[Interobserver and intraobserver variation: a problem of validity in epidemiologic studies of arterial pressure].
In carrying out blood pressure epidemiologic studies there may be different factors that can affect internal and external validity and thus eliminate the inferential process. As part of the Hypertension and Risk Factors Associated Study conducted in March 1987 in Cuajimalpa de Morelos, Mexico City, 23 nursing students were standardized on the blood pressure auscultatory method using a sound picture and measuring intraobserver and interobserver agreement through intraclass correlation coefficient. Even though initial standardization sessions showed difficulties in the use of instruments and in the reading of blood pressure levels, final K (kappa) values measuring interobserver agreement increased from 0.25 to 0.86. Omega values measuring intraobserver agreement fluctuated between 0.86 and 0.98. This epidemiologic technique is proposed in order to improve internal and external validity of blood pressure studies.
Departamento de Epidemiología, Escuela de Salud Pública de México, Instituto Nacional de Salud Pública, SSA.
J A
JA
Escamilla Cejudo
J
J
Escobedo de la Peña
R
R
Chávez Domínguez
D
D
Colmenares Viladomat
D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods; D003951:Diagnostic Errors; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000453:epidemiology; D015203:Reproducibility of Results; D013338:Students, Nursing
La variación interobservador e intraobservador: un problema de validez en los estudios epidemiólogicos de presión arterial.