The Turkish version of the self-care behaviors scale for rheumatoid arthritis patients: cross-cultural adaptation and psychometric evaluation

Abstract

Background

Self-care behaviors play an important role in disease management and improving the health outcomes of rheumatoid arthritis (RA) patients. However, currently available Turkish instruments to measure self-care behaviors in RA patients are not disease-specific or have low reliability. The aim of this study was to adapt the Self-Care Behaviors Scale (SCBS), developed specifically for RA patients, into Turkish and evaluate its psychometric properties.

Methods

The study was conducted with 378 RA patients admitted to the Rheumatology Outpatient Clinic of a university hospital. Content validity, construct validity, internal consistency and test-retest reliability examined the psychometric properties of the scale.

Results

The SCBS-T with its seven factors and 25 items was found to be valid (KMO = 0.957; Bartlett’s test χ2 = 6614.69, p < 0.001), to explain 67.80% of the total variance, and to have good fit indices (χ2/df = 2.920; GFI = 0.861; CFI = 0.925; RMSEA = 0.078; TLI = 0.912; SRMR = 0.045). The scale’s overall Cronbach’s α coefficient was 0.86, while the subscales ranged between 0.74 and 0.81. One-week interval test-retest reliability was 0.81.

Conclusions

The high validity and reliability results of the SCBS-T indicate that the scale will form a strong basis for its routine use by health professionals in clinical settings and for the development of educational programs on the self-care of RA patients.

Background

Rheumatoid arthritis (RA) is a chronic, inflammatory, and autoimmune disease that primarily affects the joints [1]. The disease is more common in women than men, and its prevalence increases with age [1, 2]. An estimated 17.6 million individuals worldwide suffered from RA in 2020, with Türkiye reporting a prevalence of 0.56% [3, 4].

Despite pharmacologic treatments to control or reduce the burden of disease, RA patients have to cope with many problems, such as pain, fatigue, stiffness, and decreased muscle strength due to progressive joint destruction, which limit their physical activities, make their daily activities difficult, and affect their quality of life [5, 6]. All these conditions can also have devastating effects on the patient’s psychological and social roles [7]. Demonstration of appropriate self-care behaviors by RA patients in coping with these difficulties and improving quality of life is an important component of effective disease management [8].

Self-care is a process that includes health promotion and disease management practices to maintain health status [9]. Self-care behaviors require individuals, especially those with chronic diseases, to adopt various general and disease-specific behaviors to maintain their physical and psychological health [10, 11]. It is very important for RA patients to perform various self-care behaviors such as physical activity, regular medication use, stress management, joint protection, healthy nutrition, and pain management to reduce the impact of disease symptoms and improve quality of life [8, 12]. Regular evaluation of RA patients’ self-care behaviors by health professionals can help control the course of the disease, organize treatment plans individually, and plan necessary interventions according to patients’ needs [5, 6, 8].

Despite the emphasis on the importance of self-care behaviors in RA, it is noteworthy that the availability of valid and reliable tools for assessing these behaviors is limited, both within our country and internationally. Although there are scales assessing self-care or self-management behaviors across chronic diseases, it is known that these scales do not include RA-specific behaviors [13, 14]. Another scale, the Arthritis Self-Efficacy Scale (ASES), restricts the patient’s self-management assessment to behaviors like function, pain, fatigue, and depression [15]. In a study conducted by Morowatisharifabad et al. (2010), a scale was developed to assess self-care behaviors in RA patients. However, this instrument was designed specifically for the study context and was not subjected to comprehensive psychometric testing [16]. Moreover, the Turkish adaptation of this tool revealed low internal consistency (Cronbach’s α = 0.675) [17], limiting its suitability for broader clinical or research applications. Based on the need for a psychometrically sound and RA-specific tool, we identified the Self-Care Behaviors Scale (SCBS), developed by Nadrian et al. [18]. The SCBS was designed to evaluate a wide range of RA-specific self-care behaviors and has been tested in different cultural settings [18, 19]. Accordingly, the aim of this study was to cross-culturally adapt the Turkish version of the Self-Care Behaviors Scale (SCBS) for RA patients and evaluate its psychometric properties.

Methods

Design, setting and sample

This methodological study was conducted between March 2023 and January 2024 with RA patients admitted to the Rheumatology Outpatient Clinic of a university hospital using a convenience sampling method. The inclusion criteria were: (1) patients diagnosed with RA according to the American Rheumatology Association (ACR) classification criteria; (2) aged 18 years or older; (3) voluntary agreement to participate in the study. Patients with Turkish reading or comprehension problems, visual or auditory problems, and patients with a diagnosis of psychiatric illness were excluded from the sample.

The study incorporated the recommendations that the sample size should be 10 times the number of items in the measurement tool and that a minimum of 300 participants should be included for factor analysis [20, 21]. The total sample for the main analysis included 378 participants. This number excludes 60 participants (30 for pre-testing and 30 for test–retest reliability) who were involved in separate stages of the study.

Data collection and instruments

Data were collected by two investigators who identified potential RA patients by considering the inclusion and exclusion criteria of the study. Participants were approached during their routine outpatient visits at the rheumatology clinic of a university hospital. The investigators provided patients with information about the study’s purpose and procedures, and requested their written informed consent to participate in the study. The data for the study were collected by the face-to-face questionnaire method using the “Patient Characteristics Form” and the “Turkish version of the Self-Care Behaviors Scale (SCBS-T)”. Participants who were included in the test-retest phase were asked to write pseudonyms on the questionnaires to ensure matching.

Patient characteristics form

This form included questions about RA patients' sociodemographic (e.g., age, gender, educational status, etc.) and disease/health status (e.g., duration of diagnosis, smoking, comorbidities, etc.).

Self-Care Behaviors Scale (SCBS)

This scale was developed by Nadrian et al. to assess the self-care behaviors of RA patients [18]. The scale consists of 25 items, including self-care behaviors, and seven subscales (physical activity, medication, stress management/others, nutrition/joints protection, management of daily activities, pain management, and tobacco/opium use). Scale items are scored as “Not al all (0 points)”, “Rarely (1 point)”, “Sometimes (2 points)”, “Often (3 points)”, and “Always (4 points)”. Three items on the scale containing inappropriate behaviors are reverse-coded. The scale's score ranges from 0–100, with higher scores indicating higher levels of performance in self-care behaviors. The internal consistency of the scale was reported to be 0.74, and the test-retest reliability was reported to be between 0.71–0.91 for the subscales [18].

Translation and cultural adaptation of the scale

We followed the guidelines proposed by Beaton et al. for the translation and cultural adaptation of the scale into Turkish [22]. We adhered to the guide’s recommendations by implementing the following six-step process:

• Step 1-Translation from English to Turkish: As part of the language validity process, a translation team of five individuals—four of whom were physicians and nursing academicians with expertise in rheumatology, and one of whom was a professional translator—independently translated the original English version of the SCBS into Turkish.

• Step 2-Synthesis of Translations: The researchers meticulously analyzed and compared the texts they received from the translation team. Expert opinions and the researchers’ reviews revealed that Turkish culture could interpret the word “opium” in the 24 th item of the scale, “Used substances, like opium, to control pain,” as illegal drugs, potentially leading to negative outcomes such as patients committing crimes. We contacted the scale’s author, changed the item to “Using strong pain medications to reduce pain,” and created a draft Turkish version of the scale.

• Step 3-Back translation: To complete the language validity procedure, two translators—who were unfamiliar with the original version but fluent in both Turkish and English—independently back-translated the Turkish version into English. We found a high level of agreement when we compared the back-translated English scale with the original version.

• Step 4-Expert panel: The content validity of the Turkish version of the scale was evaluated by a panel of experts who were not part of the translation team. The panel consisted of three specialist physicians (with at least five years of experience) and four nursing faculty members (with postgraduate education and at least five years of experience), all of whom had expertise in both rheumatology and the development/adaptation of measurement tools. The experts assessed each item using the Davis technique (a: item is appropriate, b: item is appropriate but needs revision, c: item needs serious revision, d: item is not appropriate) [23]. This technique yields a content validity index (CVI) by dividing the number of experts who marked (a) and (b) for a given item by the total number of experts, with an expectation of a CVI value > 0.80 [23]. The results obtained from seven experts showed that the scale had a high level of comprehensibility, with a CVI value of 0.91.

• Step 5-Pre-testing: Following the expert panel evaluation, face validity of the adapted scale was assessed through a pre-test with a sample from the target population (30 RA patients) to ensure that the scale was clear, understandable, and culturally appropriate. During the pre-testing step, the researcher was present while the participants completed the questionnaire and recorded their opinions on the items, if any. All patients reported that the items were understandable. As no concerns were raised regarding wording or cultural relevance, no modifications were deemed necessary, and the adapted version was finalized for use in the main study.

• Step 6-Submission to developers and psychometric testing of the pre-final version of the translated instrument: Following the pre-testing phase, the pre-final version of the Turkish SCBS was submitted to the original developers for appraisal of the adaptation process. The developers reviewed the documentation, which included all reports and forms detailing the translation, synthesis, back-translation, expert panel evaluation, and pre-testing processes. No modifications or additional recommendations were provided by the developers, and the adaptation was approved.

Subsequently, the psychometric evaluation of the pre-final version was conducted with the target population. Construct validity was assessed through exploratory and confirmatory factor analyses. Reliability was examined by internal consistency (Cronbach’s alpha) and one-week interval test-retest reliability (30 RA patients). The procedures for these psychometric assessments are detailed in the "Data analysis" section. The psychometric evaluation process of the SCBS-T is summarized in Fig. 1.

Fig. 1

Adaptation process of the Turkish version of the SCBS

Data analysis

The study data were analyzed on the SPSS (Statistical Package for Social Sciences) for Windows 29.0 and AMOS (Analysis of Moment Structures) 29 software packages. Data were checked for normal distribution using skewness/kurtosis values and the Kolmogorov Smirnov test. Descriptive statistics (number, percentage, mean, and standard deviation) were used for the sociodemographic and disease characteristics of the participants.

The seven-factor structure of the scale was examined by exploratory (EFA) and confirmatory (CFA) factor analyses. Before the EFA, Kaiser-Meyer-Olkin (KMO) and Bartlett’s tests were applied to determine the suitability of the data for factor analysis. Bartlett’s test was expected to be significant, and the KMO value was expected to be greater than 0.50 [24]. The EFA was conducted using Principal Axis Factoring (PAF) as the extraction method, which is appropriate for identifying latent constructs based on shared variance among items. Since the underlying factors of the scale—such as physical activity, medication adherence, pain management, and stress management—were assumed to be correlated, an oblique rotation method (Direct Oblimin) was used. CFA with the maximum likelihood estimation method is used to verify the accuracy of the data. The goodness-of-fit index criteria were determined as the chi-square/degree of freedom (χ2/df < 5), goodness-of-fit index (GFI > 0.85), comparative fit index (CFI > 0.90), root mean square error of approximation (RMSEA < 0.08), Tucker-Lewis Index (TLI) ≥ 0.90, Standardized Root Mean Residual (SRMR) ≤ 0.06, and factor loadings were expected to be ≥ 0.30 [25, 26].

Internal consistency reliability was tested with Cronbach’s alpha (α) coefficient, and the acceptable value was ≥ 0.70 [27]. The intraclass correlation coefficient (ICC) was used to determine test-retest reliability (stability), and the acceptable value was determined as ≥ 0.70 [28]. The significance level was accepted as p < 0.05.

Results

Characteristics of the RA patients

The mean age of the RA patients who participated in the study was 55.71 ± 13.61 years, the majority were female (77.0%), and 33.6% had high school education or more (Table 1). Of the patients, 81.5% were married, more than half had equal income-expenditure status, and 75.1% reported having a nuclear family type. Patients had been diagnosed with RA for a mean of 12.61 ± 8.61 years, more than half (57.9%) had comorbidities, and 37.8% were smokers. The patient’s disease activity score was 2.50 ± 0.94. Of the 33.1% patients had deformities and 6.9% had extra-articular involvement.

Table 1 Characteristics of the RA patients (n = 378)

Validity

Construct validity

According to EFA, the original seven-factor structure of the scale was appropriate (KMO = 0.957; Bartlett’s test χ2 = 6614.69, p < 0.001) and explained 67.80% of the total variance. The items’ communalities ranged from 0.584 to 0.929, indicating that no item required removal. As a result of EFA, factor loadings ranged between 0.316 and 0.835.

The CFA, which confirmed the original seven-factor structure of the SCBS-T, calculated standardization factor loadings between 0.67 and 0.90 (physical activity = 0.67–0.80, medication = 0.75–0.84, stress management/others = 0.75–0.89, nutrition/joints protection = 0.72–0.82, management of daily activities = 0.83–0.87, pain management 0.87–0.90, tobacco/drug use = 0.84–0.88) (Table 2; Fig. 2). The fit indices of the SCBS-T were found as χ2/df = 2.920; GFI = 0.861; CFI = 0.925; RMSEA = 0.078; TLI = 0.912; SRMR = 0.045.

Table 2 Confirmatory factor analysis results of SCBS-T

Fig. 2

Factor structure of SCBS-T

Reliability

Internal consistency

As a result of internal consistency analyses, the overall Cronbach α coefficient of the SCBS-T was 0.867 (Table 3). The Cronbach α coefficients of the subscales were 0.782 for physical activity, 0.747 for medication, 0.788 for stress management/others, 0.760 for nutrition/joints protection, 0.797 for management of daily activities, 0.811 for pain management, and 0.753 for tobacco/drug use.

Test-retest

The ICC value of the SCBS-T for one-week interval test-retest reliability was found to be 0.815 and between 0.774 and 0.875 for the subscales (Table 3).

Table 3 Results of the reliability analysis of the Turkish version of NSCS

Discussion

This study demonstrated that the SCBS-T showed excellent reliability and construct validity, as well as internal consistency among items and consistent results when repeated in the Turkish population. RA patients clearly understood the scale items, there was no missing data, and it took approximately 5–10 min to complete. Only a few additions between language versions were necessary to make the content most understandable to the patient, without requiring major modifications to make the scale culturally appropriate. We believe that the SCBS-T, which provides valid and reliable data, will help rheumatology nurses and physicians to determine the self-care behaviors of RA patients and to plan health education and health promotion programs for patients within the framework of self-care behaviors.

In the development study of the scale, the sample consisted of 436 RA patients with a mean age of 53 years, 87% female, 79% married, 71% with primary school education or less, and 81% with a follow-up period of three years or more [18]. The validation study of the Korean version of the scale reported a mean age of 61.58 years for the sample (n = 203), with 68.5% female, 41.4% high school graduates, 78.3% married, 62.6% diagnosed for 1–10 years, and 65.5% with comorbidities [19]. Therefore, the RA population in this study is similar to other scale validation studies.

The results of the CFA conducted to confirm the construct validity of the SCBS-T in the study reveal that it largely meets the specified goodness-of-fit criteria and can be used as a reliable measurement tool. The fit criteria for the original version of the SCBS were reported as χ2/df = 1.84, CFI = 0.942, TLI = 0.916, RMSEA = 0.043; and for the Korean version as χ2/df = 2.29, GFI = 0.85, CFI = 0.91, RMSEA = 0.07, TLI = 0.89 [18, 19]. In this context, the Turkish version of the scale is generally similar to the original model fit results (especially for CFI and RMSEA values), and some fit criteria (e.g., GFI and TLI) are better than the Korean version. This may be due to the reduction of the scale to 19 items—five factors in the Korean version with the removal of six items and various factors related to the self-care of RA patients in Korea. The Korean version of the SCBS reveals that the removed questions encompass the entire subscales of medication (Items 7, 8, and 9) and tobacco/drug use (Items 24 and 25) [19]. This suggests that self-care behaviors such as taking medications regularly and as prescribed, smoking, using narcotic painkillers, and visiting the physician regularly may have differed between cultures. Previous studies in Korean RA patients reported high rates of medication adherence (65.0–90.0%) [29, 30], low rates of smoking (9.8%) [31], and most of them did not use narcotic pain medications or products [32]. As a result, the self-care behaviors associated with these scale items may not have provided comprehensive information for Korean RA patients. However, previous studies in Türkiye reported that RA patients had lower levels of treatment compliance (30–48%) [33, 34] and higher rates of smoking (26–30%) [35, 36]. In addition, 37.8% of RA patients reported smoking in this study. The responses to question 25 of the scale, “Using strong painkillers to reduce pain” were as follows: 58.2% not at all, 16.1% rarely, 13.8% sometimes, 6.3% often, and 5.6% always. These results suggest that self-care behaviors related to these items in the scale may be distinctive and informative for the Turkish population, and therefore the Turkish version should retain these items. Furthermore, the long-term diagnosis of RA in a significant proportion of the participants may have enhanced the validity of the scale by demonstrating their familiarity with self-care behaviors. The mean SCBS-T score of 69.71 ± 12.04 supports this idea.

The study evaluated the reliability of the SCBS-T using internal consistency and test-retest methods. In the study, the internal consistency of the SCBS-T was found to be high at 0.86 and between 0.74 (Medication)− 0.81 (Pain Management) for the sub-scales. In the original study, Cronbach’s α was 0.74 for the overall scale, while the sub-scale with the lowest internal consistency was reported as “Tobacco/Drug Use” with 0.29 and the highest was reported as “Medication” with 0.85 [18]. The authors emphasized that the low internal consistency of “Tobacco/Drug Use” may be due to the low number of items. The internal consistency of the five-factor Korean version of the scale was reported to be 0.88 for the overall scale and 0.77 (Pain Managemet)–0.89 (Physical Activitiy) for the sub-scales [19]. Considering that the internal consistency of the previous similar scale adapted into Turkish by Karalar et al. (2020) was reported to be as low as 0.67 [17], it can be said that the SCBS-T is a more reliable tool for assessing the self-care behaviors of Turkish RA patients. According to the test-retest analysis of the SCBS-T, 30 RA patients who completed the scales one week apart showed high and acceptable ICC values (0.81 for the overall scale and 0.77–0.87 for the subscales), indicating good temporal stability. In the original scale study, all subscales reported ICC values greater than 0.70 (0.75–0.91), consistent with our study [18].

Limitations

This study has some limitations. The concurrent validity could not be performed due to the low internal consistency of the Turkish version of the other similar self-care behaviors scale and the lack of similar RA-specific scales. Because the study is cross-sectional, the data only reflect the study period. In addition, the self-report-based nature of the scale may have caused response bias. Conducting the study at a single center may limit the generalizability of the results.

Conclusion

This study demonstrated that the SCBS-T is a highly valid and reliable tool for assessing the self-care behaviors of RA patients. Rheumatology nurses and physicians can assess patients’ self-care levels using the SCBS-T and provide more individualized recommendations for disease management based on the results. Furthermore, health professionals can utilize SCBS-T data to enhance the self-care knowledge and skills of RA patients, validate the efficacy of intervention programs to enhance self-care, and ultimately enhance the patients’ quality of life.