Drug Attitude and Medication Adherence of Patients with Early Psychosis in South Korea: Mediating Effect of Medication Adherence Self-Efficacy

Figures & data

Table 1 Participant Characteristics, and Differences in Medication Adherence by Characteristics

Characteristic	Category	n (%)	MA
			Mean ± SD	t/F
Gender	Male	79 (47.6)	30.11 ± 4.41	–0.41
	Female	87 (52.4)	30.40 ± 4.72
Age (yrs)	Mean ± SD	27.76 ± 7.66
	20–29	118 (71.1)	29.73 ± 4.88	2.05
	30–39	30 (18.1)	31.30 ± 3.57
	40–49	15 (9.0)	32.20 ± 3.19
	≥50	3 (1.8)	31.33 ± 2.52
Education status	High school or less	43 (25.9)	30.30 ± 4.34	0.05
	Undergraduate	107 (64.5)	30.27 ± 4.66
	Graduate	16 (9.6)	30.27 ± 4.56
Marital status	Single	152 (91.6)	30.12 ± 4.66	–1.37
	Married	14 (8.4)	31.86 ± 3.11
Medical insurance	Medicare	158 (95.2)	30.26 ± 4.57	–0.07
	Medicaid	8 (4.8)	30.38 ± 4.72
Occupational status	Unemployed	114 (68.7)	29.81 ± 4.65	–1.89
	Employed	52 (31.3)	31.25 ± 4.26
Socioeconomic status	Low	34 (20.5)	29.06 ± 4.98	2.27
	Moderate	68 (41.0)	31.04 ± 3.43
	High	64 (38.6)	30.08 ± 5.25
Relationship with family	Bad^a	9 (5.4)	26.00 ± 8.93	7.64***
	Moderate^b	30 (18.1)	28.70 ± 4.97	a<b, c
	Good^c	127 (76.5)	30.94 ± 3.77
Frequency of	None	68 (41.0)	29.44 ± 5.07	1.93
Hospitalization after	Once	74 (44.5)	30.77 ± 4.27
Onset	Twice or more	24 (14.5)	31.04 ± 3.63
Family history of mental illness	No	138 (83.1)	30.22 ± 4.61	–0.25
	Yes	28 (16.9)	30.46 ± 4.39
Self-administered own medication	No	51 (30.7)	28.63 ± 5.02	–3.16**
	Yes	115 (69.3)	30.994.17
Age of first psychotic episode (yrs)	Mean ± SD	25.42 ± 7.77

Notes: **p<0.01; ***p<0.001. ^a–cRepresent three groups used to examine the level of differences in relationship with family using the Scheffe test as the post hoc analysis.

Abbreviations: MA, medication adherence; SD, standard deviation; F, F-value using one-way t, t-value using t-test ANOVA.

Table 2 Descriptive Statistics for Major Variables

Variables	Range	Mean ± SD	Skewness	Kurtosis
Drug attitude	–10 to +10	4.18 ± 4.31	–0.701	–0.008
Medication adherence self-efficacy	8 to 40	33.44 ± 5.16	–0.919	2.284
Medication adherence	7 to 35	30.27 ± 4.56	–1.395	3.393

Abbreviation: SD, standard deviation.

Table 3 Correlations Among Major Variables

Variables	DA	MASE	MA
	r	r	r
1. Drug attitude	1	–	–
2. Medication adherence self-efficacy	0.334***	1	–
3. Medication adherence	0.393***	0.697***	1

Note: ***p<0.001.

Abbreviations: DA, drug attitude; MA, medication adherence; MASE, medication adherence self-efficacy; r, Pearson’s Correlation Coefficient.

Table 4 Mediating Effects of MASE on the Relationship Between DA and MA

Step	Pathway	B	SE	β	t	Adj. R^2	F
1	DA → MASE	0.399	0.058	0.334	4.532***	0.106	20.540***
2	DA → MA	0.414	0.074	0.386	5.608***	0.144	31.451***
3	DA → MA	0.184	0.058	0.172	3.200**	0.534	104.689***
	MASE → MA	0.575	0.047	0.660	12.313***

Notes: **p<0.01; ***p<0.001.

Abbreviations: DA, drug attitude; MA, medication adherence; MASE, medication adherence self-efficacy; B, unstandardized regression coefficient; SE, standard error; β, standardized regression coefficient; t, t-value using t-test; Adj.R², Adjusted R-squared; F, F-value using ANOVA.

Table 5 Verification of the Bootstrapping Mediation Effect

Medication Adherence Self-Efficacy	B	SE	Bootstrap 95% CI
Indirect effect	0.230	0.061	0.124, 0.361
Direct effect	0.185	0.058	0.071, 0.298
Total effect	0.414	0.074	0.267, 0.560

Abbreviations: B, unstandardized regression coefficient; CI, confidence interval; SE, standard error.

Onitsuka T, Hirano Y, Nakazawa T, et al. Toward recovery in schizophrenia: current concepts, findings, and future research directions. Psychiatry Clin Neurosci. 2022;76(7):282–291. doi:10.1111/pcn.13342

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