Blood Pressure-Lowering Effects of Biofeedback Treatment in Hypertension: A Meta-Analysis of Randomized Controlled Trials.

Abstract

To examine the blood pressure-lowering effects of biofeedback treatment in patients with essential hypertension, a meta-analysis was conducted on studies published between 1966 and 2001. A total of 22 randomized controlled studies with 905 essential hypertensive patients were selected for review. Compared with clinical visits or self-monitoring of blood pressure (non-intervention controls), biofeedback intervention resulted in systolic and diastolic blood pressure reductions that were greater by 7.3 mmHg (for systole; 95% confidence interval: 2.6 to 12.0) and 5.8 mmHg (for diastole; 95% confidence interval: 2.9 to 8.6). Compared with sham or non-specific behavioral intervention controls, the net reductions in systolic and diastolic blood pressures by biofeedback intervention were 3.9 (95% confidence interval: -0.3 to 8.2) and 3.5 (-0.1 to 7.0) mmHg, respectively. The results of multiple regression analysis also indicated that biofeedback intervention decreased systolic and diastolic blood pressures more than non-intervention controls (p < 0.001), but not more than sham or non-specific behavioral intervention controls (p > 0.05), when controlling for the effects of initial blood pressures. When biofeedback intervention types were classified into two types, simple biofeedback and relaxation-assisted biofeedback, only the relaxation-assisted biofeedback significantly decreased both systolic and diastolic blood pressures (p < 0.05) compared with those in sham or non-specific behavioral intervention controls. The results suggested that biofeedback was more effective in reducing blood pressure in patients with essential hypertension than no intervention. However, the treatment was only found to be superior to sham or non-specific behavioral intervention when combined with other relaxation techniques. Further studies will be needed to determine whether biofeedback itself has an antihypertensive effect beyond the general relaxation response.

Relaxation therapies for the management of primary hypertension in adults: a Cochrane review

“…16,17 and the reference lists of included RCTs and of meta-analyses [5][6][7]12,13,[18][19][20] identified from the searches. There was no language restriction.…”

“…60 Comparison with other meta-analyses Four major meta-analyses of RCTs of relaxation therapies for hypertension have been conducted. 5,6,12,13 These included different trials from our review because of the different time period for reporting of trials, different inclusion criteria, different judgements about whether individual trials were randomized, controlled and maintained any antihypertensive medication at a constant dose. They also used different methods of analysis: in particular, all analysed change scores, whereas we preferred final values, firstly because change scores are often chosen after observation of data to correct for 'unlucky' randomization, which results in a biased estimate of the effect of treatment 61 and, secondly, because they include less measurement error.…”

“…11 Previous systematic reviews of relaxation therapies for treating hypertension 5,6,12,13 provided conflicting evidence. Furthermore, recent metaanalyses 6,13 were restricted to autogenic training and biofeedback, respectively, and only one of these meta-analyses 12 was restricted to studies with a minimum length of follow-up (6 months). As treatment for hypertension is likely to be a life-long process, short-term studies may not be relevant to establishing long-term benefits.…”

Biofeedback treatment of prehypertension: analyses of efficacy, heart rate variability and EEG approximate entropy

“…Biofeedback, as a non-pharmacological intervention, is effective to treat hypertension. 3 A meta-analysis conducted by Nakao et al 4 showed that biofeedback intervention decreased systolic blood pressure (SBP) and diastolic blood pressure (DBP) more than nonintervention controls; but only the relaxation-assisted biofeedback and not the simple biofeedback significantly decreased both SBP and DBP versus sham or non-specific behavioural interventions. Whether biofeedback could decrease BP in prehypertensives is unclear.…”

Relax, but is there rest for the blood pressure?

“…Previous publications provided conflicting evidence, reviewed only a limited number of relaxation techniques or were restricted to studies covering only a short follow-up period. 1,[6][7][8] Given these limitations, Dickinson et al 9 provided a refreshing and comprehensive systematic review of the available clinical trials of relaxation therapies for the management of primary hypertension in adults, which is published in the current issue of the Journal of Human Hypertension. They evaluated the effectiveness of relaxation to lower high blood pressure in their review and metaanalysed the available data.…”