Medication Adherence and its Predictors in Community Elderly Patients with Hypertension

Sang Geun Bae; Hye Ji Jeon; Hyeon Su Yang; Bo Kyoung Kim; Ki Soo Park

doi:10.15384/kjhp.2015.15.3.121

Korean J Health Promot > Volume 15(3); 2015 > Article

Bae, Jeon, Yang, Kim, and Park: Medication Adherence and its Predictors in Community Elderly Patients with Hypertension

Original Article

Korean Journal of Health Promotion 2015;15(3):121-128.

Published online: December 19, 2015

DOI: https://doi.org/10.15384/kjhp.2015.15.3.121

Medication Adherence and its Predictors in Community Elderly Patients with Hypertension

Sang Geun Bae¹, Hye Ji Jeon², Hyeon Su Yang², Bo Kyoung Kim², Ki Soo Park^2,³

¹Department of Preventive Medicine, Kyungpook National University School of Medicine, Daegu, Korea

²Department of Preventive Medicine and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea

³Regional Cardiocerebrovascular Disease Center, Gyeongsang National University Hospital, Jinju, Korea

Corresponding author：Ki Soo Park, MD, PhD Department of Preventive Medicine and Institute of Health Sciences, Gyeongsang National University School of Medicine, 15 Jinju-daero 816beon-gil, Jinju 52727, Korea
Tel: +82-55-772-8095, Fax: +82-55-772-8099 E-mail: parkks@gnu.ac.kr

Received May 30, 2015 Accepted September 09, 2015

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

ABSTRACT

Background

Medication adherence is important for hypertension management but still stay low level. It is reasonable method to classify medication nonadherence into intentional nonadherence and unintentional nonadherence and manage it according to this categories. This study aimed to explore medication adherence and its predictors in community patients with hypertension, especially dividing into intentional nonadherence and unintentional nonadherence.

Methods

Study subjects included 1,988 patients who were prescribed hypertension drugs among 2012 community health survey subjects of 10 cities in Gyeongsangnamdo and we analyzed medication adherence with hypertension and its predictors. We conducted chi-square test for nominal variable and ANOVA test for continuous variable and use multinominal regression to analyze independent predictors of intentional nonadherence and unintentional nonadherence in contrast to medication adherence.

Results

Of the 1,988 patients, 49.7% were adherent, 26.1% were unintentionally nonadherent and 24.2% intentionally nonadherent. Independent predictors of unintentional nonadherence were depressive symptoms (odds ratio [OR]=1.696, P=0.047) and arthritis (OR=1.319, P=0.030) and independent predictors of intentional nonadherence were cardiocerebrovascular disease (OR=1.464, P=0.044), self-efficacy (OR=0.984, P=0.007), beliefs about medications questionnaire (necessity [OR=0.834, P<0.001] and concern [OR=1.236, P<0.001]).

Conclusions

In order to manage hypertension in community, improvement in medication adherence is needed. Depressive symptom and self-efficacy need to be managed, but especially patients’beliefs about their medication need to be considered to improve intentional nonadherence.

Keywords: Medication adherence, Hypertension, Intention

Table 1.

General characteristics and medication adherence^a

	Total	Medication adherence			P^b
		Adherent	Non-adherent
		Adherent	Unintentional	Intentional
Age, y	68.8±10.4	69.3±9.9 (A)	69.3±10.2 (B)	67.1±11.3 (C)	<0.001 (A=B≠C)
Sex					0.659
Male	675 (34.0)	344 (51.0)	168 (24.9)	163 (24.1)
Female	1,313 (66.0)	645 (49.1)	350 (26.7)	318 (24.2)
Educational level					0.119
≤Primary school	786 (39.5)	401 (51.0)	195 (24.8)	190 (24.2)
Middle school	658 (33.1)	333 (50.6)	184 (28.0)	141 (21.4)
≥High school	544 (27.4)	255 (46.9)	139 (25.6)	150 (27.6)
Monthly income^c, million (Korean won)					0.218
<100	1,245 (65.3)	621 (49.9)	324 (26.0)	300 (24.1)
100-200	313 (16.4)	160 (51.1)	88 (28.1)	65 (20.8)
200-300	174 (9.1)	86 (49.4)	37 (21.3)	51 (29.3)
≥400	175 (9.2)	76 (43.4)	51 (29.1)	48 (27.4)
Spouse					0.312
Yes	1,236 (62.2)	609 (49.3)	336 (27.2)	291 (23.5)
No	752 (37.8)	380 (50.5)	182 (24.2)	190 (25.3)
Depressive symptoms					0.015
Yes	98 (4.9)	35 (35.7)	33 (33.7)	30 (30.6)

No	1,890 (95.1)	954 (50.5)	485 (25.7)	451 (23.9)
Self-rated health status					0.417
Good or normal	912 (45.9)	466 (51.1)	237 (26.0)	209 (22.9)
Bad	1,076 (54.1)	523 (48.6)	281 (26.1)	272 (25.3)
Good sleep					0.167
Yes	923 (46.4)	458 (49.6)	256 (27.7)	209 (22.6)
No	1,065 (53.6)	531 (49.9)	262 (24.6)	272 (25.5)
CVD					0.604
Yes	229 (11.5)	108 (47.2)	60 (26.2)	61 (26.6)
No	1,759 (88.5)	881 (50.1)	458 (26.0)	420 (23.9)
Arthritis					0.064
Yes	823 (41.4)	387 (47.0)	235 (28.6)	201 (24.4)
No	1,165 (58.6)	602 (51.7)	283 (24.3)	280 (24.0)
Stress^c					0.071
High	484 (24.4)	226 (46.7)	122 (25.2)	136 (28.1)
Low	1,502 (75.6)	762 (50.7)	395 (26.3)	345 (23.0)
Health education					0.087
Yes	587 (29.5)	287 (48.9)	140 (23.9)	160 (27.3)
No	1,401 (70.5)	702 (50.1)	378 (27.0)	321 (22.9)
Social support	17.1±3.4	17.2±3.4 (A)	17.2±3.4 (B)	16.6±3.5 (C)	0.002 (A=B≠C)
Self efficacy	34.6±11.8	35.2±12.0 (A)	34.3±11.7 (B)	33.4±11.5 (C)	0.017 (A=B≠C)

Total 1,988 (100.0) 989 (49.7) 518 (26.1) 481 (24.2) Abbreviation: CVD, cardiocerebrovascular disease.

^aValues are presented as N (%) or mean±SD.

^bCalculated by chi-squre-test or analysis of variance (Turkey multiple comparison).

^cMissing values are presented.

Table 2.

BMQ and medication adherence^a

	Total	Medication adherence			P^b
		Adherent	Non-adherent
		Adherent	Unintentional	Intentional
BMQ (necessity)	17.6±3.9	17.9±3.9 (A)	17.7±3.8 (B)	16.6±3.8 (C)	<0.001 (A=B≠C)
BMQ (concerns)	13.6±2.9	13.3±2.9 (A)	13.4±3.0 (B)	14.4±2.9 (C)	<0.001 (A=B≠C)

Abbreviation: BMQ, beliefs about medicines questionnaire.

^aValues are presented as mean±SD.

^bCalculated by analysis of variance (Turkey multiple comparison).

Table 3.

Predictors of medication adherence^a

	Unintentional nonadherence versus adherence				Intentional nonadherence versus adherence
	OR	95% CI		P	OR	95% CI		P
	OR	Lower	Upper	P	OR	Lower	Upper	P
Stress (high/low)	0.958	0.728	1.261	0.759	1.171	0.882	1.556	0.275
Depressive symptoms (yes/no)	1.696	1.008	2.854	0.047	1.376	0.782	2.423	0.268
Self-rated health status (good or normal/bad)	0.949	0.737	1.221	0.683	0.813	0.620	1.067	0.136
CVD (yes/no)	1.084	0.758	1.549	0.658	1.464	1.010	2.122	0.044
Arthritis (yes/no)	1.319	1.028	1.693	0.030	1.288	0.984	1.685	0.065
Health education (yes/no)	0.898	0.699	1.154	0.266	1.027	0.793	1.330	0.839
Social support	0.999	0.966	1.033	0.958	0.970	0.935	1.007	0.108
Self efficacy	0.993	0.983	1.004	0.208	0.984	0.973	0.996	0.007
BMQ (necessity)	0.971	0.938	1.005	0.096	0.834	0.802	0.868	<0.001
BMQ (concerns)	1.019	0.977	1.062	0.393	1.236	1.179	1.296	<0.001

Abbreviations: OR, odds ratio; CI, confidence interval; CVD, cardiocerebrovascular disease; BMQ, beliefs about medicines questionnaire.

^aCalculated by multinomial regression, adjusted for age, sex, education, monthly income and spouse.

Table 4.

Predictors of beliefs about medication questionnaire^a

	Necessity			Concerns
	Unstandardized coefficients		P	Unstandardized coefficients		P
	B	SE	P	B	SE	P
Stress (high/low)	-0.311	0.197	0.116	-0.165	0.161	0.305
Depressive symptoms (yes/no)	-0.509	0.384	0.185	-0.332	0.313	0.289
Self-rated health status(good or normal/bad)	1.516	0.180	<0.001	0.801	0.146	<0.001
CVD (yes/no)	-1.374	0.256	<0.001	-0.592	0.208	0.005
Arthritis (yes/no)	-0.628	0.182	0.001	-0.281	0.148	0.058
Health education (yes/no)	0.636	0.178	<0.001	-0.446	0.145	0.002
Social support	0.068	0.024	0.005	-0.028	0.020	0.162
Self efficacy	-0.022	0.008	0.004	-0.019	0.006	0.003

Abbreviations: B, β SE, standard error; CVD, cardiocerebrovascular disease.

^aCalculated by multiple regression adjusted for age, sex, education, monthly income and spouse.

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