Development and validation of a brief observer-rated screening scale for depression in elderly medical patients.
OBJECTIVE
to develop a depression screening scale that does not rely on verbal communication.


METHODS
an acute geriatric unit in a teaching hospital.


METHODS
96 patients (mean age 81 years, range 68-92, 59 women); 40% of the initial study group of 50 and 22% of the validation group of 46 were diagnosed as depressed.


METHODS
we devised a scale using nine items which could be rated by an observer; we determined inter-rater reliability, sensitivity, specificity and predictive values for each item compared with a Geriatric Mental State-AGECAT diagnosis of depression; we validated a final scale of six items.


RESULTS
inter-rater reliability was poor for two items (irritability and sleep disturbance) while two items (sleep disturbance and night sedation) had poor sensitivity; we omitted these items in a revised scale. Re-analysis of data from the initial study showed that a cut-off of > or = 3 on the revised scale gave a sensitivity of 83%, a specificity of 95%, a positive predictive value of 0.89 and a negative predictive value of 0.90. Spearman's correlation coefficient between the six-item questionnaire and the Hamilton rating scale was 0.79. In the validation study, the cut-off score of > or = 3 on the revised six-item scale had a sensitivity of 90%, specificity of 72%, a positive predictive value of 0.69 and a negative predictive value of 0.96.


CONCLUSIONS
this simple, short, observation-based screening scale completed by nurses is sensitive and specific in identifying depression in elderly medically ill patients, and may be a useful addition to clinical practice.
Hammond
M F
MF
Geriatric Medicine, University Clinical Department, Liverpool, UK. mhammond@liverpool.ac.uk
O'Keeffe
S T
ST
Barer
D H
DH
D000368:Aged; D000369:Aged, 80 and over; D003863:Depression / Q000175:diagnosis*; D005260:Female; D015577:Geriatric Assessment; D006299:Health Services for the Aged; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales / Q000592:standards; D012680:Sensitivity and Specificity