retest reliability (ICC=0.71) were also good. A priori associations between DEMQOL and the psychological and physical domains of the WHOQOL-BREF, the GDS-15 and the Barthel Index were supported, indicating good construct validity. Associations between DEMQOL-Proxy and the measures mentioned were weaker. The factor solution for the Spanish version of DEMQOL showed a three factor solution that accounted for 44.4% of the total variance; and a four-factor solution for DEMQOL- Proxy that accounted for 53.3% of the total variance.

As per the results found, the Spanish version of DEMQOL and DEMQOL-Proxy are reliable and valid in patients with mild/moderate dementia who are living at home.

Doing there is no consensus for a multidimensional definition of Quality of Life (QoL) in dementia, and that informant- and self-perceptions of QoL differed substantially, lately it has been proposed to analyze Overall QoL using a simple item. Our objective was to investigate Overall QoL and how this perception among people with Cognitive Impairment and Dementia is associated with other variables. Thus, obtained predictor variables of QoL will act as confirmatory indexes to corroborate the self-reported QoL in clinical setting.

We conducted a cross-sectional survey where 106 participants with Cognitive Impairment (CI) and Dementia completed a face to face interview including diagnosis of dementia (DSM-III-R / DSM-IV), sociodemographic information, health perception and a list of chronic medical conditions, depressive symptoms (GDS-15) and functional ability (Barthel Index). Quality of life was measured with the self-assessment of overall QoL item from WHOQOL-BREF.

Mean age was 78.7 y.o. (SD: 7.1, range 55-91); 64.8% were female and 50% had primary school or more. Ordinal Logistic Regression analysis showed four factors correlated with a better QoL: (1) patients rating their health as good or more than good, (2) patients considering themselves healthy, (3) patients reporting not having depression, and (4) patients having less depressive symptoms (lower GDS scores).

A single-item global rating of patient QoL could prove useful in assessing QoL of most mild-to-moderate-stage CI and dementia patients. Affective states should be considered when assessing QoL in patients with CI and dementia; consistently, negative mood have a detrimental impact on QoL.