Factors influencing adherence to psychopharmacological medications in psychiatric patients: a structural equation modeling approach

Figures & data

Figure 1 Research framework and model construction.

Note: Use of the MMAS-8 is protected by the US copyright laws. Permission for use is required. A licensure agreement is available from Donald E Morisky, ScD, ScM, MSPH, Professor, Department of Community Health Sciences, UCL A School of Public Health, 650 Charles E Young Drive South, Los Angeles, CA 90095-1772; [email protected].
Abbreviations: DAI-10, Drug Attitude Inventory – 10 Items; MMAS-8, Morisky Medication Adherence Scale.

Table 1 Successive logistic regression models for sociodemographic, clinical, attitudinal, and perceived health control variables

Model 1 Sociodemographic variables
Variables	B (SE)	ORa	95% CI
Female gender	0.057 (0.15)	1.06	0.78–1.43
Age	0.03* (0.005)	1.03	1.02–1.04
University degree	0.42** (0.21)	1.53	1.01–2.33
Model 2 Sociodemographic + clinical variables
Variables	B (SE)	OR	95% CI
Female gender	0.13 (0.17)	1.14	0.82–1.60
Age	0.03* (0.00)	1.03	1.02–1.04
University degree	0.48** (0.22)	1.63	1.05–2.53
Diagnosis of depression	−0.35 (0.20)	0.70	0.47–1.06
Diagnosis of anxiety	−0.46** (0.24)	0.63	0.39–1.01
Model 3 Sociodemographic + clinical + attitudinal variables
Variables	B (SE)	OR	95% CI
Female gender	0.13 (0.17)	1.16	0.82–1.63
Age	0.02* (0.00)	1.03	1.01–1.04
University degree	0.58** (0.23)	1.79	1.14–2.80
Diagnosis of depression	−0.35 (0.20)	0.70	0.47–1.06
Diagnosis of anxiety	−0.46** (0.24)	0.63	0.39–1.01
DAI-10 – Positive = Pharmacophilia	0.98* (0.16)	2.67	1.92–3.72
CPS – Passive	0.55 (0.33)	1.74	0.90–3.33
Model 4 Sociodemographic + clinical + attitudinal + perceived health control variables
Variables	B (SE)	OR	95% CI
Age	0.02* (0.00)	1.02	1.01–1.04
University degree	0.38 (0.24)	1.47	0.92–2.36
DAI-10 – Positive = Pharmacophilia	0.75* (0.18)	2.14	1.49–3.07
CPS – Passive	0.59 (0.34)	1.81	0.91–3.60
MHLC-C Internal	−0.03* (0.01)	0.97	0.94–0.99
MHLC-C Chance	−0.04* (0.01)	0.95	0.93–0.97
MHLC-C Doctor	0.07* (0.02)	1.07	1.02–1.13

Notes:

a OR is the exponent of B.

* P<0.01,

** P<0.05.

Abbreviations: B, β coefficient in logistic regression; CI, confidence interval; CPS, Control Preferences Scale; DAI-10, Drug Attitude Inventory – 10 Items; MHLC-C, Multidimensional Health Locus of Control Scale Form C; OR, odds ratio; SE standard error.

Figure 2 SEM analysis (standardized values) of data outlined after the framework for treatment adherence, according to MMAS-8 scale scores.

Note: Use of the MMAS-8 is protected by the US copyright laws. Permission for use is required. A licensure agreement is available from Donald E Morisky, ScD, ScM, MSPH, Professor, Department of Community Health Sciences, UCL A School of Public Health, 650 Charles E Young Drive South, Los Angeles, CA 90095-1772; [email protected].
Abbreviations: AGFI, χ² Adjusted Goodness of Fit Index; CFI, Comparative Fit Index; GFI, χ² Goodness of Fit Index; HPRS, Hong Psychological Reactance Scale; MHLC-C, Multidimensional Health Locus of Control Scale, Form C; MMAS-8, Morisky Medication Adherence Scale; NFI, Normed Fit Index; NNFI, Non Normed Fit Index; RMSEA, Root Mean Square Error of Approximation; SEM, Structural Equation Modelling.