Character Strengths Use in Diabetes Self-management Scale (SUDM)

1. Abstract

The Character Strengths Use in Diabetes Self-management Scale (SUDM) is an empirically validated psychometric instrument designed to evaluate the operationalization and application of intrinsic personal positive traits within the daily therapeutic regimens of patients diagnosed with type 2 diabetes mellitus (T2DM). Developed by Ruey-Hsia Wang and colleagues (2023), the instrument fills a critical gap at the intersection of positive psychology and behavioral endocrinology by systematically assessing how individuals mobilize psychological strengths to navigate the demands of chronic illness care. The scale comprises 12 items configured across three structurally distinct yet inter-correlated latent dimensions: learning proactively, taking on challenges, and thinking positively. Each item is scored on a 5-point Likert scale spanning from 0 (“extremely disagree”) to 4 (“extremely agree”), generating subscale scores ranging from 0 to 16 and a total score indicating the comprehensive utilization of character strengths in self-care behaviors.

Psychometric evaluation in clinical populations demonstrated robust internal consistency, with Cronbach’s alpha coefficients ranging from .78 to .91 across the subscales and total scale. Exploratory factor analysis (EFA) established a stable three-factor structure accounting for 69.44% of the total cumulative variance, which was subsequently corroborated by confirmatory factor analysis (CFA) demonstrating exceptional goodness-of-fit indices (χ²/df = 1.52, CFI = 0.97, NFI = 0.93, GFI = 0.92, and RMSEA = 0.06). Construct and criterion-related validity were established through statistically significant positive correlations with diabetes-specific health-related quality of life, alongside significant negative prospective associations with both baseline and 9-month follow-up glycosylated hemoglobin (HbA1c) levels. The SUDM represents an advanced diagnostic and research instrument that enables healthcare providers, clinical health psychologists, and endocrinologists to shift beyond deficit-based intervention models toward personalized, strength-based chronic disease self-management paradigms.

2. Keywords

Character Strengths Use, Type 2 Diabetes Mellitus, Diabetes Self-Management, Positive Psychology, Learning Proactively, Taking on Challenges, Thinking Positively, Glycemic Control, Health-Related Quality of Life, Psychometrics, Factor Analysis, Chronic Disease Care

3. Authors

The Character Strengths Use in Diabetes Self-management Scale was developed by a multidisciplinary team of clinical nurse scientists, endocrinologists, and behavioral psychometricians in Taiwan:

• Ruey-Hsia Wang, PhD, RN: Professor, College of Nursing, Kaohsiung Medical University, Kaohsiung, Taiwan. (ORCID: 0000-0001-9323-7389; Email: [email protected])
• Chia-Chan Kao, PhD, RN: Associate Professor, School of Nursing, I-Shou University, Kaohsiung, Taiwan. (ORCID: 0000-0003-2846-5590)
• Yi-Ching Su, MSN, RN: Doctoral Researcher, College of Nursing, Kaohsiung Medical University, Kaohsiung, Taiwan.
• Shi-Yu Chen, MD: Attending Physician, Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
• Hui-Chun Hsu, MD: Chief Physician and Clinical Specialist, Lee’s Endocrinology Clinic, Pingtung, Taiwan.
• Chieh-Hua Lu, MD: Attending Physician, Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
• Kuen-Yung Jone, PhD: Associate Professor, School of Psychology, Kaohsiung Medical University, Kaohsiung, Taiwan.

Corresponding Author Address: Dr. Ruey-Hsia Wang, College of Nursing, Kaohsiung Medical University, No. 100 Shih-Chuan 1st Road, San-Min District, Kaohsiung City 80708, Taiwan.

4. Purpose

Managing type 2 diabetes mellitus is an intensive, relentless behavioral undertaking that requires patients to integrate complex lifestyle modifications into their daily lives, including dietary restrictions, structured physical activity, routine self-monitoring of blood glucose, pharmacological compliance, and preventative foot and eye care. Historically, behavioral medicine and diabetology have approached self-management through a pathological or deficit-oriented lens, focusing primarily on non-compliance, diabetes distress, depression, anxiety, and perceived self-care barriers. Although recognizing psychological vulnerabilities remains crucial, this paradigm frequently overlooks the internal psychological assets and characterological resiliencies that drive proactive, sustained health behaviors.

The primary purpose of the Character Strengths Use in Diabetes Self-management Scale (SUDM) is to operationalize, quantify, and evaluate the specific deployment of personal character strengths directly within the contextual framework of chronic diabetes management. Grounded in the premise that possessing a psychological trait is distinct from actively utilizing it in goal-directed behaviors, the SUDM assesses functional behavior rather than passive moral disposition. The instrument evaluates how individuals actively harness their psychological capital to maintain strict glycemic control, overcome acute treatment setbacks, and sustain psychological well-being over extended periods.

In clinical practice, the SUDM provides endocrinologists, diabetes nurse educators, and clinical health psychologists with an evidence-based diagnostic tool to identify actionable psychological resources. By identifying whether a patient struggles with proactive information seeking, navigating regimen barriers, or cultivating an adaptive cognitive outlook, clinicians can tailor self-management education programs to leverage the patient’s existing strengths rather than relying solely on didactic disease instruction. In research domains, the SUDM establishes a standardized metric for testing strength-based behavioral interventions, examining longitudinal trajectories of metabolic control, and clarifying the psychological mechanisms linking positive cognitive-behavioral processes to physiological outcomes such as sustained glycated hemoglobin (HbA1c) stabilization.

5. Psychological Construct

The construct assessed by the SUDM is character strengths use in diabetes self-management, conceptualized as an individual’s conscious mobilization of healthy, productive, and intrinsically driven cognitive, affective, and behavioral capacities toward chronic disease maintenance. Drawing upon positive psychological frameworks, character strengths are defined as positive, morally valued, and trait-like capacities for thinking, feeling, and behaving that promote human flourishing and optimal performance. Within the SUDM, this construct is contextualized into three correlated, empirical dimensions:

1. Learning Proactively

This subscale captures an individual’s epistemic drive, curiosity, and proactive commitment toward mastering the knowledge and technical skills necessary for managing their condition. Diabetes is an evolving metabolic illness requiring ongoing education regarding macronutrient counting, insulin kinetics, glycemic variability, and microvascular complications. Rather than waiting passively for clinical consultations, an individual demonstrating proactive learning actively reads relevant literature, solicits practical guidance from healthcare providers, questions changes in physiological parameters, and updates their behavioral protocols. For example, a patient scoring high in this dimension will independently investigate the carbohydrate impact of a novel food item or review updated self-monitoring technologies, viewing knowledge acquisition as an empowering instrument of autonomy.

2. Taking on Challenges

Chronic disease maintenance invariably presents acute behavioral disruptions, ranging from persistent hypoglycemic episodes and medication adverse effects to social pressures around food and fluctuating motivational reserves. The taking on challenges dimension assesses psychological grit, perseverance, courage, and resilience when encountering these self-care barriers. Rather than succumbing to behavioral avoidance or learned helplessness, individuals utilizing this strength interpret metabolic disruptions as solvable operational problems. An illustrative behavioral manifestation includes maintaining dietary rigor despite dining in adverse social settings, resuming exercise routines following a clinical setback, or consistently monitoring blood glucose when emotional exhaustion tempts omission.

3. Thinking Positively

This dimension operationalizes the emotional, cognitive, and attributional tendencies that sustain hope, optimism, and positive perspective-taking amidst the ongoing psychological burden of diabetes. Diabetes distress frequently stems from catastrophic interpretations of future complication risks or self-blame regarding glycemic fluctuations. Thinking positively does not signify unrealistic denial; rather, it reflects an adaptive explanatory style, cognitive reframing, and future-oriented hope. Patients who mobilize this strength acknowledge the seriousness of their medical condition while actively directing attention toward health gains, personal self-efficacy, and confidence in their capacity to preserve long-term vitality through diligent self-regulation.

6. Theoretical Framework

The SUDM is theoretically anchored in the intersection of Positive Psychology and Social Cognitive Theory. The conceptual baseline originates from the Values in Action (VIA) classification of character strengths formulated by Martin Seligman and Christopher Peterson (2004). Peterson and Seligman conceptualized character strengths as universally recognized, positive psychological traits that provide pathways to human flourishing. However, subsequent theoretical expansions by psychometricians such as Alex Linley (2008) and Govindji and Linley (2007) introduced an essential distinction: possessing a character strength is fundamentally different from actively using it. Strength use represents the behavioral execution and situational application of these capacities in specific life arenas.

Wang and colleagues (2023) translated this distinction into behavioral medicine, positing that while general character strengths provide latent psychological reserves, their functional efficacy in chronic disease management depends on domain-specific mobilization. In diabetes care, individuals face continuous cognitive decision-making and physical demands. When patients actively mobilize strengths such as curiosity, persistence, and hope within their daily routines, they generate positive emotional states that expand cognitive-behavioral repertoires, consistent with Barbara Fredrickson’s (2001) Broaden-and-Build Theory.

Furthermore, the SUDM incorporates Albert Bandura’s self-efficacy mechanisms within Social Cognitive Theory. Self-efficacy—the subjective conviction that one can execute courses of action to achieve designated performances—is reinforced when an individual reflects on successful strength deployment. When patients operationalize proactive learning or persistent problem-solving, their perceived mastery increases, fostering stronger behavioral adherence. By synthesizing Peterson and Seligman’s character strengths taxonomy, Linley’s strengths application paradigm, and Bandura’s behavioral regulation principles, the SUDM establishes a coherent theoretical model: character strengths use operates as a core psychological driver that directly influences self-management behavior, subsequently mitigating diabetes distress, elevating health-related quality of life, and improving long-term metabolic markers.

7. Validity

The psychometric development of the SUDM followed rigorous methodological standards to demonstrate comprehensive construct, concurrent, and predictive criterion-related validity among individuals diagnosed with type 2 diabetes mellitus.

Construct and Factorial Validity

Initial content and face validity were established through comprehensive literature analyses and expert evaluation panels comprising clinical endocrinologists, diabetes specialist nurses, and behavioral scientists. The structural integrity of the 12-item instrument was systematically assessed using a split-sample structural equation modeling approach. Exploratory factor analysis (EFA) performed on the primary calibration sample supported a clear, three-dimensional factor structure without significant item cross-loadings. Confirmatory factor analysis (CFA) conducted on an independent validation cohort corroborated this structural model, displaying strong factor loadings across all items (> 0.46) and excellent global fit indices, confirming that the empirical data fit the proposed theoretical construct closely.

Concurrent and Convergent Validity

Concurrent validity was examined by evaluating the association between the SUDM and established psychological and disease-specific patient-reported outcome measures. The total SUDM score demonstrated statistically significant positive correlations with diabetes-specific quality of life (HRQoL), indicating that individuals who actively deploy character strengths in their self-management routines experience less functional impairment, greater psychological well-being, and lower perceived disease interference.

Predictive and Criterion-Related Validity

A notable strength of the SUDM’s validation process is its prospective clinical predictive validity. The scale exhibited statistically significant negative correlations with baseline glycosylated hemoglobin (HbA1c) levels as well as prospective 9-month follow-up HbA1c levels. In clinical diabetology, HbA1c represents the definitive objective bio-marker of average blood glucose concentrations over the preceding 8 to 12 weeks. The observed prospective negative relationship demonstrates that higher scores on the SUDM reliably predict improved long-term glycemic regulation, confirming the instrument’s clinical utility beyond purely subjective psychological self-reports.

8. Reliability

The reliability of the SUDM has been rigorously verified through multiple psychometric indicators assessing internal consistency and measurement precision across clinical cohorts.

In the scale development and validation investigation reported by Wang et al. (2023), the internal consistency of the overall 12-item SUDM scale yielded a high Cronbach’s alpha coefficient of .91, indicating strong item interrelatedness without excessive redundancy. The internal consistency coefficients for the individual subscales similarly met stringent psychometric thresholds:

• Learning Proactively: Cronbach’s α = .88
• Taking on Challenges: Cronbach’s α = .84
• Thinking Positively: Cronbach’s α = .78

The scale demonstrated a high degree of measurement reliability, with subscale and total reliability values remaining stable across demographic strata, including age brackets, sex, and duration of diabetes diagnosis. Item-total correlations for all twelve individual items consistently exceeded the recommended .40 threshold, confirming that each specific item contributes reliably to the measurement of its designated latent factor. Standard errors of measurement (SEM) were minimal, indicating that the SUDM provides stable and precise quantification of character strengths use across varied clinical contexts.

9. Factor Analysis

The latent structural architecture of the SUDM was established through sequential exploratory and confirmatory factor analytic procedures conducted on a convenience sample of Taiwanese outpatients diagnosed with type 2 diabetes recruited from specialized endocrine clinics.

Exploratory Factor Analysis (EFA)

Prior to factor extraction, data suitability was verified via the Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy and Bartlett’s test of sphericity, both confirming adequate inter-item correlation matrices. Principal axis factoring with oblique rotation was conducted, allowing for theoretical correlation among underlying dimensions. The number of retainable factors was determined through examination of the Scree plot, eigenvalues exceeding 1.0, and theoretical parsimony. A three-factor solution emerged cleanly from the analysis. Following systematic item-reduction steps that eliminated ambiguous, weakly loading, or cross-loading candidates, the final 12-item scale accounted for 69.44% of the cumulative total variance. Each of the three extracted dimensions contributed meaningfully to this total:

• Factor 1 (Learning Proactively): 4 items capturing the systematic acquisition of disease management knowledge and techniques.
• Factor 2 (Taking on Challenges): 4 items loading onto perseverance, behavioral courage, and overcoming daily self-care obstacles.
• Factor 3 (Thinking Positively): 4 items representing cognitive reframing, emotional resilience, and optimistic outcome expectations.

Confirmatory Factor Analysis (CFA)

The three-factor structural model was subsequently tested using confirmatory factor analysis via covariance-based structural equation modeling. Every item loaded significantly on its designated latent factor (p < .001), with standardized factor loadings consistently exceeding 0.46, confirming convergent validity at the indicator level. Global model fit indices demonstrated robust alignment between the empirical covariance matrix and the hypothesized three-factor measurement model:

• Normed Chi-Square (χ²/df): 1.52 (within the ideal < 2.0 to 3.0 range indicating low sample sensitivity and parsimonious fit)
• Comparative Fit Index (CFI): 0.97 (surpassing the standard ≥ 0.95 criterion for superior fit)
• Normed Fit Index (NFI): 0.93 (exceeding the acceptable ≥ 0.90 threshold)
• Goodness-of-Fit Index (GFI): 0.92 (exceeding the standard ≥ 0.90 criterion)
• Root Mean Square Error of Approximation (RMSEA): 0.06 (with a 90% confidence interval ranging from 0.03 to 0.09, well below the conservative 0.08 threshold for acceptable model fit)

10. Instrument / Measurement Tool

• Instrument Name: Character Strengths Use in Diabetes Self-management Scale
• Acronym: SUDM
• Test Type: Original psychometric self-report questionnaire / Patient-Reported Outcome Measure (PROM)
• Construct Assessed: Frequency and degree of character strengths mobilization in daily diabetes self-care behaviors
• Total Item Count: 12 items
• Subscales / Factor Structure:
  • Learning Proactively (4 items)
  • Taking on Challenges (4 items)
  • Thinking Positively (4 items)
• Response Format: 5-point Likert-type scale scored from 0 to 4:
  • 0 = Extremely disagree
  • 1 = Disagree
  • 2 = Neutral / Neither agree nor disagree
  • 3 = Agree
  • 4 = Extremely agree
• Scoring Protocol:
  • No items are reverse-scored; all twelve items are positively framed.
  • Subscale summary scores are calculated by summing the four items within each domain (range: 0 to 16 points per subscale).
  • The total scale score is derived by summing all 12 items (overall scale range: 0 to 48 points).
  • Higher summary and subscale scores denote a greater, more consistent mobilization of character strengths within diabetes self-management routines.
• Target Population: Adult patients (18 years and older) diagnosed with type 2 diabetes mellitus (T2DM)
• Administration Modality: Paper-and-pencil self-administration, digital survey platforms, or clinical face-to-face assisted interviews; average completion time is approximately 3 to 5 minutes.

11. Permissions & Fee and Test Year

• Year of Development: 2023
• Original Language: Traditional Chinese (developed and psychometrically evaluated in Taiwanese clinical cohorts; reported academically in English).
• Copyright & Intellectual Property: Copyright © 2023 by the authors (Ruey-Hsia Wang et al.) and John Wiley & Sons Ltd on behalf of the Journal of Advanced Nursing.
• Commercial Use: Commercial use, distribution, or inclusion in fee-for-service clinical platforms without prior authorization is strictly prohibited.
• Licensing & Permissions: Non-commercial academic research and clinical use generally require formal authorization from the primary corresponding author. Interested investigators should submit requests directly to Dr. Ruey-Hsia Wang via email at [email protected].
• Fee: Free of charge for academic, non-commercial, and clinical research purposes upon obtaining permission.

12. References

• Bandura, A. (1997). Self-efficacy: The exercise of control. W. H. Freeman and Company.
• Fredrickson, B. L. (2001). The role of positive emotions in positive psychology: The broaden-and-build theory of positive emotions. American Psychologist, 56(3), 218–226. https://doi.org/10.1037/0003-066X.56.3.218
• Govindji, R., & Linley, P. A. (2007). Strengths use, self-concordance and well-being: Implications for strengths coaching and coaching psychologists. International Coaching Psychology Review, 2(2), 143–153. https://doi.org/10.53841/bpsicpr.2007.2.2.143
• Linley, P. A. (2008). Average to A+: Realising strengths in yourself and others. CAPP Press.
• Peterson, C., & Seligman, M. E. P. (2004). Character strengths and virtues: A handbook and classification. American Psychological Association; Oxford University Press.
• Wang, R.‐H., Kao, C.‐C., Su, Y.‐C., Chen, S.‐Y., Hsu, H.‐C., Lu, C.‐H., & Jone, K.‐Y. (2023). Character Strengths Use in Diabetes Self-management Scale: Development and psychometric testing. Journal of Advanced Nursing, 79(10), 4034–4043. https://doi.org/10.1111/jan.15723

13. Items of the Scale