Objective To estimate the level of undertreatment of hypertension in a population-based study by taking into account the co-existence of additional cardiovascular risk factors in untreated hypertensives, uncontrolled blood pressure among pharmacologically treated hypertensives and within-person variability in blood pressure and total cholesterol. Design Cross-sectional. Setting Two population-based surveys on cardiovascular disease risk factors conducted during 1987-1995 in The Netherlands. Participants 56 026 men and women aged 20-59 years. Main outcome measures Prevalence of hypertension, of treatment and of undertreatment of hypertension, Undertreated hypertensives were those who were treated pharmacologically, but whose blood pressure was still elevated and those who inappropriately received no medication for the treatment of hypertension. Results During the past decade in The Netherlands, 30% of the hypertensive women and 47% of the hypertensive men aged 20-59 years were undertreated for hypertension. In both men and women treated pharmacologically, 42 and 29%, respectively, still had elevated blood pressure levels. Of those hypertensive men and women not treated pharmacologically, 53 and 34%, respectively, should have been treated when additional cardiovascular risk factors were taken into account. Among those diagnosed but untreated for hypertension, 58 and 31% of the men and women, respectively, should have been treated pharmacologically. Conclusion A considerable proportion of hypertensives were undertreated for hypertension. To decrease the undertreatment of hypertension, it is necessary to obtain better control of blood pressure in patients already being treated, increase the detection of hypertension and improve adherence to the current guidelines. J Hypertens 16:1371-1378 (C) 1998 Lippincott Williams & Wilkins.
