Adherence To Medication Among Patients With Chronic Hepatits B Based On The Therapy Of Planned Behavior

ObjectiveIt aims to investigate the medication adherence and related factors on patients with chronic hepatitis B（CHB）receiving the antiviral therapy.The structural equation model was employed to identify how subject norms,behavior attitude,behavior intention and perceptual behavioral control contribute to their self-management behaviors in patients with CHB and provide evidence on medication adherence based on the theory of planned behavior.MethodsBased on the theory of planning behavior,combined with the literature review,the first draft of the questionnaire was formed.A total of 10 experts were invited to conduct 2rounds of expert letters to screen the questionnaire items.In July 2020,a total of 120outpatients with CHB who met the included criteria was selected by convenience sampling method for pre-investigation.After revising the questionnaire,the reliability and validity of the questionnaire was underwent by internal consistency reliability,content validity and exploratory factor analysis.A cross-sectional study with convenience sampling method collected 225 outpatients with CHB of the Qingdao No 6^th People’s Hospital during August and October 2020 was included in the data analysis.Medication adherence was measured using the Morisky Medication Adherence Scale（MMAS-8）.Descriptive statistical methods were used to explore the personal characteristics,variables in theory of planned behavior model,as well as medication adherence behavior of outpatients.The structural equation model was employed to explore the impact of latent variables of theory of planned behavior on medication adherence.Data analysis was performed using SPSS22.0 and AMOS22.0.Two-sided P values of 0.05 were considered statistically significant.Results1.Four common factors,which were named as behavioral attitude,subjective norm,perceptual behavioral control and behavioral intention were extracted from the questionnaire.The cumulative variance contribution rate was 76.99%,the internal consistency Cronbach’sαcoefficient was 0.83.The model fits well and the questionnaire has good reliability and validity.2.A total of 225 outpatients with CHB,mean age of 41.8（9.4）and 47%of men,was included in the current analysis.Only 18.7%had high adherence（score of 8）,48.9%had medium adherence（score of 6 to<8）,and 32.4%were measured with low adherence（score of<6）.3.Between the medication adherence groups,the variables of school years,health education,antiviral therapy duration and visiting hospital was significantly different（P<0.05 for all comparisons）.In a multivariable logistic model,older than 45 years（OR=0.17,P<0.01）,doctor rank（OR=0.17,P<0.01）,health education（OR=0.11,P<0.01）,visiting hospital（OR=0.20,P<0.01）were protective factors on medication adherence of CHB patients,whereas living alone（OR=7.45,P<0.01）and disease duration（OR=4.22,P<0.01）were risk factors on medication adherence.3.According to Pearson correlation analysis,behavior intention was positive correlation with perceptual behavioral control（r=0.81,P<0.01）and subject norms（r=0.54,P<0.01）.The medication adherence was positive correlation with behavior intention（r=0.51,P<0.01）,perceptual behavioral control（r=0.63,P<0.01）and subject norms（r=0.52,P<0.01）.4.The structural equation model showed that behavior attitude and subject norms were the most important predictor of medication adherence,with exerts indirect effect on behavior.The corresponding coefficients of correlation were 0.13*0.66=0.09 and0.39*0.66=0.25,respectively.Behavior attitude and subject norms had indirect effect on medication adherence through behavior intention.Moreover,perceptual behavioral control had both direct and indirect effect on medication adherence,with coefficients of correlation of 0.14,and 0.32,respectively.The model based on the theory of planned behavior could explain 58.5%of the variance of medication adherence of the patients with CHB.Conclusions:1.Chronic hepatitis B medication adherence Questionnaire had good reliability and validity,which can be used to study medication adherence of CHB patients.2.Our findings indicated that medication adherence of CHB patients with antiviral therapy was moderate.Increasing age,doctor rank,health education and visiting hospital were protective factors on medication adherence,whereas disease duration and living alone were associated with lower medication adherence.3.The behavioral attitude,subjective norms and perceptual behavioral control indirectly affected medication adherence in adults with CHB based on the structural equation model.