Effectiveness of low-cost reminder package combined with case-based health education to improve hypertensive patients' medication adherence: a clustered randomized controlled trial

Figures & data

Figure 1 Flowchart

Table 1 Sociodemographic characteristics of participants before and after intervention

Sociodemographic characteristics	Baseline (%)			Endpoint (%)			Comparison between baseline and endpoint: χ^2
	Control	Intervention	χ^2	Control	Intervention	χ^2	Control	Intervention
Number (%)	297(49.8)	299(50.2)		256(49.4)	262(50.6)
Gender			7.675*			8.061*	0.058	0.261
Male	112(37.7)	81(27.1)		94(36.7)	66(25.2)
Female	185(62.3)	218(72.9)		162(63.3)	196(74.8)
Age (years)			10.619*			11.947*	0.053	0.059
≤49	64(21.5)	35(11.7)		57(22.3)	29(11.1)
50-59	144(48.5)	158(52.8)		124(48.4)	140(53.4)
60+	89(30.0)	106(35.5)		75(29.3)	93(35.5)
Education			17.042*			14.791*	0.466	0.114
Primary school and below	33(11.1)	52(17.4)		31(12.1)	44(16.8)
Middle school	157(52.9)	183(61.2)		128(50.0)	159(60.7)
High school and above	107(36.0)	64(21.4)		97(37.9)	59(22.5)
Marital status			0.198			0.497	0.167	0.012
Married	280(94.2)	285(96.0)		239(93.4)	251(95.8)
Unmarried	14(4.8)	12(4.0)		14(5.4)	11(4.2)
Missing	3(1.0)			3(1.2)
Family income			6.963			4.514	0.359	0.227
<900	90(30.3)	87(29.1)		72(28.1)	79(30.2)
900-1409	50(16.8)	61(20.4)		46(18.0)	54(20.6)
1410-2499	72(24.2)	79(26.4)		63(24.6)	65(24.8)
2500-3499	30(10.1)	46(15.4)		27(10.6)	40(15.3)
3500+	38(12.8)	25(8.4)		33(12.9)	23(8.8)
Missing	17(5.7)	1(0.3)		15(5.9)	1(0.4)
Ethnicity			0.175			0.033	0.009	0.014
Han	287(96.6)	287(96.0)		247(96.5)	252(96.2)
Other	10(3.4)	12(4.0)		9(3.5)	10(3.8)
Antihypertensive medication history			2.467			1.887	0.030	0.065
<5	110(37.0)	95(31.8)		96(37.5)	85(32.5)
5-9	77(25.9)	77(25.8)		68(26.6)	69(26.3)
10+	108(36.4)	126(42.1)		92(35.9)	108(41.2)
missing	2(0.7)	1(0.3)		0	0
Other chronic medication-taking history			1.414			1.252	0.052	0.057
No	143(48.1)	130(43.5)		121(47.3)	112(42.8)
Yes	150(50.5)	166(55.5)		132(51.5)	149(56.9)
Missing	4(1.4)	3(1.0)		3(1.2)	1(0.3)

Note: *P<0.05.

Table 2 Results of multi-level modeling on intervention effectiveness in patients’ medication adherence, SBP and DBP

Variable	Baseline (SD)	6-month follow-up(SD)	Difference in change between groups (95% CI)^a	ICC
MA^b
Control	4.36 (1.02)	4.39 (1.02)	0.287 (0.103,0.471)*	0.006
Intervention	4.33 (1.02)	4.62 (0.78)
MA (ITT^c)
Control	4.30 (1.09)	4.39 (1.02)	0.287 (0.102, 0.473)*	0.002
Intervention	4.28 (1.08)	4.62 (0.78)
SBP
Control	135.3 (16.9)	136.6 (14.8)	0.536 (−3.207, 4.278)	0.020
Intervention	134.1 (16.6)	136.1 (14.9)
DBP
Control	81.6 (10.5)	83.9 (9.9)	−0.927 (−3.283, 1.428)	0.022
Intervention	77.0 (10.2)	78.6 (9.6)

Notes: ^aDifference in change between groups was calculated with multilevel modeling, adjusting for clustering level, gender, age, education, ethnicity, marital status, antihypertensive medication history, self-efficacy, and other chronic medication-taking history. ^bN=518 (those who completed the intervention). ^cN=596, Intention-to-treat analysis. *P<0.05.

Abbreviations: MA, medication adherence; ICC, intracluster correlation coefficient; SBP, systolic blood pressure; DBP, diastolic blood pressure.

Table 3 Comparison of participants’ performance on individual items of medication adherence scale before and after intervention

Items	Control group (N=256)			Intervention group (N=262)			Diff^a
	Improve	Maintain	Deteriorate	Improve	Maintain	Deteriorate
1. Stopped taking medication without telling doctors when disease status deteriorated	11.3%	75.0%	13.7%	17.6%	76.3%	6.1%	0.134*
2. Stopped taking medication once BP was under control	11.7%	82.8%	5.5%	15.3%	81.3%	3.4%	0.064
3. Taking medication regularly and on time according to doctors’ recommendations	9.8%	77.7%	12.5%	11.1%	79.4%	9.5%	0.024
4. Never forget taking medications	20.3%	59.4%	20.3%	18.3%	66.0%	15.6%	0.015
5. Taking medications even if BP was normal for a consecutive period of time	14.8%	68.8%	16.4%	18.5%	71.2%	10.4%	0.058*

Notes: ^aDifference in change between groups in terms of individual items after controlling for clustering level, gender, age, education, ethnicity, marital status, antihypertensive medication history, self-efficacy, and other chronic medication-taking history (multilevel modeling results). *P<0.05.