title: Definition of a Geriatric Depression Scale cutoff based upon quality of life: a population-based study.
abstract: OBJECTIVE
  The cutoff scores for the Geriatric Depression Scale (GDS) commonly adopted in clinical and research settings are based upon other neuropsychological tests. However, any intervention for depression should aim at improving subjective quality of life (QoL). We searched for a GDS cutoff level that might identify a decrease in perceived QoL using a scale that also allows formal cost-effectiveness calculations.
  
  
  METHODS
  Quality of life was assessed by the Health Utilities Index, Mark 3 in all 344 residents of Tuscania (Italy) aged 75 years and above. Mood was assessed by both the 30-item GDS and the derived 15-item GDS. The association of GDS with low QoL was analyzed by multivariable logistic regression. Receiver operating characteristic curve analysis was adopted to estimate the overall predictive value and the best GDS cutoff for poor QoL.
  
  
  RESULTS
  The 30-item GDS score was associated with increased probability of a worse QoL (odds ratio (OR) = 1.07, 95% confidence (CI) = 1.02-1.12, p = 0.003); also, it was a fair predictor of worse QoL (area under the curve (AUC) = 0.72; 95% CI = 0.67-0.76). The best GDS score cutoff for identifying a poor QoL was above 9/30. Results were similar (OR = 1.07, 95% CI = 1.02-1.12, p = 0.003, and AUC = 0.72, 95% CI = 0.67-0.76) for the short GDS form for a cutoff above 5/15.
  
  
  CONCLUSIONS
  Among older subjects, depressive symptoms are associated with reduced QoL; GDS scores above 9/30 or 5/15 best predict poor perceived health-related QoL. These cutoff scores could therefore identify subjects in whom treatment is more likely to improve QoL and to yield a favorable cost-effectiveness ratio. Copyright © 2017 John Wiley & Sons, Ltd.
authors.affiliation: Unit of Geriatrics, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy.
authors.forename: Alice
authors.identifier: http://orcid.org/0000-0002-6167-053X
authors.initials: A
authors.lastname: Laudisio
authors.affiliation: Unit of Geriatrics, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Antonelli Incalzi
authors.affiliation: Department of Homecare Service, Azienda Sanitaria Locale Roma E, Rome, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Gemma
authors.affiliation: Department of Geriatrics, Neurosciences, and Orthopaedics, Catholic University of Medicine, Rome, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Marzetti
authors.affiliation: Department of Geriatrics, Neurosciences, and Orthopaedics, Catholic University of Medicine, Rome, Italy.
authors.forename: Gino
authors.initials: G
authors.lastname: Pozzi
authors.affiliation: Department of Geriatrics, Neurosciences, and Orthopaedics, Catholic University of Medicine, Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Padua
authors.affiliation: Department of Geriatrics, Neurosciences, and Orthopaedics, Catholic University of Medicine, Rome, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Bernabei
authors.affiliation: Department of Geriatrics, Neurosciences, and Orthopaedics, Catholic University of Medicine, Rome, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zuccalà
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003866:Depressive Disorder / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D007558:Italy; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life / Q000523:psychology*; D012372:ROC Curve
keywords: depressive symptoms; elderly; epidemiology; quality of life