OBJECTIVES: To assess reliability in terms of inter-observer agreement of blood pressure (BP) readings. Various health professionals and measuring systems. Influence of observer's experience. DESIGN: Observational, descriptive, cross-sectional study. SETTING: Urban health centre, Córdoba. PARTICIPANTS: 131 hypertensive, randomised patients, belonging to a functional care unit. 11 were excluded. MEASUREMENTS: To reduce variability: course on the right way to take blood pressure, otoscope and verification of visual sharpness of observers, calibration and validation of measuring devices, limited time and blinding of measurements. 4 BP measurements per patient: 3 with mercury sphygmomanometer (2 simultaneously, one individual) and one with an automatic device. Descriptive, clinical and somatometric variables were gathered. Inter-observer agreement was evaluated through the intraclass correlation coefficient (ICC), the mean of differences method (MDM) and the simple concordance index (CI). An ICC > 0.75 was thought acceptable. A difference > 5 mmHg was thought clinically relevant (MDM and CI). MAIN RESULTS: Acceptable consistency for MDM: alone, systolic and diastolic pressure of OBS 1/ OBS 2, bi-auricular, -6.1/+8.9 mmHg and -6.8/+5.8 mmHg. Less favourable results: for systolic and diastolic pressure: OBS 1/AUTO -20.9/25.0 and -16.4/15.1; OBS 2/AUTO -22.8/24.4 and -16.6/15.2. Remaining intervals always > 10 mmHg; CI > 0.75 in all comparisons except diastolic pressure OBS 1/AUTO and diastolic pressure OBS 2/AUTO (0.69 in both cases). 41% of comparisons were > 5 mmHg. No differences in less expert professionals were found. CONCLUSIONS: Inaccuracy of the standard BP measurement method (mercury sphygmomanometer) for MDM and CI. Contradictory conclusions according to method of measurement. Differences not clinically acceptable.
OBJECTIVES: To assess reliability in terms of inter-observer agreement of blood pressure (BP) readings. Various health professionals and measuring systems. Influence of observer's experience. DESIGN: Observational, descriptive, cross-sectional study. SETTING: Urban health centre, Córdoba. PARTICIPANTS: 131 hypertensive, randomised patients, belonging to a functional care unit. 11 were excluded. MEASUREMENTS: To reduce variability: course on the right way to take blood pressure, otoscope and verification of visual sharpness of observers, calibration and validation of measuring devices, limited time and blinding of measurements. 4 BP measurements per patient: 3 with mercury sphygmomanometer (2 simultaneously, one individual) and one with an automatic device. Descriptive, clinical and somatometric variables were gathered. Inter-observer agreement was evaluated through the intraclass correlation coefficient (ICC), the mean of differences method (MDM) and the simple concordance index (CI). An ICC > 0.75 was thought acceptable. A difference > 5 mmHg was thought clinically relevant (MDM and CI). MAIN RESULTS: Acceptable consistency for MDM: alone, systolic and diastolic pressure of OBS 1/ OBS 2, bi-auricular, -6.1/+8.9 mmHg and -6.8/+5.8 mmHg. Less favourable results: for systolic and diastolic pressure: OBS 1/AUTO -20.9/25.0 and -16.4/15.1; OBS 2/AUTO -22.8/24.4 and -16.6/15.2. Remaining intervals always > 10 mmHg; CI > 0.75 in all comparisons except diastolic pressure OBS 1/AUTO and diastolic pressure OBS 2/AUTO (0.69 in both cases). 41% of comparisons were > 5 mmHg. No differences in less expert professionals were found. CONCLUSIONS: Inaccuracy of the standard BP measurement method (mercury sphygmomanometer) for MDM and CI. Contradictory conclusions according to method of measurement. Differences not clinically acceptable.
Authors: Enrique Martín-Rioboó; Amador López Granados; Luis Cea Calvo; Luis Angel Pérula De Torres; Emilio García Criado; Manuel P Anguita Sánchez; Lisardo García Matarín; Rafael Molina Díaz; Tomas Ureña Fernández Journal: Aten Primaria Date: 2009-04-26 Impact factor: 1.137