Design
This study is part of the larger chronic kidney disease nurse-led self-management support program (CKD-NLSM) study [16]. First, forward, and backward translations were conducted by a panel of experts who reviewed the translations and conducted cultural adaptation. The Malay version of CKD-SM (MCKD-SM) was subjected to psychometric assessment.
Instruments
Chronic Kidney Disease Self-Management (CKD-SM)
The CKD-SM, which refers to a self-administered instrument, has been deployed to assess self-management behaviour among CKD patients [9]. Approval to use of CKD-SM was granted by the developer. This 29-item instrument is composed of the following four factors:
Factor 1: Self-integration consists of 11 items (7, 11-12, 14, 18-19, 22-23, 25-26, & 28). It examines how a patient attains a balanced life via lifestyle adjustment by incorporating the recommended treatment regimens and self-management activities.
Factor 2: Problem-solving consists of 9 items (2, 5-6, 9, 16, 20, 24, 27, & 29). It explores a patient’s capability of seeking resources and gaining information on CKD to overcome the issues.
Factor 3: Seeking Social Support has 5 items (1, 3-4, 10, & 15). It examines a patient’s capability in seeking support from important others to address issues related to CKD.
Factor 4: Adherence to Recommended Regimens consists of 4 items (8, 13, 17, & 21). It assesses if a patient follows the recommended treatment and healthcare regimens.
The four-point Likert scale was deployed for all items; 1 (never) to 4 (always). The total scores for each factor are as follows: Self-integration (11-44), Problem-solving (9-36), Seeking Social Support (5-20), and Adherence to Recommended Regimen (4-16). The overall score is between 29 and 116, whereby higher scores signify better CKD self-management behaviour. For early-stage CKD, the original English CKD-SM instrument showed good internal consistency with 0.88 score for Cronbach’s alpha and good sampling adequacy with 0.89 score for Kaiser-Meyer-Olkin (KMO) [9]. A 2-week test–retest analysis of CKD-SM in early-stage CKD indicated good stability with intraclass correlation coefficient (ICC) of 0.72 [9].
Setting
This study was carried out at the Nephrology Clinic located in a tertiary teaching hospital situated in Kuala Lumpur, Malaysia. The patients there were referred by general practitioners from other healthcare centres. The clinic supports patients with early CKD right through to those who need renal replacement therapy (RRT). Patients with CKD Stages 2–5 are managed by nephrologists and qualified CKD nurse-educators.
Inclusion and exclusion criteria
The following lists the inclusion criteria for this study:
(a) Adult with CKD stages 3–4 (defined as eGFR of 15–59 ml/min/173 m2 with evidence of kidney damage)
(b) Age ≥ 18 years
(c) Able to understand, speak, and read the Malay language.
Additionally, the participants must not participate in cognitive debriefing, as well as not diagnosed of pre-existing cognitive/vision impairment and serious illness (cancer, stroke, and dementia).
Data collection and procedure
Data collection was conducted between June 2019 and September 2020. Eligible participants were identified by researchers at the Nephrology Clinic and were recruited using consecutive sampling. After obtaining informed consent by the participants, self-administered instruments on MCKD-SM, Kidney Disease Knowledge Survey (KiKS), and Self-efficacy for Managing Chronic Disease (SEMCD) were distributed to the participants. Demographic data of the participants (gender, age, marital status, ethnicity, employment status, & academic background) were captured in a quiet room located at the clinic. Other medical information, including CKD stages, was gathered from medical records. Re-testing was performed 2 weeks later.
Translation and cultural adaptation process
The English to Malay translation process was executed in four steps [17, 18], namely: forward-translation, expert panel consideration and back-translation, pre-testing and cognitive debriefing, as well as the final version (see Fig. 1). First, the original instrument was forward translated from English to Malay in an independent manner by two professional bilingual native Malay speakers from the Faculty of Languages and Linguistics, in University Malaya. Next, two initial forward translations were discussed with different points reconciled and harmonized to produce MCKD-SM. After that, this instrument was assessed in terms of idiomatic, semantic, and conceptual equivalence by 10 experts (1 nephrologist, 2 nursing academicians with experience in instrument validation, 2 CKD nurses, 2 family medicine specialists, & 3 CKD patients) [19]. Both translations were reviewed by them prior to discussing in iteration and reaching a consensus on MCKD-SM instrument. Back translation from Malay to English was carried out by 2 qualified local bilingual translators from non-medical background and who were blinded to the original English versions. The translation was re-discussed by the experts to ascertain its similarity with the original instrument and the final MCKD-SM was agreed to move to the next stage.
Pre-testing and cognitive debriefing
Instrument pilot was performed using purposive sample of ten CKD Malay patients, recruited from the selected Nephrology Clinic. The participants filled in the self-administered instrument within 10-15 minutes. Next, they were requested to provide feedback on the clarity of words and sentences of the instrument, as well as its intelligibility in all aspects of the instrument. Minor changes were made, such as replacing some translated terms to more commonly used terms suggested by the patients, for example item 2: “thinking over reasons about bad laboratory data” and item 13: “Don’t follow care providers’ suggestion to exercise” were translated as “Memikirkan sebab-sebab mengenai data makmal yang teruk” and “Tidak mematuhi cadangan penyedia penjagaan untuk bersenam”, respectively. Next, the patients suggested ‘teruk’ (bad) to be replaced with ‘tidak baik’ (less good), and ‘penyedia penjagaan’ (care providers) with ‘pengamal perubatan’ (medical practitioners)”. The final version of the MCKD-SM was assessed for consistency and validation analysis reflected in COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) approach [20].
Psychometric evaluation
Psychometric measurement properties include convergent validity, factor analysis, internal consistency, and intra-rater test-retest reliability [16]. Exploratory factor analysis (EFA). was performed by applying the principal component extraction and Promin rotation methods. In this context, polychoric correlation method was executed, which is suitable for ordinal variables and items with the Likert-type response scale. Polychoric correlation is advised when the univariate distributions of ordinal items are asymmetric or with excess of kurtosis. The Factor 10.10.02 program [21] was applied to conduct the EFA. Parallel analysis was performed to determine the number of factors using optimal parallel analysis (random permutation) option in the software [22]. The scree plot was used to support the parallel analysis findings.
Internal consistency was examined using Cronbach's α coefficient. Cronbach’s α < 0.70 denotes inadequate consistency, while 0.70–0.90 signifies adequate internal consistency [23]. Intra-rater 2-week test-retest reliability was performed by estimating the ICC. The ICC of 0.70 is the minimum standard for reliability [24]. Pearson’s correlation coefficient was performed to assess the correlations between kidney disease knowledge (KiKS) and self-efficacy (SEMCD) with MCKD-SM.
The KiKS measures patients’ knowledge about kidney disease, especially those who need not undergo RRT [25]. This 28 items KiKS is composed of three factors that measure general knowledge on kidney disease, kidney functions, and progression symptoms. Correct response is given a score of 1, while 0 for otherwise. With total score ranging at 0-28, higher scores denote higher knowledge level of kidney disease.
The 6-item SEMCD measures the self-efficacy of chronic disease patients [26]. The 10-point Likert scale was employed in this instrument: 1 (not at all confident) to 10 (totally confident). With the total score ranging at 6-60, higher scores denote better self-efficacy.
It was hypothesised that MCKD-SM would correlate with KiKS and SEMCD at ~ 0.25 [16]. Correlation coefficient scores of 0.20-0.40, 0.40-0.70, 0.70-0.90, and > 0.90 indicate weak, moderate, strong, and very strong correlations, respectively [27].
Sample size
In light of psychometric properties analysis, the sample size had been based on the 1:10 ratio for each item [19, 24] signifying 290 participants were needed for this study because MCKD-SM is composed of 29 items. After Considering 20% incomplete responses, 363 (290/0.8) participants were invited for this study. During the 2-week intra-rater test-retest testing, 50 participants were re-invited for participation [24].
Statistical analysis
The gathered data were analysed using Statistical Package for Social Science (SPSS) version 25.0 (SPSS, Chicago, IL) and FACTOR (10.10.02) software [21]. Descriptive statistics were generated for individual item scores and demographic data. The EFA using principal component analysis (PCA), a crucial aspect in tool development, was deployed to ensure the content and number of factors in the initial items set. The KMO and Bartlett’s test of Sphericity were executed as well. The retained factors were determined using the following criteria: scree plot, theoretical interpretability of the resultingfactor structure, and eigenvalues >1. Next, the items were chosen based on four criteria, as follows: conceptual coherence of items with individual factor, factor loading > 0.3 [28], no cross-factor loaded items, and minimum factor membership of three items. After that, the internal consistency of MCKD-SM was determined based on Cronbach's α. Test–retest reliability was determined using ICC with receipt of completed retest instrument. As for convergent validity, Pearson correlations among CKD self-management behaviour, kidney disaese knowledge and self-efficacy were ascertained as all scores displayed normal distribution.