The Ottawa 3DY Predicts Mortality in a Prospective Cohort Study

Abstract

Background 

The Ottawa 3DY (O3DY) is a simple measure of cognition. 

Objectives 

1) To determine if the O3DY predicts mortality; and 2) To compare the discrimination of the O3DY to the Mini-Mental State Examination (MMSE) and Modified MMSE (3MS). 

Methods 

Analyses of a population based cohort study of 1,751 participants aged 65+; conducted in 1991/2 with follow-up over five years. The O3DY, age, sex, education, comorbid conditions, the MMSE, and the 3MS were measured: 4.5% of the participants had missing data for the O3DY; 42.8% were considered as positive (one or more errors), and 52.7% were considered as negative (no errors). Logistic regression models were constructed with the outcome of death at time 2. A Receiver Operator Curve (ROC) was constructed and the Area Under the ROC (AUROC) was calculated using a c-statistic. 

Results 

The unadjusted odds ratio (OR) and 95% confidence interval (CI) for mortality was 1.96 (1.56, 2.47); and the adjusted OR was 1.33 (1.02, 1.72). The AUROC was 0.66 for the 3MS, 0.65 for the MMSE, and 0.60 for the O3DY. 

Conclusions 

The O3DY predicts mortality over a long time frame, although the discrimination is less than that of longer measures of cognition.