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Importance of Adherence and the Role of Nonfinancial Barriers
Clinical Therapeutics/Volume 33, Number 9, 2011
Editorial Importance of Adherence and the Role of Nonfinancial Barriers Medication adherence is an umbrella term used to describe the concepts of compliance and persistence with prescribed medication. More prosaically, it refers to the practice of people taking the medicine that is prescribed to them and the issues that arise from their failure to do so. No generally accepted measure of adherence exists,1 and a range of direct and indirect methods has been deployed to measure this behavior, including direct observation of intake, patient questionnaire, and prescription refill patterns. Perhaps unsurprisingly, the level of adherence observed has been shown to vary with how it is measured.2 Estimates of adherence vary among diseases,3,4 as well as among patient groups, differentiated, for example, in terms of age or insurance coverage.3,4 Among developed economies generally, the World Health Organization estimates the average adherence to long-term therapy for chronic illness to be 50%.5 The impact of nonadherence on patient outcomes is often significant, though not axiomatic.2,4,6,7 This is similarly the case with respect to its impact on health care costs. In several studies, use of other health care services, such as unscheduled practitioner visits and inpatient stays, as well as total health care costs were found to rise with nonadherence.3,4,6,8 In other studies, however, the decrease in pharmacotherapy costs associated with nonadherence counterbalanced the increase in costs associated with other aspects of care.9 In part, different findings may reflect the different methodological approaches used in studies, but more likely they reflect genuine differences in the impact of nonadherence for treatment of particular diseases in particular contexts. That said, in the United States alone, the economic burden of nonadherence generally has been estimated at $100 billion,10 with chronic conditions making a significant contribution to the total. The heterogeneity in the level and impact of nonadherence among diseases and patients is noteworthy. It underscores the importance of understanding the multiplicity of reasons that give rise to nonadherence, both in the development of appropriate policy responses and in modeling its consequences in cost-effectiveness analyses. Neither a one-size-fits-all solution nor a one-size-fits-all set of assumptions in modeling is appropriate to deal with what might be better viewed as a set of phenomena rather than a single phenomenon.5 These issues have been discussed at some length in the literature, as has the role of financial barriers in nonadherence and how such barriers may be lessened or eliminated.5,11 An area that perhaps warrants greater attention is that of nonfinancial barriers to adherence, including health literacy. Whereas basic literacy skills, such as reading, arithmetic, and using documents are core attributes of the broader concept, health literacy refers to the set of skills that people need in order to obtain, process, and use information to function effectively in the health care environment. The precise definition of low health literacy is an issue that continues to be debated,12 but that low health literacy may have a significant role in nonadherence is recognized.13 Ethnic minority groups are disproportionately affected by low health literacy, but the majority of those with low health literacy skills in the United States are white, native-born Americans, as the latter group represents the largest segment of the population.14 Health literacy, akin to financial literacy, affects a greater proportion of citizens and can be viewed as a public health goal.15 In a recent systematic review, 6 studies were identified that provided moderate evidence that low health literacy was related to poorer skills in taking medications.16 Two of these were dosing-instrument studies that reported poorer performance among persons with low health literacy.17,18 As the subjects of these studies were child caregivers and parents, there is little evidence to suggest that nonadherence is intentional. It is accepted that nonadherence is a health systems issue,5 and it is acknowledged among the health literacy advocacy community that addressing low health literacy is also a systems issue.19 Although efforts such as “patientcentered labeling” have shown some promise,20 where nonadherence arises as a result of low health literacy, effective remedies require not just better communication but tailored communication and the provision of incentives to ensure that communication happens and is acted upon.
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Volume 33 Number 9
Editorial As the prevalence and complexity of chronic conditions increase with population aging, the roles of pharmacotherapy and adherence in the cost and cost-effective treatment of illness are likely to gain importance. Within the context of increasing fiscal stringency, the opportunity costs of nonadherence, already significant, will likely increase, as will the importance of developing cost-effective solutions to it. The issue is likely to broaden, moreover, as treatment successes in areas such as cancer render diseases once thought of as acute more akin to chronic conditions, where adherence may emerge as an issue. Solutions must reflect the multifaceted nature of nonadherence and the importance of tackling these issues on a system-wide basis. Health literacy is a particular issue; addressing it is possible, and given the position of pharmacists as dispensers of medicines, they may have a pivotal role in tackling the problem. Ciaran O’Neill, PhD Cairns School of Business and Economics NUI Galway Galway, Ireland Diarmuid Coughlan, MPharm, MSc (Health Econ) Department of Health Policy and Management Bloomberg School of Public Health Johns Hopkins University Baltimore, Maryland
REFERENCES 1. Farmer KC. Methods for measuring and monitoring medication regimen adherence in clinical trials and clinical practice. Clin Ther. 1999;21:1074 –1090. 2. Asche C, LaFleur J, Conner C. A review of diabetes treatment adherence and the association with clinical and economic outcomes. Clin Ther. 2011;33:74 –109. 3. Roebuck MC, Liberman JN, Gemmill-Toyama M, Brennan TA. Medication adherence leads to lower health care use and costs despite increased drug spending. Health Aff (Millwood). 2011;30:91–99. 4. Halpern R, Becker L, Iqbal SU, et al. The association of adherence to osteoporosis therapies with fracture, all-cause medical costs, and all-cause hospitalizations: a retrospective claims analysis of female health plan enrollees with osteoporosis. J Manag Care Pharm. 2011;17:25–39. 5. World Health Organization. Adherence to long-term therapies: evidence for action. 2003. http://www.who.int/chp/knowledge/ publications/adherence_full_report.pdf. Accessed July 1, 2011. 6. Lau DT, Nau DP. Oral antihyperglycemic medication nonadherence and subsequent hospitalization among individuals with type 2 diabetes. Diabetes Care. 2004;27:2149 –2153. 7. McDermott MM, Schmitt B, Wallner E. Impact of medication nonadherence on coronary heart disease outcomes. A critical review. Arch Internal Med. 1997;157:1921–1929. 8. Sokol MC, McGuigan KA, Verbrugge RR, Epstein RS. Impact of medication adherence on hospitalization risk and healthcare cost. Med Care. 2005;43:521–530. 9. Mattke S, Martorell F, Hong SY, et al. Anti-inflammatory medication adherence and cost and utilization of asthma care in a commercially insured population. J Asthma. 2010;47:323–329. 10. Lewis A. Noncompliance: a $100 billion problem . Remington Report. 1997;5:14 –15. 11. Goldman DP, Joyce GF, Zheng Y. Prescription drug cost sharing: associations with medication and medical utilization and spending and health. JAMA. 2007;298:61– 69. 12. Wolf MS, Feinglass J, Thompson J, Baker DW. In search of ‘low health literacy’: threshold vs. gradient effect of literacy on health status and mortality. Soc Sci Med. 2010;70:1335–1341. 13. Ngoh LN. Health literacy: a barrier to pharmacist-patient communication and medication adherence. J Am Pharm Assoc (2003). 2009;49:e132– e149. 14. Vernon J, Trujillo A, Rosenbaum S, DeBuono B. Low Health Literacy: Implications for National Health Policy. University of Connecticut, National Bureau of Economic Research: Storrs, Conn; 2007. 15. Nutbeam D. Health literacy as a public health goal: a challenge for contemporary health education and communication strategies into the 21st century. Health Promot Int. 2000;15:259 –267.
September 2011
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Clinical Therapeutics 16. Berkman ND, Sheridan SL, Donahue KE, et al. Low health literacy and health outcomes: an updated systematic review. Ann Intern Med. 2011;155:97–107. 17. Yin HS, Dreyer BP, Foltin G, et al. Association of low caregiver health literacy with reported use of nonstandardized dosing instruments and lack of knowledge of weight-based dosing. Ambul Pediatr. 2007;7:292–298. 18. Yin HS, Mendelsohn AL, Wolf MS, et al. Parents’ medication administration errors: role of dosing instruments and health literacy. Arch Pediatr Adolesc Med. 2010;164:181–186. 19. Volandes AE, Paasche-Orlow MK. Health literacy, health inequality and a just healthcare system. Am J Bioeth. 2007;7:5–10. 20. Wolf MS, Davis TC, Curtis LM, et al. Effect of standardized, patient-centered label instructions to improve comprehension of prescription drug use. Med Care. 2011;49:96 –100.
doi:10.1016/j.clinthera.2011.08.001
1224
Volume 33 Number 9
Editorial Importance of Adherence and the Role of Nonfinancial Barriers Medication adherence is an umbrella term used to describe the concepts of compliance and persistence with prescribed medication. More prosaically, it refers to the practice of people taking the medicine that is prescribed to them and the issues that arise from their failure to do so. No generally accepted measure of adherence exists,1 and a range of direct and indirect methods has been deployed to measure this behavior, including direct observation of intake, patient questionnaire, and prescription refill patterns. Perhaps unsurprisingly, the level of adherence observed has been shown to vary with how it is measured.2 Estimates of adherence vary among diseases,3,4 as well as among patient groups, differentiated, for example, in terms of age or insurance coverage.3,4 Among developed economies generally, the World Health Organization estimates the average adherence to long-term therapy for chronic illness to be 50%.5 The impact of nonadherence on patient outcomes is often significant, though not axiomatic.2,4,6,7 This is similarly the case with respect to its impact on health care costs. In several studies, use of other health care services, such as unscheduled practitioner visits and inpatient stays, as well as total health care costs were found to rise with nonadherence.3,4,6,8 In other studies, however, the decrease in pharmacotherapy costs associated with nonadherence counterbalanced the increase in costs associated with other aspects of care.9 In part, different findings may reflect the different methodological approaches used in studies, but more likely they reflect genuine differences in the impact of nonadherence for treatment of particular diseases in particular contexts. That said, in the United States alone, the economic burden of nonadherence generally has been estimated at $100 billion,10 with chronic conditions making a significant contribution to the total. The heterogeneity in the level and impact of nonadherence among diseases and patients is noteworthy. It underscores the importance of understanding the multiplicity of reasons that give rise to nonadherence, both in the development of appropriate policy responses and in modeling its consequences in cost-effectiveness analyses. Neither a one-size-fits-all solution nor a one-size-fits-all set of assumptions in modeling is appropriate to deal with what might be better viewed as a set of phenomena rather than a single phenomenon.5 These issues have been discussed at some length in the literature, as has the role of financial barriers in nonadherence and how such barriers may be lessened or eliminated.5,11 An area that perhaps warrants greater attention is that of nonfinancial barriers to adherence, including health literacy. Whereas basic literacy skills, such as reading, arithmetic, and using documents are core attributes of the broader concept, health literacy refers to the set of skills that people need in order to obtain, process, and use information to function effectively in the health care environment. The precise definition of low health literacy is an issue that continues to be debated,12 but that low health literacy may have a significant role in nonadherence is recognized.13 Ethnic minority groups are disproportionately affected by low health literacy, but the majority of those with low health literacy skills in the United States are white, native-born Americans, as the latter group represents the largest segment of the population.14 Health literacy, akin to financial literacy, affects a greater proportion of citizens and can be viewed as a public health goal.15 In a recent systematic review, 6 studies were identified that provided moderate evidence that low health literacy was related to poorer skills in taking medications.16 Two of these were dosing-instrument studies that reported poorer performance among persons with low health literacy.17,18 As the subjects of these studies were child caregivers and parents, there is little evidence to suggest that nonadherence is intentional. It is accepted that nonadherence is a health systems issue,5 and it is acknowledged among the health literacy advocacy community that addressing low health literacy is also a systems issue.19 Although efforts such as “patientcentered labeling” have shown some promise,20 where nonadherence arises as a result of low health literacy, effective remedies require not just better communication but tailored communication and the provision of incentives to ensure that communication happens and is acted upon.
1222
Volume 33 Number 9
Editorial As the prevalence and complexity of chronic conditions increase with population aging, the roles of pharmacotherapy and adherence in the cost and cost-effective treatment of illness are likely to gain importance. Within the context of increasing fiscal stringency, the opportunity costs of nonadherence, already significant, will likely increase, as will the importance of developing cost-effective solutions to it. The issue is likely to broaden, moreover, as treatment successes in areas such as cancer render diseases once thought of as acute more akin to chronic conditions, where adherence may emerge as an issue. Solutions must reflect the multifaceted nature of nonadherence and the importance of tackling these issues on a system-wide basis. Health literacy is a particular issue; addressing it is possible, and given the position of pharmacists as dispensers of medicines, they may have a pivotal role in tackling the problem. Ciaran O’Neill, PhD Cairns School of Business and Economics NUI Galway Galway, Ireland Diarmuid Coughlan, MPharm, MSc (Health Econ) Department of Health Policy and Management Bloomberg School of Public Health Johns Hopkins University Baltimore, Maryland
REFERENCES 1. Farmer KC. Methods for measuring and monitoring medication regimen adherence in clinical trials and clinical practice. Clin Ther. 1999;21:1074 –1090. 2. Asche C, LaFleur J, Conner C. A review of diabetes treatment adherence and the association with clinical and economic outcomes. Clin Ther. 2011;33:74 –109. 3. Roebuck MC, Liberman JN, Gemmill-Toyama M, Brennan TA. Medication adherence leads to lower health care use and costs despite increased drug spending. Health Aff (Millwood). 2011;30:91–99. 4. Halpern R, Becker L, Iqbal SU, et al. The association of adherence to osteoporosis therapies with fracture, all-cause medical costs, and all-cause hospitalizations: a retrospective claims analysis of female health plan enrollees with osteoporosis. J Manag Care Pharm. 2011;17:25–39. 5. World Health Organization. Adherence to long-term therapies: evidence for action. 2003. http://www.who.int/chp/knowledge/ publications/adherence_full_report.pdf. Accessed July 1, 2011. 6. Lau DT, Nau DP. Oral antihyperglycemic medication nonadherence and subsequent hospitalization among individuals with type 2 diabetes. Diabetes Care. 2004;27:2149 –2153. 7. McDermott MM, Schmitt B, Wallner E. Impact of medication nonadherence on coronary heart disease outcomes. A critical review. Arch Internal Med. 1997;157:1921–1929. 8. Sokol MC, McGuigan KA, Verbrugge RR, Epstein RS. Impact of medication adherence on hospitalization risk and healthcare cost. Med Care. 2005;43:521–530. 9. Mattke S, Martorell F, Hong SY, et al. Anti-inflammatory medication adherence and cost and utilization of asthma care in a commercially insured population. J Asthma. 2010;47:323–329. 10. Lewis A. Noncompliance: a $100 billion problem . Remington Report. 1997;5:14 –15. 11. Goldman DP, Joyce GF, Zheng Y. Prescription drug cost sharing: associations with medication and medical utilization and spending and health. JAMA. 2007;298:61– 69. 12. Wolf MS, Feinglass J, Thompson J, Baker DW. In search of ‘low health literacy’: threshold vs. gradient effect of literacy on health status and mortality. Soc Sci Med. 2010;70:1335–1341. 13. Ngoh LN. Health literacy: a barrier to pharmacist-patient communication and medication adherence. J Am Pharm Assoc (2003). 2009;49:e132– e149. 14. Vernon J, Trujillo A, Rosenbaum S, DeBuono B. Low Health Literacy: Implications for National Health Policy. University of Connecticut, National Bureau of Economic Research: Storrs, Conn; 2007. 15. Nutbeam D. Health literacy as a public health goal: a challenge for contemporary health education and communication strategies into the 21st century. Health Promot Int. 2000;15:259 –267.
September 2011
1223
Clinical Therapeutics 16. Berkman ND, Sheridan SL, Donahue KE, et al. Low health literacy and health outcomes: an updated systematic review. Ann Intern Med. 2011;155:97–107. 17. Yin HS, Dreyer BP, Foltin G, et al. Association of low caregiver health literacy with reported use of nonstandardized dosing instruments and lack of knowledge of weight-based dosing. Ambul Pediatr. 2007;7:292–298. 18. Yin HS, Mendelsohn AL, Wolf MS, et al. Parents’ medication administration errors: role of dosing instruments and health literacy. Arch Pediatr Adolesc Med. 2010;164:181–186. 19. Volandes AE, Paasche-Orlow MK. Health literacy, health inequality and a just healthcare system. Am J Bioeth. 2007;7:5–10. 20. Wolf MS, Davis TC, Curtis LM, et al. Effect of standardized, patient-centered label instructions to improve comprehension of prescription drug use. Med Care. 2011;49:96 –100.
doi:10.1016/j.clinthera.2011.08.001
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Volume 33 Number 9