Stress management intervention for primary prevention of hypertension: Detailed results from phase I of trials of hypertension prevention (TOHP-I)

PURPOSE: Stress Management Intervention (SMI) was one of seven nonpharmacol ogic approaches evaluated in Phase I Trials of Hypertension Prevention (TOH P-I) for efficacy in lowering diastolic blood pressure (BP) in healthy men and women aged 30 to 54 years with diastolic BP 80-89 mm Hg. METHODS: A total of 242 and 320 participants were randomized to SMI or an a ssessment only" SMI Control, respectively, at four clinical centers. The SM I consisted of 37 contact hours in 21 group and two individual meetings ove r 18 months and included: training in four relaxation methods, techniques t o reduce stress reactions, cognitive approaches, communication skills, time management, and anger management within a general problem-solving format. Standardized protocols detailed methods and timing for collecting BP, psych osocial measures, and urinary samples from both SMI and SMI Control partici pants. RESULTS: In intention-to-treat analyses, although significant baseline to t ermination BP reductions were observed in both groups, net differences betw een the SMI and SMI Control groups' BP changes (mean (95% CI)) were not sig nificant: -0.82 (-1.86, 0.22) for diastolic BP, and -0.41 (-1.96, 1.01) for systolic BP. Extensive adherence sub-group analyses found one effect: a si gnificant 1.36 mm Hg (p = 0.01) reduction in diastolic BP relative to SMI C ontrols at the end of the trial for SMI participants who completed 61% or m ore of intervention sessions. CONCLUSIONS: While the TOHP-I SMI was acceptable to participants as evident from high levels of session completion, the absence of demonstrated BP low ering efficacy in intention-to-treat analyses suggests that the TOHP-I SMI is an unlikely candidate for primary prevention of hypertension in a genera l population sample similar to study participants. The isolated finding of significant diastolic BP lowering in SMI participants with higher adherence provides very weak evidence of SMI BP lowering efficacy and may be a chanc e finding. Whether similar or other stress management interventions can pro duce significant BP lowering in populations selected for higher levels of B P, stress, or intervention adherence remains to be demonstrated. Ann Epidem iol 2000;10:45-58. Published by Elsevier Science Inc.