Biomaterial Database

[Ambulatory blood pressure, reproducibility, variability and change, placebo effect]. 1991

B Vaïsse, and Y Delage, and L Poggi

Service de médecine interne, CHU Timone, Marseille.

Blood pressure assessment by ambulatory recordings is a recent clinical method. What is the reproducibility and variability of the results and what is the circadian variation of blood pressure? How useful is the technique for evaluating therapeutic efficacy? Several groups have reported that the reproducibility is good within a group of patients but that this is not observed in case by case and measurement by measurement analysis; however, when the periods of observation are sufficiently long (several hours) the recordings are comparable. In clinical practice for an individual patient, it would seem better to compare the average daily pressure load, at rest and during activity, which is more reproducible than the hourly average of blood pressure. The circadian variation of blood pressure and short-term (within the hour) or long-term (24 hours) variability have been analysed in depth and although the ambulatory blood pressure shows the same circadian variation as invasive arterial measurement, it does not show instantaneous variability. The placebo effect is not marked when a large group of patients is studied. On the other hand, case by case analysis shows the persistance of this phenomenon in small numbers of cases and, in practice, these results make the maintenance of a placebo period in therapeutic trials a necessity. In conclusion, ambulatory blood pressure recording in daily medical practice enables the study of therapeutic variations in blood pressure over a 24 hour period. However, it does not yet enable satisfactory analysis of the variability of blood pressure.

UI	MeSH Term	Description	Entries
D006973	Hypertension	Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.	Blood Pressure, High,Blood Pressures, High,High Blood Pressure,High Blood Pressures
D010919	Placebos	Any dummy medication or treatment. Although placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition, the concept has been extended to include treatments or procedures, especially those administered to control groups in clinical trials in order to provide baseline measurements for the experimental protocol.	Sham Treatment
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D001795	Blood Pressure Determination	Techniques used for measuring BLOOD PRESSURE.	Blood Pressure Determinations,Determination, Blood Pressure
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D004341	Drug Evaluation	Any process by which toxicity, metabolism, absorption, elimination, preferred route of administration, safe dosage range, etc., for a drug or group of drugs is determined through clinical assessment in humans or veterinary animals.	Evaluation Studies, Drug,Drug Evaluation Studies,Drug Evaluation Study,Drug Evaluations,Evaluation Study, Drug,Evaluation, Drug,Evaluations, Drug,Studies, Drug Evaluation,Study, Drug Evaluation
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000553	Ambulatory Care	Health care services provided to patients on an ambulatory basis, rather than by admission to a hospital or other health care facility. The services may be a part of a hospital, augmenting its inpatient services, or may be provided at a free-standing facility.	Outpatient Care,Outpatient Health Services,Clinic Visits,Health Services, Outpatient,Outpatient Services,Services, Outpatient Health,Urgent Care,Care, Ambulatory,Care, Outpatient,Care, Urgent,Cares, Urgent,Clinic Visit,Health Service, Outpatient,Outpatient Health Service,Outpatient Service,Service, Outpatient,Service, Outpatient Health,Services, Outpatient,Urgent Cares,Visit, Clinic,Visits, Clinic
D015203	Reproducibility of Results	The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.	Reliability and Validity,Reliability of Result,Reproducibility Of Result,Reproducibility of Finding,Validity of Result,Validity of Results,Face Validity,Reliability (Epidemiology),Reliability of Results,Reproducibility of Findings,Test-Retest Reliability,Validity (Epidemiology),Finding Reproducibilities,Finding Reproducibility,Of Result, Reproducibility,Of Results, Reproducibility,Reliabilities, Test-Retest,Reliability, Test-Retest,Result Reliabilities,Result Reliability,Result Validities,Result Validity,Result, Reproducibility Of,Results, Reproducibility Of,Test Retest Reliability,Validity and Reliability,Validity, Face
D015990	Placebo Effect	An effect usually, but not necessarily, beneficial that is attributable to an expectation that the regimen will have an effect, i.e., the effect is due to the power of suggestion.	Placebo Response,Effect, Placebo,Response, Placebo