A Systematic Review of Adherence to Cardiovascular Medications in Resource-Limited Settings
- 480 Downloads
Medications are a cornerstone of the prevention and management of cardiovascular disease. Long-term medication adherence has been the subject of increasing attention in the developed world but has received little attention in resource-limited settings, where the burden of disease is particularly high and growing rapidly. To evaluate prevalence and predictors of non-adherence to cardiovascular medications in this context, we systematically reviewed the peer-reviewed literature.
We performed an electronic search of Ovid Medline, Embase and International Pharmaceutical Abstracts from 1966 to August 2010 for studies that measured adherence to cardiovascular medications in the developing world. A DerSimonian-Laird random effects method was used to pool the adherence estimates across studies. Between-study heterogeneity was estimated with an I2 statistic and studies were stratified by disease group and the method by which adherence was assessed. Predictors of non-adherence were also examined.
Our search identified 2,353 abstracts, of which 76 studies met our inclusion criteria. Overall adherence was 57.5% (95% confidence interval [CI] 52.3% to 62.7%; I2 0.98) and was consistent across study subgroups. Studies that assessed adherence with pill counts reported higher levels of adherence (62.1%, 95% CI 49.7% to 73.8%; I2 0.83) than those using self-report (54.6%, 95% CI 47.7% to 61.5%; I2 0.93). Adherence did not vary by geographic region, urban vs. rural settings, or the complexity of a patient’s medication regimen. The most common predictors of poor adherence included poor knowledge, negative perceptions about medication, side effects and high medication costs.
Our study indicates that adherence to cardiovascular medication in resource-limited countries is sub-optimal and appears very similar to that observed in resource-rich countries. Efforts to improve adherence in resource-limited settings should be a priority given the burden of heart disease in this context, the central role of medications in their management, and the clinical and economic consequences of non-adherence.
KEY WORDScardiovascular medications cardiovascular disease compliance cardiovascular risk reduction
This work was not funded by any external sources.
Conflict of Interest
- 1.WHO. Adherence to Long-term Therapies: Evidence for action. World Health Organisation 2003.Google Scholar
- 7.International Monetary Fund. World economic and financial surveys: List of emerging and developing economies; 2009.Google Scholar
- 8.Wells G, Shea B, O'Connell D, Peterson J, Welch V, Losos M. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomized studies in meta-analyses.Google Scholar
- 9.West S, King V, Carey ST, et al. Systems to Rate the Strength Of Scientific Evidence: Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services; 2002 April 2002.Google Scholar
- 11.Jaynes ET. Confidence intervals vs. Bayesian intervals. In: Harper WL, Hooker CA, eds. Foundations of probability theory, statistical inference, and statistical theories of science. Dordrecht: Reidel; 1976.Google Scholar
- 12.Stuart A, Ord JK. Kendall's Advanced Theory of Statistics. 6th ed. London: Arnold Publishers; 1994.Google Scholar
- 22.Buabeng K. Unaffordable drug prices: the major cause of non-compliance with hypertension medication in Ghana. J Pharm Pharm Sci. 2004;7:350–2.Google Scholar
- 25.Chen W, Huang X, Zheng J, Huang W. Survey on drug compliance of patients with hypertension in residents at Shangmeilin new community in Shenzhen. Chin J Clin Rehabil. 2004;8:5790–1.Google Scholar
- 30.Feng L, Lui J, Duan Y. Medical order-obeying behavior in 164 patients with essential hypertension. Chin J Clin Rehabil. 2005;9:150–1.Google Scholar
- 32.Hadi N, Rostami-Gooran N. Determinant factors of medication compliances in hypertensive patients of Shiraz, Iran. Archives of Iranian Medicine. 2004;7:292–6.Google Scholar
- 44.Naddaf A. Lifestyle of hypertensive patients and their drug compliance. Bulletin of Pharmaceutical Sciences. 2004;27:307–14.Google Scholar
- 50.Salome Kruger H, Gerber JJ. Health beliefs and compliance of black South African outpaitents with antihypertensive medication. Journal of Social and Administrative Pharmacy. 1998;15:201–9.Google Scholar
- 55.Unterhalter B. Compliance with Western medical treatment in a group of black ambulatory hospital patients. Soc Sci Med [Med Psychol Med Sociol]. 1979;13A:621–30.Google Scholar
- 56.Xiao H-M, Jiang X-Y. Drug compliance of elderly patients with hypertension. Chin J Clin Rehabil. 2005;9:30–1.Google Scholar
- 67.Cui J. Association of educational level and behavior of medical compliance with the level of blood glucose in diabetic patients. Chin J Clin Rehabil. 2005;2005:36.Google Scholar
- 78.Yousuf M, Ali M, Bano I. Non-compliance of drug therapy in diabetics- Experience at Lahore. Pakistan Journal of Medical Sciences. 2001;17:74–8.Google Scholar
- 79.Zhang CY, Xie S, Li Y, Li Z. Survey of the drug compliance of type 2 diabetic patients in Chenghai district of Shantou city. Chin J Clin Rehabil. 2005;9:14–5.Google Scholar
- 84.Asefzadeh S, Asefzadeh M, Javadi H. Care management: Adherence to therapies among patients at Bu-Alicina Clinic, Qazvin, Iran. Journal of Research in Medical Sciences. 2005;10:343–8.Google Scholar