Factors associate with adherence to anti hypertensive treatment among essential hypertensive patients

THE MINISTRY OF EDUCATION AND TRAINING UNIVERSITY OF ECONOMICS HO CHI MINH CITY VIETNAM PHAN THI VAN FACTORS ASSOCIATE WITH ADHERENCE TO ANTI-HYPERTENSIVE TREATMENT AMONG ESSENTIAL HYPERTENSIVE PATIENTS The thesis submitted in partial fulfillment of the requirement for the degree of MASTER IN DEVELOPMENT ECONOMICS HO CHI MINH CITY, 2017 THE MINISTRY OF EDUCATION AND TRAINING UNIVERSITY OF ECONOMICS HO CHI MINH CITY VIETNAM PHAN THI VAN FACTORS ASSOCIATE WITH ADHERENCE TO ANTI-HYPERTENSIVE TREATMENT AMONG ESSENTIAL HYPERTENSIVE PATIENTS Health Economics and Management Code: 60310105 The thesis submitted in partial fulfillment of the requirement for the degree of MASTER IN DEVELOPMENT ECONOMICS Academic Supervision Dr TRUONG DANG THUY HO CHI MINH CITY, 2017 DECLARATION “I certify the content of this thesis entitled “Factors impact medication treatment adherence among essential hypertensive patients” has not already been submitted for any degree and is not being currently submitted for any other degrees I certify that, to be the best of my knowledge, any help received in preparing this thesis and all sources used, have been acknowledged in this dissertation” Signature Phan Thị Vân Date: May 3rd, 2017 ACKNOWLEDGEMENT First and foremost, I would like to express my sincere thanks to my thesis academic supervisor Dr Truong Dang Thuy of Development Economics Faculty at the University of Economics Ho Chi Minh City Vietnam for his enthusiastic guidance, useful comments and continuous support during my thesis completion Besides my thesis academic supervisor, I also would like to gratefully thank the Board of Director, Scientific Committee and/or Ethics Committee of fours hospitals: Tam Duc Hospital, Ho Chi Minh Heart Hospital, Ho Chi Minh University Medical Center and District Hospital for their review and approval so that the research could be conducted at the hospitals The next sincere thanks, I would like to send to the doctors and nurses at Outpatient and/ or Inpatient Departments of Tam Duc Hospitals, Ho Chi Minh Heart Hospital, Ho Chi Minh University Medical Center and District Hospital, who had created good conditions so that the data of this research were effectively collected Next to the last, I would like to sincerely thank all patients who agreed to participate into an interview on their visit date at the hospitals Finally, I would like to thank my family members who unfailingly encourage and support me during the thesis process TABLE OF CONTENTS COVER PAGE DECLARATION ACKNOWLEDGEMENT TABLE OF CONTENTS ABBREVIATION LIST OF TABLES LIST OF FIGURES ABTRACT CHAPTER 1: INTRODUCTION 1.1 Background information .1 1.2 Research objectives 1.3 Research methods and data 1.4 Structure of the thesis CHAPTER LITERATURE REVIEW 2.1 Theoretical literature 2.1.1 Hypertension and essential hypertension 2.1.2 Adherence 2.2 Experimental research reviews .9 2.2.1 Adherent measurement 2.2.2 Factors influence compliance 13 2.2.3 Methodology 17 CHAPTER 3: RESEARCH METHODOLOGY 3.1 Analytical framework 19 3.2 Estimated analysis model 20 3.3 Interpretation of the variables .20 3.3.1 Dependent variables 20 3.3.2 Independent variables 22 3.4 Data collection 26 3.5 Study design 27 3.6 Population 28 3.6.1 Inclusion criteria 28 3.6.2 Exclusion criteria 28 3.7 Sample size 28 3.8 Ethical issue .29 CHAPTER 4: DATA ANALYSIS AND EMPITICAL RESULT 4.1 Descriptive statistics and basis estimation 30 4.1.1 Descriptive statistics 30 4.1.2 Descriptive statistics in Adherence group 31 4.2 Regression Models .38 4.2.1 Result of full regression model of DMMAS and NEWADH 38 4.2.2 Heterokelasticity 40 4.2.3 Correlation/multicollinearity tests 40 4.2.4 Factors associate with adherence .41 4.2.4.1 Model 1: MMAS-8 .41 4.2.4.2 Model 2: Pill-counting without BMI 46 CHAPTER 5: DISCUSSION AND CONCLUSION 50 REFERENCE APPENDIX 1: QUESTIONNAIRE IN ENGLISH APPENDIX 2: QUESTIONNAIRE IN VIETNAMESE: BẢNG CÂU HỎI APPENDIX 3: STATA OUTPUT Descriptive statistics 1.1 Socio-demographic charateristics 1.2 Perception of patient 1.3 Complex of antihypertensive drug Descriptive statistics in Adherence group 2.1 MMAS-8 model 2.2 Pill Counting Model Full logistic regression models 3.1 Full regression model MMAS-8-DMMAS 3.2 Full regression model Pill-counting – NEWADH 3.3 Full regression model MMAS-8- adjusted analyses 3.4 Full regression model NWEADH – adjusted analyses Multicollinearity test 4.1 VIF test for Multicollinearity - DMMAS 4.2 VIF test for Multicollinearity – NEWADH 4.3 Test for standard normal distribution of AGE and BMI 4.4 Pearson test for correlation between Age and BMI Auxiliary Regression without BMI/without AGE 5.1 DMMAS: unadjusted analyses without BMI 5.2 DMMAS: adjusted analyses without BMI 5.3 NEWADH: unadjusted analyses without BMI 5.4 NEWADH: adjusted analyses without BMI 5.5 DMMAS – unadjusted analyeses without AGE 5.6 NEWADH - unadjusted analyeses without AGE Descriptive statistics of concomitant diseases ABBREVIATIONS BMQ: Belief Model Questionnaire CMA: Cumulative medication adherence DMMAS: Dependent variable defined as adherence in MMAS-8 model IPQ-R: Illness Perception Questionnaire HBM: Health Belief Model HTN: Hypertension MMAS-4: The 4-item Morisky Medical Scale MMAS-8: The 8-items Morisky Medical Scale MRCT: Medication regimen complexity index NEWADH: Dependent variable defined as adherence in Pill-counting model WHO: World Health Organization LIST OF TABLES Table 1: Summary of dependent variables 24 Table 2: Summary of independent variables 25 Table 3: Descriptive statistics of socio-demographic characteristics 33 Table 4: Descriptive statistics of patient’s perception of hypertension 34 Table 5: Descriptive statistics of complex of anti-hypertensive drug 34 Table 6: Descriptive statistics of socio-demographic in adherence groups: MMAS-8 and Pill counting 36 Table 7: Descriptive statistics of Patient perception on hypertension in adherence groups: MMAS-8 and Pill counting 37 Table 8: DMMAS full regression model 38 Table 9: NEWADH full regression model 39 Table 10: Changes in term of sign and significance of coefficients- NEWADH auxiliray regression 42 Table 11: Relationship between factors and adherence- adjusted analyses – MMAS-8 43 Table 12: Relationship between factors and adherence- unadjusted analyses– Pill Counting Model without BMI 44 Table 13: Relationship between factors and adherence- adjusted analyses – Pill counting Model without BMI 45 t a b v i s i t n e w a d h F o l l o w u p n e w a d h 1 v i s i t n o y e s T o t a l T o t a l 5 t a b p r e s n e w a d h F o l l o w i n g p r e n e w a d h s c r i p t 1 i n o y e s T o t a l t a b l i f e T o t a l 1 4 6 n e w a d h L i f e s t y l e n e w a d h c h a n g e n o y e s T o t a l T o t a l 1 5 t a b r e m n e w a d h R e m e m b e r n u m b e r o f m e d i c a t i o n n e w a d h t a k e n n o y e s T o t a l 4 1 T o t a l 1 t a b a e n e w a d h M e d i c a t i o n n e w a d h a d v e 1 1 T o t a l r s e e v e N o Y e s T o t a l 3 t a b e f f e c t n e w a d h E f f e c t o f a n t i h y p e r t e n s i o n n e w a d h d o n ' t k 5 n o w n o t a l l 4 1 1 m e d i c a t a t w e l l T o t a l m o d e r a t e l y w T o t a l FULL LOGISTIC REGRESSION MODELS: 3.1 Full regression model- MMAS-8-DMMAS L o g i s t i c r e g r e s s i o n N b L ) P L o g l i k e l i h o o d = - 2 u m b e r o f o s R c h i ( = r o b > c h i = P s e u d o R = = 5 d m m a s C o e f S t d E r r z P > | z | [ % C o n f I n t e r v a l ] a g 4 - 7 7 6 7 - 7 - 9 - - 4 5 - - - 8 8 - - 9 5 - - 6 7 - - 8 8 7 - - 4 1 8 - 1 - 5 2 7 - - 9 - 7 8 - - 7 4 e b m i y r s m a r - - 9 ( o m i t t e d ) i e d u s e c o n d a r y h i g h s c h o o l C o l l e g e o r u n i v e r s i t y P o s t 8 - 2 6 - ( e m p t y ) u n i v e r s i t y - g e n d e r w o r k j o b l e s s o r n o t w o r k i n g w o r k i n g r e t i r e d o t h e r s 6 - 9 - ( e m p t y ) 9 8 ( o m i t t e d ) - 7 d i f f i n s 2 6 9 u I n s u r a n c e 7 p a y i n s u r 3 a n c e s u p p o r t e 6 - 1 3.2 Full regression model- NEWADH L o g i s t i c r e g r e s s i o n N b L ) P L o g l i k e l i h o o d = - n e w a d h C o e f a g - e b m i y r s m a r u m b e r o f o = s R c h i ( = r o b > c h i = P s e u d o R P > | z | [ % C o n f I n t e r v a l ] 2 - - 3 4 - 5 8 - 5 7 7 - 4 4 4 2 - 2 - 0 - 6 - 1 - 3 2 3 - 1 2 - - 8 - 4 3 - 9 - - - 2 5 - 8 S t d E r r z = 85 0 0 i e d us e c o n - 2 1 d a r y - 2 h i g h s c h o o lC o l l e g e o r u n i v e r s i t yP o s t u n i v e r s i t y - 9 ( e m p t y ) 6 ( e m p t y ) - g e n d e r w o r kj o b l e s s o r n o t w o r k i n g 3 9 3 3 w o r k i n g r e t i r e d o t 5 h e r s ( e m p t y ) 2 5 1 ( o m i t t e d ) 5 7 d i f f i n s u ( e m p t y ) ( o m i t t e d ) no I n s u r a n c e p a 2 yi n s u r a n c es u p p o r t e - 5 3.3 Full regression model- MMAS-8-DMMAS- adjusted analyses L o g i s t i c r e g r e s s i o n N b W P L o g p s e u d o l i k e l i h o o d = - u s a r m b e r o f o = l d c h i ( ) o b > c h i = P s e u d o R = = R o b u s t d m m a s C o e f a g S t d E r r z P > | z | [ % C o n f I n t e r v a l ] 8 - 0 1 1 - 2 8 - 0 - 4 s m - 3 - - a r 0 6 - 7 - - 5 9 - 1 - 0 - - 7 - - 6 4 - - 7 8 - - 7 8 - 6 0 7 - 8 - 9 - 9 2 5 - 0 - 0 - 6 4 e b m i y r ( o m i t t e d ) i e d u s e c o n d a r y h i g h s c h o o l C o l l e g e o r u n i v e r s i t y P o s t u n i v e r s i t y 8 - 2 - w o r o r k i n g w o r k i n g r e t - 7 - 0 i n s y i n s u r a n c e s u ( e m p t y ) 8 1 - 5 n c e p a 9 ( o m i t t e d ) d i f f u I n s u r a 9 3 - i r e d o t h e r s 4 1 ( e m p t y ) g e n d e r k j o b l e s s o r n o t w 2 4 9 - 0 9 3 8 p p o r t e - 1 2 d i n c o n o m e 3.4 Full regression model- NEWADH- adjusted analyses L o g i s t i c r e g r e s s i o n L o g p s e u d o l i k e l i h o o d N b W P = - u s a r m b e r o f o = l d c h i ( ) o b > c h i = P s e u d o R = = R o b u s t n e w a d h a g e b m i y r s m a r C o e f - S t d E r r z P > | z | [ % C o n f I n t e r v a l ] - 0 - - - 4 7 6 - 9 9 7 3 - 3 - 1 - - 8 i e d u s e c o n d a r y h i g h s c h o o l C o l l e g e o r u - 2 1 - 2 ( e m p t y ) 9 - 7 - 8 ( e m p t y ) n i v e r s i t y P o s t u n i v e r s i t y - 9 7 4 - 7 g e n d e r w o r k j o b l e s s o r n o t w o r k i n g w o r k i n g r e t 1 4 3 9 7 - i r e d o t h e r s ( e m p t y ) 3 9 5 - - 6 2 7 ( o m i t t e d ) 1 0 d i f f i n s u n 0 ( e m p t y ) ( o m i t t e d ) o I n s u r a n c e p a y i n s u r 3 a n c e s u p p o r t e d - 5 2 0 - - 3 - - 6 N o t e : f a i l u r e s a n d s u c c e s s e s c o m p l e t e l y d e t e r m i n e d 2 3 4 4 MULTICOLLINEARITY TEST 4.1 VIF test for multicollinearity -DMMAS v i f , r e d u n c e n t e V a r i a b l e V I F a g e 6 8 b m i y r s / V I F e d u g e n d e r w o r k 3 d i f f i n s u 1 p a y i n c o n o m e d t i m e s a e e f f e c t v i s i t M e a n 4.2 V I F 8 1 5 3 1 8 4 2 6 1 1 3 7 6 4 VIF test for multicollinearity - NEWADH v i f , u n c e n t e r e d V a r i a b l e V I F a g e b m i y r s 4 m a r i e d u 9 g e n d e r w o r k 3 d i f f 1 p a y i n c o n o m e d 1 t i m e s a e e f f e c t M e a n F V I 1 / V I F 2 6 5 5 6 9 5 0 2 9 3 7 9 0 3 01 02 Density 03 04 4.3 Test for standard normal distribution of AGE and BMI 60 Patient age 40 80 100 15 05 Density 15 20 20 25 BMI 30 35 4.4 Pearson test for correlation between Age and BMI pwcorragebmi,star(0.1) age bmi age1.0000 b m i - *1 0 0 40 AUXILIARY REGRESSION WITHOUT BMI/ WITHOUT AGE 5.1 DMMAS- unadjusted analyses without BMI L o g i s t i c r e g r e s s i o n L o g l i k e l i h o o d = d m m a s N b L ) P - C o e f a g e y r - 0 s m a r i u m b e r o f o s R c h i ( = r o b > c h i = P s e u d o R S t d E r r z P > | z | = = [ % C o n I n t e r v f a l ] 8 5 - 2 7 - 6 - 6 6 - 9 2 - 7 - 9 3 - - 9 9 - 5 - 1 4 - 1 6 - 7 - 6 - 2 1 6 - 1 - 9 7 9 - 9 1 9 - 7 7 - - 3 ( o m i t t e d ) e d u s e c o n d a r y h i g h s c h o o l C o l l e g e o r u n i v e r s i t y P o s t 5 - 2 2 - 3 u n i v e r s i t y g e n d e r w o r k j o b l e s s o r n o t w o r k i n g w o r k i n g r e t i r e d o t h e r s i n s 8 9 ( e m p t y ) 3 - - 4 - 8 ( e m p t y ) 9 8 ( o m i t t e d ) 5 8 7 7 n c e p a y i n s u r a n c e s u p p o r t e d 2 - d i f f u I n s u r a 7 - 1 1 - 6 5 2 1 - 2 5.2 DMMAS- Adjusted analyses (ROBUST) without BMI L o g i s t i c r e g r e s s i o n N b W P L o g p s e u d o l i k e l i h o o d = - u s a r m b e r o f o = l d c h i ( ) o b > c h i = P s e u d o R = = 0 R o b u s t d m m a s C o e f a g e y - 0 r s m a u s e c o n d a r y h i g h s c h o o l C o l l e g e o r u P > | z | [ % C o n f 2 0 1 - 5 - 5 5 - 5 - - 9 8 - 5 - 1 - 7 4 - - 2 2 - 6 7 - - - 6 - - 9 3 - 3 6 4 1 - 5 7 - - 5 5 - 2 2 - 3 n i v e r s i t y P o s t u n i v e r s i t y z I n t e r v a l ] ( o m i t t e d ) r i e d S t d E r r 9 0 8 ( e m p t y ) - 5 g e n d e r w o r k j o b l e s s o r n o t w o r k i n g w o r k i n g r e t i r e d o t h e r s - - 4 - 8 3 8 9 ( o m i t t e d ) d i f f i n s ( e m p t y ) 7 6 7 u I n s u r a n c e p a y i n s u r a n c e s u p p o r t e d - 1 1 - 8 5.3 NEWADH- UNADJUSTED ANALYSES WITHOUT BMI L o g i s t i c r e g r e s s i o n N b L ) P L o g l i k e l i h o o d = - n e w a d h a g e y r s m a r i C o e f u m b e r o f o s R c h i ( = = r o b > c h i = 0 0 P s e u d o R S t d E r r z = P > | z | [ % C o n f I n t e r v a l ] - 9 - - 8 9 2 - 9 3 5 - 5 8 e d u s e c o n ( e m p t y ) - 8 4 - - 9 3 o o l C o l l e g e o r u - 1 4 6 - - 4 n i v e r s i t y P o s t - 0 - 8 d a r y h i g h s c h ( e m p t y ) u n i v e r s i t y g e n d e r w o r k j o b l e s s o r n o t w o r k i n g w o r k i n g r e - 7 r s ( e m p t y ) 5 0 - 5 1 7 1 - 8 4 - 7 1 - 8 1 4 - 4 6 - - 4 8 - 9 0 t i r e d o t h e ( o m i t t e d ) 1 d i f f i n ( e m p t y ) ( o m i t t e d ) s u n o I n s u r a n c e p a 8 y i n s u r a n c e s u p p o r t e d - 8 0 2 5.4 NEWADH- ADJUSTED ANALYSES WITHOUT BMI L o g i s t i c r e g r e s s i o n b s L o g p s e u d o l i k e l i h o o d = W a l d c h i ( ) N u m b e r o f o = P r o b c h i > P s e u R d o = 3 0 = - = R o b u s t n e w a d h a g e y r s m a r i C o e f - 9 S t d E r r z P > | z | [ % C o n f I n t e r v a l ] 9 - - 3 - 9 - 1 8 5 0 7 6 8 e d u s e c o n d ( e m p t y ) - 8 9 - - o o l C o l l e g e o r u - 1 4 6 9 - - - n i v e r s i t y P o s t - 9 0 - 4 - 5 a r y h i g h s c h ( e m p t y ) u n i v e r s i t y g e n d e r w o r k j o b l e s s o r n o t w o r k i n g w o r k i n g r e t - 7 ( e m p t y ) 5 2 - 9 1 3 9 6 - 0 8 1 2 5 - - 3 2 6 i r e d o t h e r s 4 ( o m i t t e d ) d i f f i n s u n 0 o ( e m p t y ) ( o m i t t e d ) I n s u r a n c e p a y i n s u r a n c e s u p p o r t e d - 8 9 4 6 N o t e : f a i l u r e s a n d s u c c e s s e s c o m p l e t e l y d e t e r m i n e d 7 5.5 DMMAS- unadjusted analyses without AGE L o g i s t i c r e g r e s s i o n N b L ) P L o g l i k e l i h o o d = - d m m a s b m C o e f u m b e r o f o s R c h i ( = r o b > c h i = P s e u d o R S t d E r r z = = 1 4 8 P > | z | [ % C o n f I n t e r v a l ] - - - r s 0 1 - 7 7 m a 0 - 9 1 - 0 - 1 2 - 5 - - 4 - - - 7 8 - - - - 9 5 - 5 - 1 9 - 3 9 - - 3 3 i y r i e d u s e c o n d 1 - a r y h i g h s c h o o l C o l l e g e o r u - 4 n i v e r s i t y P o s t w o r k j o b l e s s o r n o t w o r k i n g - - n g r e t 7 7 ( e m p t y ) 9 5 5 ( o m i t t e d ) i r e d o - 1 5 4 d i f f i n s 9 3 - 9 w o r k i t h e r s ( e m p t y ) u n i v e r s i t y g e n d e r ( o m i t t e d ) 6 6 4 8 u I n s u r a n c e p a y i n s u r 6 a n c e s u p p o r t e d - 2 4 5 5.6 NEWADH- unadjusted analyses without AGE L o g i s t i c r e g r e s s i o n N b L ) P L o g l i k e l i h o o d = - 6 n e w a d h b m i y r s m a r i C o e f u m b e r o f o s R c h i ( = = r o b > c h i = 0 P s e u d o R S t d E r r z P > | z | = [ % C o n f I n t e r v a l ] - - 3 - 4 1 1 9 - - 3 - 8 1 2 1 3 - 1 8 - 2 - 9 1 - - 6 - 0 - 8 9 9 - 3 - 8 - 2 7 2 - - 2 8 2 - 8 0 - 4 9 - 3 e d u s e c o n d - 8 a r y h i g h s c h ( e m p t y ) o o l C o l l e g e o r u - 6 1 8 n i v e r s i t y P o s t ( e m p t y ) u n i v e r s i t y g e n d e r w o r k j o b l e s s o r n o t w o r k i n g - 0 2 1 4 w o r k i - 7 n g r e t i r e d o t h e r s - 7 2 ( e m p t y ) ( o m i t t e d ) 0 d i f f i n s u n ( e m p t y ) ( o m i t t e d ) o I n s u r a n c e 5 p a y i n s u r 0 a n c e s u p p o r t e d 1 - 8 7 3 1 - 7 - 5 6 DESCRIPTIVE STATISTICS OF CONCOMITANT DISEASE t a b c a d C o r o n a r y a r t e r y d i F r e q P e r c e n t s e a s e n o 8 y e s 0 0 T o t a l t a b C u m 8 0 0 c v d C a r d i o v a s c u l a r d i s e a s e s t a b P e r c e n t n o y e s 0 0 T o t a l F r e q C u m 0 0 d i a b t D i a b e t e t y p e F r e q n o y e s 1 0 0 T o t a l t a b C u m 0 0 d l p D i s l i p i d e m i a t a b F r e q P e r c e n t n o y e s 1 1 0 0 T o t a l P e r c e n t C u m 0 0 c v a C e l e b r o v a s c u l a r a c c i d e n t t a b P e r c e n t n o y e s T o t a l l F r e q C u m 0 0 0 0 r e n a R e n a l d i s e F r e q P e r c e n t a s e n o y e s T o t a l 6 1 0 0 C u m 0 0 ... to assess factors associate with adherence to anti- hypertensive treatment among essential hypertensive patients The specific objectives are:  Identify rate of medication adherence  Assess associate. .. contribute to blood pressure control and prevent its complications This research is to determine the factors associate with adherence to antihypertensive treatment among essential hypertensive patients? ??... medication treatment adherence among essential hypertensive patients 3.1 ANALYTICAL FRAMEWORK Figure 3.1: Factors contribute to hypertensive treatment adherence (X3) (X1) (X2) Complex antihypertensive