Reliability and validity of the Geriatric Depression Scale in depression in Parkinson's disease

Abstract

The objective of this study was to investigate reliability and validity of the self rated 30 item Geriatric Depression Scale (GDS) in screening and diagnosis of depression in Parkinson's disease (PD). The study sample comprised 109 non-demented patients with PD admitted to the movement disorders outpatient unit. The reference diagnosis of depression was made according to DSM-IV criteria. Discriminant validity and internal consistency of the total scale were studied. Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated for different cutoff scores. Receiver operating characteristics (ROC) analysis was also carried out. The sample comprised 56 patients with and 53 without depression. In the discriminant validity analysis, the mean total GDS score of subjects with depression was significantly higher compared with those without depression. The Cronbach's a score was 0.92 and the split half correlation coefficient 0.91. The cutoff score of 13/14 provided the highest sum of sensitivity and specificity level. The sensitivity of this cutoff score was 0.78 and specificity 0.85, while PPV was 0.84 and NPV 0.79. The area under the curve value in the ROC analysis was 0.891. Sensitivity and specificity analysis showed that cutoff scores of 8/9 or 9/10 could be useful for screening and 14/15 or 15/16 for diagnostic purposes. This study showed that the 30 item GDS, with its high discriminant validity, internal consistency, and reasonably clear cutoff scores, could be a useful screening or diagnostic self rated depression scale in patients with PD.

Detecting depression in Parkinson disease

“…28,35,36,39,42,43 For the GDS-15, cutoff points 5-9 were amenable to meta-analysis for major depression (table e- 57 These questions are focused on cognitive symptoms and not somatic symptoms, to avoid any overlap with normal aging or comorbid disease changes. 50 There is no question about suicide. 28 …”

Exploring a capacity to screen of the European Portuguese version of the 15-item Geriatric Depression Scale

“…Other authors (Ertan, Ertan, Kızıltan, & Uyguçgil, 2005;Huang, Hsieh, Wu, & Lu, 2017;Weintraub, Oehlberg, Katz, & Stern, 2006) have attested the reliability and validity of the GDS among patients with Parkinson's Disease. GDS has also been identified as a suitable tool for screening purpose in older adults with different gender, educational level and age (Conradsson, 2013;Chiesi et al, 2017;Dias et al, 2017).…”

Evaluation and delivery of ambulatory rehabilitation for people with Parkinson's disease

“…[91][92][93] Many tools have been validated in patients with PD and had their reliability assessed. 81,[94][95][96][97] The minimal detectable change (MDC) has also been established for some measures (Table 4). 94,98 Appropriate selection of these instruments will enable holistic patient assessment, in addition to allowing comparison with other studies for the purpose of research and review.…”