Given this paper's focus, it is important to note that differences in rates of lifetime mood disorders between patients with (34.0%) and without (34.5%) informant data were not statistically significant. Primary care patients for whom we have informant data scored higher in trait Openness (p = 0.001) than those without informant data; there were no differences in other traits.
Demographic characteristics are reported in . Descriptive statistics for the five personality domains are shown in . Internal consistency coefficients are comparable to those reported in the manual (Costa and McCrae, 1992
), which range from 0.68 to 0.86. shows the number of patients diagnosed with current and lifetime mood disorders, and also reports modified kappas along with sensitivity and specificity statistics. Sensitivity is poor, particularly for minor depression. Modified kappas are higher for major depression (current and lifetime) than for minor depression.
Patient (n = 191) and informant (n = 191) demographics and relationship characteristics
Patient personality: descriptive statistics (N = 191)
Summary of informant accuracy and informant-patient agreement statistics
Multivariate analyses of the accuracy of informant-derived lifetime mood disorder diagnoses
As shown in , specificity is better when patients are higher in Extraversion and in Agreeableness; specificity is worse when patients are higher in Conscientiousness. In other words, disagreeable patients, those who are more introverted, and those who are dependable and achievement-oriented were more likely to have friends and relatives who incorrectly believed that they have suffered from or are suffering from a mood disorder. There were no other significant predictors of lifetime specificity.
Patient personality predictors of the sensitivity and specificity of informant-reported mood disorders
Turning to the sensitivity of lifetime mood disorder diagnoses, as hypothesized, the mood disorders of patients higher in Extraversion are less likely to be reported correctly. Worse sensitivity was also observed when patients were higher in Agreeableness. Sensitivity is not appreciably lower when patients are lower in Openness.
With respect to covariates, the sensitivity of informant-derived lifetime mood disorder diagnoses is better when patients live alone (Wald Z (1) = 3.41; p < 0.001) and when patients have higher MMSE scores (Wald Z (1) = 2.62; p < 0.01). Sensitivity of informant-derived lifetime diagnoses is also better when informants are spouses (Wald Z (1) = 3.60; p < 0.001) and higher in Openness (Wald Z (1) = 2.99; p < 0.005). No other covariate significantly influenced the sensitivity of informant-reported lifetime mood disorder diagnoses.
Multivariate analyses of the specificity of informant-derived current mood disorder diagnoses
As reveals, specificity is worse when patients are higher in Conscientiousness; specificity improves with higher levels of Agreeableness. Patients with better cognitive function were more likely to have a friend or relative correctly believe that they were not suffering from a mood disorder (Wald Z (1) = 3.05; p < 0.005). In other words, the specificity of informant-reported current mood disorder diagnoses suffers with declining patient MMSE scores.
Bivariate analyses of the sensitivity of informant-derived current mood disorder diagnoses
Bivariate analyses reveal no statistically significant associations between sensitivity and patient Neuroticism (r = 0.20), Extraversion(r = −0.11), Openness (r = 0.04), Agreeableness, (r = −0.32), and Conscientiousness (r = 0.08). Sensitivity is associated with patient CIRS (r = 0.43; p = 0.04), but there were no significant associations with other covariates.