Comparison of survey and physician claims data for detecting hypertension

Using linked data from the Manitoba (Canada) Heart Health Survey (MHHS) and physician service claims files we assessed the degree to which self-reported hypertension and clinically measured hypetension agreed with physician claims hypertension, and examined the likely sources of disagreement. The overall agreement between survey and claims data for hypertension detection was moderate to high: 82% (kappa = 0.56) for self-reported and physician claims hypertension, and 85% (kappa = 0.60) for clinically measured and physician claims hypertension. In the comparison between self-report and physician claims, those who were classified as obese, diabetic, or a homemaker were significantly more likely to have a hypertension measure not confirmed by the other. Disagreement between clinically measured and physician claims was also more common among the obese and homemakers, as well as those on medication for heart diseases, elevated cholesterol levels (LDL), and 35 years of age and older. The high overall level of agreement among these three measures suggest that each may be used with confidence as an indication of hypertension; however, the agreement appears lower among individuals presenting a more complicated clinical profile.