Accuracy of visual estimation in diagnosing obese individuals- a blinded study

摘要

Background: Obesity is a recognised risk factor for metabolic diseases. The clinic visit allows a platform to identify patients at risk but consultation time may be limited. Visual estimation is routinely used when addressing obesity. This may lead to either an accurate or misdiagnosis of BMI, which affects management. The validity of visual scoring in engaging BMI and waist circumference is yet to be tested. Methods: Questionnaires estimating weight, height, BMI and WC were randomly distributed to doctors and patients attending different outpatient clinics. True measurements were recorded and blinded. Data was matched and analysed using SPSS. Results: In patient only analysis, 49% of patients under reported their own weight and 68% under reported their waist circumference. In physician group analysis, we found that in patients who are obese, 81% were estimated as obese by doctors. In patients who are overweight, 63% were estimated as overweight, and 25.7% as normal. In the normal weight group, 69.5% were estimated as normal. Overall, 72% of BMI was estimated correctly by doctors. There is no accuracy difference in doctor's and patient's weight estimation. Patients are not aware of the effect of abdominal obesity to health with poor insight. Conclusions: Visual estimation would miss accurate diagnosis in overweight individuals and should not replace true anthropometric measurements.