Birtwhistle RV, Godwin MS, Delva D, et al: Randomised equivalence trial comparing three month and six month follow up of patients with hypertension by family practitioners. Brit Med J 2004;328(7433):204-9.
The National Committee on Detection, Evaluation and Treatment of High Blood Pressure (JNC 7) recommends that once blood pressure is stabilized, follow-up every 3 to 6 months is appropriate. To compare the effects of a 3-month or 6-month follow-up, 609 patients aged 30 to 74 years with essential hypertension who were receiving drug treatment from 1 of 50 family practices in Ontario, Canada, were randomized to return every 3 or 6 months for follow-up.
After 3 years, there were no significant differences between the groups in blood pressure control, adherence to medication, or patient satisfaction. Patients in both groups visited their doctor more often than their assigned follow-up times, but the 6-month group had fewer visits to the doctor overall (mean 16.2 visits compared to 18.8 visits in the 3-month group, P <0.0001).
About 20% of patients' hypertension was out of control at any time during the study in both groups. Factors other than how often a patient returns for follow-up may be more important determinants of blood pressure control.