Review: Cognitive behavioral techniques reduce blood pressure when compared with no therapy but not when compared with placebo therapy
ACP J Club. 1993 Sept-Oct;119:44. doi:10.7326/ACPJC-1993-119-2-044
Eisenberg DM, Delbanco TL, Berkey CS, et al. Cognitive behavioral techniques for hypertension: are they effective? Ann Intern Med. 1993 Jun 15;118:964-72.
To determine if behavioral techniques (meditation, relaxation, stress management, and biofeedback) are effective in reducing blood pressure (BP) and to estimate the size of the effect.
English-language studies (1970 to 1991) were identified with a MEDLINE search, using the terms hypertension; autogenic training; behavior therapy; aversion therapy; biofeedback; cognitive therapy; desensitization; implosive therapy; relaxation techniques; hypnosis; suggestion; autosuggestion; stress, psychological; meditation; nonpharmaceutical; nondrug; and guided imagery.
Studies were selected if they were randomized trials of nonpregnant adults with a history of mild-to-moderate essential hypertension, included ≥ 1 study group treated with a cognitive behavioral intervention, had a concurrent control group, and had a detailed description of all interventions and assessments of BPs.
Mean systolic and diastolic BP for baseline and final assessment, length of baseline period, type of control (waiting list, no therapy, or placebo), scientific quality, and type of cognitive therapy. Data extraction was done by 2 of 3 raters blinded to the source and other scores.
26 of 857 studies passed selection criteria. They represented 35 groups and 1264 participants (mean age 49 y, 65% men). Biofeedback (n = 6 groups), meditation (n = 2), relaxation (n = 15), stress management (n = 3), and combinations of behavioral therapies (n = 9) were studied. Half of the groups had ≥ 13 participants per group. The mean follow-up was 90%. Data from the studies were combined by using a random-effects model. In studies with baseline BP determined for 1 day and wait-list controls, systolic and diastolic BP for the cognitive therapy group fell 13.4 (95% CI 9.3 to 17.6) and 9.0 (CI 5.2 to 12.9) mm Hg more than the BP in the untreated control groups (P < 0.05 for both decreases). Comparable decreases from studies with baseline BP over more than 1 day were 4.1 (CI 1.4 to 6.8) and 4.0 (CI 1.6 to 6.4) mm Hg. BP changes were not significant when cognitive therapies were compared with placebo-treated control groups.
Cognitive behavioral therapies reduce systolic and diastolic blood pressures more than no therapy but not more than placebo therapy. The decreases are small.
Sources of funding: John E. Fetzer Institute; Waletzky Charitable Trust; Henry J. Kaiser Family Foundation; Department of Health and Human Services.
For article reprint: Dr. D.M. Eisenberg, Division of General Medicine and Primary Care, Beth Israel Hospital, 330 Brookline Avenue, Boston, MA 02215, USA. FAX 617-667-7070.
Biofeedback, relaxation training, meditation, and similar techniques have been popular in the lay press as approaches to control the body's response to stressors and to treat several diseases, including hypertension. Unfortunately, as this well-designed review shows, the performance of these techniques in controlling blood pressure has not matched the enthusiasm of the popular media. This report is worth reading, not only for the results and conclusion but as a lesson in doing a well-structured review of an important clinical issue (1). The question was clearly focused, the literature search was exhaustive, the quality of the studies was assessed, and the data were handled appropriately. Most important, the methods are fully described, allowing the reader to judge the authors' use of common sense in setting the criteria for study selection and analyzing the pooled data. The reader can be confident that this is the best information available.
The results of this review match those of a previous article (2) in finding little evidence of effectiveness of these approaches in treating hypertension and can be applied immediately to clinical practice. The data presented reinforce the importance of measuring baseline blood pressure over more than 1 day before starting treatment in patients with mild-to-moderate hypertension. Although behavioral techniques may be helpful in other conditions, such as headache or in otherwise improving the quality of life, they will not lead to clinically important changes in blood pressure.
David L. Bronson, MD
The Cleveland Clinic FoundationCleveland, Ohio, USA
1. Oxman AD.Meta-statistics: Help or Hindrance? ACP J Club. 1993 May-Jun:A13 (Ann Intern Med. vol 118, suppl 3).
2. Joint National Committee on Decision, Evaluation, and Treatment of High Blood Pressure. The Fifth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC V). Arch Intern Med. 1993;153:154-83.