Speech characteristics and behavior-type assessment in the multiple risk factor intervention trial (MRFIT) structured interviews

Four speech characteristics (SCs) were scored from 626 audiotaped Structured Interviews (SIs) designed to assess behavior type in the Multiple Risk Factor Intervention Trial (MRFIT). Analyses suggested that interviewers relied upon respondents' voice emphasis, speed of speaking, speed of answering, and answer content (in that order) for behavior typing. Across the clinics, there were large differences in the degree that each interviewer and auditor used these SCs for behavior-type judgments, and these differences appear to be related to differences in interauditor reliability. Correlations between the various SCs were very low, suggesting that key operationally defined characteristics of Type A behavior occurred independently in the SI. Analysis of interviewers' SCs indicated that they spoke and asked questions more quickly of Type A than Type B subjects--suggesting that interviewers' behaviors were biased by respondents' behavior type. Overall, the findings indicate the complexity of the behavior-type judgment process and how the criteria for assessment may change depending upon interviewer or population differences.