Patient trust was measured using a slightly modified version of the 11-item Trust in the Physician Scale developed from Anderson and Dedrick13 as previously described.6 At the time of the study, the Trust in Physician Scale was the only published measure of patient trust. One item, “My doctor is a real expert in taking care of medical problems like mine” was modified to read “My doctor is well qualified to manage (diagnose and treat or make an appropriate referral) medical problems like mine,” to be appropriate for the primary care setting. On the basis of a pilot study of the scale, response labels were changed from (1=strongly disagree; 2=disagree; 3=uncertain; 4=agree; 5=strongly agree) to (1=totally disagree; 2=disagree; 3=neutral; 4=agree; 5=totally agree).6 The scale was scored by transforming the mean response score (calculated after reverse coding the negative items) to a 0 to 100 scale. Patient trust was assessed again at 1 and 6 months after the enrollment visit by mail survey.
Statistical Analysis
The association between specific physician behaviors and level of trust was assessed using Pearson correlation coefficients. Behaviors were ranked on the basis of the relative strength of the correlations.
Results
Of 803 consecutive patients, 561 were eligible for enrollment. Of those, 414 (74%) enrolled and completed the previsit and postvisit questionnaires at the time of the index visit, 52 (9%) refused, 15 (3%) saw the physician and left before being approached by the research assistant, and 74 (13%) enrolled but failed to complete both questionnaires.
Among the 414 enrolled patients, 334 (81%) completed the 1-month and 343 (83%) completed the 6-month follow-up questionnaires. Patients who did not complete the 1-month and 6-month questionnaires were compared with those who did with respect to age, length of the relationship with the physician, sex, race, education, and self-reported health status. Those who did complete the questionnaires at 6 months were virtually the same as those who did not at 1 month with respect to these characteristics. Those who did not complete the questionnaires at 6 months were slightly younger (45 vs 48 years), had been seeing their physician for a slightly shorter time at study enrollment (mean = 37 months vs 43 months), were more likely to be men (45% vs 36%), and were more likely to be nonwhite (41% vs 31%) than those who did complete the questionnaire, but they were virtually identical with respect to education and health status. None of these differences reached statistical significance.
The average age of the physicians was 47 years (range=34-73 years), with an average of 16 years in practice (range=8-44 years). Physicians were predominately men (85%) and white (70%), and most were in group practice (70%). Patients also had a mean age of 47 years and were predominately women (62%). Approximately two thirds (68%) of the patients were white, and 81% had graduated from high school. More than half (55%) reported at least one chronic medical condition, and almost half (45%) reported their health as being less than very good.
The correlation between physician behaviors during the visit, as rated by the patient, and trust immediately following the visit ranged from 0.46 to 0.64 Table 1. The 5 behaviors that were most strongly associated with trust immediately after the visit were: (1) being comforting and caring, (2) demonstrating competency, (3) encouraging and answering questions, (4) explaining what they were doing, and (5) referring to a specialist if needed. Behaviors least important for trust were: (1) gentleness during examination, (2) discussing options/asking opinions, (3) making eye contact, and (4) treating as an equal. Correlations between specific behaviors and trust decreased over time, with a range of 0.38 to 0.58 at 1 month and 0.27 to 0.46 at 6 months after the initial visit. The same pattern of the strength of associations between trust and specific behaviors remain essentially stable, with the exceptions of “being available when needed” and “working to adjust treatment.” Being available when needed was one of the behaviors least associated with trust at the index visit (ranked 16th out of 19) but moved up to be ranked 12th at 1 month and sixth at 6 months. Working to adjust treatment was also less important at the initial visit (ranked 14th out of 18), compared with 1 month (ranked 7th) and 6 months (ranked 8th).
The associations between specific behaviors and trust at the time of the enrollment visit were examined for the following subgroups of patients: men versus women, aged younger than 45 years versus 45 years and older, and length of relationship 2 years or less versus more than 2 years Table W2*. These subgroups were selected a priori for exploration and generation of hypotheses but without any particular hypothesis regarding the pattern of associations between behaviors and trust within each subgroup. As shown in Table 2, being comforting and caring, demonstrating competency in diagnosis and treatment, and expressive communication (encouraging and answering questions, explaining, and checking understanding) were among the behaviors most strongly associated with trust for all groups. Letting the whole story be told or finding out all the reasons for the visits (2 receptive communication behaviors) were strongly associated with trust in most of the groups. Referring to a specialist if needed was one of the behaviors most strongly associated with trust among women, younger patients, and established patients. Respecting feelings and opinions was among the most strongly associated behaviors only for younger patients, and checking progress was among the most strongly associated behaviors only for women.