Agreement between 'time-blind' and 'time-non-blind' assessments of depressive symptomatology

In a 4-week study, two methods were used simultaneously in the assessment o f depressive symptomatology with videotaped structured clinical interviews: a 'time-non-blind' (TNB) method (chronological order, observer aware of th e previous duration of drug treatment) and a 'time-blind' (TB) method (no c hronological order, rater unaware of the previous duration of treatment). S ixty newly admitted depressed inpatients with Montgomery-Asberg Depression Rating Scale scores higher than 20 were assessed before (D0), after 10 days (D10) and after 28 days (D28) of antidepressant treatment. Agreement betwe en TNB and TB methods on the Montgomery-Asberg Depression Rating Scale, mea sured by intra-class correlation coefficients, was good at D0 (0.68), excel lent at D10 (0.81) and D28 (0.86), but not significantly different between D0, D10 and D28. The statistical method of Bland and Altman (1986) was also used to evaluate the degree of agreement. Results of this second analysis were in accordance with the intra-class correlation coefficient results, an d showed significantly (P < 0.05) higher D0-D28 and D10-D28 intrasubject ch anges with the TB method, which were largely accounted for by some particul ar items (inner tension, pessimism, lassitude). With the Clinical Global Im pression-Severity score, the Bland and Altman method failed to show signifi cant differences between the two methods, and compared with the Montgomery- Asberg Depression Rating Scale, intra-class correlation coefficients were l ower with larger confidence intervals, suggesting that global ratings are l ess reliable than itemized symptom ratings. (C) 1999 Elsevier Science Irela nd Ltd. All rights reserved.