Impact of health literacy on medication-related information processing, adherence, and quality of life

국문 초록 (Abstract)

건강정보 이해능력은 개인의 건강 등 다양한 요소에 직접적인 영향을 주기에 매우 중요하다. 제한된 건강정보 이해능력은 약물 투약 오류 및 복약 불순은 등으로 이어져 건강 상태 및 삶의 질을 악화시킬 수 있습니다. 그런데도 이전 연구는 각 요소와의 연관성을 정의하는 데 한계가 있었다. 본 연구는 한국인의 복약 정보 처리 방법 및 복약순응도가 건강정보 이해능력 및 삶의 질 간에 연관성을 파악하고자 하였다.
본 연구는 305명의 한국인 성인을 대상으로 cross-sectional 설문을 통해 인구학적 특징, 건강정보 이해능력, 복약 정보 처리 방법, 복약순응도 및 삶의 질 요인을 파악하였다. 인구 통계 학적 특성에 따른 건강정보 이해능력의 분석은 정규 및 비정규 분포형 변수에 따라 Student t test 혹은 Mann-Whitney U test를 이용하였고 카테고리별 변수 간 차이를 분석하기 위해 Chi Square test에 실시되었다. 이후 AMOS를 활용하여 구조 방정식 모델(SEM)을 이용하여 각 변수의 상관관계가 분석하였고 요인 분석을 통해 잠재 변수를 파악한 후 joint significant test를 통해 매개 효과를 검증하였다. 모델 적합도는 RMSD, TLI, 및 CFI 통계 기법을 사용하여 검증하였다.
분석 결과, 본 구조 방정식 모델에서 두 가지 경로가 확인되었습니다. 첫째, 건강정보 이해능력은 복약 안내문 읽기(B = 0.12; p<005)와 긍정적으로 연관되었고, 이는 복약 순응도 준수(B = 0.26; p<0.01)를 개선함으로써 삶의 질 향상(B = 0.15; p<0.05)의 향상에 유의한 영향을 보여주었다. 두 번째는 건강정보 이해능력은 복약 안내문 이해력(B = 0.17; p<0.01)와 긍정적으로 연관되었고, 이는 복약 순응도 준수(B =0.13; p<0.05)와 삶의 질 향상(B = 0.25; p<0.01) 향상에 유의한 영향을 보여주었다. 인구학적 변인 중 교육 수준은 건강정보 이해능력(B = 0.18; p<0.01)와 복약 안내문 이해력(B = 0.25; p<0.01)에 긍정적인 영향을 보여주었다. 여성과 높은 연령대는 복약 안내문 읽는 데는 긍정적인 영향을 미치지만 복약 안내문 해석에는 부정적인 영향을 미치는 것으로 나타났다.
결론적으로 제한된 건강정보 이해능력은 복약 안내문에 참조된 정보를 덜 읽거나 복약 안내문을 부정확하게 이해함으로써 삶의 질과 복약순응도에 부정적인 영향을 미칠 수 있다. 한편, 적절한 건강정보 이해능력은 복약 안내문에 참조된 정보를 더 주의 깊게 읽거나 복약 안내문을 정확하게 이해함으로써 삶의 질과 복약순응도에 긍정적인 영향을 미칠 수 있다. 결론적으로 제한된 건강정보 이해능력 및 삶의 질을 개선하기 위해서는 의약품 관련 정보를 처리 관련 전문적인 훈련 및 프로그램 개발이 권장된다.

다국어 초록 (Multilingual Abstract)

Health literacy has become vital as it can directly impact an individual’s health outcomes and various factors. Low health literacy can lead to misunderstanding of medication and non-adherence to medication which can worsen health status and quality of life. Nonetheless, previous studies have limitations in defining the associations with each element. This study is to investigate whether medication-related information processing and medication adherence explain the relationship between health literacy and quality of life in Korean adults.
The cross-sectional survey was conducted on 305 adults to find the factors: health-related information, health literacy, behaviors of processing medication-related information, quality of life, and adherence in South Korea. The Student t-test was employed for continuous variables with normal distributions, and the Mann-Whitney U test was applied for variables without normal distribution. Moreover, the Chi-square test was used for categorical variables to compare the demographic characteristics and key study variables between individuals with adequate and inadequate health literacy. After examining the correlation of the main research variables, structural equation modeling (SEM) was applied to assess the association between patients’ health literacy level, behaviors of processing medication-related information, quality of life, and medication adherence. The latent variables were identified through factor analysis and the joint significance test was then used to test the mediation effects. The model fit test was conducted with root-mean-squared deviation (RMSD), Tucker-Lewis index (TLI), comparative fit index (CFI), and the chi-square statistic.
Two significant pathways were identified. First, health literacy was positively associated with reading medication guides (B = 0.12; p<005), which was also linked with medication adherence(B = 0.26; p<0.01) and quality of life (B = 0.15; p<0.05). The second, health literacy was positively related to precise understanding of prescription instructions (B = 0.17; p<0.01), which was related to adherence (B = 0.13; p<0.05) and quality of life (B = 0.25; p<0.01). Among demographic variables, education levels have a positive effect on health literacy (B = 0.18; p<0.01) and understanding the prescription instructions (B = 0.25; p<0.01). The female gender and higher age groups have a positive effect on reading medication guides (B = 0.13; p<0.05) and (B = 0.36; p<0.01), respectively, while the negative impact on the understanding the prescription instructions (B = -0.10; p<0.05) and (B = -0.42; p<0.01), respectively.
The reading drug label and understanding prescription guides demonstrated pathways by which health literacy impacts quality of life and medication adherence. Restricted health literacy can negatively affect the quality of life and medication adherence by reading less information on the medication guides or inaccurate understanding of prescription instructions. On the other hand, adequate health literacy levels can positively impact the quality of life and medication adherence by reading more information on the medication guides or an accurate understanding of prescription instructions. The results recommend training on processing medication-related information to improve limited health literacy, adherence, and quality of life.

목차 (Table of Contents)

• 1. INTRODUCTION 1
• 1.1 Background 1
• 1.2 Health Literacy Assessment 6
• 1.2.1 International Health Literacy Tools 6
• 1.2.2 Korea Health Literacy Tools 10
• 1.3 Recent Health Literacy Studies 14
• 1.4 Structural Equation Model in Health Literacy 17
• 1.5 Goals and Objectives 19
• 2. METHODS 20
• 2.1 Model Development 20
• 2.2 Study Participants 25
• 2.3 Data Collection Procedure 27
• 2.4 Measures 28
• 2.4.1 Characteristics of Survey Participants 29
• 2.4.2 Health Literacy 31
• 2.4.3 Reading OTC Drug Labels 32
• 2.4.4 Understanding Prescription Instructions 36
• 2.4.5 Information Seeking Behaviors 38
• 2.4.6 Adherence to Medication Guides 39
• 2.4.7 Quality of Life 40
• 2.5. Statistical Analysis 41
• 3. RESULTS 43
• 3.1 Measures 43
• 3.1.1 Characteristics of Participants 43
• 3.1.2 Health Literacy 46
• 3.1.3 Reading OTC Drug Labels 50
• 3.1.4 Understanding Prescription Instructions 54
• 3.1.5 Information Seeking Behaviors 57
• 3.1.6 Adherence to Medication Guides 58
• 3.1.7 Quality of Life 60
• 3.2 Health Literacy by Demographic Variables 61
• 3.3 Correlations between Indicators 64
• 3.4 Factor Structures 66
• 3.4.1 Facture Structure of Reading OTC Drug Labels 66
• 3.4.2 Facture Structure of Information Seeking Behaviors 69
• 3.5 Mediation Effects with SEM Model 71
• 4. DISCUSSION 75
• 4.1 Overview 75
• 4.2 Summary of Results 80
• 4.3 Implications/Limitations 83
• 5. CONCLUSION 88
• REFERENCES 90
• APPENDIX SURVEY QUESTIONNAIRES 105
• 국문초록 129