Observer variability of Osler's maneuver in detection of pseudohypertension

Pseudohypertension in the elderly occurs when blood pressure is overestimated because of inelastic, sclerotic arteries. Osler's maneuver (OM), the palpability of a pulseless artery, is recommended as a non-invasive test to detect pseudohypertension, despite limited data concerning its reproducibility. We assessed the maximum achievable inter-and intra-observer agreement of OM among 6 examiners: cardiologists, geriatricians and general internists. Each examiner performed OM twice on 65 elderly hypertensive men attending the general medicine and geriatric clinics. The inter-observer agreement for brachial and radial examinations was 79 and 70%, while intra-observer agreement was 82 and 75%, respectively. After adjusting for chance agreement the kappa values for inter-observer agreement for brachial and radial arteries were 0.38 (95% confidence interval (CI): 0.21-0.55) and 0.37 (0.28-0.46), respectively. Similarly, the kappa values for intra-observer agreement were 0.45 (95% CI: 0.35-0.55) and 0.49 (0.39-0.59). Kappa values never exceeded 0.6 in any time period, suggesting no training effect. OM cannot be recommended as a screening test for pseudohypertension given this low inter- and intra-observer agreement.