Objective To determine whether disagreement between doctors and patients may be linked to the production of health inequalities.

Methods INTERMEDE is a multidisciplinary study of doctor/patient interaction. These results are from the quantitative cross-sectional phase. 27 GPs located in Paris, Nantes and Toulouse volunteered to participate in the study. 585 eligible patients were included after being approached in the GP's waiting room. Pre-consultation questionnaires were used to collect information on patients and doctors. Post-consultation mirrored-questionnaires were used to collect information from the GPs and patients, respectively, about what happened during the consultation. The outcome of interest is the difference between patient's perception of their own health status and patient's health status as evaluated by their doctor. Health status is categorised into three groups: very good/good; average; bad/very bad. The difference between the two health status variables provides an outcome variable indicating whether or not the patient and doctor agree on the patient's health status. Social position was measured using education level categorised into three groups: low; medium and high.

Results Patients with the highest level of education were most likely to agree with their doctors about their health status (75.4%) compared to those with a medium (74.8%) or a low (50.4%) education level. Among patients with a low education level who disagree with their doctors, 75.4% evaluate their health as being worse than their doctor's evaluation compared to 59.2% and 55.5% of those with a medium and high education level, respectively (p<0.001). The association was then tested in a multivariate multilevel logistic regression to adjust for a doctor-level effect as well as doctor's sex, patient's sex, age smoking, alcohol, BMI, duration of the relationship between patient and doctor in years, and frequency of consultation. Patients with the lowest education level were 4.1 times (95% CI 1.9 to 8.6, p<0.001) more likely to disagree with their doctor about their health status, evaluating their health as being worse than their doctor's evaluation, compared to patients with a high education level. No doctor-level effect was observed.

Conclusion Disagreement between patients and doctors on patient's health status was related to the patient's social position. Doctors underestimated their patient's health relative to the patient's own evaluation when patients had a low education level. This could potentially lead to differences in diagnosis and follow-up and consequently to exacerbating health inequalities.