Influence of contextual variables on blood pressure in the elderly

This research evaluated determinants of blood pressure in elderly subjects. Measurements were obtained from 30 subjects in three contexts; in the home measured by the subject, in the home measured by the experimenter, and in a psychophysiological laboratory measured by the experimenter. Four measurements were obtained in the two home conditions and two were obtained in the laboratory condition. For systolic blood pressure, the effects of condition, repeated measurement, and order of treatment presentation were significant. For diastolic blood pressure, the effect of condition was significant. A comparison of sample variances revealed greater variances for systolic blood pressure. It was concluded that initial blood pressure measurements obtained in a laboratory should be regarded as distinct from those obtained later, as the early measurements may be subject to elevation imposed by the context. Due to differing patterns of results for systolic and diastolic pressures as well as differences in variability, it was concluded that there exist conceptual problems with a construct such as mean arterial pressure.