Prevalence of treatment-resistant hypertension after considering pseudo-resistance and morbidity: a cross-sectional study in Irish primary care

• Published in: British journal of general practice Vol. 68; no. 671; pp. e394 - e400
• Main Authors: Hayes, Peter, Casey, Monica, Glynn, Liam G, Molloy, Gerard J, Durand, Hannah, O'Brien, Eoin, Dolan, Eamon, Newell, John, Murphy, Andrew W
• Format: Journal Article
• Language: English
• Published: England Royal College of General Practitioners 01-06-2018
• Subjects: Aged; Antihypertensive Agents - therapeutic use; Blood pressure; Blood Pressure Monitoring, Ambulatory - statistics & numerical data; Comorbidity; Cross-Sectional Studies; Diuretics - therapeutic use; Female; Humans; Hypertension; Hypertension - diagnosis; Hypertension - drug therapy; Hypertension - epidemiology; Ireland - epidemiology; Male; Medical treatment; Morbidity; Prevalence; Primary care; Treatment Outcome; White Coat Hypertension - epidemiology; Ireland; primary care; dosing; hypertension; pseudo-resistances; adherence; cross-sectional studies
• ISSN: 0960-1643; 1478-5242
• DOI: 10.3399/bjgp18x696221

To confirm treatment-resistant hypertension (TRH), ambulatory blood pressure measurement (ABPM) must exclude white-coat hypertension (WCH), three or more medications should be prescribed at the optimal doses tolerated, and non-adherence and lifestyle should be examined. Most previous studies have not adequately considered pseudo-resistance and merely provide an apparent TRH (aTRH) prevalence figure.
To conduct a cross-sectional study of the prevalence of aTRH in general practice, and then consider pseudo-resistance and morbidity.
With support, 16 practices ran an anatomical therapeutic chemical (ATC) drug search, identifying patients on any possible hypertensive medications, and then a search of individual patients' electronic records took place.
ABPM was used to rule out WCH. The World Health Organization-defined daily dosing guidelines determined adequate dosing. Adherence was defined as whether patients requested nine or more repeat monthly prescriptions within the past year.
Sixteen practices participated (
= 50 172), and 646 patients had aTRH. Dosing was adequate in 19% of patients, 84% were adherent to medications, as defined by prescription refill, and 43% had ever had an ABPM. Using a BP cut-off of 140/90 mmHg, the prevalence of aTRH was 9% (95% confidence interval [CI] = 9.0 to 10.0). Consideration of pseudo-resistance further reduced prevalence rates to 3% (95% CI = 3.0 to 4.0).
Reviewing individual patient records results in a lower estimate of prevalence of TRH than has been previously reported. Further consideration for individual patients of pseudo-resistance additionally lowers these estimates, and may be all that is required for management in the vast majority of cases.