A Cross-Sectional Observational Study to Evaluate Psychological Well-Being, Depression, and Health-Related Quality of Life and Their Demographic and Clinical Correlates in Adults With Type 2 Diabetes Attending an Outpatient Metabolic Clinic
Conditions: Type 2 Diabetes Mellitus (T2DM), Health-related Quality of Life, Depressive Symptoms, Psychological Well-being, Spiritual Well-being
Sponsor: National Taiwan University Hospital

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STUDY PROTOCOL 
Version 1.0 – Date: September 9, 2025 
 
Document Type: Study Protocol 
Official Title: A Cross-Sectional Observational Study to Evaluate Psychological Well-Being, 
Depression, and Health-Related Quality of Life and Their Demographic and Clinical Correlates 
in Adults With Type 2 Diabetes Attending an Outpatient Metabolic Clinic 
Sponsor: National Taiwan University Hospital 
Principal Investigator: Prof. Ching-Yuan Wang, MD, PhD, Department of Metabolism, 
National Taiwan University Hospital 
Study Coordinator: Yi-Chieh Chung, MSN, RN, Department of Metabolism, National Taiwan 
University Hospital 
NCT Number: Pending assignment 
Protocol Version and Date: Version 1.0 – September 9, 2025 
IRB Approval: National Taiwan University Hospital REC – Approval No. 202508155RIND 
Study Site: Outpatient Metabolism Clinic, National Taiwan University Hospital, Taipei, Taiwan 
Confidentiality Statement: This document contains confidential information that must not be 
disclosed to anyone other than the study sponsor, investigators, and authorized regulatory 
authorities without prior written permission. 
 
 
Signatures 
Principal Investigator: _______________________________   Date: _______________ 
Study Coordinator: _________________________________   Date: _______________ 

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1. Study Summary 
 
This study investigates the psychological well-being, depression severity, and health-related 
quality of life among adults with Type 2 Diabetes. It aims to identify demographic and clinical 
correlates that may influence these outcomes to inform integrated physical and psychological care 
strategies in diabetes management. 
 
2. Study Design 
 
This is a cross-sectional observational study conducted at a single site (National Taiwan 
University Hospital). Participants will complete standardized questionnaires during one outpatient 
visit. There is no follow-up period, and no intervention is administered. 
 
3. Study Population 
 
Eligible participants include adults (≥20 years old) diagnosed with Type 2 Diabetes attending the 
outpatient metabolism clinic. Exclusion criteria include inability to consent or complete 
questionnaires due to cognitive impairment or language barriers. 
 
4. Sample Size 
 
A total of approximately 500 participants are anticipated, based on feasibility and sufficient 
statistical power to detect medium effect sizes in multivariate analyses (α = 0.05, power = 0.8). 
 
5. Data Collection Instruments 
 
Participants will complete the following validated instruments: 
- EQ-5D-5L for health-related quality of life. 
- PHQ-9 for depression severity. 
- Shalom Scale for psychological well-being. 
In addition, demographic and clinical data (e.g., age, sex, education, diabetes duration, HbA1c, 
BMI, and complications) will be collected from medical records or self-report. 
 

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6. Variables and Measures 
 
Independent variables include demographic (age, sex, education, marital status, employment), 
and clinical variables (HbA1c, BMI, disease duration, complications).  
Dependent variables include Shalom Scale total score (psychological well-being), PHQ-9 total 
score (depression severity), and EQ-5D-5L index and VAS (health-related quality of life). 
 
7. Statistical Analysis Plan 
 
Data will be analyzed using descriptive statistics, correlation analysis (Pearson’s r), group 
comparisons (t-test or ANOVA), and multiple linear regression to identify predictors of 
psychological well-being.  
All analyses will be performed using SPSS or R statistical software, with a significance level of 
0.05. 
 
8. Confidentiality and Data Protection 
 
Participant information will be coded and de-identified. Only authorized research staff will have 
access to the key linking identifiers to data. Data will be stored securely in password-protected 
systems approved by the institution and retained for at least three years following study 
completion. 
 
9. Ethical Considerations 
 
This study was reviewed and approved by the National Taiwan University Hospital Research 
Ethics Committee (Approval No. 202508155RIND). Participation is voluntary, and all 
participants will provide written informed consent. The study poses minimal risk as it involves 
only questionnaire completion and data collection from existing medical records. 
10. Contact Information 
 
Principal Investigator: Prof. Ching-Yuan Wang, MD, PhD 
Study Coordinator: Yi-Chieh Chung, MSN, RN 
Department of Metabolism, National Taiwan University Hospital 
Tel: +886-2-2312-3456 
Email: yi-chieh.chung@ntuh.gov.tw 
 

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This English version is prepared for public posting on ClinicalTrials.gov under 42 CFR Part 11.