Objective To identify various types of non-adherence among users of antihypertensive medications by establishing components of adherence measures and use these components for measuring the prevalence of non-adherence. Setting Twelve community pharmacies from the Danish county of Funen. Method Users of antihypertensive medication were included in the study. 2,914 medication users received questionnaires by mail. Participating patients were asked to fill in two questionnaire regarding demographics, self-reported blood pressure, and various adherence measures. Two factor analyses were conducted based on responses to questions. Main outcome measures Medication-taking behaviour and self-efficacy (beliefs about ability and capacity to accomplish a task), respectively. Other measures of non-adherence collected by questionnaire were also addressed in the data for comparison of prevalence with the developed concepts. Results 1,426 (49%) participants answered the questionnaires. The analyses resulted in two sets of components: three adherence behaviour measures and two self-efficacy measures which showed similarities in concepts. The adherence behaviour measures included two concepts of intentional nonadherence (associated with aspects of self-regulation and effect concerns, respectively) and one measure of non-intentional non-adherence. Prevalence of the developed measures of behaviour related non-adherence ranged from 10.3 to 34.9% depending on which type of non-adherence measure was used. Established measures of non-adherence resulted in prevalence between 2.2 and 39.6%. Conclusions The study showed that concepts of non-adherence measurements could be determined including self-efficacy aspects, unintentional non-adherence and intentional non-adherence related to self-regulation and effect concerns respectively. The prevalence of the adherence behaviour components were found to be between 10.3 and 34.9%, which is in the range of expected values. Associations between the new concepts of non-adherence measurement and characteristics of nonadherers remain to be established and would be a subject for further studies.
Antihypertensives Non-adherence Self-efficacy
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We are grateful for the support from all participating patients, pharmacy staff and general practitioners who contributed to the project. The project was overviewed by a steering committee consisting of members representing pharmacies, general practitioners and researchers, and we are thankful for their support and efforts throughout the study.
Conflicts of interest
To our knowledge, none of the authors have any conflicts of interest.
Nissen NK, Rasmussen S. 2008 Heart Statistics-Focus on gender and social difference. <2008 HjerteStatistik-Fokus på køn og social forskelle>. Copenhagen: The Danish Heart Foundation and National Institute of Public Health University of Southern Denmark; 2008.Google Scholar
Adherence to long-term therapies: evidence for action. Noncommunicable diseases and mental health adherence to long term therapies project. Geneva: World Health Organisation; 2003. ISBN 92 4 154599 2.Google Scholar
Horne R, Weinman J, Barber N, Elliott R, Morgan M. Concordance, adherence and compliance in medicine taking. Report for the national co-ordination centre for NHS service delivery and organisation R&D (NCCSDO); December 2005. Available from http://www.sdo.nihr.ac.uk/files/project/76-final-report.pdf.
The 6th report of the joint national commission on high blood pressure. Arch Int Med 1997;157: 2413–56.Google Scholar
Urquhart J. The odds of the three nons when an aptly prescribed medicine isn’t working: non-compliance, non-absorption, non-response. Br J Clin Pharmacol. 2002;54:212–20.PubMedCrossRefGoogle Scholar
Ho PM, Magid DJ, Shetterly SM, Olson KL, Peterson PN, Masoudi FA, et al. Importance of therapy intensification and medication nonadherence for blood pressure control in patients with coronary disease. Arch Intern Med. 2008;168:271–6.PubMedCrossRefGoogle Scholar
Mazzaglia G, Ambrosioni E, Alacqua M, Filippi A, Sessa E, Immordino V, et al. Adherence to antihypertensive medications and cardiovascular morbidity among newly diagnosed hypertensive patients. Circulation. 2009;120:1598–605.PubMedCrossRefGoogle Scholar
Horne R, Clatworthy J, Polmear A, Weinman J. Do hypertensive patients’ beliefs about their illness and treatment influence medication adherence and quality of life? J Hum Hypertens. 2001;Suppl 1:65–8.Google Scholar
Clifford S, Barber N, Horne R. Understanding different beliefs held by adherers, unintentional nonadherers, and intentional nonadherers: application of the necessity–concerns framework. J Psychosom Res. 2008;64:41–6.PubMedCrossRefGoogle Scholar
Rickles N, Svarstad B. Relationships between multiple self-reported nonadherence measures and pharmacy records. Res Social Adm Pharm. 2007;3:363–77.PubMedGoogle Scholar
Sumartojo E. When tuberculosis treatment fails. A social behavioural account of patient adherence. Am Rev Respir Dis. 1993;147:1311–20.PubMedGoogle Scholar
Matza LS, Park J, Coyne KS, Skinner EP, Malley KG, Wolever RQ. Derivation and validation of the ASK-12 adherence barrier survey. Ann Pharmacother. 2009;43:1621–30.PubMedCrossRefGoogle Scholar
Garber MC, Nau DP, Erickson SR, Aikens JE, Lawrence JB. The concordance of self-report with other measures of medication adherence: A summary of the literature. Med Care. 2004;42:649–52.PubMedCrossRefGoogle Scholar
Hansen RA, Kim MM, Song L, Tu W, Wu J, Murray MD. Comparison of methods to assess medication adherence and classify nonadherence. Ann Pharmacother. 2009;43:413–22.PubMedCrossRefGoogle Scholar
Vrijens B, Urquhart J. Patient adherence to prescribed antimicrobial drug dosing regimens. J Antimicrob Chemother. 2005;55:616–27.PubMedCrossRefGoogle Scholar
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;37:113–24.PubMedCrossRefGoogle Scholar
Morisky DE, Green LW, Levine DM. Concurrent and predictive validity of a self-reported measure of medication adherence. Med Care. 1986;24(1):67–74.PubMedCrossRefGoogle Scholar
Ogedegbe G, Mancuso CA, Allegrante JP, Charlson ME. Development and evaluation of a medication adherence self-efficacy scale in hypertensive African-American patients. J Clin Epidemiol. 2003;56:520–9.PubMedCrossRefGoogle Scholar
Insel KC, Reminger SL, Hsiao C-P. The negative association of independent personality and medication adherence. J Aging Health. 2006;18:407–18.PubMedCrossRefGoogle Scholar
Horne R, Weinman J, Hankins M. The beliefs about medicines questionnaire: the development and evaluation of a new method for assessing the cognitive representation of the medication. Psychol Health. 1999;14:1–24.CrossRefGoogle Scholar
Horne R, Hankins M, Jenkins R. The satisfaction with information about medicines scale (SIMS new measurement tool for audit and research. Qual Health Care. 2001;10:135–40.PubMedCrossRefGoogle Scholar
Weintraub M. Intelligent noncompliance with special emphasis on the elderly. Contemp Pharm Pract. 1981;4:8–11.PubMedGoogle Scholar
Vrijens B, Vincze G, Kristanto P, Urquhart J, Burnier M. Adherence to prescribed antihypertensive drug treatments: longitudinal study of electronically compiled dosing histories. BMJ. 2008;336:1114–20.PubMedCrossRefGoogle Scholar
Grant RW, Devita NG, Singer DE, Meigs JB. Polypharmacy and medication adherence in patients with type 2 diabetes. Diabetes Care. 2003;26:1408–12.PubMedCrossRefGoogle Scholar
Farmer KC. Methods for measuring and monitoring medication regimen adherence in clinical trials and clinical practice. Clin Ther. 1999;21:1074–90.PubMedCrossRefGoogle Scholar