|Year : 2017 | Volume
| Issue : 2 | Page : 75-81
Treatment satisfaction, medication adherence, and blood pressure control among adult Nigerians with essential hypertension
Gabriel Uche Pascal Iloh1, Agwu Nkwa Amadi2
1 Department of Family Medicine, Federal Medical Centre, Umuahia, Abia State; Department of Public Health, Federal University of Technology, Owerri, Imo State, Nigeria
2 Department of Public Health, Federal University of Technology, Owerri, Imo State, Nigeria
|Date of Web Publication||18-May-2017|
Gabriel Uche Pascal Iloh
Department of Family Medicine, Federal Medical Centre, Umuahia, Abia State
Source of Support: None, Conflict of Interest: None
BACKGROUND: Hypertension treatment satisfaction has been the subject of recent research particularly in developing countries and is widely recognized as patient-oriented outcome of quality of care. However, in Nigeria, little is known on the role of hypertensive treatment satisfaction on medication adherence and blood pressure (BP) control.
AIM: The study was aimed at determining the role of treatment satisfaction in medication adherence, and BP control among adult Nigerians with essential hypertension.
MATERIALS AND METHODS: A descriptive study was carried out on 140 adult hypertensive patients who have been on treatment for at least 6 months at a primary care clinic in Nigeria. Hypertension treatment satisfaction and medication adherence were assessed in the previous 30 days using pretested, interviewer-administered questionnaire on self-reported satisfaction and adherence to therapy, respectively. A goal BP control referred to BP of < 140/90 mmHg at the end of study visit.
RESULTS: The age of the study participants ranged from 32 to 83 years with mean age of 52 ± 7.4 years. There were 56 (40.0%) male and 84 (60.0%) female. Hypertension treatment satisfaction, medication adherence, and BP control rates were 78.6%, 42.9%, and 35.0%, respectively. Hypertension treatment satisfaction was significantly associated with medication adherence (P = 0.01) and BP control (P = 0.031).
CONCLUSION: This study has demonstrated variabilities in treatment satisfaction, medication adherence, and BP control among the study population. Medication adherence and BP control were significantly associated with treatment satisfaction. This study urges consideration of treatment satisfaction alongside with medication adherence and BP control.
Keywords: Adult Nigerians, essential hypertension, medication adherence, primary care, treatment satisfaction
|How to cite this article:|
Iloh GU, Amadi AN. Treatment satisfaction, medication adherence, and blood pressure control among adult Nigerians with essential hypertension. Int J Health Allied Sci 2017;6:75-81
|How to cite this URL:|
Iloh GU, Amadi AN. Treatment satisfaction, medication adherence, and blood pressure control among adult Nigerians with essential hypertension. Int J Health Allied Sci [serial online] 2017 [cited 2017 Aug 17];6:75-81. Available from: http://www.ijhas.in/text.asp?2017/6/2/75/206426
| Introduction|| |
Hypertension is one of the principal noncommunicable diseases and is the leading cause of cardiovascular disease-related deaths worldwide., It is a clinical and family health problem that is escalating particularly in nations undergoing health transitions., Globally, about 1 billion adults aged 18 years and above have hypertension with two-thirds of this figure emanating from developing countries  and by 2025 an estimated 1.56 million adults will be living with hypertension. The burden of hypertension has been reported to vary from one geographic region to another since it may be influenced by sociobiological and family factors., While the mortality from hypertension has declined in recent years in developed nations, at the same time, the deaths from hypertension have increased at faster rate in low- and middle-income countries accounting for 80% of deaths due to hypertension-related complications.
It has been established that medication adherence and control of blood pressure (BP) to recommended goal lead to decrease in cardiovascular-related morbidity and mortality among hypertensive patients , resulting in satisfaction with care  and improvement in health-related quality of care. The primary aim of antihypertensive treatment is therefore to achieve a treat-to-target BP of <140/90 mmHg for the general population and <130/80 mmHg for special high-risk patients such as diabetes mellitus, renal disease, myocardial infarction, and stroke. However, goal BP control with medication requires adherence with prescribed medications , and recommended lifestyles.
Several factors have been documented in biomedical literature to affect hypertension treatment ranging from patient-related factors, physician-related factors, and health system-related factors., Among the patient-related factors are competing psychosocial issues, patient-reported outcome of satisfaction with hypertension treatment, medication adherence, and clinical outcome of BP control.,, Patient satisfaction studies have been used as an instrument for quality of health-care evaluation and are conceptually defined as the patient's judgment on the quality and goodness of care., Patient satisfaction is therefore directly associated with the degree of satisfaction with expected care and is linked with cognitive evaluation, affective disposition, and emotional reactions to the components of care services such as medication adherence and BP control.,
Numerous general measures of treatment satisfaction have been described in biomedical literature with majority of patient satisfaction study tools emanating from developed countries. However, there is no universally accepted instrument for measuring treatment satisfaction that would permit comparison across different global populations, types of medication, and patient disease conditions., There exist general satisfaction tools such as Satisfaction with Outpatient Services, Patient Judgment of Hospital Quality, Treatment Satisfaction Questionnaire for Medication (TSQM) with versions of TSQM-14, TSQM-11, TSQM-9, Satisfaction with Medicine Questionnaire, and Medical Interview Satisfaction Scale with version (MISS) of MISS-29 and MISS-21 among others. Similarly, various methods of assessing medication adherence at the point of care have been described such as medication possession ratio, Self-administered and Reported Therapy (SAT), Morisky Adherence Scale-4, Modified Morisky Medication Adherence Scale-8, Modified Morisky Adherence Predictor Scale, Brief Medication Questionnaire, and Medication Adherence Rating Scale. However, there is no gold standard for precise measurement of medication adherence that can be applied across global patients and substantial heterogeneity exists in the measured domains of adherence.,,
Researchers have reported varying level of treatment satisfaction, medication adherence, and BP control in different global population with variable results.,,,, Of paramount concern is that research studies in Nigeria have reported high prevalence of hypertension with low level of medication adherence, low BP control with none reporting treatment satisfaction among Nigerians with essential hypertension.0,,, In Nigeria, hypertension treatment satisfaction remains a significant challenge particularly in primary care settings and is likely to affect adherence with medication and invariably BP control. This type of study has not been done in primary care settings in Nigeria; hence, there is a lack of knowledge of the role of treatment satisfaction in medication adherence and BP control. The knowledge of the role of hypertension treatment satisfaction on medication adherence and BP control will guide in defining primary care-driven multidisciplinary interventions to improve medication adherence and enhance treatment satisfaction as well as achieve BP control. It is against this background that the authors were motivated to determine the role of hypertension treatment satisfaction on medication adherence and BP control among Nigerians with essential hypertension in a primary care clinic of a tertiary hospital in South-East Nigeria.
| Materials and Methods|| |
This was a clinic-based descriptive study carried out on 140 patients from April 2011 to November 2011 at a primary care clinic in Nigeria.
The hospital is located in Abia State, South-East Nigeria. Until recently, the capital city of the state and its environ have witnessed an upsurge in the number of banks, hotels, schools, markets, industries, and junk food restaurants in addition to the changing dietary and social lifestyles. The Department of Family Medicine of the hospital serves as a primary care clinic within the tertiary hospital setting of the medical center. All adult patients excluding those who need emergency health-care services, pediatric patients, and antenatal women are first seen at the Department of Family Medicine where diagnoses are made. Patients who need primary care are managed and followed up in the clinic while those who need other specialists care are referred to the respective core specialist clinics for further management.
The inclusion criteria were adult hypertensive patients aged ≥18 years who gave informed consent, had been on outpatient treatment for hypertension in the clinic for at least 6 months, and who recorded at least three clinic visits (recruitment visit, penultimate visit before the end of study, and end of study visit).
Exclusion criteria included critically ill patients, those with an established cause of hypertension, and special high-risk populations such as hypertensive patients with diabetes mellitus, renal disease, and previous adverse cardiovascular events such as myocardial infarction and stroke.
Sample size estimation was determined using the formula for estimating minimum sample size for descriptive studies  using the formula n = Z2pq/d2 and nf = n/1 +n/N, where n = desired sample size when population is more than 10,000, nf = desired sample size when population is <10,000, Z = standard normal deviate set at 1.96 which corresponds to 95% confidence limit, P = authors assumed that 50% (0.50) would be satisfied with treatment, adhered to medication and have goal BP control, and d = desired level of precision set at 0.05. The sample size was determined using an estimated population size of 200 adult hypertensive patients based on the previous annual hypertensive patients' attendance records at the Family Medicine Clinic. These 200 adult hypertensive patients excluded other hypertensive patients referred to and being followed up in cardiology clinic and other outpatient clinics of the medical center. Diabetic hypertensives were also excluded from the study. This gave a sample estimate of 132 patients. However, selected sample of 140 patients were used to allow for attrition.
The eligible patients for the study were consecutively recruited for the study based on the inclusion criteria until the sample size of 140 was achieved.
The study instrument consisted of sections on sociodemographic data, information on medication adherence, hypertension treatment satisfaction, and BP control in the previous 1 month.
Medication adherence was assessed by the use of pretested, interviewer-administered questionnaire on 30-day SAT. Patients were seen at the recruitment visit and at the end of the study visit. At the end of the study visit, the adherence section of the data collection tool was administered. Information collected at the end of the study visit included (1) how many times per day do you take your BP medication?, (2) how many tablets do you take specific to your hypertensive condition?, (3) how often do you take your BP medication (all times, most times, sometimes, rarely, and never)?, (4) how many dose (s) of your antihypertensive drugs have you missed in the previous 1 month?, and (5) how much of your previous BP medication is remaining after the previous 1 month visit? Adherence was graded using an ordinal scoring system of 0–4 points developed by the authors from a review of the literature ,,,,,,,,, as follows: all the time = 4 points, most times = 3 points, sometimes = 2 points, rarely = 1 point, and never = 0. Four points indicated adherence while 0–3 points meant nonadherence.
Hypertension treatment satisfaction was studied using questionnaire tool that was designed by the authors to suit Nigerian environment through robust review of relevant literature on outpatient treatment satisfaction.,,,,,,,,,,,, The specific domains of treatment satisfaction examined were satisfaction with current treatment, convenience of treatment, flexibility of treatment, and continuity with present treatment. Satisfaction with each of the specific domains of treatment was given an ordinal score in a six-point Likert scale of extremely satisfied = 5 points, very satisfied = 4 points, satisfied = 3 points, dissatisfied = 2 points, very dissatisfied = 1 point, and extremely dissatisfied = 0.
Pretesting of the hypertension treatment satisfaction and medication adherence section of the study instrument was done at the Family Medicine Clinic of the medical center. Five hypertensive patients were haphazardly used for the pretesting of the hypertension treatment satisfaction and medication adherence questionnaires which lasted for 1 day. The pretesting was done to assess the applicability of the questionnaire tools. All the patients used for the pretesting of the questionnaire instrument gave valid and reliable responses confirming the clarity and applicability of the questionnaire tools and questions were interpreted with the same meaning as intended.
BP readings were based on the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure classification and guidelines.
The authors defined hypertension as a systolic and/or diastolic BP ≥140/90 mmHg or documented use of antihypertensive medications in a person previously diagnosed with hypertension. An adherent patient was defined as one who had a score of 4 points (took all the prescribed doses of anti-hypertensive medication(s) all-times) in the previous 30 days by the end of the study visit while those that scored 0–3 points and missed a day dose of antihypertensive medications meant nonadherence. A patient was defined as having goal BP control if his or her BP at the end of study visit was <140/90 mmHg. Overall satisfaction referred to those who scored at least 3 points in all the domains examined while Specific satisfaction to the subscales of items of satisfaction referred to those that scored at least 3 points in specific domain. Overall dissatisfaction referred to those who scored 0–2 points in all the domains examined while Specific dissatisfaction to the subscales of items of satisfaction referred to those that scored 0–2 points in specific domain.
The ethical clearance was obtained from the Ethics Committee of the hospital. Consent was also obtained from the patients.
The results generated were analyzed using software Statistical Package for Social Sciences version 13.0, Inc., Chicago, IL, USA, for the calculation of percentages for categorical variables. Percentages and frequencies were compared by Chi-square test. The level of statistical significance was set at P < 0.05.
| Results|| |
The age of the study participants ranged from 32 to 83 years with mean age of 52 ± 7.4 years. There were 56 (40.0%) male and 84 (60.0%) female with a male-to-female ratio of 1:1.5. Other basic demographic characteristics are shown in [Table 1].
Of the 140 hypertensive patients studied, 110 (78.6%) were satisfied with the hypertension treatment received while 30 (21.4%) were not satisfied. More so, 60 (42.9%) of the hypertensive patients were adherent with antihypertensive medication while 80 (57.1%) of them were not adherent with medication. Furthermore, 49 (35.0%) of the patients had good BP control while 91 (65.0%) of them were uncontrolled [Table 2].
|Table 2: Hypertension treatment satisfaction, medication adherence and blood pressure control among the patients|
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Of the 110 hypertensive patients who were satisfied with treatment, 56 (50.9%) were adherent with medication and 54 (49.1%) were nonadherent with medication. Similarly, of the 60 (42.9%) hypertensive patients who were adherent with medication, 56 (50.9%) were satisfied with treatment and 4 (13.3%) were dissatisfied with treatment. The difference was statistically significant (Χ2 = 13.61; P = 0.01) [Table 3].
|Table 3: Association between overall hypertension treatment satisfaction and medication adherence|
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Of the 110 hypertensive patients who were satisfied with treatment, 44 (40.0%) had good BP control and 66 (60.0%) had poor BP control. Similarly, of the 49 (35.0%) hypertensive patients who had their BP controlled, 44 (40.0%) were satisfied with treatment and 5 (16.7%) were dissatisfied with treatment. The difference was statistically significant (Χ2 = 6.75; P = 0.031) [Table 4].
|Table 4: Association between overall hypertension treatment satisfaction and blood pressure control|
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| Discussion|| |
This study has demonstrated the association of hypertension treatment satisfaction with medication adherence and BP control among the study participants. The finding of this study has buttressed the reports of the influence of hypertension treatment satisfaction on medication adherence and BP control.,,, The success or failure of hypertension treatment outcome depends on optimal treatment satisfaction to achieve adequate medical adherence and control of BP to the treat-to-target goal. Dissatisfaction with hypertension treatment has negative consequences on BP control which could lead increased hospitalization, cost of care, hypertension-related stroke, and death. The clinicians in Nigeria though aware of hypertension, its treatment, fatal and nonfatal outcomes of medication nonadherence and uncontrolled BP, but they have not made it a routine or have time out of their busy clinic hours to assess for satisfaction with hypertension treatment. The awareness and knowledge of treatment satisfaction in the management of hypertension will guide in defining multidisciplinary approaches to improving medication adherence and BP control through ensuring that hypertensive patients are satisfied with treatment they receive as they navigate the care pathway in the hospital environment.
Medication adherence was significantly higher in patients who were satisfied with their hypertension treatment compared with dissatisfied patients. The finding of this study is in consonance with the role of antihypertensive medication adherence on subjective outcome of patient satisfaction with treatment.,,,,, Clinicians attending hypertensive patients should therefore enquire on satisfaction with treatment to avert higher risk of medication nonadherence and its attendant complications. The finding of this study has implications for physician–patient interaction and communications  which are central to optimizing medication adherence as well as enable patient participate in the hypertension management. There is therefore need to address the barriers and inhibitors to treatment satisfaction  if the potentials of hypertensive medications are to be fully harnessed.
This study has shown that patients who were satisfied with their treatment had good BP control. This finding is in agreement with research studies that have demonstrated the role of treatment satisfaction on BP control., As the impetus for the prevention of adverse hypertension-related end organ damage grows, emphasis should also be focused on measures of treatment satisfaction. Hypertension treatment satisfaction and BP control are associated with more health benefits and less risk of adverse cardiovascular and renal endpoints. Without regular feedback on satisfaction with antihypertensive treatment between clinician and patient, a dissatisfied patient with poor BP control may never achieve BP control, or come back to the hospital or recommend the hospital to the general public. Taking cognizance of the role of treatment satisfaction on BP control remains relevant in the drive to lower the BP to the recommended treat-to-target goal. This will enable Nigerians with essential hypertension to benefit from the life-saving advantages of goal BP control.
The authors recognized the limitations imposed by the self-reported measure of adherence for the study. Furthermore, the sample size for the study was relatively small but was more than the minimum estimated sample size for the study and was the number of patients seen within the duration of the study.
The questionnaire was administered by the researchers and trained research assistants. This could have introduced interviewers' influence and bias, since some patients could not clinically give true responses to questions related to adherence in the presence of their physicians. However, pretesting of the questionnaire internally and externally using the same research assistants did not reveal this limitation. In addition, the respondents were assured of confidentiality before the interview.
| Conclusion|| |
This study has demonstrated variabilities in treatment satisfaction, medication adherence, and BP control among the study population. Medication adherence and BP control were significantly associated with treatment satisfaction. However, treatment satisfaction did not translate to marginally higher medication and BP control. This study urges consideration of treatment satisfaction alongside with medication adherence and BP control.
Further research directions
Future research directions are required to explore the factors that influence treatment dissatisfaction, medication nonadherence, and poor BP control. This will provide additional clinical data for intervention purposes.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
World Health Organization. Noncommunicable Diseases Country Profile. Geneva: World Health Organization; 2014.
World Health Organization, Centre for Diseases Control. Atlas of Heart Disease and Stroke. Geneva: World Health Organization, Centre for Diseases Control; 2014.
Iloh GU, Amadi AN. Essential hypertension in adult Nigerians in a primary care clinic: A cross sectional study of the prevalence and associated family socio-biological factors in Eastern Nigeria. Eur J Prev Med 2014;2:81-9.
Kearney PM, Whelton M, Reynolds K, Muntner P, Whelton PK, He J. Global burden of hypertension: Analysis of worldwide data. Lancet 2005;365:217-23.
Krousel-Wood M, Thomas S, Muntner P, Morisky D. Medication adherence: A key factor in achieving blood pressure control and good clinical outcomes in hypertensive patients. Curr Opin Cardiol 2004;19:357-62.
Simpson SH, Eurich DT, Majumdar SR, Padwal RS, Tsuyuki RT, Varney J, et al.
A meta-analysis of the association between adherence to drug therapy and mortality. BMJ 2006;333:15.
Zyoud SH, Al-Jabi SW, Sweileh WM, Morisky DE. Relationship of treatment satisfaction to medication adherence: Findings from a cross-sectional survey among hypertensive patients in Palestine. Health Qual Life Outcomes 2013;11:191.
Trevisol DJ, Moreira LB, Kerkhoff A, Fuchs SC, Fuchs FD. Health-related quality of life and hypertension: A systematic review and meta-analysis of observational studies. J Hypertens 2011;29:179-88.
Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr., et al.
The Seventh report of the joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure: The JNC 7 report. JAMA 2003;289:2560-72.
Iloh GU, Ofoedu JN, Njoku PU, Amadi AN, Godswill-Uko EU. Medication adherence and blood pressure control amongst adults with primary hypertension attending a tertiary hospital primary care clinic in Eastern Nigeria. Afr J Prim Health Care Fam Med 2013;5:446.
Iloh GU, Ofoedu JN, Njoku PU, Amadi AN. Blood pressure control among geriatric Nigerians with essential hypertension in a rural hospital in South-Eastern Nigeria. Port Harcourt Med J 2013;7:50-8.
Iloh GU, Amadi AN, Okafor GO, Ikwudinma AO, Odu FU, Godswill-Uko EU. Adherence to lifestyle modifications among adult hypertensive Nigerians with essential hypertension in a primary care clinic of a tertiary hospital in resource-poor environment of Eastern Nigeria. Br J Med Med Res 2014;4:3478-90.
Ogedegbe G. Barriers to optimal hypertension control. J Clin Hypertens (Greenwich) 2008;10:644-6.
Odusola AO, Hendriks M, Schultsz C, Bolarinwa OA, Akande T, Osibogun A, et al.
Perceptions of inhibitors and facilitators for adhering to hypertension treatment among insured patients in rural Nigeria: A qualitative study. BMC Health Serv Res 2014;14:624.
Arun M, Venkat P, Venkateswaramurthy N. A study on impact of clinical interventions on relationship between treatment satisfaction and medication adherence in hypertensive patients. J Pharm Sci Res 2016;8:190-7.
Wang PS, Bohn RL, Knight E, Glynn RJ, Mogun H, Avorn J. Noncompliance with antihypertensive medications: The impact of depressive symptoms and psychosocial factors. J Gen Intern Med 2002;17:504-11.
Ogedegbe G, Harrison M, Robbins L, Mancuso CA, Allegrante JP. Barriers and facilitators of medication adherence in hypertensive African Americans: A qualitative study. Ethn Dis 2004;14:3-12.
Iloh GU, Ofoedu JN, Njoku PU, Odu FU, Ifedigbo CV, Iwuamanam KD. Evaluation of patients' satisfaction with quality of care provided at the National Health Insurance Scheme clinic of a tertiary hospital in South- Eastern Nigeria. Niger J Clin Pract 2012;15:469-74. [Full text]
Iloh GU. Quality of care in Africa: Managing patients expectations and renewing their confidence in service delivery: The best baseline for calibration in Africa. In: Saldana JR, editor. Quality of Health Care: From Evidence to Implementation. New York: Nova Publishers; 2015. p. 269-90.
Lavsa SM, Holzworth A, Ansani NT. Selection of a validated scale for measuring medication adherence. J Am Pharm Assoc (2003) 2011;51:90-4.
Revicki DA. Patient assessment of treatment satisfaction: Methods and practical issues. Gut 2004;53 Suppl 4:iv40-4.
Shikiar R, Rentz AM. Satisfaction with medication: An overview of conceptual, methodologic, and regulatory issues. Value Health 2004;7:204-15.
Keegan O, Mcgee HA. A Guide to Hospital Outpatient Satisfaction Surveys. Practical Recommendations and the Satisfaction with Outpatient Services (SWOPS) Questionnaire; 2003.
Rubin HR, Ware JE Jr., Nelson EC, Meterko M. The patient judgments of hospital quality (PJHQ) questionnaire. Med Care 1990;28 9 Suppl:S17-8.
Atkinson MJ, Sinha A, Hass SL, Colman SS, Kumar RN, Brod M, et al.
Validation of a general measure of treatment satisfaction, the Treatment Satisfaction Questionnaire for Medication (TSQM), using a national panel study of chronic disease. Health Qual Life Outcomes 2004;2:12.
Rejas J, Ruiz MA, Pardo A, Soto J. Minimally important difference of the Treatment Satisfaction with Medicines Questionnaire (SATMED-Q). BMC Med Res Methodol 2011;11:142.
Wolf MH, Putnam SM, James SA, Stiles WB. The medical interview satisfaction scale: Development of a scale to measure patient perceptions of physician behavior. J Behav Med 1978;1:391-401.
Barbosa CD, Balp MM, Kulich K, Germain N, Rofail D. A literature review to explore the link between treatment satisfaction and adherence, compliance, and persistence. Patient Prefer Adherence 2012;6:39-48.
Saarti S, Hajj A, Karam L, Jabbour H, Sarkis A, El Osta N, et al.
Association between adherence, treatment satisfaction and illness perception in hypertensive patients. J Hum Hypertens 2016;30:341-5.
Akpa MR, Alasia DD, Emem-Chioma PC. An appraisal of hospital based blood pressure control in Port Harcourt, Nigeria. Niger Health J 2008;8:27-30.
Sani MU, Mijinyawa MS, Adamu B, Abdu A, Borodo MM. Blood pressure control among treated hypertensives in a tertiary health institution. Niger J Med 2008;17:270-4.
Okwuonu CG, Ojimadu NE, Okaka EI, Akemokwe FM. Patient-related barriers to hypertension control in a Nigerian population. Int J Gen Med 2014;7:345-53.
Araoye MO. Sample size determination. Research Methodology with Statistics for Health and Social Sciences. Ilorin: Nathadex Publishers; 2004. p. 115-21.
Morisky DE, Ang A, Krousel-Wood M, Ward HJ. Predictive validity of a medication adherence measure in an outpatient setting. J Clin Hypertens (Greenwich) 2008;10:348-54.
Ramli A, Ahmad NS, Paraidathathu T. Medication adherence among hypertensive patients of primary health clinics in Malaysia. Patient Prefer Adherence 2012;6:613-22.
AlGhurair SA, Hughes CA, Simpson SH, Guirguis LM. A systematic review of patient self-reported barriers of adherence to antihypertensive medications using the World Health Organization multidimensional adherence model. J Clin Hypertens (Greenwich) 2012;14:877-86.
Bharmal M, Payne K, Atkinson MJ, Desrosiers MP, Morisky DE, Gemmen E. Validation of an abbreviated Treatment Satisfaction Questionnaire for Medication (TSQM-9) among patients on antihypertensive medications. Health Qual Life Outcomes 2009;7:36.
Atkinson MJ, Kumar R, Cappelleri JC, Hass SL. Hierarchical construct validity of the Treatment Satisfaction Questionnaire for Medication (TSQM version II) among outpatient pharmacy consumers. Value Health 2005;8 Suppl 1:S9-24.
Sokol MC, McGuigan KA, Verbrugge RR, Epstein RS. Impact of medication adherence on hospitalization risk and healthcare cost. Med Care 2005;43:521-30.
Baune BT, Aljeesh YI, Bender R. The impact of non-compliance with the therapeutic regimen on the development of stroke among hypertensive men and women in Gaza, Palestine. Saudi Med J 2004;25:1683-8.
Chiolero A, Burnier M, Santschi V. Improving treatment satisfaction to increase adherence. J Hum Hypertens 2016;30:295-6.
Ren XS, Kazis LE, Lee A, Zhang H, Miller DR. Identifying patient and physician characteristics that affect compliance with antihypertensive medications. J Clin Pharm Ther 2002;27:47-56.
[Table 1], [Table 2], [Table 3], [Table 4]