Validity and Reliability of the Korean Version of the Self‐Care Self‐Efficacy Scale for Patients With Heart Failure: A Psychometric Evaluation

ABSTRACT

Aim

The psychometric properties of the 10‐item Self‐Care Self‐Efficacy scale have not yet been established in the Korean language. This study aimed to evaluate its validity and reliability among Korean patients with heart failure (HF).

Methods

A total of 159 patients with HF participated (mean age: 65.40 ± 9.62 years; 60.1% male). Construct validity was assessed using confirmatory factor analysis. Criterion validity was examined by assessing the correlation of self‐efficacy with HF symptom status and physical function and by comparing self‐efficacy levels across the New York Heart Association classes. Reliability was evaluated using Cronbach's alpha, McDonald's omega and factor determinacy.

Results

Confirmatory factor analysis fit indices were as follows: comparative fit index = 0.977, Tucker–Lewis index = 0.966, standardised root mean square residual = 0.041 and root mean square error of approximation = 0.065 (90% CI = 0.038–0.090). Criterion validity was supported by significant correlations between self‐efficacy and symptom status (r = −0.331, p < 0.001) and physical function (r = 0.299, p < 0.001). Self‐efficacy scores were significantly higher in patients with lower New York Heart Association class (I/II) than higher class (III or IV) (F = 4.68, p = 0.011). Reliability estimates were robust: Cronbach's α = 0.913, McDonald's omega = 0.902 and factor determinacy = 0.941.

Conclusion

This study supports the validity and reliability of the Self‐Care Self‐Efficacy scale in Korean for assessing self‐care self‐efficacy among patients with HF. Clinicians should consider evaluating and enhancing patients' self‐care self‐efficacy to effectively manage HF symptoms, especially considering functional severity.

Summary

• What Is Already Known About This Topic?

  • Self‐care self‐efficacy is a key modifiable factor that supports patients' engagement in self‐care behaviours and is associated with better outcomes in heart failure (HF).
  • The 10‐item Self‐Care Self‐Efficacy (SCSE) scale is a theory‐based instrument validated in patients with HF and other chronic illnesses.
  • The SCSE scale had not been psychometrically validated for Korean‐speaking patients with HF, despite cultural differences that may influence self‐care confidence and behaviour.
• What This Paper Adds?

  • This study demonstrates strong internal consistency of the Korean SCSE scale, with Cronbac's alpha, McDonal's omega and factor determinacy all exceeding 0.90.
  • Construct validity was confirmed via confirmatory factor analysis, and criterion validity was supported by significant associations with symptom status, physical function and symptom‐related functional limitations.
• Implications of This Study

  • Clinicians can use the validated Korean SCSE scale to identify patients with low self‐care self‐efficacy and implement targeted strategies to strengthen patients' confidence in managing symptoms and maintaining physical function.
  • This study supports the development of culturally tailored interventions that enhance self‐efficacy—particularly in managing symptom burden and functional limitations. The Korean SCSE scale offers a reliable tool for evaluating self‐efficacy in both clinical assessments and as an outcome measure in intervention research.

1. Introduction

Heart failure (HF) is a complex clinical syndrome caused by structural or functional impairment of ventricular filling or ejection, resulting in symptoms such as dyspnea, fatigue and fluid retention (American Heart Association ^2023b) which often indicate disease progression (Jering et al. 2021). In Korea, HF prevalence has steadily increased, with approximately 2.6% of the population affected in 2020—equating to over 1.3 million people—and projections estimate that more than 1.7 million individuals will be affected by 2040 (Lee et al. 2024; Lee et al. ²⁰¹⁶). This growing burden underscores the need for effective patient self‐care. Although self‐care behaviours can prevent symptom exacerbation and slow disease progression, adherence remains suboptimal worldwide (Auld et al. 2018; Calero et al. ²⁰²⁰; Hashimoto et al. ²⁰²³; Lee et al. ²⁰¹⁸; Liljeroos et al. ²⁰²⁰; Liu et al. ²⁰²³; Niriayo et al. ²⁰²⁴; Zhang et al. ²⁰²³). Self‐care self‐efficacy (hereafter, self‐efficacy)—defined as an individual's confidence in performing self‐care behaviours (Riegel et al. 2009)—plays a central role in facilitating adherence and improving outcomes (Riegel et al. 2022). It also mediates self‐care decisions influenced by complex interactions among problem‐related, personal and environmental factors (Riegel et al. 2022; Zhang et al. ²⁰²³). As a modifiable factor, self‐efficacy is a promising target for interventions aiming to enhance HF self‐care and overall patient health (Jaarsma et al. 2017; Okada et al. ²⁰²³; Riegel et al. ²⁰¹⁷).

Thus, a reliable and valid measure of self‐efficacy is needed to assess the effects of interventions on self‐care behaviour changes and HF management. One such instrument is the Self‐Care Self‐Efficacy (SCSE) scale, which was developed to measure confidence in performing self‐care behaviours associated with adherence to therapeutic guidelines, monitoring and recognition of symptoms and problem‐solving in response to changing symptoms (Riegel n.d.). Initially, the SCSE scale was developed as a 6‐item measure within the broader self‐care scale. The revised 10‐item version can now be administered independently or alongside scales assessing self‐care behaviours (Riegel n.d.). Both versions of the SCSE scale—the 6‐item and 10‐item versions—have been translated into multiple languages, including English, Italian and Korean (Riegel n.d.). The psychometric properties of the 6‐item SCSE scale have been validated both as part of the self‐care scale and as a stand‐alone measure of self‐efficacy (Kim et al. 2018; Riegel et al. ²⁰⁰⁹; Vellone et al. ²⁰¹³). In contrast, the psychometric properties of the revised 10‐item version have been tested in various patient populations, including a single group of patients with HF as well as multiple chronic illness populations—primarily HF—from the United States (HF), China (HF), Italy (multiple chronic conditions) and Brazil (HF) (Yu et al. 2021). However, this version has not yet been evaluated in Korean patients with HF.

Additionally, HF symptoms, physical function and symptom‐induced impairment of physical function are major problem factors influencing self‐care decision‐making according to the Situation‐Specific Theory of Heart Failure Self‐Care (Riegel et al. 2022). While the influence of personal factors, such as self‐efficacy, on HF self‐care is well‐established (Riegel et al. 2022), the impact of symptoms or symptom‐induced functional impairment (assessed using the New York Heart Association [NYHA] classification) on self‐care has yielded inconsistent results (Auld et al. 2018; Graven et al. ²⁰¹⁵; Lee et al. ²⁰¹⁵; Liu et al. ²⁰²³; Yang and Kang ²⁰¹⁸; Zhang et al. ²⁰²³). Furthermore, interactions between personal and problem factors associated with self‐care are not yet fully understood. For example, some studies suggest that fewer symptoms or greater symptom‐induced functional impairment facilitates better self‐care (Yang and Kang 2018; Zhang et al. ²⁰²³), while others indicate that more severe symptoms enhance self‐care engagement (Auld et al. 2018; Lee et al. ²⁰¹⁵; Liu et al. ²⁰²³). Further research into the relationship between self‐efficacy and other determinants that influence self‐care decisions—particularly problem factors such as HF symptoms, physical function and symptom‐induced functional impairment—can provide a deeper understanding of the dynamic interactions between personal and problem factors in HF self‐care. This knowledge may also help clarify whether self‐efficacy reduces the negative effects of symptoms on self‐care, addressing this gap in understanding and aiding in the development of more effective interventions while improving the predictive power of HF self‐care. Therefore, this study aimed to evaluate the psychometric properties—including validity and reliability—of the Korean version of the SCSE (K‐SCSE) scale in patients with HF. Specifically, the study addressed the following research questions:

1. Does the K‐SCSE scale demonstrate construct validity and acceptable internal consistency among patients with HF?

2. Is criterion validity supported by significant associations between K‐SCSE scores and symptom status, physical function and symptom‐related functional limitations?

2. Methods

2.1. Study Design and Setting

For this psychometric testing of the K‐SCSE scale in patients with HF, a cross‐sectional study design was used. Data on self‐efficacy in self‐care, HF symptom status and physical function were collected from four university‐affiliated hospitals located in metropolitan, suburban and regional cities in South Korea from June 2019 to February 2022. These clinical sites offered both outpatient and inpatient care, providing diverse settings that may have influenced patients' symptom experiences, engagement in self‐care and perceived self‐efficacy.

2.2. Sample

To determine an appropriate sample size for the CFA of the one‐factor K‐SCSE scale with 10 items, we applied the widely accepted 10:1 participant‐to‐item ratio (Kline 2023), which recommends at least 10 participants per item. Therefore, a minimum of 90 participants was required. The final sample consisted of 159 patients with HF, exceeding the recommended threshold to ensure statistical adequacy.

Patients were eligible for inclusion if they were 19 years of age or older, had been diagnosed with HF by a cardiologist and were receiving optimal HF medications, including angiotensin‐converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor–neprilysin inhibitors, beta‐blockers and diuretics. Exclusion criteria included diagnosis of neurocognitive disorders, such as Alzheimer's disease, dementia, stroke or psychiatric conditions involving cognitive impairment that could interfere with self‐efficacy in self‐care or comorbid terminal illnesses (e.g., cancer and end‐stage organ failures other than HF) that would interfere with self‐care behaviour.

2.3. Instrument Translation and Cultural Adaption

After obtaining permission from the original developer, the SCSE scale was translated into Korean following the recommended ‘Instrument Translation Process’ (Riegel ^2020a):

• Step1:Forward translation. Two bilingual nurse scholars independently translated the original English SCSE scale into Korean. Both translators were fluent in English and Korean and had expertise in self‐care and HF. An expert panel comprising three specialists in HF research and instrument development reviewed and synthesised the two versions, resolving discrepancies and achieving consensus.
• Step2:Content evaluation and cultural adaptation. A graduate nursing student assessed agreement between the two forward translations using a 4‐point Likert scale (1 strongly disagree to 4 strongly agree). The expert panel evaluated each item's relevance and appropriateness for Korean clinical settings. The scale‐level content validity indices were acceptable (S‐CVI/Ave = 0.97; S‐CVI/UA = 0.90).
• Step3:Backward translation. Two individuals proficient in English and Korean but unfamiliar with the SCSE scale independently back‐translated the reconciled Korean version into English. The same expert panel compared the back‐translations to the original instrument to identify and resolve any discrepancies. For example, the item ‘Evaluate the importance of your symptoms’ was back‐translated as ‘Judge the importance of your symptoms’. While the original item uses the term ‘evaluate’, the panel agreed to retain the Korean equivalent of ‘Judge’ to enhance naturalness and clarity in Korean, particularly for a general population. In this context, ‘Judge’ more accurately reflects self‐reflective decision making, as the item asks responders to rate their confidence in recognising the importance of their own symptoms. All discrepancies were reviewed item by item in real time through an online meeting platform, and consensus was reached through iterative discussion until semantic and conceptual equivalence was achieved.
• Step4:Linguistic and semantic review. A language expert reviewed the final version for semantic clarity and cultural equivalence. Final approval was obtained from the original instrument developer, and the K‐SCSE scale was uploaded to the developer's official website (Riegel n.d.).

2.4. Measures

2.4.1. Self‐Care Self‐Efficacy

The SCSE scale was used to assess self‐care self‐efficacy (SCSE) of patients with HF (Yu et al. 2021). The SCSE scale consists of 10 items assessing an individual's confidence in performing self‐care maintenance, symptom monitoring and perception and management actions, rated on a 5‐point Likert scale (1 = not confident, 5 = extremely confident). Following established scoring guidelines (Riegel ^2020b), standardised scores from 0 to 100 are computed, with higher scores indicating greater self‐efficacy. Psychometric properties of a prior 6‐item version within the self‐care scales have been reported previously (Kim et al. 2018; Riegel et al. ²⁰⁰⁹; Vellone et al. ²⁰¹³); however, the properties of the 10‐item SCSE scale remain unknown. Cross‐cultural validation of the 10‐item version has been reported with acceptable or mediocre CFA model fit reflecting construct validity in populations with chronic illnesses, primarily HF (Yu et al. 2021). Reliability of the 10‐item SCSE scale for patients with HF has previously been reported, with Cronbach's alpha of 0.933 in Americans and 0.891 in Chinese (Hong Kong) patients (Yu et al. 2021). In this study, Cronbach's alpha of the scale in Korean patients with HF was 0.913.

2.4.2. HF Symptom Status

The Korean Symptom Status Questionnaire (K‐SSQ)–HF is used to assess HF symptom status (Heo et al. 2017). The K‐SSQ consists of seven individual symptoms, including dyspnea during daytime, dyspnea when lying down, fatigue, chest pain, edema, sleeping difficulty and dizziness, with each symptom having four subitems: presence assessed with dichotomous options (yes/no) and frequency, severity and distress rated using 4‐point Likert response options. The total scores represent the summed subitem scores for each symptom and range from 0 to 84, with higher scores indicating more severe symptom status. The reliability and validity of the K‐SSQ have been supported in samples from both the United States and South Korea (Heo et al. 2017; Heo et al. ²⁰¹⁵).

2.4.3. Physical Function

The Korean Activity Status Index (Sung et al. 2000) is used to assess the physical function of patients with HF. It consists of 15 physical activities, each evaluated with dichotomous self‐reported response options (yes/no) and assigned weights based on energy expenditure. The total score is calculated as the sum of the weighted values of these 15 activities, ranging from 0 to 79, with higher scores indicating better physical function. The validity of the Korean Activity Status Index has been supported among Korean patients who underwent treadmill exercise stress testing (Sung et al. 2000).

Demographic characteristics were collected using a standard questionnaire; these included age, sex, marital status and educational level. Clinical characteristics were collected from medical records reviewed by trained nurses; these data included HF aetiology, left ventricular ejection fraction and prescribed medications. The trained nurses also assessed symptom‐induced functional severity related to HF using the NYHA functional classification system (American Heart Association ^2023a) and comorbidities using the Charlson Comorbidity Index (Charlson et al. 1987).

2.5. Procedure and Ethical Considerations

Ethical approval was obtained from the Institutional Review Boards of the four participating university‐affiliated hospitals (reference numbers: GAIRB 2019‐187, HC19QEDI0070, HYUH 2019‐12‐017‐008 and CNUH 2021‐055). Patients were recruited through face‐to‐face interactions in the cardiology outpatient clinics and inpatient wards of the participating hospitals. At each site, cardiologists initially referred potentially eligible patients based on clinical judgement and medical records. After receiving the referral, a master's‐prepared research assistant and three trained researchers introduced the study to each participant, confirmed eligibility based on predefined criteria and obtained written informed consent prior to enrollment.

Data were collected through face‐to‐face interviews conducted in private settings such as designated research areas or inpatient consultation rooms. During data collection, the research nurses ensured that participants completed the questionnaires independently, provided clarification when needed and monitored for signs of fatigue or distress. Assistance was offered as necessary to support completion without coercion. All procedures were conducted in accordance with institutional ethical guidelines and the principles of the Declaration of Helsinki (World Medical ²⁰¹³).

2.6. Data Analysis

To assess the psychometric properties of the K‐SCSE scale, the data analysis followed the sequence: (1) construct validity, (2) criterion‐related validity and (3) reliability.

Construct validity was examined through confirmatory factor analysis (CFA) using Mplus Version 8 (Muthén and Muthén ^1998–2017). The model was estimated using the maximum likelihood method. Model fit was evaluated using multiple indices, including comparative fit index (CFI ≥ 0.90), Tucker–Lewis index (TLI ≥ 0.90), root mean square error of approximation (RMSEA ≤ 0.08) and standardised root mean square residual (SRMR ≤ 0.06) (Hong 2000). Factor loadings were examined to ensure that all items had significant loadings (≥ 0.50). Criterion‐related validity was examined by calculating Pearson's correlation coefficients with 95% confidence intervals between K‐SCSE scores, HF symptom status and physical function. Effect sizes were interpreted using Cohen's criteria: r = 0.10 to < 0.30 (small), 0.30 to < 0.50 (medium), and ≥ 0.50 (large). Additionally, self‐efficacy levels were compared across NYHA classes. Differences in K‐SCSE scores across NYHA classes were examined using Welch's one‐way analysis of variance (ANOVA) due to a violation of the homogeneity of variance assumption, followed by Games–Howell post hoc tests. Reliability of the K‐SCSE scale was evaluated by calculating Cronbach's alpha, McDonald's omega and factor determinacy to assess internal consistency. All analyses were conducted using SPSS Statistics for Windows, version 27.0 (IBM Corp. ²⁰²⁰), with a significance level of p < 0.05.

3. Results

3.1. Sample Characteristics

A total of 159 patients with HF participated in this study. Their mean age was 65.40 ± 9.62 years, and the majority were male (60.1%) and married (73.2%) (Table 1). More than half of the participants (55.3%) had less than a high school education. HF severity, classified according to the NYHA functional classes, was distributed as follows: Class I, 14.2%; Class II, 70.3%; Class III, 11.6% and Class IV, 3.9%. Approximately one‐third (27.9%) of the participants had ischaemic heart disease as the underlying cause of HF. The mean left ventricular ejection fraction was 46.52% ± 16.57% (range 10.0%–78.0%). Most patients were receiving optimal medical treatment, including angiotensin‐converting enzyme inhibitors (13.2%), angiotensin receptor blockers (50.9%), angiotensin receptor–neprilysin inhibitors (10.1%), beta‐blockers (81.8%) and/or diuretics (70.4%). Nearly half of the participants (45.3%) had moderate to high comorbidity levels, as indicated by their Charlson Comorbidity Index scores.

TABLE 1.

Sample characteristics of patients with heart failure (N = 159).

Variables		n (%) or mean (SD)	Range
Age (year)		65.40 (9.62)	50–91
Sex	Male	95 (60.1)
Marital status	Married	115 (73.2)
Education level	< High school graduate	88 (55.3)
	High school graduate	45 (28.3)
	College degree or higher	26 (16.4)
NYHA classes	I	22 (14.2)
	II	109 (70.3)
	III	18 (11.6)
	IV	6 (3.9)
Heart failure aetiology	Ischemic	43 (27.9)
	Hypertension	22 (14.3)
	Valvular	14 (9.1)
	Idiopathic	46 (29.9)
	Others	29 (18.8)
CCI	Low level (< 3)	87 (54.7)
	Moderate level (3–4)	40 (25.2)
	High level (≥ 5)	32 (20.1)
LVEF (%)		46.52 (16.57)	10.00–78.00
Medications a (yes)	ACEI	21 (13.2)
	ARB	81 (50.9)
	ARNI	16 (10.1)
	Beta‐blocker	130 (81.8)
	Loop diuretics	112 (70.4)
	Statins	78 (49.1)
	Aspirin	55 (34.6)
	Digoxin	21 (13.2)

Abbreviations: ACE, angiotensin‐converting enzyme inhibitors; ARB, angiotensin II receptor blockers; ARNI, angiotensin receptor–neprilysin inhibitors; CCI, Charlson Comorbidity Index; LVEF, left ventricular ejection fraction; NYHA, New York Heart Association class; SD, standard deviation.

^a Multiple responses.

3.2. Item Analyses

As shown in Table 2, the mean scores for each item ranged from 3.17 to 4.03 on a 5‐point scale. The skewness and kurtosis values for all items fell within the acceptable range of −1 to 1, indicating an approximately normal distribution of responses.

TABLE 2.

Item descriptive analysis and scales scores of the Korean Self‐Care Self‐Efficacy (K‐SCSE) scale (N = 159).

Scale items	Mean	SD	Skewness	Kurtosis
In general, how confident are you that you can
1. Keep yourself stable and free of symptoms?	3.35	1.21	−0.09	−0.86
2. Follow the treatment plan been given?	4.03	1.14	−0.95	−0.01
3. Persist in following the treatment plan even when difficult?	3.67	1.32	−0.53	−0.95
4. Monitor you condition routinely?	3.77	1.27	−0.59	−0.82
5. Persist in routinely monitoring your condition even when difficult?	3.72	1.27	−0.51	−0.89
6. Recognise changes in your health if they occur?	3.88	1.10	−0.52	−0.76
7. Evaluate the importance of your symptoms?	3.51	1.30	−0.33	−0.98
8. Do something to relieve your symptoms?	3.54	1.21	−0.34	−0.77
9. Persist in finding a remedy for your symptoms even when difficult?	3.58	1.19	−0.41	−0.68
10. Evaluate how well a remedy works?	3.18	1.27	−0.08	−0.80
Overall	36.24	9.29	−0.27	−0.74

Abbreviation: SD, standard deviation.

3.3. Validity and Reliability

3.3.1. Construct Validity

The results of CFA supported an acceptable model fit for the K‐SCSE scale (Table 3): χ ² = 57.95, p = 0.002; CFI = 0.977, TLI = 0.966, SRMR = 0.041 and RMSEA = 0.065 (90% confidence interval [0.038, 0.090], p = 0.165). The unidimensional structure comprising 10 items was supported by strong factor loadings, with all items exceeding 0.50 (range: 0.62―0.79), indicating statistical significance and acceptable construct validity.

TABLE 3.

Fit indices from CFA model and reliability indices of internal consistency of the Korean Self‐Care Self‐Efficacy (K‐SCSE) scale (N = 159).

	CFA model							Internal consistency
	χ 2	p	CFI	TLI	SRMR	RMSEA (90% CI)	$p$ (RMSEA)	Cronbach's alpha	McDonald's omega	Factor determinacy
K‐SCSE	57.95	0.002	0.977	0.966	0.041	0.065 (0.038–0.090)	0.165	0.913	0.902	0.941

Abbreviations: CFA, constructive factor analysis; CFI, comparative fit index; K‐SCSE, Korean version of Self‐Care Self‐Efficacy scale; RMSEA, root mean square error of approximation; SRMR, standardised root mean square residual; TLI, Tucker–Lewis index.

3.3.2. Criterion Validity

Criterion validity was further supported by examining hypothesised associations with clinical outcomes. As expected, self‐efficacy was negatively correlated with symptom status (r = −0.331, 95% CI [−0.467, −0.181], p < 0.001) and positively correlated with physical function (r = 0.299, 95% CI [0.140, 0.439], p < 0.001), indicating moderate and small effect sizes, respectively (Table 4). Additionally, self‐efficacy was compared across NYHA classes (Table 5). Patients with lower functional severity (NYHA Classes I/II) reported significantly higher mean self‐efficacy (37.10 ± 8.55) compared to those with moderate (Class III, 30.83 ± 12.64) or severe severity (Class IV, 31.17 ± 7.52) (Welch's F = 3.74, p = 0.038). Post hoc analyses revealed that patients in NYHA Classes I/II had significantly higher self‐efficacy than those in Class III, confirming the hypothesised pattern.

TABLE 4.

Criterion validity: relationships between the Korean Self‐Care Self‐Efficacy (K‐SCSE) scale, symptom status, and physical function (N = 159).

	Symptom status (mean ± SD, 15.48 ± 13.08)			Physical function (mean ± SD, 43.14 ± 21.73)
	r	p	95% CI	r	p	95% CI
Self‐care self‐efficacy (mean ± SD, 36.24 ± 9.29)	−0.331	< 0.001	(−0.465, −0.182)	0.299	< 0.001	(0.144, 0.439)

TABLE 5.

Differences of the Korean Self‐Care Self‐Efficacy (K‐SCSE) scale by NYHA classes (N = 159).

		n (%)	SCSE	F	p
NYHA	I/II a	131 (84.5)	37.10 ± 8.55	3.74	0.038
	III b	18 (11.6)	30.83 ± 12.64		(a > b)
	IV c	6 (3.9)	31.17 ± 7.52

Abbreviations: NYHA, New York Heart Association class; SCSE, self‐care self‐efficacy.

^a no or mild symptoms with normal physical activity.

^b moderate symptoms with less than normal physical activity.

^c severe symptoms with features of heart failure with minimal physical activity and even at rest.

3.3.3. Internal Consistency Reliability

The K‐SCSE scale demonstrated strong internal consistency, with Cronbach's α = 0.913, McDonald's omega = 0.902 and factor determinacy = 0.941 (Table 3). These results indicate that the K‐SCSE scale reliably measures the underlying construct of SCSE and is appropriate for use in clinical and research settings.

4. Discussion

The results of this study supported the validity (construct validity, including factor structure and criterion‐related validity) and reliability of the SCSE scale in Korean among patients with HF. The construct validity of the SCSE scale in Korean was supported by good model fit. Further evidence for validity was demonstrated through significant associations between lower self‐care self‐efficacy and higher HF symptom status, as well as lower physical function. Additionally, self‐efficacy levels differed according to functional severity; patients with greater physical impairment (NYHA III or IV) exhibited lower self‐efficacy compared to those with less severe impairment (NYHA I and II). All reliability estimates of the SCSE scale in Korean were acceptable, with Cronbach's alpha, McDonald's omega and factor determinacy coefficients all exceeding 0.90.

Self‐care self‐efficacy, which enables patients to actively engage in HF self‐care (Riegel et al. 2022), is a key target for interventions aiming to prevent HF exacerbation and improve health outcomes (Baradaranfard et al. 2018; Hudiyawati et al. ²⁰²³; Okada et al. ²⁰²³; Peyman et al. ²⁰²⁰; Qiu and Yu ²⁰²³; Riegel et al. ²⁰²²). Therefore, the assessment of self‐efficacy requires a valid and reliable measure. One such measure is the theoretically driven SCSE scale, whose psychometric properties were first reported among Koreans with HF. Building on the good model fit of the 6‐item SCSE scale among Koreans with HF—which demonstrated robust fit indices (CFI = 0.950, TLI = 0.916, SRMR = 0.048 and RMSEA = 0.130 [90% confidence interval [0.075, 0.187]]) and unidimensionality with standardised factor loadings ranging from 0.53 to 0.91 (Kim et al. 2018)—the factor structure of the 10‐item SCSE scale also showed good fit for a single‐factor model in this study. Key differences in the 10‐item version included the addition of an item addressing routine condition monitoring and three items assessing confidence in adhering to therapeutic plans, monitoring health conditions and seeking symptom relief when challenges arise. Both Korean versions demonstrated good model fit, supporting construct validity. Additionally, the 10‐item version provided further construct validity through expanded attributes aligned with updated self‐care measures (Riegel et al. 2019).

The CFA results of the SCSE scale in Korean presented some consistent findings, along with certain differences compared with previous studies. A unidimensional structure (one‐factor model) has previously been reported for both the 6‐item (Vellone et al. 2013) and 10‐item SCSE scales designed primarily for patients with chronic illness, particularly HF. The present study supports the unidimensionality of the 10‐item SCSE scale, further confirming this underlying structure. However, culture‐specific variations may exist, as indicated by partial metric measurement equivalence and partial scalar invariance documented in prior research, suggesting that certain items function differently across populations (Yu et al. 2021). This indicates that although the construct of self‐efficacy is comparable across groups, some items may be systematically interpreted or responded to differently due to cultural norms, linguistic variation, or differing healthcare experiences. Despite these variations, the construct of self‐efficacy remains stable and acceptable across diverse cultural groups. In an investigation of the cross‐cultural validation of the SCSE scale involving patients from the United States (HF), China (HF), Italy (multiple chronic conditions) and Brazil (HF), construct validity was supported, with model fit indices ranging from acceptable to mediocre (RMSEA = 0.031 [China] to 0.098 [United States], CFI = 0.955 [United States] to 0.994 [China], TLI = 0.934 [United States] to 0.991 [China] and SRMR = 0.033 [China] to 0.049 [Brazil]) (Yu et al. 2021). Such findings suggest that, although self‐efficacy is influenced by cultural factors, its fundamental structure remains consistent across populations (Yu et al. 2021).

Hypothetical relationships among self‐care self‐efficacy, HF symptom status, physical function and symptom‐induced functional severity—as well as their complex interactions with self‐efficacy—further supported the validity of the K‐SCSE scale. All of these factors play a key role in self‐care behaviours within the framework of the Situation‐Specific Theory of Heart Failure Self‐Care (Riegel et al. 2022). In this study, the level of self‐efficacy among Korean patients was low, with an average score of 36, which is below the adequacy threshold of 70. Bivariate analysis in Koreans with HF revealed that self‐efficacy was negatively associated with HF symptom status but positively associated with physical function. Additionally, patients with greater physical impairment (NYHA III or IV) showed lower self‐efficacy compared to those with milder impairment (NYHA I and II). This finding suggests that HF symptoms may hinder rather than promote the development of self‐efficacy. Meanwhile, the influence of symptoms in HF on self‐care has been widely reported, though findings remain inconsistent. Some studies suggest that more severe symptoms lead to increased engagement in self‐care (Auld et al. 2018; Lee et al. ²⁰¹⁵; Liu et al. ²⁰²³), while others indicate that more severe symptoms result in decreased self‐care engagement (Graven et al. 2015; Yang and Kang ²⁰¹⁸). In contrast, a study testing the Situation‐Specific Theory of Heart Failure Self‐Care model (Zhang et al. 2023) found that better physical function (measured as physical activities) significantly predicted improved self‐care, aligning with our findings of a positive relationship between physical function and self‐efficacy. However, that study also found that a more severe NYHA functional class was associated with better self‐care, contradicting our findings that patients with NYHA Classes III or IV had lower self‐efficacy. These discrepancies highlight the need for further investigation into the role of symptoms in self‐efficacy and self‐care. Specifically, it remains unclear whether symptoms serve as a catalyst or a barrier to self‐efficacy and self‐care. Future research should investigate the role of self‐efficacy in fostering effective and ongoing self‐care, particularly by examining mediating or moderating mechanisms that elucidate the processes underlying self‐care and enhance the effectiveness of self‐care interventions (Qiu and Yu 2023; Riegel et al. ²⁰²²; Yu et al. ²⁰²¹).

In this study, reliability was assessed using multiple methods of internal consistency, including Cronbach's α, McDonald's omega and factor determinacy. All reliability estimates were strong, with coefficients exceeding 0.90, consistent with a previous 6‐item version of the SCSE scale in Korean, which reported coefficients of 0.88, 0.88 and 0.96. This earlier version was incorporated into the US and Italian Self‐Care of Heart Failure Index, version 6.2 (Kim et al. 2018). Similarly, in a 10‐item SCSE scale tested in multinational samples—including the United States, Hong Kong, Italy and Brazil—Cronbach's alpha, composite reliability and factor determinacy coefficients were highly acceptable, with all coefficients ≳ 0.90 (Yu et al. 2021). The findings of this study further support the reliability of the K‐SCSE scale, reinforcing its applicability as a reliable measure in East Asian cultures.

These findings have important implications for nursing practice. The validated K‐SCSE scale can serve as a practical clinical tool for nurses to assess patients' self‐efficacy in managing HF. Identifying individuals with low self‐efficacy allows for the prioritisation of tailored education, counselling and motivational strategies. Nurse‐led interventions that reinforce symptom recognition, treatment adherence and timely response to symptom changes may significantly enhance self‐care outcomes. Integrating the K‐SCSE scale into routine nursing assessments can support personalised care planning and proactive symptom management.

4.1. Strengths and Limitations

This study provides additional psychometric evidence supporting the use of the SCSE scale in Koreans with HF. It also addresses a gap in the self‐care theory of HF by expanding our understanding of self‐efficacy as a crucial mechanism underlying its well‐established relationship with self‐care. In addition, the study explores how self‐efficacy interacts with other problem factors affecting self‐care—specifically HF symptom status, physical function and symptom‐induced functional severity—which have been understudied.

However, several limitations should be acknowledged. First, the sample size used for CFA in this study was relatively small; ideally, 175 participants are required to achieve a power of 0.81 (Muthén and Muthén 2002). Second, the majority of patients were either asymptomatic (NYHA Class I, 14.2%) or mildly symptomatic (NYHA Class II, 70.3%), which may limit generalisability. Given that symptom severity can influence self‐care behaviours and self‐efficacy (Auld et al. 2018; Graven et al. ²⁰¹⁵; Lee et al. ²⁰¹⁵; Riegel et al. ²⁰²²; Zhang et al. ²⁰²³), further validation of the SCSE scale in a larger and more clinically diverse sample is warranted. Additionally, although this study utilised multiple methods to assess internal consistency reliability, it did not evaluate test–retest or inter‐rater reliability. The cross‐sectional design precluded repeated measurements, and the self‐administered nature of the SCSE scale renders inter‐rater reliability inapplicable. This limits evaluation of the scale's temporal stability, which should be addressed in future longitudinal studies to further establish the instrument's robustness.

5. Conclusion

The results of the CFA supported the construct validity of the Korean version of the SCSE scale for assessing self‐care self‐efficacy in patients with HF. Construct validity was further strengthened by examining self‐care self‐efficacy in relation to HF symptom status, physical function and symptom‐induced functional severity, thereby addressing a gap in self‐care theory (Riegel et al. 2022). All measures of internal consistency demonstrated high reliability, confirming that the SCSE scale is valid and reliable for use among Korean patients with HF.

Given that self‐care self‐efficacy is a key facilitator of self‐care behaviours, clinicians—particularly nurses—should routinely assess and enhance this construct to improve symptom management and overall health outcomes. The SCSE scale can be effectively integrated into clinical nursing practice to guide individualised care. Nurses are uniquely positioned to apply the scale in practice, using it to identify patients in need of support and deliver evidence‐based, tailored interventions that empower patients in managing their conditions.

Author Contributions

J.K. designed the study. J.K. and M.A. collected the data. M.A. analysed the data. J.K. and M.A. prepared the manuscript. All authors approved the final version for submission.

Conflicts of Interest

The authors declare no conflicts of interest.

Kim, J. , and An M.. 2025. “Validity and Reliability of the Korean Version of the Self‐Care Self‐Efficacy Scale for Patients With Heart Failure: A Psychometric Evaluation.” International Journal of Nursing Practice 31, no. 5: e70045. 10.1111/ijn.70045.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.