Discrepancy Among Self-Reported Adherence, Prescription Refills, and Actual Anticoagulant Control

10.1097/jnr.0000000000000374

Pai-En CHIU；Hsuan-Ming TSAO；Chuan-Hsiu TSAI

warfarin ； adherence ； polypharmacy

The Journal of Nursing Research

28卷1期（2020 / 02 / 01）

1 - 8-005

英文

Background: Patients must adhere to their prescribed warfarin regimens and regularly monitor the anticoagulation effect to maintain therapeutic levels. The ability to evaluate regimen adherence accurately is crucial to the success of patient coaching. However, prevention of thromboembolic events is challenging when the association between medication adherence and the actual amount of anticoagulant agent taken cannot be determined. Purpose: This study used self-reported medication taken and prescription refills to (a) verify warfarin medication adherence and (b) assist clinicians to determine the discrepancy between medication adherence and anticoagulant control efficacy. Methods: This study was conducted at a national-university-affiliated hospital in Yilan County, Taiwan. Structured questionnaires and medical record reviews were adopted. A 100-point visual analog scale was used to measure the reported adherence of participants, whereas medication refill adherence was compared against self-reported adherence. Finally, degree of adherence was evaluated based on time in therapeutic range. Results: This study included 192 participants. Half (n = 94, 49%) were women, and the mean age was 69.6 years. Mean scores were 92.2% for the visual analog scale and 87.3% for medication refill adherence. Medication adherence correlated significantly with age, as reflected in the visual analog scale scores (p ＜ .05). The participants who were receiving polypharmacy with five types of medicines or less attained higher visual analog scale scores, whereas participants who were on warfarin for 2-12 months exhibited higher medication refill adherence. Time in therapeutic range correlated negatively with age, although stability improved with therapy duration. Conclusions/Implications for Practice: Despite their high self-reported adherence levels, patients of advanced age require careful monitoring of their time in therapeutic range. The participants in this study who were on warfarin for a relatively longer time exhibited higher stability in the therapeutic range, despite their low medication refill adherence. The results of this study suggest that patient age, duration of warfarin therapy, and poly-pharmacy are factors associated with medication adherence. The findings may facilitate future assessments of warfarin adherence in patients as well as the implementation of more effective clinical nursing procedures and management practices.

1. Albert, N. M.(2008).Improving medication adherence in chronic cardiovascular disease.Critical Care Nurse,28(5),54-64.
2. Auyeung, V.,Patel, J. P.,Abdou, J. K.,Vadher, B.,Bonner, L.,Brown, A.,Arya, R.(2016).Anticoagulated patient's perception of their illness, their beliefs about the anticoagulant therapy prescribed and the relationship with adherence: Impact of novel oral anticoagulant therapy-study protocol for the switching study: A prospective cohort study.BMC Hematology,16(1),22.
3. Benjamin, E. J.,Blaha, M. J.,Chiuve, S. E.,Cushman, M.,Das, S. R.,Deo, R.,Muntner, P.(2017).Heart disease and stroke statistics-2017 update: A report from the American Heart Association.Circulation,135(10),e146-e603.
4. Bieszk, N.,Patel, R.,Heaberlin, A.,Wlasuk, K.,Zarowitz, B.(2003).Detection of medication nonadherence through review of pharmacy claims data.American Journal of Health-System Pharmacy,60(4),360-366.
5. Chan, P. H.,Li, W. H.,Hai, J. J.,Chan, E. W.,Wong, I. C. K.,Tse, H. F.,Siu, C. W.(2016).Time in therapeutic range and percentage of international normalized ratio in the therapeutic range as a measure of quality of anticoagulation control in patients with atrial fibrillation.Canadian Journal of Cardiology,32(10),1247.e23-1247.e28.
6. Connolly, S. J.,Pogue, J.,Eikelboom, J.,Flaker, G.,Commerford, P.,Franzosi, M. G.,Yusuf, S.(2008).Benefit of oral anticoagulant over antiplatelet therapy in atrial fibrillation depends on the quality of international normalized ratio control achieved by centers and countries as measured by time in therapeutic range.Circulation,118(20),2029-2037.
7. Cruess, D. G.,Localio, A. R.,Platt, A. B.,Brensinger, C. M.,Christie, J. D.,Gross, R.,Kimmel, S. E.(2010).Patient attitudinal and behavioral factors associated with warfarin non-adherence at outpatient anticoagulation clinics.International Journal of Behavioral Medicine,17(1),33-42.
8. Fatkullina, F.,Morozkina, E.,Suleimanova, A.,Khayrullina, R.(2016).Terminological multifaceted educational dictionary of active type as a possible way of special discourse presentation.International Journal of Environmental & Science Education,11(17),10081-10089.
9. Gallagher, B. D.,Muntner, P.,Moise, N.,Lin, J. J.,Kronish, I. M.(2015).Are two commonly used self-report questionnaires useful for identifying antihypertensive medication nonadherence?.Journal of Hypertension,33(5),1108-1113.
10. Gazmararian, J. A.,Kripalani, S.,Miller, M. J.,Echt, K. V.,Ren, J.,Rask, K.(2006).Factors associated with medication refill adherence in cardiovascular-related diseases: A focus on health literacy.Journal of General Internal Medicine,21(12),1215-1221.
11. Kääriäinen, M.,Paukama, M.,Kyngäs, H.(2013).Adherence with health regimens of patients on warfarin therapy.Journal of Clinical Nursing,22(1-2),89-96.
12. Kalichman, S. C.,Cain, D.,Fuhrel, A.,Eaton, L.,Fonzo, K. D.,Ertl, T.(2005).Assessing medication adherence self-efficacy among low-literacy patients: Development of a pictographic visual analogue scale.Health Education Research,20(1),24-35.
13. Kimmel, S. E.,Chen, Z.,Price, M.,Parker, C. S.,Metlay, J. P.,Christie, J. D.,Gross, R.(2007).The influence of patient adherence on anticoagulation control with warfarin: Results from the International Normalized Ratio Adherence and Genetics (IN-RANGE) Study.Archives of Internal Medicine,167(3),229-235.
14. Lusardi, M. M.,Jorge, M.,Nielsen, C. C.(2013).Orthotics and prosthetics in rehabilitation.St. Louis, MI:Elsevier Saunders.
15. Marcatto, L. R.,Sacilotto, L.,Bueno, C. T.,Facin, M.,Strunz, C. M.,Darrieux, F. C.,Santos, P. C.(2016).Evaluation of a pharmacogenetic-based warfarin dosing algorithm in patients with low time in therapeutic range-Study protocol for a randomized controlled trial.BMC Cardiovascular Disorders,16(1),224.
16. Mayet, A. Y.(2016).Patient adherence to warfarin therapy and its impact on anticoagulation control.Saudi Pharmaceutical Journal,24(1),29-34.
17. McRae-Clark, A. L.,Baker, N. L.,Sonne, S. C.,DeVane, C. L.,Wagner, A.,Norton, J.(2015).Concordance of direct and indirect measures of medication adherence in a treatment trial for cannabis dependence.Journal of Substance Abuse Treatment,57,70-74.
18. Ministry of Health and Welfare, Taiwan, ROC. (2019). Cerebrovascular disease. Retrieved from https://www.hpa.gov.tw/Pages/List.aspx?nodeid=213 (Original work published in Chinese)
19. Okumura, K.,Komatsu, T.,Yamashita, T.,Okuyama, Y.,Harada, M.,Konta, Y.,Norekvål, T. M.(2011).Time in the therapeutic range during warfarin therapy in Japanese patients with nonvalvular atrial fibrillation-A multicenter study of its status and influential factors.Circulation Journal,75(9),2087-2094.
20. Oterhals, K.,Deaton, C.,De Geest, S.,Jaarsma, T.,Lenzen, M.,Moons, P.,Strömberg, A.(2014).European cardiac nurses' current practice and knowledge on anticoagulation therapy.European Journal of Cardiovascular Nursing,13(3),261-269.
21. Pamboukian, S. V.,Nisar, I.,Patel, S.,Gu, L.,McLeod, M.,Costanzo, M. R.,Heroux, A.(2008).Factors associated with non-adherence to therapy with warfarin in a population of chronic heart failure patients.Clinical Cardiology,31(1),30-34.
22. Parker, C. S.,Chen, Z.,Price, M.,Gross, R.,Metlay, J. P.,Christie, J. D.,Kimmel, S. E.(2007).Adherence to warfarin assessed by electronic pill caps, clinician assessment, and patient reports: Results from the IN-RANGE study.Journal of General Internal Medicine,22(9),1254-1259.
23. Platt, A. B.,Localio, A. R.,Brensinger, C. M.,Cruess, D. G.,Christie, J. D.,Gross, R.,Kimmel, S. E.(2008).Risk factors for nonadherence to warfarin: Results from the IN-RANGE study.Pharmacoepidemiology & Drug Safety,17(9),853-860.
24. Van Damme, S.,Van Deyk, K.,Budts, W.,Verhamme, P.,Moons, P.(2011).Patient knowledge of and adherence to oral anticoagulation therapy after mechanical heart-valve replacement for congenital or acquired valve defects.Heart & Lung,40(2),139-146.
25. Wallentin, L.,Yusuf, S.,Ezekowitz, M. D.,Alings, M.,Flather, M.,Franzosi, M. G.,RE-LY Investigators(2010).Efficacy and safety of dabigatran compared with warfarin at different levels of international normalised ratio control for stroke prevention in atrial fibrillation: An analysis of the RE-LY trial.The Lancet,376(9745),975-983.
26. Wang, Y.,Kong, M. C.,Ko, Y.(2013).Compairson of three medication adherence measures in patients taking warfarin.Journal of Thrombosis,36(4),416-421.
27. Wu, S. H.,Tsauo, J. Y.,Lin, S. I.,Chang, K. C.,Lee, H. C.(2011).Effects of multifaceted fall prevention program on community-dwelling elderly with different fall risks.Formosan Journal of Physical Therapy,36(4),315-330.
28. Yahaya, A. H.M.,Hassali,M. A.,Awaisu, A.,Shafie, A. A.(2009).Factors associated with warfarin therapy knowledge and anticoagulation control among patients attending a warfarin clinic in Malaysia.Journal of Clinical and Diagnostic Research,3(4),1663-1670.
29. Zeber, J. E.,Manias, E.,Williams, A. F.,Hutchins, D.,Udezi, W. A.,Roberts, C. S.,ISPOR Medication Adherence Good Research Practices Working Group(2013).A systematic literature review of psychosocial and behavioral factors associated with initial medication adherence: A report of the ISPOR medication adherence & persistence special interest group.Value in Health,16(5),891-900.