{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,2,21]],"date-time":"2025-02-21T14:08:15Z","timestamp":1740146895269,"version":"3.37.3"},"reference-count":45,"publisher":"Public Library of Science (PLoS)","issue":"1","license":[{"start":{"date-parts":[[2023,1,20]],"date-time":"2023-01-20T00:00:00Z","timestamp":1674172800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000601","name":"De Montfort University","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000601","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>The burden of cardiovascular disease (CVD) is rising in Kenya and non-adherence to cardiovascular pharmacotherapy is a growing global public health issue that leads to treatment failure, an increased risk of cardiac events and poor clinical outcomes. This study assessed adherence to selected cardiovascular therapy medications among CVD patients attending outpatient clinics at Kenyatta National Hospital, Kenya by determining drug concentration(s) in patient dried blood spot (DBS) samples. Patients who had been taking one or more of the five commonly prescribed CVD medications (amlodipine, atenolol, atorvastatin, losartan, and valsartan) for at least six months were enrolled. Each patient completed a short questionnaire about their medication history and then provided a finger-prick blood spot sample from which drug concentrations were determined by liquid chromatography-high resolution mass spectrometry analysis. Two hundred and thirty-nine patients (62.3% female) participated in the study. The median number of medications used by patients was 2 (IQR 75%-25% is 3\u20131). Less than half (117; 49.0%) of patients were adherent to their prescribed CVD pharmacotherapy. Binary regression analysis revealed a significant correlation between non-adherence and the number of medications in the treatment regimen (Odds Ratio (OR) 1.583; 95%CI: 0.949\u20132.639; P-value = 0.039) and that gender was not an independent predictor of medication adherence (OR 1.233; 95%CI: 0.730\u20132.083; P-value = 0.216). Valuable information about adherence to each medication in the patient\u2019s treatment regimen was obtained using quantitative DBS analysis showing that adherence to CVD medications was not uniform. DBS sampling, due its minimally invasive nature, convenience and ease of transport is a useful alternative matrix to monitor adherence to pharmacotherapies objectively, when combined with hyphenated mass spectrometry analytical techniques. This information can provide physicians with an evidence-based novel approach towards personalization and optimization of CVD pharmacotherapy and implementing interventions in the Kenyan population, thereby improving clinical outcomes.<\/jats:p>","DOI":"10.1371\/journal.pone.0280137","type":"journal-article","created":{"date-parts":[[2023,1,20]],"date-time":"2023-01-20T18:32:56Z","timestamp":1674239576000},"page":"e0280137","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":2,"title":["Utilizing quantitative dried blood spot analysis to objectively assess adherence to cardiovascular pharmacotherapy among patients at Kenyatta National Hospital, Nairobi, Kenya"],"prefix":"10.1371","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8040-0159","authenticated-orcid":true,"given":"David","family":"Wata","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"John","family":"Ogwu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Louise","family":"Dunford","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Graham","family":"Lawson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5246-3603","authenticated-orcid":true,"given":"Sangeeta","family":"Tanna","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2023,1,20]]},"reference":[{"key":"pone.0280137.ref001","unstructured":"World Health Organisation (WHO), Cardiovascular diseases (CVDs). 2021. https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/cardiovascular-diseases-(cvds)."},{"key":"pone.0280137.ref002","unstructured":"World Health Organisation (WHO), Kenya launches national cardiovascular disease management guidelines. 2018. https:\/\/www.afro.who.int\/news\/kenya-launches-national-cardiovascular-disease-management-guidelines-0."},{"key":"pone.0280137.ref003","unstructured":"Ministry of Health Kenya, Kenya Healthcare Policy 2014\u20132030. 2014. https:\/\/www.ncikenya.or.ke\/documents\/kenya-health-policy.pdf."},{"key":"pone.0280137.ref004","unstructured":"Ministry of Health, Kenya Essential Medicines List-2019. 2019. https:\/\/www.health.go.ke\/wp-content\/uploads\/2020\/07\/Kenya-Essential-Medicines-List-2019.pdf."},{"key":"pone.0280137.ref005","unstructured":"Sabate E. Adherence to long-term therapies: Evidence for action, World Health Organization, Switzerland, 2003. https:\/\/apps.who.int\/iris\/handle\/10665\/42682."},{"key":"pone.0280137.ref006","first-page":"1","volume-title":"Analytical Chemistry for Assessing Medication Adherence","author":"S Tanna","year":"2016"},{"key":"pone.0280137.ref007","doi-asserted-by":"crossref","first-page":"588","DOI":"10.1007\/s11096-020-00976-8","article-title":"Prevalence and risk factors of drug-related problems identified in pharmacy-based medication reviews","volume":"42","author":"R Sell","year":"2020","journal-title":"Int J Clin Pharm"},{"key":"pone.0280137.ref008","doi-asserted-by":"crossref","first-page":"e84","DOI":"10.1093\/pubmed\/fdy088","article-title":"Adherence to cardiovascular medication: a review of systematic reviews","volume":"41","author":"KH Leslie","year":"2019","journal-title":"J Public Health-UK"},{"key":"pone.0280137.ref009","doi-asserted-by":"crossref","first-page":"3028","DOI":"10.1161\/CIRCULATIONAHA.108.768986","article-title":"Medication adherence: its importance in cardiovascular outcomes","volume":"119","author":"PM Ho","year":"2009","journal-title":"Circulation"},{"key":"pone.0280137.ref010","doi-asserted-by":"crossref","first-page":"1455","DOI":"10.1161\/CIRCULATIONAHA.109.904003","article-title":"Medication adherence in cardiovascular disease","volume":"121","author":"S Baroletti","year":"2010","journal-title":"Circulation"},{"key":"pone.0280137.ref011","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1016\/j.pcad.2013.02.001","article-title":"Adherence to cardiovascular medications: Lessons learned and future directions","volume":"55","author":"IM Kronish","year":"2013","journal-title":"Prog Cardiovasc Dis"},{"issue":"4","key":"pone.0280137.ref012","doi-asserted-by":"crossref","first-page":"684","DOI":"10.1111\/bcp.12339","article-title":"Impact of statin adherence on cardiovascular disease and mortality outcomes: a systematic review","volume":"78","author":"MA De Vera","year":"2014","journal-title":"Br J Clin Pharmacol"},{"key":"pone.0280137.ref013","doi-asserted-by":"crossref","first-page":"1495","DOI":"10.1016\/j.amjcard.2009.12.077","article-title":"Problems of nonadherence in cardiology and proposals to improve outcomes","volume":"105","author":"JB Garner","year":"2010","journal-title":"Am J Cardiol"},{"key":"pone.0280137.ref014","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1016\/j.ahj.2011.06.007","article-title":"Medication adherence: a call for action","volume":"162","author":"HB Bosworth","year":"2011","journal-title":"Am Heart J"},{"key":"pone.0280137.ref015","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1007\/s11886-017-0918-y","article-title":"Improving Medication Adherence in Coronary Heart Disease","volume":"19","author":"LL Zullig","year":"2017","journal-title":"Curr Cardiol Rep"},{"key":"pone.0280137.ref016","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1016\/j.amjms.2016.01.010","article-title":"Medication adherence: truth and consequences","volume":"351","author":"MT Brown","year":"2016","journal-title":"Am J Med Sci"},{"key":"pone.0280137.ref017","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1186\/2049-3258-72-37","article-title":"Adherence influencing factors\u2013a systematic review of systematic reviews","volume":"72","author":"T Mathes","year":"2014","journal-title":"Arch Public Health"},{"issue":"5","key":"pone.0280137.ref018","doi-asserted-by":"crossref","first-page":"e0251115","DOI":"10.1371\/journal.pone.0251115","article-title":"Adherence to cardiovascular pharmacotherapy in Iraq: A mixed methods approach using quantitative dried blood spot analysis and the 8-item Morisky Medication Adherence Scale","volume":"16","author":"A Alalaqi","year":"2021","journal-title":"PLoS ONE"},{"key":"pone.0280137.ref019","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/B978-0-12-805463-5.00002-X","volume-title":"Analytical Chemistry for Assessing Medication Adherence","author":"S Tanna","year":"2016"},{"key":"pone.0280137.ref020","doi-asserted-by":"crossref","first-page":"2825","DOI":"10.4155\/bio.14.189","article-title":"Dried blood spot analysis to assess medication adherence and to inform personalization of treatment","volume":"6","author":"S Tanna","year":"2014","journal-title":"Bioanalysis"},{"key":"pone.0280137.ref021","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.clinms.2018.08.002","article-title":"Volumetric absorptive microsampling (VAMS) coupled with high-resolution, accurate-mass (HRAM) mass spectrometry as a simplified alternative to dried blood spot (DBS) analysis for therapeutic drug monitoring of cardiovascular drugs","volume":"10","author":"S Tanna","year":"2018","journal-title":"Clin Mass Spectrom"},{"key":"pone.0280137.ref022","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1016\/j.jchromb.2012.04.013","article-title":"Quantitative determination of atenolol in dried blood spot samples by LC-HRMS: A potential method for assessing medication adherence","volume":"897","author":"G Lawson","year":"2012","journal-title":"J Chromatogr B Analyt. Technol Biomed Life Sci"},{"key":"pone.0280137.ref023","doi-asserted-by":"crossref","first-page":"1963","DOI":"10.4155\/bio.15.110","article-title":"Self-sampling and quantitative analysis of DBS: can it shift the balance in over-burdened healthcare systems?","volume":"7","author":"S Tanna","year":"2015","journal-title":"Bioanalysis"},{"key":"pone.0280137.ref024","article-title":"Family support and medication adherence among residents with hypertension in informal settlements of Nairobi, Kenya: a mixed-method study","author":"S Xiong","year":"2022","journal-title":"J Hum Hypertens"},{"key":"pone.0280137.ref025","first-page":"059","article-title":"Illness Perceptions and Adherence to Medication Regimen among Hypertensive Patients Attending a County Referral Hospital in Kenya","volume":"7","author":"SO Otenyo","year":"2021","journal-title":"J Hypertens Manage"},{"issue":"1","key":"pone.0280137.ref026","doi-asserted-by":"crossref","first-page":"e023995","DOI":"10.1136\/bmjopen-2018-023995","article-title":"Association of lifestyle modification and pharmacological adherence on blood pressure control among patients with hypertension at Kenyatta National Hospital, Kenya: a cross-sectional study","volume":"9","author":"S Kimani","year":"2019","journal-title":"BMJ open"},{"issue":"7","key":"pone.0280137.ref027","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1111\/tmi.13078","article-title":"Compliance with follow-up and adherence to medication in hypertensive patients in an urban informal settlement in Kenya: comparison of three models of care","volume":"23","author":"N Kuria","year":"2018","journal-title":"Trop Med Int Health"},{"issue":"1","key":"pone.0280137.ref028","doi-asserted-by":"crossref","first-page":"33","DOI":"10.5334\/gh.787","article-title":"Determinants of Mortality from Cardiovascular Disease in the Slums of Nairobi, Kenya","volume":"15","author":"FM Wekesah","year":"2020","journal-title":"Glob Heart"},{"key":"pone.0280137.ref029","doi-asserted-by":"crossref","first-page":"1709","DOI":"10.1016\/j.jpba.2017.04.045","article-title":"Quantitative LC-HRMS determination of selected cardiovascular drugs, in dried blood spots, as an indicator of adherence to medication","volume":"142","author":"D Bernieh","year":"2017","journal-title":"J Pharm Biomed Anal"},{"key":"pone.0280137.ref030","unstructured":"Bernieh D. Application of microsampling methods to cardiovascular medication adherence assessment. Doctoral thesis, De Montfort University, UK 2017. https:\/\/dora.dmu.ac.uk\/handle\/2086\/16370."},{"key":"pone.0280137.ref031","unstructured":"Alalaqi A. Assessment of nonadherence to cardiovascular medications in Iraq by 8-items Morisky Medication Adherence Scale and analysis of dried blood spots. Doctoral Thesis, De Montfort University, UK 2019. https:\/\/dora.dmu.ac.uk\/handle\/2086\/19036."},{"key":"pone.0280137.ref032","first-page":"814","article-title":"The implications of therapeutic complexity on adherence to cardiovascular medications","volume":"171","author":"NK Choudhry","year":"2011","journal-title":"Arch Intern Med"},{"key":"pone.0280137.ref033","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1186\/s12877-017-0558-5","article-title":"Non-adherence to medication regimens among older African-American adults","volume":"17","author":"M Bazargan","year":"2017","journal-title":"BMC Geriatr"},{"issue":"1","key":"pone.0280137.ref034","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1111\/j.1472-8206.2009.00757.x","article-title":"The challenge of polypharmacy in cardiovascular medicine","volume":"24","author":"M Volpe","year":"2010","journal-title":"Fundam Clin Pharmacol"},{"key":"pone.0280137.ref035","doi-asserted-by":"crossref","first-page":"31","DOI":"10.2174\/1871525715666170529093442","article-title":"Polypharmacy in Cardiovascular Medicine: Problems and Promises!","volume":"15","author":"M Abolbashari","year":"2017","journal-title":"Cardiovasc Hematol Agents Med Chem"},{"key":"pone.0280137.ref036","first-page":"61","article-title":"Patient adherence and preference considerations in managing cardiovascular risk: focus on single pill and amlodipine\/atorvastatin fixed combination","volume":"3","author":"F Aslam","year":"2009","journal-title":"Patient Prefer and Adher"},{"issue":"21","key":"pone.0280137.ref037","doi-asserted-by":"crossref","first-page":"2076","DOI":"10.1161\/CIRCULATIONAHA.115.008722","article-title":"Access to Medications for Cardiovascular Diseases in Low- and Middle-Income Countries","volume":"133","author":"VJ Wirtz","year":"2016","journal-title":"Circulation"},{"key":"pone.0280137.ref038","article-title":"Quality and brands of amoxicillin formulations in Nairobi, Kenya","author":"LC Koech","year":"2020","journal-title":"Biomed Research International"},{"key":"pone.0280137.ref039","doi-asserted-by":"crossref","first-page":"361","DOI":"10.2147\/RMHP.S348816","article-title":"Patients Access to Medicines\u2014A Critical Review of the Healthcare System in Kenya","volume":"15","author":"AM Toroitich","year":"2022","journal-title":"Risk Manage. Healthc Policy"},{"issue":"4","key":"pone.0280137.ref040","doi-asserted-by":"crossref","first-page":"e181662","DOI":"10.1001\/jamanetworkopen.2018.1662","article-title":"Prevalence and estimated economic burden of substandard and falsified medicines in low- and middle-income countries: A systematic review and meta-analysis","volume":"1","author":"S Ozawa","year":"2018","journal-title":"JAMA Netw Open"},{"key":"pone.0280137.ref041","doi-asserted-by":"crossref","first-page":"e002640","DOI":"10.1136\/bmjgh-2020-002640","article-title":"Availability and affordability of medicines and cardiovascular outcomes in 21 high-income, middle-income and low-income countries","volume":"5","author":"CK Chow","year":"2020","journal-title":"BMJ Global Health"},{"issue":"9","key":"pone.0280137.ref042","doi-asserted-by":"crossref","first-page":"e015302","DOI":"10.1161\/JAHA.119.015302","article-title":"Access to Cardiovascular Disease and Hypertension Medicines in Developing Countries: An Analysis of Essential Medicine Lists, Price, Availability, and Affordability","volume":"9","author":"MJ Husain","year":"2020","journal-title":"Journal of the American Heart Association"},{"issue":"3","key":"pone.0280137.ref043","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1001\/jamacardio.2018.4936","article-title":"Association of Statin Adherence With Mortality in Patients With Atherosclerotic Cardiovascular Disease","volume":"4","author":"F Rodriguez","year":"2019","journal-title":"JAMA Cardiol"},{"issue":"7","key":"pone.0280137.ref044","doi-asserted-by":"crossref","first-page":"e0219266","DOI":"10.1371\/journal.pone.0219266","article-title":"Factors associated with poor adherence to medication among hypertensive patients in twelve low and middle income Sub-Saharan countries","volume":"14","author":"D Macquart de Terline","year":"2019","journal-title":"PLoS ONE"},{"key":"pone.0280137.ref045","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1515\/cclm-2019-0820","article-title":"Hyphenated mass spectrometry techniques for assessing medication adherence: advantages, challenges, clinical applications and future perspectives","volume":"58","author":"S Tanna","year":"2020","journal-title":"Clin Chem Lab Med"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0280137","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,1,20]],"date-time":"2023-01-20T18:33:30Z","timestamp":1674239610000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0280137"}},"subtitle":[],"editor":[{"given":"Jed N.","family":"Lampe","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2023,1,20]]},"references-count":45,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2023,1,20]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0280137","relation":{},"ISSN":["1932-6203"],"issn-type":[{"type":"electronic","value":"1932-6203"}],"subject":[],"published":{"date-parts":[[2023,1,20]]}}}