Data Elements
The data elements we used in these analyses were derived from 4 sources. First, we used the demographics and practice survey completed by participants to characterize participants. Second, we used a data file composed of variables derived from the standardized patient checklist (an instrument designed to evaluate pursuit of presenting symptoms, DSM-III-R criteria, patient education, and management recommendations or decisions, which was completed by the standardized patients immediately after each encounter), and variables abstracted from the medical record to classify whether the physician was successful in recognizing depression. Any of the following indicators were used when classifying encounters as successful: discussion of depression with the standardized patient, diagnosis of depression in the medical record, prescription for an antidepressant, or a recommendation for ongoing counseling with a social worker, psychiatrist, or psychologist. The third data file contained information from the debriefing telephone calls with the physicians. The final data source was the ISIE-81 coded data from the encounter dialogue.38
Data Analysis
To evaluate the use of broad questioning in either medical or psychosocial categories, we compared the proportion of the interview devoted to broad questions (ISIE-81 codes 11, 12, 31, and 32) between physicians who recognized depression and those who did not. To evaluate how the blend of broad and narrow questioning contributed to a successful diagnosis of depression, a dependent measure (DM1) was created in the analysis file that would allow comparisons of interview characteristics between physicians who recognized depression and those who did not. The DM1 consisted of the percentage of broad medical and broad psychosocial questions divided by the sum of all broad and narrow questions (total percentage). A high percentage on this measure indicated that the majority of questions asked by the physician were broad questions. Finally, we examined whether physicians interrupted patients to redirect the encounter (ISIE-81 code 16).
To evaluate how the use of affective interview behaviors contributed to the diagnosis of depression, 2 different measures were used. One was an individual ISIE-81 code (code 18, elicits feelings), which indicates physicians were asking about or commenting on patient feelings. The second measure was a composite of 3 ISIE-81 codes (DM2) including use of summary statements (code 14), asking about feelings (code 18), and showing approval (code 19). To address timing or sequencing effects in the use of broad to focused questioning, each visit was divided into quartiles and the distribution of open-ended to focused questioning was explored in each quartile. Comparisons were made by treating percentiles as means.
Descriptive statistics were used to characterize study participants and encounters. All tests comparing performance on the basis of whether depression was successfully diagnosed were 2-tailed. An a level of 0.05 was considered statistically significant, except when more than 1 test was used on the same study variable. In those cases, the a levels were set at 0.025. Independent t tests were used to compare continuous data between those who recognized depression and those who did not. Levene’s F test was used to evaluate the variance between 2 groups, and multivariate analysis of variance was used for multivariate comparisons.
Results
A total of 77 internists and family physicians who met eligibility requirements were visited by an unannounced standardized patient. Results on the use of diagnostic criteria in recognizing and managing depression are reported elsewhere.34 Depression was recognized in 79% (61 of 77) of the standardized patients. Complete ISIE-81 data were only available for 59 physicians. Transcripts were not available for 21.3% of the first visits and 28% of the second visits because of either poor sound quality of recordings or mechanical failure. When depression was recognized, it usually occurred during the first visit. Recordings of encounters varied widely in length, from 4 to 35 minutes with a mean of 14.9 minutes. Therefore in our analysis of questioning sequence, quartile length differs considerably across physicians. In some cases quartile length is very short.
We found that physicians talked almost twice as much as patients (0.44 per visit vs 0.24, P <.001). We also found that patients’ talking dominated the early portion of the encounter, while physicians’ talking dominated the latter portion. Of the 59 cases with sufficiently complete data for transcript analysis, 43 were successfully recognized as depression, and 16 were not. Forty-nine percent of the participants were from northern New England, 34% from Washington, and 17% from Alabama. Physicians from northern New England were overrepresented because of specialty and sex-specific recruitment difficulties at other sites. There were no statistical differences in physician characteristics by site. The mean age of physician participants was 44.2 years; 66% were men; 64% were family physicians; and 85% were board certified. We found no differences in physician characteristics between those who did and did not recognize depression. We also found no differences in physician versus patient verbal activity over time between those who successfully recognized depression and those who did not.