healthmedicinet

Participants and procedures

One hundred and fifty nine different new patients (74 males and 85 females) participated
in this observational, cross-sectional study. They are patients at outpatient department
of the Department of Family Medicine of large-scale hospital, Japan. The patients
came from both rural and urban areas and were from a wide range of socioeconomic classes.
All of the patients were over 15 years of age, and most patients generally had common
medical problems such as hypertension, hypercholesterolemia, and diabetes. First,
we checked whether this was a first visit and asked if the prospective participant
were willing to participate, and if he or she declined, no further effort was made.
Second, we gave them instructions about the purpose and meaning of the study and told
them that they could decline from this study anytime when they want to. Third, we
obtained each participant’s signature. Parental permission was obtained for patients
whose age is less than 20 years old.

Each patient was interviewed by one of 26 family physicians, 98 family medicine residents,
or 35 medical students having family medicine clinical clerkship. These interviews
were videotaped for evaluation.

Informed consents were obtained from patients and physicians prior to any observation
of the medical interviews. The research protocol of this study was approved by the
Research Ethical Committee of the Mie University School of Medicine.

Outcome measurements

The videotaped medical interview skills were reviewed by trained researchers using
the Takemura Medical Interview Rating Scale (TMIRS) (Table 1) 16]. Some systems of the Roter interaction analysis system were used to build this scale
17]. “Feelings of anxiety” and “depressive feelings” were also operationally defined
(Table 2). These items were all combined into a single sheet to allow us to count the skills
that doctor’s used and patients’ emotional responses.

Table 1. Definition of each medical interview skill (Medical Interview Evaluation System)

Table 2. Definition of feelings of anxiety and depressive feelings

This scale was assessed for reliability. First, for each videotaped interview, an
evaluator used the scale to evaluate the number of skills used by the physician. Second,
the same evaluator did a second review a random selection of 25 interviews 2 months
after the first review. The kappa value was calculated and found to be 0.93.

Interview length was considered as a confounder, because longer interview duration
was presumed to positively influence our findings 18]. In addition, patients’ sex, sex matching between patient and physician, and affiliation
(student, resident and family physician) were also obtained as other possible confounders.

Statistical analyses

Demographic data were obtained first. Then, we used a generalized linear model (GLM)
to assess the relationship between a physician’s use of these interview skills and
verbal indications of feelings of anxiety or depression. Because our observation of
physicians’ interview skills and patients’ emotional disclosures were recorded as
count data, we modeled the relationship using the Poisson distributions and log link
function. After the generalized linear model was estimated, we verified the variance
inflation factors of each independent variable and the covariates (VIF). Finally,
we evaluated goodness of fit of the estimated model using Akaike Information Criteria
(AIC).

Statistical significance was set as p  0.05 for all measures. We used R version 3.1.1 19] for statistical analyses. Generalized linear model analyses were conducted using
the “glm” function. There was no missing data.