Original Article

Hypertens Research 2008 31, 1765–1771; doi:10.1291/hypres.31.1765

Physicians' Ability to Predict Patients' Adherence to Antihypertensive Medication in Primary Care

Andreas Zeller1, Anne Taegtmeyer1, Benedict Martina2, Edouard Battegay1,3 and Peter Tschudi2

  1. 1Medical Outpatient Department, University Hospital Basel, Basel, Switzerland
  2. 2Institute of Primary Health Care, University Hospital Basel, Basel, Switzerland
  3. 3Division of Internal Medicine, University Hospital Zürich, Zürich, Switzerland

Correspondence: Zeller Andreas, M.D., Medical Outpatient Department, University Hospital Basel, Petersgraben 4, CH–4031 Basel, Switzerland. E-mail: zellera@uhbs.ch

Received 14 May 2008; Accepted 2 July 2008.



Addressing adherence to medication is essential and notoriously difficult. The purpose of this study was to determine physicians' ability to predict patients' adherence to antihypertensive therapy. Primary care physicians were asked to predict the adherence to medication of their hypertensive patients (n=42) by using a visual analogue scale (VAS) at the beginning of the study period. The patients were asked to report their adherence to medication using a VAS. The adherence was then monitored by using a Medical Event Monitoring System (MEMS) for 42±14 d. The means±SD (range) of MEMS measures for timing adherence, correct dosing, and adherence to medication were 82±27% (0 to 100%), 87±24percnt; (4 to 100%), and 94± 18% (4 to 108%), respectively. The physicians' prediction of their patients' adherence was 92± 15% The Spearman rank correlations between the physician's prediction and the MEMS measures of timing adherence, correct dosing, and adherence to medication was 0.42 (p=0.006), 0.47 (p=0.002), and –0.02 (p=0.888), respectively. The patients reported their own adherence to medication at 98±2% (range 83 to 100%). The Spearman correlations between the reported and actual behaviours were 0.27 (p=0.08) for timing adherence, 0.25 (p=0.12) for correct dosing, and 0.11 (p=0.51) for adherence to medication. The physicians' ability to predict patients' adherence to antihypertensive medication is limited and not accurate for identifying non-adherent patients in clinical practice. Even patients themselves are unable to give accurate reports of their own adherence to medication.


hypertension, adherence, compliance, primary care, visual analogue scale



  1. Dahlof B, Lindholm LH, Hansson L, Schersten B, Ekbom T, Wester PO: Morbidity and mortality in the Swedish Trial in Old Patients with Hypertension (STOP-Hypertension). Lancet 1991; 338: 1281–1285. | Article | PubMed | ISI | ChemPort |
  2. Hansson L, Zanchetti A, Carruthers SG, et al: Effects of intensive blood-pressure lowering and low-dose aspirin in patients with hypertension: principal results of the Hypertension Optimal Treatment (HOT) randomised trial. HOT Study Group. Lancet 1998; 351: 1755–1762. | Article | PubMed | ISI | ChemPort |
  3. Osterberg L, Blaschke T: Adherence to medication. N Engl J Med 2005; 353: 487–497. | Article | PubMed | ISI | ChemPort |
  4. Melnikow J, Kiefe C: Patient compliance and medical research: issues in methodology. J Gen Intern Med 1994; 9: 96–105.
  5. Urquhart J: Patient non-compliance with drug regimens: measurement, clinical correlates, economic impact. Eur Heart J 1996; 17 (Suppl A): 8–15. | PubMed | ChemPort |
  6. Vitolins MZ, Rand CS, Rapp SR, Ribisl PM, Sevick MA: Measuring adherence to behavioral and medical interventions. Control Clin Trials 2000; 21: 188S–194S.
  7. Norell SE: Accuracy of patient interviews and estimates by clinical staff in determining medication compliance. Soc Sci Med [E] 1981; 15: 57–61.
  8. Gilbert JR, Evans CE, Haynes RB, Tugwell P: Predicting compliance with a regimen of digoxin therapy in family practice. Can Med Assoc J 1980; 123: 119–122.
  9. Bangsberg DR, Hecht FM, Clague H, et al: Provider assessment of adherence to HIV antiretroviral therapy. J Acquir Immune Defic Syndr 2001; 26: 435–442.
  10. Gross R, Bilker WB, Friedman HM, Coyne JC, Strom BL: Provider inaccuracy in assessing adherence and outcomes with newly initiated antiretroviral therapy. Aids 2002; 16: 1835–1837.
  11. Miller LG, Liu H, Hays RD, et al: How well do clinicians estimate patients' adherence to combination antiretroviral therapy? J Gen Intern Med 2002; 17: 1–11.
  12. Murri R, Ammassari A, Trotta MP, et al: Patient-reported and physician-estimated adherence to HAART: social and clinic center-related factors are associated with discordance. J Gen Intern Med 2004; 19: 1104–1110.
  13. Macintyre CR, Goebel K, Brown GV: Patient knows best: blinded assessment of nonadherence with antituberculous therapy by physicians, nurses, and patients compared with urine drug levels. Prev Med 2005; 40: 41–45.
  14. Bland JM, Altman DG: Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986; 1: 307–310. | PubMed | ISI | ChemPort |
  15. Wetzels GE, Nelemans P, Schouten JS, Prins MH: Factsb and fiction of poor compliance as a cause of inadequate blood pressure control: a systematic review. J Hypertens 2004; 22: 1849–1855. | Article | PubMed | ISI | ChemPort |
  16. Paterson DL, Swindells S, Mohr J, et al: Adherence to protease inhibitor therapy and outcomes in patients with HIV infection. Ann Intern Med 2000; 133: 21–30. | PubMed | ISI | ChemPort |
  17. Svarstad BL, Chewning BA, Sleath BL, Claesson C: The Brief Medication Questionnaire: a tool for screening patient adherence and barriers to adherence. Patient Educ Couns 1999; 37: 113–124.
  18. Zeller A, Schroeder K, Peters TJ: An adherence self–report questionnaire facilitated the differentiation between nonadherence and nonresponse to antihypertensive treatment. J Clin Epidemiol 2008; 61: 282–288.
  19. Wetzels G, Nelemans P, van Wijk B, Broers N, Schouten J, Prins M: Determinants of poor adherence in hypertensive patients: development and validation of the "Maastricht Utrecht Adherence in Hypertension (MUAH)-questionnaire." Patient Educ Couns 2006; 64: 151–158.
  20. Bailey JE, Lee MD, Somes GW, Graham RL: Risk factors for antihypertensive medication refill failure by patients under Medicaid managed care. Clin Ther 1996; 18: 1252–1262. | PubMed |
  21. Beardon PH, McGilchrist MM, McKendrick AD, McDevitt DG, MacDonald TM: Primary non–compliance with prescribed medication in primary care. BMJ 1993; 307: 846–848. | PubMed | ChemPort |
  22. Stephenson BJ, Rowe BH, Haynes RB, Macharia WM, Leon G: The rational clinical examination. Is this patient taking the treatment as prescribed? JAMA 1993; 269: 2779–2781. | Article | PubMed |
  23. Morisky DE, Green LW, Levine DM: Concurrent and predictive validity of a self-reported measure of medication adherence. Med Care 1986; 24: 67–74. | Article | PubMed | ChemPort |
  24. Fodor GJ, Kotrec M, Bacskai K, et al: Is interview a reliable method to verify the compliance with antihypertensive therapy? An international central–European study. J Hypertens 2005; 23: 1261–1266.
  25. Insull W: The problem of compliance to cholesterol altering therapy. J Intern Med 1997; 241: 317–325.
  26. Wickstrom G, Bendix T: The "Hawthorne effect".what did the original Hawthorne studies actually show? Scand J Work Environ Health 2000; 26: 363–367. | PubMed | ISI | ChemPort |
  27. Urquhart J, De Klerk E: Contending paradigms for the interpretation of data on patient compliance with therapeutic drug regimens. Stat Med 1998; 17: 251–267; discussion 387–389. | Article | PubMed | ChemPort |
  28. Mengden T, Binswanger B, Spuhler T, Weisser B, Vetter W: The use of self–measured blood pressure determinations in assessing dynamics of drug compliance in a study with amlodipine once a day, morning versus eveni ng. J Hypertens 1993; 11: 1403–1411.
  29. McKenney JM, Munroe WP, Wright JT Jr: Impact of an electronic medication compliance aid on long–term blood pressure control. J Clin Pharmacol 1992; 32: 277–283.
  30. Burnier M, Schneider MP, Chiolero A, Stubi CL, Brunner HR: Electronic compliance monitoring in resistant hypertension: the basis for rational therapeutic decisions. J Hypertens 2001; 19: 335–341. | Article | PubMed | ISI | ChemPort |
  31. Oyugi JH, Byakika–Tusiime J, Charlebois ED, et al: Multiple validated measures of adherence indicate high levels of adherence to generic HIV antiretroviral therapy in a resource–limited setting. J Acquir Immune Defic Syndr 2004; 36: 1100–1102.
  32. Giordano TP, Guzman D, Clark R, Charlebois ED, Bangsberg DR: Measuring adherence to antiretroviral therapy in a diverse population using a visual analogue scale. HIV Clin Trials 2004; 5: 74–79.


These links to content published by NPG are automatically generated.