Accuracy and congruence of patient and physician weight-related discussions: from Project CHAT (Communicating Health: Analyzing Talk)

Abstract

Objective

Primary care providers should counsel overweight patients to lose weight. Rates of self-reported weight-related counseling vary, perhaps due to self-report bias. We assessed accuracy and congruence of weight-related discussions among patients, physicians, and audio-recorded encounters.

Methods

We audio recorded encounters between physicians (n=40) and their overweight/obese patients (n=461) at five community-based practices. We coded weight-related content and surveyed patients and physicians immediately after the visit. Generalized linear mixed models assessed factors associated with accuracy.

Results

Overall, accuracy was moderate: patient (67%), physician (70%), and congruence (62%). When encounters contained weight-related content were analyzed, patients (98%) and physicians (97%) were highly accurate and congruent (95%) but when weight was not discussed patients and physicians were more inaccurate and incongruent (patient 36%; physician 44%; 28% congruence). Physicians less comfortable discussing weight were more likely to misreport that weight was discussed [OR = 4.5 (95% CI=1.88–10.75, p<0.001)]. White physicians with African-American patients were more likely to report accurately no discussion about weight than White physicians with White patients OR=0.30 (95% CI=0.13–0.69, p<0.01).

Conclusion

Physician and patient self-report of weight-related discussions were highly accurate and congruent when audio-recordings indicated weight was discussed, but not when recordings indicated no weight discussions. Physician overestimation of weight discussions when weight is not discussed constitutes missed opportunities for health interventions.

INTRODUCTION

The prevalence of obesity in the United States remains high with corresponding comorbidity and mortality.^1–4 Thus, preventing and managing obesity is vital. Physician counseling or referral to intensive behavioral interventions might promote patient weight loss.^5–9 However, before physician counselling or referral can be effective patients must first receive a message related to their weight. Wide variation exists between patient and provider recall of weight-related discussions.^10–17 Greiner showed that physician reports of weight discussions are not always congruent with patient reports; however, they did not compare physician reports to objective records of what they discussed.¹⁰ None has used audio-recordings to verify accuracy and congruence of weight-related discussions among physicians with overweight and obese patients.^8,18–20 The purpose of this study is to compare audio-recorded visits of weight-related discussions with patient and physician reports. A secondary aim is to assess whether any patient, physician, or visit-level factors predict accuracy or congruence of patient or physician reports.

METHODS

This study's methodology has been described elsewhere.⁸ Briefly, Project CHAT (Communicating Health: Analyzing Talk) was a three-year observational study that audio recorded preventive and chronic care encounters. The study was approved by the Duke School of Medicine Institutional Review Board.⁸

Physician Recruitment

Research staff approached 54 primary care physicians in community-based practices in North Carolina. Forty-two of these consented; however two physicians withdrew prior to contacting patients leaving 40 physicians participating in the study. Physicians were told the study would assess how they discussed preventive health with their patients (the focus on weight was not disclosed). After written consent, physicians completed a baseline questionnaire that assessed demographic factors and contained questions regarding their beliefs about counseling about weight, nutrition and physical activity (PA). To mask the focus on weight, the questionnaire included the same questions for smoking and alcohol use.

Patient recruitment

Research staff reviewed scheduled appointments via physician's electronic schedules to identify patients scheduled for visits scheduled three weeks in advance. Staff mailed patients a letter signed by their physician that described the study as examining how physicians discuss preventive health. Patients could opt out. One week later, research staff called patients to assess eligibility and conduct a baseline questionnaire that assessed demographic factors (including height and weight for self-reported BMI) and psychosocial factors associated with improving weight, nutrition, PA. Questions about smoking and alcohol use were included to help mask the focus on weight.

Patients were eligible if they were English-speaking, age ≥18 years, cognitively competent, not pregnant, and had a body mass index (BMI) ≥ 25. 461 eligible patients gave written consent and participated in the study. Figure 1 shows the patient recruitment flowchart.

Figure 1.

Patient recruitment flowchart

Data Collection

Research staff inconspicuously placed audio recorder sin the examination room and activated them before the clinical encounters. Immediately following, research staff met with patients to verify patient self-reported BMI using stadiometers and calibrated scales. Research staff then administered the post-visit questionnaire that asked patients to respond yes/no if during the encounter their physician discussed surgery or medication related to weight, asked them about, gave advice for, assessed readiness to change for, assisted with, or referred them to a specialist for: diet, PA or weight. Staff assessed patient vital signs to mask the focus on weight. To avoid interrupting clinic flow, staff administered a short, easy to complete, and less comprehensive post-visit survey for physicians. Physicians were asked to respond yes/no if during the encounter they had discussed diet, PA, BMI/weight, smoking or alcohol with their patients.

Data Analysis

In the audio-recordings, coders confirmed three primary weight-related topics raised either by physicians or patients: diet, PA, and BMI/weight. Coders used a detailed codebook that provided specific instructions, including precise definitions of codes and examples. A weight-related topic was defined as any mention of weight/BMI, diet/nutrition or exercise/PA by patient or physician. Four coders were rigorously trained (by SA) for 20 hours to identify weight-related content until a high level of reliability was achieved. All four coders coded a random sample of 20% of all audio-recordings to obtain inter-rater reliability of the coding system. Cohen's Kappa was used to calculate inter-rater reliability for each segment. All coders had strong agreement (Diet = Cohen's Kappa .79, C.I. = .77, .82; Physical Activity Cohen's Kappa = .69, C.I. = .67, .72; Weight Cohen's Kappa = .67, C.I. = .64, .71).

Patient and physician post-visit questionnaire responses were cross-tabulated with audio-recordings to assess accuracy of their self-report of any weight related discussions. Patients or physicians were deemed “accurate” if the audio-recording confirmed their post-visit questionnaire response that they did or did not discuss one or more topics related to diet, PA or BMI/weight. Physicians and patients were deemed “congruent” if they were both accurate and their reports matched the audio-recording.

PROC GENMOD was used to fit two generalized linear mixed models with a logit link to account for clustering of patients within physician to examine the likelihood of patient (model 1) and physician (model 2) being inaccurate when weight was not discussed using covariates described in the baseline questionnaire. We identified the following theoretically-relevant covariates a priori to include in the analyses: for model 1 covariates included patient sociodemographic factors (age, gender, education), physician race, visit factor length of conversation and patient motivation to lose weight (very motivated vs. somewhat to not at all motivated). Motivation to lose weight was measured using a 7-point Likert scale (1 =not at all to 7=very much). For model 2 covariates included physician gender and physician race, patient BMI (overweight vs. obese), visit factor length of conversation and physician level of comfort discussing weight (very comfortable vs. mostly to not at all comfortable. Physician comfort discussing weight was measured using a 5-point Likert scale (1=not at all comfortable to 5=very comfortable). Few patients and physicians rated themselves as Asian; thus for race concordance dyads Whites and Asians/Pacific Islanders were categorized as “White.” Model building started with testing the association of all covariates. To be conservative, only those covariates significant at p≤ 0.50 were retained for modeling. However, the small sample size for the “no weight discussed” group (n=141) limited the number of covariates that could be included in the model. All analyses were performed using SAS V9.2 (SAS Institute, Inc. Cary, NC). Significance for models was set at p<0.05.

RESULTS

Participant/Visit Characteristics

Table 1 contains relevant sociodemographic variables, race concordance, and visit characteristics. Forty physicians (mean age 47.3±7.2 years) and 461 patients (mean age 58.9±3.9 years) participated in the study. Among the 461 patients, 90% had at least one or more of the following weight-related chronic diseases: diabetes, hypertension, hyperlipidemia, and arthritis.

Table 1.

Patient, physician and visit characteristics

Patient Factors (n=461)	Mean (SD) or %
Race
White/Asian	66%
Black	35%
Female	66%
Body Mass Index (BMI)
Obese (BMI>30)	54%
Physician Factors (n=40)
Race
White/Asian/Pacific Islander	85%
Black	15%
Female	60%
Race Concordance (dyads)
White physician-White patienta	61%
White physician-Black patient	23%
Black physician-White patient	4%
Black physician-Black patient	12%
Type of visit
Preventive	28%
Chronic care	63%
Preventive and Chronic	7%
Not reported	2%

^aFor race concordance dyads Whites and Asians/Pacific Islanders were categorized as `White' (only two patients and one physician reported their ethnicity as Asian, and two physicians reported their ethnicity as Asian/Pacific Islander).

Accuracy and Congruency

Table 2 describes accuracy and congruence of patients and physicians. According to the objective coding, weight was discussed in 69% of the encounters (n=320). Weight discussions were cross-checked against audio-recordings for 461 dyads (patients and their physician) and stratified into “weight discussed” (n=320) and “weight not discussed” (n=141). Physicians reported discussing the following topics when surveyed immediately after the encounter: weight (48%), nutrition (52%), PA (62%), smoking (34%) and alcohol (20%).

Table 2.

Accuracy and congruence of physician and patient self report

Accuracya	%
Overall (n=461)
Physician	70
Patient	67
When weight was discussed (n=320)
Physician	97
Patient	98
When weight not discussed (n=141)
Physician	44
Patient	36
Congruenceb
Overall (n=461)	62
When weight was discussed (n=320)	95
When weight was not discussed (n=141)	28

^aDefinition of accurate: physicians or patients were accurate if they correctly reported that weight was/was not discussed and verified by audio recording

^bDefinition of congruence: both patient and physician were accurate if they correctly reported that weight was/was not discussed and verified by audio recording

Overall, accuracy (self-report confirmed by audio) was 70% for physicians and 67% for patients; congruence (patient and physician agreement confirmed by audio) was moderate (62%). In encounters coded as containing weight-related content (n=320), overall accuracy was almost perfect: physicians (97%) and patients (98%). In terms of physician accuracy, 31 physicians (78%) were 100% accurate for all their patients (247 or 77% of total patients). In terms of patient accuracy, all the patients of 36 physicians (290 or 91% of total patients) were 100% accurate. For discussions that included weight, overall congruence between patients and physicians was 95%: 179 encounters (56%) were 100% congruent if one (7/320), two (21/320) or all three topics (151/320) were discussed.

When weight was not discussed (n=141), overall accuracy was much lower for physicians (44%) and patients (36%). In terms of physician accuracy, 10 physicians (25%) were 100% inaccurate for all their patient encounters (26 or 18% of total patients), whereas nine physicians (23%) were 100% accurate for all their patient encounters (25 or 18% of total patients). The remaining 21 physicians (58%) were accurate for 37 patients (26%) and inaccurate for 53 patients (38%). In terms of patient accuracy, all the patients of nine physicians, (21 or 14.9% of total patients) were 100% inaccurate. For the remaining 120 patients, 42 (29.8%) were accurate and 78 (55.3%) were inaccurate across 31 physicians.

Overall, congruence was also low (28%) when weight was not discussed. Specifically, 13 physicians (33%) had encounters with 33 patients (23%) in which both patient and physician was inaccurate (0% congruence). Twenty-seven physicians (67%) had encounters with 37 patients (26%) in which both patient and physician was accurate (100% congruence). In the remaining 71 patient encounters (51%) either patient or physician was inaccurate (0% congruence).

Models

Given the lack of variability in encounters coded as containing weight-related content, we did not model for predictors of accuracy for these encounters. In encounters where weight was not discussed, no significant factors predicted patient accuracy (Table 3). However, in the physician model, physicians who were less comfortable discussing weight were more likely to report that weight was discussed when the audio-recording indicated that weight was not discussed OR = 4.5 (95% CI=1.88–10.75, p<0.001) (Table 4). Race concordance of the dyad was also a significant predictor. White physicians with African-American patients were more likely to report accurately that weight was not discussed than White physicians with White patients OR=0.30 (95% CI=0.13–0.69, p<0.01).

Table 3.

Probability of patient report of a weight-related discussion that was not verified by the audio-recording

Variable	Odds Ratio (95% CI)	p-value
Physician race
Black	4.35 (0.69–27.28)	0.12
White	1.00
Education
Greater than high school	1.43 (0.69–2.93)	0.33
High school or less	1.00
Patient gender
Male	1.79 (0.91–3.52)	0.09
Female	1.00
Time spent with patient (minutes)
One unit increase	1.03 (0.98–1.08)	0.21

Footnote: Patient age and motivation to lose weight were not significant at the univariate level (p>0.50) and were not included the model.

Table 4.

Probability of physician report of a weight-related discussion that was not verified by the audio-recording

Variable	Odds Ratio (95% CI)	p-value
Patient BMI
Obese	1.61 (0.87–3.01)	0.14
Overweight	1.00
Physician comfortable discussing weight
Mostly to not at all	4.50 (1.88–10.75)	<0.001
Very comfortable	1.00
Race concordance
Black patient & White physician	0.30 (0.13–0.69)	.005
White patient & White physician	1.00
White patient & Black physician	0.27 (0.01–6.98)	0.43
White patient & White physician	1.00
Black patient & Black physician	2.03 (0.36–12.62)	0.45
White patient & White physician	1.00
Time spent with patients (minutes)
One unit increase	1.06 (1.00–1.11)	0.053

Footnote: Gender was not significant at univariate level (p>0.50) and was not included in the model.

DISCUSSION

There were three key findings in this study. First, physician and patient self-reports of weight-related discussions were highly accurate and congruent when weight discussions occurred. Second, when weight was not discussed, physicians and patients were much less accurate and congruent. Finally, physicians who were less comfortable discussing weight and dyads in which both physician and patient were White/Asian were more likely to report that a weight discussion had occurred when it did not.

That patients and physicians are highly accurate and congruent when weight is discussed suggests that there is value in assessing patient and physician self-reports of weight discussions (i.e., diet, PA, weight). It appears that when physicians talk about weight, patients recall that weight was discussed. For physicians who discuss weight-related matters with their patients, the findings of this study should be encouraging given that patients recalled that weight-related topics were discussed and many accurately recalled the specific components of those discussions (i.e. PA, nutrition). Weight-related messages, when delivered, seem to be received. However, there is a difference between reporting that a message is received and whether or not that message is understood. This is a complex issue. It is possible in our study that both patient and physician accurately reported that a weight-related topic was discussed during the clinical visit, but what the patient heard was not what the physician thought s/he discussed. Implications of these results might be that to insure that messages that are given are received, physicians who discuss weight with their patients might summarize the discussion and allow patients to make any corrections.

Future studies using audio-recordings to assess physician-patient communication can include post-visit qualitative measures to help clarify what health messages physicians think they impart and what health messages patients believe they receive.

Physicians and patients were less accurate in their recall of weight related discussions when weight was not discussed (i.e., reported a weight discussion when none occurred). Our results differ from those from earlier studies that showed that physicians and patients tend to underreport health promotion discussions.¹⁹ In contrast, we found that when audio-recordings indicated that weight was not discussed, many physicians and patients overestimated the occurrence of weight-related discussions. This finding was perplexing. It is possible that on some rare occasions, physicians and patients recalled weight-related conversations that did not have a direct weight-related purpose. One example could have been when physicians and patients were discussing adding more fiber to help with constipation. Even though adding fiber might help with weight loss, coders would not have counted this as nutrition that was “weight-related” but patients and physicians might have counted this as discussing nutrition. There is error in every measurement tool. We cannot tease apart patients and physicians' interpretations of what was “weight-related.” It also is possible, but unlikely, that physicians and patients did not answer the questions carefully and agreed that all topics were discussed, or that physicians who, for the most part were completing the questionnaires immediately after the encounter, may have been rushed. However, the data do not confirm this as physicians reported discussing alcohol and smoking to a much lesser extent than weight, nutrition, or PA. Also, neither patient nor physician knew the study was about weight; only 2% (7/461) patients and 3% (1/40) of physicians guessed the study hypothesis involved examining weight-related discussions. Regardless of the reason behind the high recall of weight-related discussions, many physicians and patients reported weight-related discussions when they did and did not occur.

Finally, there were no significant factors that predicted patient inaccuracy when weight was not discussed. This is inconsistent with previous reports indicating that demographic and psychosocial factors are related to patient recall.^21,22 Two factors predicted whether physicians over-reported. First, physicians who were uncomfortable discussing weight may have avoided talking about weight yet reported they did because they know or believe it is part of their clinical responsibility and desire to appear more conscientious.¹⁹ Second, race concordance was also a significant predictor. White physicians with African-American patients were more likely to report accurately that weight was not discussed than White physicians with White patients. Previous work indicates that in clinical visits that are race concordant, visits are longer and patients tend to be more participatory (i.e., they ask more questions).²³ However, some reports suggest that race concordance does not appear to be positively associated with the prevalence of weight-related discussions.²⁴

Only six African-American physicians were in this sample, making it difficult to assess effects for the African-American physician-patient dyad. However, in the White-White dyads, patients might have been acting in a more participatory manner, and this influenced physicians to recall weight discussions even when coders did not observe weight-related content. Because we grouped Whites with Asians/Pacific Islanders, it is possible that cultural differences and communication (i.e., limited English language proficiency) may explain in part why White physicians-White patients were more likely to report the occurrence of a weight discussion when none took place. However, this is unlikely given the small numbers of Asians/Pacific Islanders in the study.

There were limitations to this study. First, this study is limited by potential bias in reporting weight discussions. Patients and physicians were aware that the study was about preventive health, which may have influenced them to report that weight was discussed when it was not.⁷ Further, we grouped Asian/Pacific Islanders with Whites for race concordance analyses, potentially affecting model significance. Also, little information was collected on the physician-patient relationship (only 2% of patients were “new patients”), in particular, the length of that relationship (which could influence trust), or preferences for communication strategies/style, both of which may have potential to influence the interpretation of communication.

CONCLUSION

When weight is discussed by physicians, patients are cognizant of those discussions, including message detail (i.e., weight, nutrition and PA). Physicians who discuss weight with their patients can follow up that the health messages delivered are received and understood by patients. Discussions about weight can act as a `priming effect' for behavior change in patients; physician advice along with follow-up or referral can positively impact a patient's attempt to lose weight.^25,26 The overestimation of weight discussions by some physicians (particularly those less comfortable discussing weight) constitutes a missed opportunity for a health intervention. Discomfort discussing weight is one of several systemic barriers reported by physicians and highlights the need for physician training for weight management counseling.²⁷ Future studies are also needed to further explore race concordance as a variable in physician communication with patients who are overweight/obese.