A group comparison of those with hypertension and other chronic illness: A factor and item level analysis of anger and hostility

A considerable body of research has suggested that essential hypertension is related to both expressed anger and suppressed hostility. This study suggests and provides some evidence that these reported results may simply have arisen as the result of a lack of proper statistical control and differential item functioning across the items on which the measures were based. Three groups of respondents were selected (a) those diagnosed as having hypertension (b) a group who admitted to having a chronic medical condition unrelated to hypertension and (c) individuals who did not have a chronic medical condition. A confirmatory factor model was used to test the structure of a measure of expressed anger and suppressed hostility. Differences were then examined across the three conditions at both the factor and item levels within a MIMIC structure and controlling for age and gender. Differential effects were found between females and males on two observed measures of expressed anger. Age had a direct effect on both the measure of expressed anger and suppressed hostility. After the effects of age and gender were controlled, no statistically significant group differences were found. Previous results indicating a difference on expressed anger and suppressed hostility may, as in the present analysis, be put down to a combination of lack of appropriate statistical control, and to ignoring the differential pattern of responding across the observed measures.