Multifactoriële interventie verbeterd hypertensie, maar niet CV eindpuntenNieuws - Sep. 13, 2010
Multifactorial intervention improves hypertension but not CV outcomes
Use of a multifactorial intervention to improve patients' adherence to antihypertensive medication improves both adherence and blood-pressure (BP) control, but does not alter all-cause mortality and cardiovascular (CV) hospitalization risk compared with standard care, study findings show.
Manel Pladevall (Henry Ford Hospital, Detroit, Michigan, USA) and colleagues say: "We did not, however, observe a direct association between adherence and BP control."Therefore, it is possible that the study intervention improved BP control through mechanisms other than improved adherence."
Pladevall and colleagues recruited 79 physicians caring for a combined total of 877 patients aged 50 years or older with uncontrolled hypertension, defined as an average systolic BP (SBP) ≥140 mmHg and/or an average diastolic BP (DBP) ≥90 mmHg.The researchers randomly allocated the physicians to provide standard care (n=39 physicians, 457 patients) or multifactorial intervention (n=40 physicians, 418 patients) in which the physicians counted their patients' pills, assigned a family member to support each patient's adherence, and gave educational information to the patients.All patients had an estimated 10-year CV risk of >30%.
After a mean follow-up period of 39 months, patients who received multifactorial intervention had a 38% lower risk for uncontrolled SBP, but not DBP, than those receiving standard care (p<0.0001). Furthermore, a greater proportion of intervention patients were at least 80% adherent to their medication at 6 months than were those receiving standard care, at 91.9% versus 85.6% (p<0.01).
However, Pladevall and colleagues found that at 5 years, rates of CV-related hospitalization or death from any cause at 5 years were not statistically different in the intervention compared with the standard-care group, at 16% versus 19% (p=0.351).
Even after adjustment for confounding factors such as gender and DBP, this difference remained nonsignificant, as reported in the journal Circulation.
The researchers speculate that their findings may have been influenced by factors such as the Hawthorne effect "whereby patients' knowledge that their adherence was being monitored caused them to change their behavior accordingly."
They therefore call for longer studies to assess patients' adherence levels long after the Hawthorne effect has attenuated.
"Future studies will also be needed to elucidate the impact of this type of intervention on CV morbidity and mortality, because this study was underpowered for those outcomes," they conclude.