title: Monitoring initial response to Angiotensin-converting enzyme inhibitor-based regimens: an individual patient data meta-analysis from randomized, placebo-controlled trials.
abstract: Most clinicians monitor blood pressure to estimate a patient's response to blood pressure-lowering therapy. However, the apparent change may not actually reflect the effect of the treatment, because a person's blood pressure varies considerably even without the administration of drug therapy. We estimated random background within-person variation, apparent between-person variation, and true between-person variation in blood pressure response to angiotensin-converting enzyme inhibitors after 3 months. We used meta-analytic mixed models to analyze individual patient data from 28 281 participants in 7 randomized, controlled trials from the Blood Pressure Lowering Trialists Collaboration. The apparent between-person variation in response was large, with SDs for change in systolic blood pressure/diastolic blood pressure of 15.2/8.5 mm Hg. Within-person variation was also large, with SDs for change in systolic blood pressure/diastolic blood pressure of 14.9/8.45 mm Hg. The true between-person variation in response was small, with SDs for change in systolic blood pressure/diastolic blood pressure of 2.6/1.0 mm Hg. The proportion of the apparent between-person variation in response that was attributed to true between-person variation was only 3% for systolic blood pressure and 1% for diastolic blood pressure. In conclusion, most of the apparent variation in response is not because of true variation but is a consequence of background within-person fluctuation in day-to-day blood pressure levels. Instead of monitoring an individual's blood pressure response, a better approach may be to simply assume the mean treatment effect.
authors.affiliation: Screening and Test Evaluation Program, School of Public Health, Edward Ford Building (A27), University of Sydney, NSW 2006, Australia. katyb@health.usyd.edu.au
authors.forename: Katy J L
authors.initials: KJ
authors.lastname: Bell
authors.forename: Andrew
authors.initials: A
authors.lastname: Hayen
authors.forename: Petra
authors.initials: P
authors.lastname: Macaskill
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Craig
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Neal
authors.forename: Kim M
authors.initials: KM
authors.lastname: Fox
authors.forename: Willem J
authors.initials: WJ
authors.lastname: Remme
authors.forename: Folkert W
authors.initials: FW
authors.lastname: Asselbergs
authors.forename: Wiek H
authors.initials: WH
authors.lastname: van Gilst
authors.forename: Stephen
authors.initials: S
authors.lastname: Macmahon
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Remuzzi
authors.forename: Piero
authors.initials: P
authors.lastname: Ruggenenti
authors.forename: Koon K
authors.initials: KK
authors.lastname: Teo
authors.forename: Les
authors.initials: L
authors.lastname: Irwig
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D016896:Treatment Outcome
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents