Reliability, validity and clinical correlates of the Quality of Life in Alzheimer's disease (QoL-AD) scale in medical inpatients.
BACKGROUND
There is a lack of standardisation in quality of life (QoL) measurements to be used in older multimorbid patients. An ideal QoL measurement should be reliable, valid, subjective, multidimensional, feasible and generic. We hypothesised that the QoL-AD (Quality of Life in Alzheimer's Disease) scale could have these properties. Our aim was to determine the psychometric properties and clinical correlations of QoL-AD in a population of elderly, multimorbid medical inpatients.


METHODS
QoL-AD was performed in 200 medical inpatients, and available caregivers. Reliability was determined using cronbach's alpha and corrected item-total correlations. The agreement between patient and proxy ratings were examined using intra-class correlations (ICC). Correlations between QoL-AD and demographic data, comorbidity, cognitive tests, ADL (activities of daily living) and depression were examined. To characterise the underlying constructs of QoL-AD, an exploratory factor analysis was performed.


RESULTS
In total, 199 patients fulfilled the QoL-AD rating, with 139 proxy ratings. Cronbach's alpha (95 % CI) was 0.74 (0.68-0.79) for patients and 0.86 (0.83-0.90) for proxies. Patient-proxy ICC (95 % CI) was 0.31 (0.16-0.46). Lower QoL was correlated to depression, cognitive impairment, ADL impairment and solitary living, but not with comorbidity. The factor analysis gave a three-factor solution, with factors representing phsyical, social and psychological well-being.


CONCLUSIONS
The QoL-AD scale showed some promising properties but more research is needed before it can be recommended in this setting. If replicated, the finding that cognitive impairment, depression and ADL impairment were more associated with lower QoL than somatic comorbidity could have clinical implications for further studies aiming to improve QoL in this population.
Clinical Memory Research Unit, Lund University, Simrisbanvägen 14, S 20502, Malmö, Sweden. gustav.torisson@med.lu.se.
Gustav
http://orcid.org/0000-0001-9012-2068
G
Torisson
Deparment of Internal Medicine, Skåne University Hospital, Malmö, Sweden.
Lars
L
Stavenow
Clinical Memory Research Unit, Lund University, Simrisbanvägen 14, S 20502, Malmö, Sweden.
Lennart
L
Minthon
Clinical Memory Research Unit, Lund University, Simrisbanvägen 14, S 20502, Malmö, Sweden.
Elisabet
E
Londos
D000203:Activities of Daily Living / Q000523:psychology; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000523:psychology*; D017028:Caregivers / Q000523:psychology; D060825:Cognitive Dysfunction / Q000523:psychology; D015897:Comorbidity; D003704:Dementia / Q000523:psychology; D003863:Depression; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007297:Inpatients / Q000523:psychology*; D008297:Male; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life / Q000523:psychology; D015203:Reproducibility of Results
Medical inpatients; Quality of life; Scale validity