AIDS and Behavior

, Volume 5, Issue 3, pp 275–281 | Cite as

Comparing Objective Measures of Adherence to HIV Antiretroviral Therapy: Electronic Medication Monitors and Unannounced Pill Counts

  • David R. Bangsberg
  • Frederick M. Hecht
  • Edwin D. Charlebois
  • Margaret Chesney
  • Andrew Moss


We compared electronic medication monitoring and electronic monitoring adjusted by interview with an unannounced pill-count adherence measure, in a cross-sectional analysis (n = 42). We used the following measures (a) electronic monitored doses (EMD: # medication monitor openings/# doses prescribed), (b) adjusted electronically monitored doses (AEMD: EMD adjusted by the number of extra openings and extra doses removed), (c) percentage of days dose taken (PDDT: % days the medication monitor was opened at least once, and (d) unannounced pill count (PC). The results showed that AEMD, EMD, and PDDT were significantly associated with PC adherence. AEMD explained 83% of the variation in PC adherence, EMD 49%, and PDDT 58%. EMD adherence was significantly lower than PC adherence (p = .02). Electronic medication monitoring measures were closely related to PC adherence. AEMD was more closely associated than EMD or PDDT. EMD may underestimate adherence due to the removal of multiple doses from the bottle at one time.

HIV adherence electronic medication monitoring MEMS pill count highly active antiretroviral therapy homeless drug use 


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  1. Arnet, I., and Haefeli, W. E. (2000). Overconsumption detected by electronic drug monitoring requires subtle interpretation. Clinical Pharmacology and Therapeutics, 67, 44–47.Google Scholar
  2. Bangsberg, D. R., Hecht, F. M., Charlebois, E. D., Zolop, A. R., Holodniy, M., Sheiner, L., Bamberger, J. D., Chesney, M. A., and Moss, A. (2000). Adherence to protease inhibitors, HIV-1 viral load, and development of drug resistance in an indigent population, AIDS, 14, 357–366.Google Scholar
  3. Bangsberg, D., and Moss, A. (1999).When should we delay highly active antiretroviral therapy? Journal of General Internal Medicine, 14, 446–448.Google Scholar
  4. Bangsberg, D., Tulsky, J. P., Hecht, F. M., and Moss, A. R. (1997). Protease inhibitors in the homeless. JAMA, 278, 63–65.Google Scholar
  5. Craig, H. M. (1985). Accuracy of indirect measures of medication compliance in hypertension, Research in Nursing Health, 8, 61–66.Google Scholar
  6. Descampes, D., Flandre, P., Calvez, V., Petavin, G., Meiffredy, V., Collin, G., Delaugerre, C., Robert-Delmas, S., Bazin, B., Aboulker, J., Pialoux, G., Raffi, F. and Brun-Vezinet, F. (2000). Mechanisms of virologic failure in previously untreated HIV-infected patients from a trial of induction-maintenance therapy, JAMA, 283, 205–211.Google Scholar
  7. Farmer, K. C. (1999). Methods for measuring and monitoring medication regimen adherence in clinical trials and clinical practice, Clinical Therapeutics, 21, 1074–1090; discussion 1073.Google Scholar
  8. Gerbert, B., Abercombie, P., Bronstone, A., Clannon, K., and Bangsberg, D. (2000). Challenges in adherence:The providers' perspective, AIDS Care, 12, 409–421.Google Scholar
  9. Gifford, A. L., Bormann, J. E., Shively, M. J., Wright, B. C., Richman, D. D., and Bozzette, S. A. (2000). Predictors of self-reported adherence and plasma HIV concentrations in patients on multidrug antiretroviral regimens, Journal of Acquired Immune Deficiency Syndrome, 23, 386–395.Google Scholar
  10. Gilbert, J. R., Evans, C. E., Haynes, R. B., and Tugwell, P. (1980). Predicting compliance with a regimen of digoxin therapy in family practice, Canadian Medical Association Journal, 123, 119–122.Google Scholar
  11. Gordis, L., Markowitz, M., and Lilienfeld, A. M. (1969). Studies in the epidemiology and preventability of rheumatic fever. IV. Aquantitative determination of compliance in children on oral penicillin prophylaxis, Pediatrics, 43, 173–182.Google Scholar
  12. Grymonpre, R. E., Didur, C. D., Montgomery, P. R., and Sitar, D. S. (1998). Pill count, self-report, and pharmacy claims data to measure medication adherence in the elderly, Annals of Pharmacotherapy, 32, 749–754.Google Scholar
  13. Haubrich, R. H., Little, S. J., Currier, J. S., Forthal, D. N., Kemper, C. A., Beall, G. N., Johnson, D., Dube, M. P., Hwang, J. Y., and McCutchan, J. A. (1999). The value of patient-reported adherence to antiretroviral therapy in predicting virologic and immunologic response. California Collaborative Treatment Group, AIDS, 13, 1099–1107.Google Scholar
  14. Havlir, D. V., Hellmann, N. S., Petropoulos, C. J., Whitcomb, J. M., Collier, A. C., Hirsch, M. S., Tebas, P., Sommadossi, J. P., and Richman, D. D. (2000). Drug susceptibility in HIV infection after viral rebound in patients receiving indinavir-containing regimens [see comments], JAMA, 283, 229–234.Google Scholar
  15. Inui, T. S., Carter, W. B., and Pecoraro, R. E. (1981). Screening for noncompliance among patients with hypertension: Is self-report the best availablemeasure? Medical Care, 19, 1061–1064.Google Scholar
  16. Kastrissios, H., Suarez, J. R., Katzenstein, D., Girard, P., Sheiner, L. B., and Blaschke, T. F. (1998). Characterizing patterns of drug-taking behavior with a multiple drug regimen in an AIDS clinical trial, AIDS, 12, 2295–2303.Google Scholar
  17. Lee, J. Y., Kusek, J. W., Greene, P. G., Bernhard, S., Norris, K., Smith, D., Wilkening, B., and Wright, J. T., Jr. (1996). Assessing medication adherence by pill count and electronic monitoring in the African American Study of Kidney Disease and Hypertension (AASK) Pilot Study, American Journal of Hypertension, 9, 719–725.Google Scholar
  18. Matsui,D., Hermann, C., Klein, J., Berkovitch, M., Olivieri, N., and Koren, G. (1994). Critical comparison of novel and existing methods of compliance assessment during a clinical trial of an oral iron chelator, Journal of Clinical Pharmacology, 34, 944–949.Google Scholar
  19. Metry, J. M., and Meyer, U. A. (1999). Drug regimen compliance. Chichester, West Sussex: Wiley.Google Scholar
  20. Paes, A. H., Bakker, A., and Soe-Agnie, C. J. (1998). Measurement of patient compliance, Pharmology World Science, 20, 73–77.Google Scholar
  21. Paterson, D. L., Swindells, S., Mohr, J., Brester, M., Vergis, E. N., Squier, C., Wagener, M. M., and Singh, N. (2000). Adherence to protease inhibitor therapy and outcomes in patients with HIV infection, Annals of Internal Medicine, 133, 21–30.Google Scholar
  22. Straka, R. J., Fish, J. T., Benson, S. R., and Suh, J. T. (1997). Patient self-reporting of compliance does not correspond with electronic monitoring: An evaluation using isosorbide dinitrate as a model drug, Pharmacotherapy, 17, 126–132.Google Scholar
  23. Vanhove, G. F., Schapiro, J. M., Winters, M. A., Merigan, T. C., and Blaschke, T. F. (1996). Patient compliance and drug failure in protease inhibitor monotherapy [letter], JAMA, 276, 1955–1956.Google Scholar
  24. Waterhouse, D. M., Calzone, K. A., Mele, C., and Brenner, D. E. (1993). Adherence to oral tamoxifen: a comparison of patient self-report, pill counts, and microelectronic monitoring [see comments], Journal of Clinical Oncology, 11(6), 1189–1197.Google Scholar
  25. Zolopa, A. R., Hahn, J. A., Gorter, R., Miranda, J., Wlodarczyk, D., Peterson, J., Pilote, L., and Moss, A. R. (1994). HIV and tuberculosis infection in San Francisco's homeless adults. Prevalence and risk factors in a representative sample [see comments], JAMA, 272(6), 455–461.Google Scholar

Copyright information

© Plenum Publishing Corporation 2001

Authors and Affiliations

  • David R. Bangsberg
    • 1
    • 2
  • Frederick M. Hecht
    • 2
  • Edwin D. Charlebois
    • 1
  • Margaret Chesney
    • 3
  • Andrew Moss
    • 4
  1. 1.Epidemiology and Prevention Interventions Center, Division of Infectious DiseasesSan Francisco General Hospital, UCSFSan Francisco
  2. 2.Positive Health ProgramSan Francisco General Hospital, UCSFSan Francisco
  3. 3.Center for AIDS Prevention Studies, UCSFSan Francisco
  4. 4.Department of Epidemiology and Biostatistics, UCSF and Medical ServiceSan Francisco General Hospital, UCSFSan Francisco

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