Prescribing of antihypertensive agents in public primary care clinics – Is it in accordance with current evidence?
Background: Large population surveys in Malaysia have consistently shown minimal improvement of blood pressure controlrates over the last 10 years. Poor adherence to antihypertensivemedication has been recognized as a major reason for poorcontrol of hypertension. This study aimed to describe the prescribing pattern of antihypertensive agents in 2 public primarycare clinics and assess its appropriateness in relation to current evidence and guidelines.
Methods: A cross-sectional survey to describe the prescribing pattern of antihypertensive agents was carried out in 2 publicprimary care clinics in Selangor from May to June 2009. Hypertensive patients on pharmacological treatment for ≥1 year whoattended the clinics within the study period of 7 weeks were selected. Appropriate use of antihypertensive agents wasdefined based on current evidence and the recommendations by the Malaysian Clinical Practice Guidelines (CPG) on theManagement of Hypertension, 2008. Data were obtained from patients’ medical records and were analysed using the SPSSsoftware version 16.0.
Results: A total of 400 hypertensive patients on treatment were included. Mean age was 59.5 years (SD ±10.9, range 28 to91 years), of which 52.8% were females and 47.2% were males. With regards to pharmacotherapy, 45.7% were on monotherapy,43.3% were on 2 agents and 11.0% were on ≥3 agents. Target blood pressure of <140/90mmHg was achieved in 51.4% ofpatients on monotherapy, and 33.2% of patients on combination of ≥2 agents. The commonest monotherapy agents beingprescribed were β-blockers (atenolol or propranolol), followed by the short-acting calcium channel blocker (nifedipine). Thecommonest combination of 2-drug therapy prescribed was β-blockers and short-acting calcium channel blocker.
Conclusion: This study shows that the prescribing pattern of antihypertensive agents in the 2 primary care clinics was notin accordance with current evidence and guidelines. β-blockers and short-acting preparations were commonly used both asmonotherapy and combination treatment. Thiazide diuretics, ACE inhibitors and long acting calcium channel blockers wereunderutilised in this study, despite robust evidence to support their use. Evidence have also shown that simplifying thenumber of daily doses is effective in improving adherence, therefore a wider use of generic once daily preparation should bestrongly advocated in public primary care clinics.
Kearney PM, Whelton M, Reynolds K, et al. Global burden of hypertension: analysis of worldwide data. Lancet. 2005;365(9455):217-23.
Yusuf S, Reddy S, Ounpuu S, et al. Global burden of cardiovascular diseases: part I: general considerations, the epidemiologic transition, risk factors, and impact of urbanisation. Circulation. 2001;104(22):2746-53.
Third National Health and Morbidity Survey 2006 (NHMS III): Hypertension and Hypercholesterolemia. National Institutes of Health, Malaysia; 2009.
Caro JJ, Speckman JL, Salas M, et al. Effect of initial drug choice on persistence with antihypertensive therapy: the importance of actual practice data. CMAJ. 1999;160(1):41-6.
Psaty BM, Manolio TA, Smith NL, et al. Time trends in high blood pressure control and the use of antihypertensive medications in older adults: the Cardiovascular Health Study. Arch Intern Med. 2002;162(20):2325-32.
Colhoun HM, Dong W, Poulter NR. Blood pressure screening, management and control in England: results from the health survey for England 1994. J Hypertens. 1998;16(6):1702-3.
Sabate E. Adherence to Long-term Therapies: Evidence for Action. Geneva, Switzerland: World Health Organization; 2003.
Malaysian Hypertension Guideline Working Group. Clinical Practice Guidelines on Management of Hypertension. 3rd ed. 2008. MOH/P/PAK/156.08 (GU).
Fischer MA, Avorn J. Economic implications of evidence-based prescribing for hypertension: can better care cost less? JAMA. 2004;291(15):1850-6.
Holmes JS, Shevrin M, Goldman B, et al. Translating research into practice: are physicians following evidence-based guidelines in the treatment of hypertension? Med Care Res Rev. 2004;61(4):453-73.
Chan SC, Chandramani T, Chen TY, et al. Audit of hypertension in general practice. Med J Malaysia. 2005;60(4):475-82.
Roslan Johari MG, Teng SC, Haliza AM, et al. The adequacy audit of outpatient management of essential hypertension cases in MOH hospitals and health centres. 6th MOH-AMM Scientific Meeting; 1-3 September 2005; Legend Hotel, Kuala Lumpur.
Tong SF, Khoo EM, Lee VKM, et al. Management of hypertension in primary care clinics: The process of care and appropriate use of pharmacological agents. Wonca Asia-Pacific Regional Conference 2009; 4-7 June 2009; Hong Kong.
Lindholm LH, Carlberg B, Samuelsson O. Should beta-blockers remain first choice in the treatment of primary hypertension? A meta-analysis. Lancet. 2005;366(9496):1545-53.
Khan N, McAlister FA. Re-examining the efficacy of beta-blockers for the treatment of hypertension: a meta-analysis. CMAJ. 2006;174(12):1737-42.
Elliot WJ, Meyer PM. Incident diabetes in clinical trials of antihypertensive drugs: a network meta-analysis. Lancet. 2007;369(9557):201-7.
Schmieder RE, Martus P, Klinbeil A. Reversal of left ventricular hypertrophy in essential hypertension. A meta-analysis of randomized double-blind studies. JAMA. 1996;275(19):1507-13.
Williams B, Lacy PS, Thom SM, et al. Differential impact of blood pressure-lowering drugs on central aortic pressure and clinical outcomes: principal results of the Conduit Artery Function Evaluation (CAFÉ) study. Circulation. 2006; 113(9):1213-25.
Leenen FH, Wilson TW, Bolli P, et al. Patterns of compliance with once versus twice daily antihypertensive drug therapy in primary care: a randomized clinical trial using electronic monitoring. Can J Cardiol. 1997;13(10):914-20.
Andrejak M, Genes N, Vaur L, et al. Electronic pill-boxes in the evaluation of antihypertensive treatment compliance: comparison of once daily versus twice daily regimen. Am J Hypertens. 2000;13(2):184-90.
Law MR, Wald NJ, Morris JK, et al. Value of low dose combination treatment with blood pressure lowering drugs: analysis of 354 randomised trials. BMJ. 2003;326(7404):1427.
The Seventh report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). United States Department of Health and Human Services; 2003.
National Collaborating Centre for Chronic Conditions, National Institute for Clinical Excellence (NICE). Hypertension: management in adults in primary care: pharmacological update. London: Royal College of Physicians; 2006.
Lim TO, Morad Z. Prevalence, awareness, treatment and control of hypertension in the Malaysian adult population: results from the national health and morbidity survey 1996. Singapore Med J. 2004;45(1):20-27.
Rampal L, Rampal S, Azhar MZ, et al. Prevalence, awareness, treatment and control of hypertension in Malaysia: a national study of 16,440 subjects. Public Health. 2008;122(1):11-8.
Schroeder K, Fahey T, Ebrahim S. How can we improve adherence to blood pressure-lowering medication in ambulatory care? Systematic review of randomised controlled trials. Arch Intern Med. 2004;164(7):722-32.