Skip to main content
Log in

Techniques for Measuring Medication Adherence in Hypertensive Patients in Outpatient Settings

Advantages and Limitations

  • Review Article
  • Published:
Disease Management & Health Outcomes

Abstract

Lack of adherence to prescribed antihypertensive regimens constitutes a barrier to adequate blood pressure control and prevention of cardiovascular events. Various means of measuring adherence to antihypertensive medications are currently available for use in clinical practice. The choice of the specific measure used in clinical practice depends on the intended use of the information, the resources available to the provider, as well as patient acceptance and convenience of the method. This article presents an overview of the advantages and limitations of the methods used to measure medication adherence that are currently available for use in outpatient settings, it also outlines provider strategies for addressing adherence issues related to antihypertensive medications.

Indirect methods used to measure adherence in the outpatient setting include self report, electronic adherence monitoring (e.g. medication event monitoring system), pharmacy refill rates, and pill counts. Direct methods include the use of bioassays or biomarkers, which involve laboratory detection of the drug or a metabolic product of the drug in a biologic fluid, or laboratory detection of a biologic marker. Direct observation of the patient taking the medication is also another direct method; however, it is impractical in the outpatient setting, especially for long-term treatment. Each of these methods has advantages and disadvantages; perhaps using a combination of methods may provide the most accurate assessment of adherence.

The information gained from measurement of adherence can help to formulate recommendations for individual patients regarding necessary adjustments to their medication-taking behavior to achieve the optimum outcome. Part of the difficulty associated with achieving better medication adherence lies in the inherent complexity of medication-taking decisions and behavior and of relationships between patients, their healthcare providers, and often others involved in the patient’s care, such as family members. Poor medication adherence and ultimately, adverse cardiovascular outcomes, is related to a variety of factors: quality of life; complexity of medication regimens; costs of medications; adverse effects of medications; demographic, behavioral, treatment and clinical variables; knowledge of hypertension and healthcare system issues; and use of non-conventional therapies. To be effective, strategies employed in clinical practice to overcome nonadherence need to take into account patients’ individual characteristics. Frequently, more than one strategy is necessary to bring about the desired level of adherence. The benefits of proven medical treatments are only available to patients who actively use them; thus, patient adherence to healthcare provider recommendations is the key mediator between medical practice and health outcomes.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Table I

Similar content being viewed by others

References

  1. Osterberg L, Blaschke T. Adherence to medication. N Engl J Med 2005; 353: 487–97

    Article  PubMed  CAS  Google Scholar 

  2. Chobanian AV, Bakris GL, Black HR, et al. The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA 2003; 289: 2560–72

    Article  PubMed  CAS  Google Scholar 

  3. Schroeder K, Fahey T, Ebrahim S. How can we improve adherence to blood pressure-lowering medication in ambulatory care? A systematic review of randomized controlled trials. Arch Intern Med 2004; 164: 722–32

    Article  PubMed  Google Scholar 

  4. Krousel-Wood MA, Thomas S, Muntner P, et al. Medication adherence: a key factor in achieving blood pressure control and good clinical outcomes in hypertensive patients. Curr Opin Cardiol 2004; 19: 357–62

    Article  PubMed  Google Scholar 

  5. Krousel-Wood MA, Hyre A, Muntner P, et al. Methods to improve medication adherence in hypertensive patients: current status and future directions. Curr Opin Cardiol 2005; 20: 296–2300

    Article  PubMed  Google Scholar 

  6. Harmon G, Lefante J, Krousel-Wood MA. Overcoming barriers: the role of providers in improving patient adherence to antihypertensive medications. Curr Opin Cardiol 2006; 21: 310–5

    Article  PubMed  Google Scholar 

  7. Burnier M, Santschi V, Favrat B, et al. Monitoring compliance in resistant hypertension: an important step in patient management. J Hypertens 2003; 21 Suppl. 2: S37–42

    CAS  Google Scholar 

  8. Kearney PM, Whelton M, Reynolds K, et al. Global burden of hypertension. Lancet 2005; 365: 217–23

    PubMed  Google Scholar 

  9. Fields LE, Burt VL, Cutler JA, et al. The burden of adult hypertension in the United States 1999 to 2000: a rising tide. Hypertension 2004; 44: 398–404

    Article  PubMed  CAS  Google Scholar 

  10. Ong KL, Cheung BMY, Man YB, et al. Prevalence, awareness, treatment, and control of hypertension among United States adults 1999–2004. Hypertension 2007; 49: 69–75

    Article  PubMed  CAS  Google Scholar 

  11. Haynes RB, McDonald HP, Garg AX. Helping patients follow prescribed treatment: clinical applications. JAMA 2002; 288: 2880–3

    Article  PubMed  Google Scholar 

  12. DiMatteo MR, Giordani PJ, Lepper HS, et al. Patient adherence and medical treatment outcomes: a meta-analysis. Med Care 2002; 40: 794–811

    Article  PubMed  Google Scholar 

  13. Bramley TJ, Gerbino PP, Nightengale BS, et al. Relationship of blood pressure control to adherence with antihypertensive monotherapy in 13 managed care organizations. J Manag Care Pharm 2006; 12: 239–45

    PubMed  Google Scholar 

  14. Farmer KC. Methods for measuring and monitoring medication regimen adherence in clinical trials and clinical practice. Clin Ther 1999; 21: 1074–90

    Article  PubMed  CAS  Google Scholar 

  15. Vitolins MZ, Rand CS, Rapp SR, et al. Measuring adherence to behavioral and medical interventions. Control Clin Trials 2000; 21 Suppl. 5: 188–94S

    Article  Google Scholar 

  16. Morisky DE, Green W, Levine DM, et al. Concurrent and predictive validity of a self-reported measure of medication adherence. Med Care 1986; 24: 67–74

    Article  PubMed  CAS  Google Scholar 

  17. Kim MT, Hill MN, Bone LR, et al. Development and testing of the Hill-Bone compliance to high blood pressure therapy scale. Prog Cardiovasc Nurs 2000; 15: 90–6

    Article  PubMed  CAS  Google Scholar 

  18. Hamilton GA. Measuring adherence in a hypertension clinical trial. Eur J Cardiovasc Nurs 2003; 2: 219–28

    Article  PubMed  Google Scholar 

  19. Moore MA. Drugs that interrupt the renin-angiotensin system should be among the preferred initial drugs to treat hypertension. J Clin Hypertens 2003; 5: 137–44

    Article  CAS  Google Scholar 

  20. Gordis L. Conceptual and methodological problems in measuring patient adherence. In: Haynes RB, Taylor DW, Sackett DL, editors. Compliance in health care. Baltimore (MD): Johns Hopkins University Press, 1979: 23–45

    Google Scholar 

  21. Shea S, Misra D, Ehrlich M, et al. Correlates of nonadherence to hypertension treatment in an inner-city minority population. Am J Public Health 1992; 82: 1607–12

    Article  PubMed  CAS  Google Scholar 

  22. Krousel-Wood M, Muntner P, Jannu A, et al. Reliability of a medication adherence measure in an outpatient setting. Am J Med Sci 2005; 330: 128–33

    Article  PubMed  Google Scholar 

  23. Hyre A, Krousel-Wood MA, Muntner P, et al. Prevalence and Predictors of poor antihypertensive medication adherence in an urban health clinic setting. J Clin Hypertension 2007; 9: 179–86

    Article  Google Scholar 

  24. Cook CL, Wade WE, Martin BC, et al. Concordance among three self-reported measures of medication adherence and pharmacy refill records. J Am Pharm Assoc 2005; 45: 151–9

    Article  Google Scholar 

  25. Garber MC, Nau DP, Erickson SR, et al. The concordance of self-report with other measures of medication adherence: a summary of the literature. Med Care 2004; 42: 649–52

    Article  PubMed  Google Scholar 

  26. Wang PS, Benner JS, Glynn RJ, et al. How well do patients report noncompliance with antihypertensive medications? A comparison of self-report versus filled prescriptions. Pharmacoepidemiol Drug Saf 2004; 13: 11–9

    Article  PubMed  CAS  Google Scholar 

  27. Svarstad BL, Chewning BA, Sleath BL, et al. The brief medication questionnaire: a tool for screening patient adherence and barriers to adherence. Patient Educ Couns 1999; 37: 113–24

    Article  PubMed  CAS  Google Scholar 

  28. Sherbourne CD, Hays RD, Ordway L, et al. Antecedents of adherence to medical recommendations: results from the Medical Outcomes Study. J Behav Med 1992; 15: 447–68

    Article  PubMed  CAS  Google Scholar 

  29. Claxton AJ, Cramer J, Pierce C. A systematic review of the associations between dose regimens and medication compliance. Clin Ther 2001; 23: 1296–310

    Article  PubMed  CAS  Google Scholar 

  30. Eisen SA, Miller DK, Woodward RS, et al. The effect of prescribed daily dose frequency on patient medication compliance. Arch Intern Med 1990; 150: 1881–4

    Article  PubMed  CAS  Google Scholar 

  31. Koehler AM, Maibach HI. Electronic monitoring in medication adherence measurement: implications for dermatology. Am J Clin Dermatol 2001; 2: 7–12

    Article  PubMed  CAS  Google Scholar 

  32. Choo PW, Rand CS, Inui TS, et al. Validation of patient reports, automated pharmacy records, and pill counts with electronic monitoring of adherence to antihypertensive therapy. Med Care 1999; 37: 846–57

    Article  PubMed  CAS  Google Scholar 

  33. Lee JY, Kusek JW, Greene PG, et al. Assessing medication adherence by pill count and electronic monitoring in the African American Study of Kidney Disease and Hypertension (AASK) pilot study. Am J Hypertens 1996; 9: 719–25

    Article  PubMed  CAS  Google Scholar 

  34. Cramer JA, Sheyer RD, Mattson RH. Compliance declines between clinic visits. Arch Intern Med 1990; 150: 1509–10

    Article  PubMed  CAS  Google Scholar 

  35. Vik SA, Maxwell CJ, Hogan DB. Measurement, correlates, and health outcomes of medication adherence among seniors. Ann Pharmacother 2004; 38: 303–12

    Article  PubMed  Google Scholar 

  36. Grant RW, Singer DE, Meigs JB. Medication adherence before an increase in antihypertensive therapy: a cohort study using pharmacy claims data. Clin Ther 2005; 27: 773–81

    Article  PubMed  Google Scholar 

  37. Steiner JF, Prochazka AV. The assessment of refill compliance using pharmacy records: methods, validity and applications. J Clin Epidemiol 1997; 50: 105–16

    Article  PubMed  CAS  Google Scholar 

  38. Christensen DB, Williams B, Goldberg HI, et al. Assessing compliance to antihypertensive medications using computer-based pharmacy records. Med Care 1997; 35: 1164–70

    Article  PubMed  CAS  Google Scholar 

  39. Hess LM, Raebel MA, Conner DA, et al. Measurement of adherence in pharmacy administrative databases: a proposal for standard definitions and preferred measures. Ann Pharmacother 2006; 40: 1280–8

    Article  PubMed  Google Scholar 

  40. Porter JA, Raebel MA, Conner DA, et al. The Long-term Outcomes of Sibutramine Effectiveness on Weight (LOSE Weight) Study; evaluating the role of drug therapy on weight management in a group HMO. Am J Manag Care 2004; 10: 369–76

    PubMed  Google Scholar 

  41. Grymonpre RE, Didur CD, Montgomery PR, et al. Pill count, self-report, and pharmacy claims data to measure medication adherence in the elderly. Ann Pharmacotherapy 1999; 32: 749–54

    Google Scholar 

  42. Stephenson BJ, Rowe BH, Haynes RB, et al. The rational clinical examination: is this patient taking the treatment as prescribed? JAMA 1993; 269: 2779–81

    Article  PubMed  CAS  Google Scholar 

  43. Silberstein RM, Blackman S. A method to evaluate whether patients take prescribed medication. Clin Pediatr 1966; 5: 239–40

    Article  CAS  Google Scholar 

  44. Azizi M, Menard J, Peyrard S, et al. Assessment of patients’ and physicians’ compliance to an ACE inhibitor treatment based on urinary N-acetyl ser-asplys-pro determination in the noninsulin-dependent diabetes, hypertension, microalbuminuria, proteinuria, cardiovascular events, and ramipril (DIABHYCAR) study. Diabetes Care 2006; 29: 1331–6

    Article  PubMed  Google Scholar 

  45. Braam RL, van Uum SHM, Russel FGM, et al. Bromide as a marker to measure adherence to drug therapy. Eur J Clin Pharmacol 2006; 62: 285–90

    Article  PubMed  Google Scholar 

  46. Donahoo WT, Bessesen DH, Higbee DR, et al. Serum lithium concentration can be used to assess dietary compliance in adults. J Nutr 2004; 134: 3133–6

    PubMed  CAS  Google Scholar 

  47. Kiortsis DN, Elisaf MS. Serum uric acid levels: a useful but not absolute marker of compliance with fenofibrate treatment. Fundam Clin Pharmacol 2001; 15: 401–3

    Article  PubMed  CAS  Google Scholar 

  48. Vitiello B, Shader RI, Parker CB, et al. Hyperforin plasma level as a marker of treatment adherence in the National Institutes of Health hypericum depression trial. J Clin Psychopharmacol 2005; 25: 243–9

    Article  PubMed  CAS  Google Scholar 

  49. Anastasio GD, Little Jr JM, Robinson MD, et al. Impact of compliance and side effects on the clinical outcome of patients treated with oral erythromycin. Pharmacotherapy 1994; 14: 229–34

    PubMed  CAS  Google Scholar 

  50. Wroe A. Intentional and unintentional nonadherence: a study of decision making. J Behav Med 2002; 25: 355–72

    Article  PubMed  Google Scholar 

  51. Johnson MJ, Williams M, Marshall ES. Adherent and nonadherent medication-taking in elderly hypertensive patients. Clin Nurs Res 1999; 8: 318–35

    Article  PubMed  CAS  Google Scholar 

  52. Lowry KP, Dudley TK, Oddone EZ, et al. Intentional and unintentional nonadherence to antihypertensive medication. Ann Pharmacother 2005; 19: 1198–203

    Article  Google Scholar 

  53. Svensson S, Kjellgren KI, Ahlner J, et al. Reasons for adherence with antihypertensive medication. Int J Cardiol 2000; 76: 157–63

    Article  PubMed  CAS  Google Scholar 

  54. De Geest S, von Renteln-Kruse W, Steeman E, et al. Compliance issues with the geriatric population. Nurs Clin North Am 1998; 33: 467–80

    PubMed  Google Scholar 

  55. Elliott WJ. Optimizing medication adherence in older persons with hypertension. Int Urol Nephrol 2003; 35: 557–62

    Article  PubMed  Google Scholar 

  56. Maro EE, Lwakatare J. Medication compliance among Tanzanian hypertensives. East Afr Med J 1997; 74: 539–42

    PubMed  CAS  Google Scholar 

  57. Feldman R, Bacher M, Campbell N, et al. Adherence to pharmacologic management of hypertension. Can J Public Health 1998; 89: 116–18

    Google Scholar 

  58. Patton K, Meyers J, Edelman Lewis B. Enhancement of compliance among patients with hypertension. Am J Manag Care 1997; 3: 1693–8

    PubMed  CAS  Google Scholar 

  59. Menzin J, Lang K, Elliott WJ, et al. Adherence to calcium channel blocker therapy in older adults: a comparison of amlodipine and felodipine. J Int Med Res 2004; 32: 233–9

    PubMed  CAS  Google Scholar 

  60. Ogedegbe G, Schoenthaler A. A systematic review of the effects of home blood pressure monitoring on medication adherence. J Clin Hypertens 2006; 8: 174–80

    Article  Google Scholar 

  61. Kravitz RL, Melnikow J. Medical adherence research: time for a change in direction? [editorial]. Med Care 2004; 42: 197–9

    Article  PubMed  Google Scholar 

Download references

Acknowledgments

This work was supported, in part, by a grant from the National Institutes of Health (grant no. R01 AG 022536), with Dr Krousel-Wood as principal investigator. The authors have no conflicts of interest that are directly relevant to the content of this review.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Marie A. Krousel-Wood MD, MSPH.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hawkshead, J., Krousel-Wood, M.A. Techniques for Measuring Medication Adherence in Hypertensive Patients in Outpatient Settings. Dis-Manage-Health-Outcomes 15, 109–118 (2007). https://doi.org/10.2165/00115677-200715020-00006

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.2165/00115677-200715020-00006

Keywords

Navigation