SCALE DEVELOPMENT: DIETARY KNOWLEDGE AND BEHAVIORS ASSESSMENT IN HEMODIALY- SIS PATIENTS

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1 Acta Medica Mediterranea, 2017, 33: 457 SCALE DEVELOPMENT: DIETARY KNOWLEDGE AND BEHAVIORS ASSESSMENT IN HEMODIALY- SIS PATIENTS OZLEM BULANTEKIN DUZALAN 1, SEZGI CINAR PAKYUZ 2 1 Cankiri Karatekin University School of Health, Department of Nursing - 2 Celal Bayar University, Manisa School of Health, Department of Nursing ABSTRACT Aim: The aim of the study was to develop a valid and reliable instrument for dietary knowledge and behaviors assessment in hemodialysis patients. Methods: This study follows a psychometric methodological design. The content validity was evaluated using a Lawshe s technique with ten experts in the field of hemodialysis. The confirmatory factor analysis, and explanatory factor analysis were used for scale validity in the study. Internal consistency analysis, item discrimination indices, and the test-retest technique were used for scale reliability. The study sample included 302 chronic hemodialysis patients. Results: Scale for Dietary Knowledge in Hemodialysis Patients (SDKHP), is a three-point Likert scale and consisting of 18 items. Cronbach's alpha reliability coefficient of the scale was The Scale for Dietary Behaviors in Hemodialysis Patients (SDBHP) is a five-point Likert scale and consisting of 13 items. Cronbach's alpha reliability coefficient of the scale was Conclusions: SDKHP and SDBHP are valid and reliable measurement tools for assessing the level of dietary knowledge and the dietary behaviors in hemodialysis patients, respectively for use by nurses and other health professionals. Key words: hemodialysis, validity, reliability, nutrition. DOI: / _2017_3_067 Received November 30, 2016; Accepted February 02, 2017 Introduction Hemodialysis is one of the replacement therapies for patients with end-stage renal disease (ESRD) (1,2). Hemodialysis patients must comply with the medication and the challenging dietary and fluid restrictions in order to obtain maximum benefit from the treatment. The dietary and fluid restrictions are particularly important components of the ESRD treatment (2). Fluid control is a major problem in hemodialysis patients (2,3) ; and it is the most crucial restriction in a patient s diet (4). Diet is a crucial part of the treatment regimen for patients receiving hemodialysis therapy; and the dietary non-compliance usually impairs the fluid-electrolyte balance, and increases the risk of malnutrition and mortality (5-7). Noncompliance with diet and fluid restriction is a common dilemma in dialysis patients (2,7-10). Patients do not generally alter their culturebased eating habits upon starting dialysis (11). For example; salty, fatty and saucey and meat dishes are typical and plentiful in Turkish cuisine.

2 458 Ozlem Bulantekin Duzalan, Sezgi Cinar Pakyuz However, if a patient eats too much meat, urea and potassium levels will rise in his/her blood. It is a major problem with patients. In addition, adherence to dialysis treatment and procedures, prescribed medicines, age, sex, level of education, job, social support, and coping mechanisms (12-14) are factors which affect the patient ability to adapt. Firstly, nurses do not radically change patients dietary management. Because they accept the change and are able to implement dietary restriction with in time. As they play an important role in hemodialysis patients' treatment, care, and training, hemodialysis nurses should familiarize themselves with their patients behaviors, attitude and knowledge about managing their dietary intake in order to both better identify the areas of incompetence in their patients and provide training in this areas (15). It is important for nurses to develop a patientspecific method of dietary and fluid management to encourage compliance and improve the quality of life of patients (11,16). Nurses collaborate with dieticians and other health professionals to facilitate self-management of fluid and dietary restrictions using educational resources such as brochures, lists of foods to avoid, websites and ongoing counseling (2,17). Presently there is no valid and reliable measurement tool to assess the knowledge and behaviors of hemodialysis patients regarding dietary and fluid management. The study was performed in order to develop the Scale for Dietary Knowledge in Hemodialysis Patients (SDKHP), and the Scale for Dietary Behaviors in Hemodialysis Patients (SDBHP). Method Study population and sample The study was conducted at five private dialysis centers located in the Istanbul province. The study population consisted of 302 chronic hemodialysis patients, who met the eligibility criteria. The inclusion criteria for the study were being under hemodialysis therapy for at least six months or more, between the ages of 18-65, literacy and agreement to participate in the study. The exclusion criteria were to be diagnosis with any psychiatric diseases, having any hearing, speaking, or mental problems. The sample size suggested for methodological studies must be 5-10 times the number of items in the scale and the sample size for this study was determined accordingly (18,19). Data collection tools The study data were obtained by having a patient fill out an introduction form developed by the investigator, the SDKHP, SDBHP and Patient Description Form (includes sociodemographic characteristics). The data were collected during face-to-face interviews with the patients, which were conducted by the investigator. The disease and therapy data and the laboratory data were obtained from patient files. The average duration for data collection was minutes for each patient. Preparation of The Scale for Dietary Knowledge in Hemodialysis Patients (SDKHP) and Dietary Behaviors in Hemodialysis Patients (SDBHP) Preparation of an Item Pool for the Scale: At the first stage of SDKHP and SDBHP, which is developed to measure the knowledge, behaviors and attitudes about dietary and fluid restriction by chronic hemodialysis patients a question pool was formed in line with the information in the literature review (7,16,20) interviews and the knowledge and experiences of the researchers. The questions were prepared and then presented to a two Turkish language specialist for critique. SDKHP, was developed as a three-point Likert scale with response options being true, false, and I don t know. The scoring was as follows: True: 1 point; False: 0 points; and I don t know: 0 points. The lowest and highest scores were 0 and 18 points, respectively. The scale consisted of a single sub-dimension. That was one reverse-scored item. (12 th item). The scale did not contain a cut-off score and the interpretation was a good level of knowledge for higher scores. SDBHP, was developed as a fivepoint Likert scale with strongly disagree, disagree, not sure, agree, and strongly agree. The scoring was as follows: strongly disagree: 1 point; disagree: 2 points; not sure: 3 points; agree: 4 points; and strongly agree: 5 points. The scale consisted of a single sub-dimension and there were no reverse-scored items. The lowest and highest scores were 13 and 65 points, respectively. The scale did not contain a cut-off score and the interpretation was a good behavioral status for higher scores. Ethical consideration For the study, ethics committee approval and the necessary institutional approvals from the respective dialysis centers were obtained.

3 Scale development: dietary knowledge and behaviors assessment in hemodialysis patients 459 Additionally, the patients completed the Patient Information and Consent Form, which was prepared by the investigator. Statistical analysis: Data collection and evaluation The data related to the disease and treatment, and biochemical parameters were obtained from patient files. The data were entered and evaluated on the Statistical Package for the Social Sciences (SPSS) program version 20.0 (SPSS, Chicago, IL, USA). The patients descriptive characteristics were assessed as percentage and mean ± standard deviation (SD). The scale was tested for reliability using the content validity, construct validity, and similar scale validity methods. In content validity, the scale items were presented to specialists for their opinions. In determining construct validity, the exploratory factor analysis (principal components analysis) was applied and the varimax rotation method was used. In reliability assessment, the internal consistency was determined using Cronbach s alpha, item analysis (item-total, itemremainder, and item-discrimination indices), and test-retest techniques. For the test-retest reliability, the relationship between the two applications was assessed using Pearson correlation analysis. Results Sociodemographic characteristics of patients The mean age of the 302 chronic hemodialysis patients in the study was ± years, and 51.3% (n=155) were male. Of the participants, 47.3% (n=143) were primary school graduates and 30% (n=91) were literate. The mean daily urine volume was ± ml, and the mean daily fluid consumption was ± ml. Validity and Reliability Analyses Content validity and structural validity analyses were used for scale validity in the study. The scales were sent to ten experts (One professor of nephrologist, two professor of internal medicine nursing, two assistant professors of internal medicine nurse, two assistant professors, one hemodialysis nursing and one dietician) for the content validity assessment. We calculated the content validity index (CVI). To determine the item CVI, the experts were asked independently to rate both the clarity (understandability) and relevance (appropriateness) of each item on a scale of 4 points (1 = not clear/relevant, 2 = somewhat clear/relevant, 3 =quite clear/ relevant, and 4= highly clear/relevant). The answers from the experts were evaluated using Lawshe's technique. Lawshe's technique uses Content Validity Ratio (CVR). The answers from the experts were evaluated by calculating the content validity ratio/index via Lawshe's technique for each item(19,21). It was 0.62 for ten experts based on the Lawshe's minimum content validity index. Accordingly, one item was removed from the knowledge scale and five items were removed from the behaviors scale, which had a content validity index < Thereby, the knowledge and behavior scales were established with 18 and 13 items, respectively. Structural Validity of the Scale for Dietary Knowledge and Behaviors in Hemodialysis Patients (SDKHP, SDBHP): Confirmatory factor analysis was applied for the structural validity of this scale. SDKHP consisted of a single factor and 18 items. Multiple fit indices were employed in the confirmatory factor analysis to assess the validity of the model. The fit indices in the scale model were: χ2=623.93, X2/sd= 4.62, CFI=0.92, NNFI=0.89, and NFI=0.88. When the coefficients were examined, indicating the association between the observed variables and factors of the model suggestive of the scale's factorial structure, it was concluded that all coefficients were sufficient. The explanatory factor analysis was applied and the Varimax rotation method was used to establish the structural validity. Kaiser Meyer Olkin (KMO) and Bartlett s tests were used to assess whether a factor analysis would be applied to the scale or not and the adequacy of the data. The scale s KMO value was and the Bartlett s test result was (p < 0.001). The number of factors was decided using the eigenvalue. Figure 1: Scree plot of the subdimensions of the SDKHP.

4 460 Ozlem Bulantekin Duzalan, Sezgi Cinar Pakyuz The study did not limit the number of factors and the factors with an eigenvalue > 1.00 were taken into the scale. The eigenvalue was and the variance was % for the first factor (Figure 1). SDBHP scale consisted of a single factor and 13 items. The first-level confirmatory factor analysis was applied for the structural validity of this scale. The fit indices were χ2=205.93, X2/sd= 3.17, CFI=0.91, NNFI=0.87, and NFI=0.85. When the coefficients examined, indicating the association between the observed variables and factors of the model suggestive of the scale's factorial structure, it was concluded that all coefficients were sufficient. The explanatory factor analysis was applied and Varimax rotation method was used to establish the structural validity. The scale s KMO value was and the Bartlett s test result was (p < 0.001). The study did not limit the number of factors and the factors with an eigenvalue > 1.00 were included in the scale. The eigenvalue was and the variance was % for the first factor (Figure 2). it can be said that the scale has a moderate reliability. A highly positive and significant correlation was Items Correlation Cronbach s Alpha Protein-containing foods increase blood urea. Legumes, meat, milk, and milk products contain high levels of protein. A high protein intake causes increased levels of phosphorus The dietary amount of protein is determined based on weight. The increased blood urea causes nausea/vomiting and bad breath. Foods such as pickles and canned products contain high levels of salt. Foods such as potatoes, bananas, and dried nuts contain high levels of potassium. A diet with low potassium will help protect the heart health. Increased levels of potassium cause weakness of muscles and heart-throb Offals, such as liver, spleen, and kidneys, are rich in proteins and fat If the dietary amount of protein is not well adjusted, I will be undernourished If the protein intake is insufficient, blood creatinine levels will increase Figure 2: Scree plot of the subdimensions of the SDBHP. Reliability Analyses of the Scale for Dietary Knowledge and Behaviors in Hemodialysis Patients (SDKHP, SDBHP): SDKHP, Cronbach s alpha reliability coefficient of the scale was It can be said that SDKHP has a high level of reliability. A highly positive and significant correlation was found between the scores obtained from the SDKHP test-retest applications (r=95; p < 0.001). This result suggests that the scale was not affected by time and always measures the same, even though time passes (19), (Table 1). SDBHP, Cronbach s alpha reliability coefficient of the scale was Based on these results, If the phosphorous amount increases in the body, the bones weaken and can be broken easily. If I eat food with high levels of phosphorous, phosphorouslowering medications are used. If high amounts of milk and milk products are consumed, the phosphorous amount increases in the body If the phosphorous amount increases in the body, the level of parathyroid increases as well. The increased level of parathyroid hormone causes itching in the body. If the fluid restriction is not adjusted well in the diet, there will be swelling in the body Table 1: Evaluation of item analysis results of SDKHP (n=302).

5 Scale development: dietary knowledge and behaviors assessment in hemodialysis patients 461 found between the scores obtained from the scale test-retest applications (r=0.95; p < 0001). This result suggests that the scale was not affected by time and always measures the same, even though time passes (19) (Table 2). Items Correlation Cronbach's Alpha I buy the food eligible for my diet while I am shopping. I always comply with my diet. I eat legumes, meat, milk, and milk products, which are rich in protein, less often in my diet. I try not to eat foods with high levels of potassium. I apply some methods to minimize the potassium in the foods. I prefer fish and chicken to red meat for my health. When I boil the foods with high levels of potassium, I throw away the water. I don't eat the foods with high levels of fat. When I feel good, I don't restrict salt. I don't eat convenience foods such as pastrami, salami, and sausages. I don't drink mineral water due to the high levels of sodium and potassium. I adjust the dietary amount of fluid as recommended to me. I weigh myself every day to check if there is excess fluid in my body Table 2: Evaluation of item analysis results of SDBHP (n=302). The test-retest technique was administered to 40 patients one month after the start of the study. For both scales, the correlation coefficient was 0.95 and the p value was 0.001, which was significant to the highest degree (r=0.95; p<0.001). Discussion Validity of the Scale for Dietary Knowledge in Hemodialysis Patients (SDKHP), Dietary Knowledge in Hemodialysis Patients (SDBHP): Content validity, structural validity, and criterion validity analyses were used for scale validity in the present study. Lawshe's technique was used for content validity, and confirmatory factor analysis and explanatory factor analysis were used for the structural and criterion validity. Expert opinion was requested for content validity. Confirmatory and explanatory factor analyses, Varimax Rotation method, KMO, and Barlett tests were used for the structural validity. Whether or not a factor analysis will be applied to a scale used and suitability of data are assessed through the Kaiser Meyer Olkin (KMO) and Bartlett tests. The KMO test assesses whether the distribution is sufficient for a factor analysis and interval is evaluated as very good (19). The scale of SDKHP, KMO value was and the Bartlett s test result was (p < 0.001). SDBHP s KMO value was and the Bartlett s test result was (p < 0.001). Multiple fit indices were employed in the confirmatory factor analysis to assess the validity of the model. The most frequently used indices (22) include chi-square goodness (χ2), root mean square error of approximation (RMSEA), comparative fit index (CFI), non-normed fit index (NNFI), normed fit index (NFI), and goodness of fit index (GFI). The values observed in the scale model indicates perfect fit if the values are Χ2/d < 3; 0 < RMSEA < 0.05; 0.97 NNFI 1; 0.97 CFI 1; 0.95 GFI 1 and 0.95 NFI 1; and acceptable fit if the values are 4 < Χ2/d < 5; 0.05 <RMSEA < 0.08; 0.95 NNFI 0.97; 0.95 CFI 0.97; 0.90 GFI 0.95 and 0.90 NFI 0.95 (23). When the fit statistics calculated by the confirmatory factor analysis were considered, it was concluded that the previously determined single-factor structure of the scale had generally a high level of fit with the collected data. The number of factors was decided using the eigenvalue. The eigenvalue is a coefficient considered in both calculating the variance explained by the factors and deciding the number of significant factors. The factors with an eigenvalue equal to or above 1.00 are considered significant factors in factor analysis (19). The study did not limit the number of factors and the factors with an eigenvalue > 1.00 were

6 462 Ozlem Bulantekin Duzalan, Sezgi Cinar Pakyuz taken into the scale. Both scales were established to have a single-factor structure and a well-explained variance. A factor loading value is a coefficient explaining the relationship of items with subdimensions. It is stated in the literature that factor loads ranging between 0.30 and 0.40 can be taken as the lower cut-off point when designing the factor pattern (19,24,25). The lower cut-off point was set at 0.30 in this study. The variance SDKHP was found % and SDBHP was %. Reliability of the Scale for Dietary Knowledge in Hemodialysis Patients (SDKHP), Dietary Knowledge in Hemodialysis Patients (SDBHP): Cronbach s alpha and the test-retest technique are used for internal consistency of the reliability analyses (19). Cronbach's alpha (analysis of internal consistency), item discrimination indices, and testretest technique were used. Cronbach s alpha and the test-retest technique were used for the reliability analyses. Numerical values 0.70 for Cronbach's alpha are sufficient in the newly-developed measurement tools. Cronbach s alpha was higher than this value for both measurement tools. Tezbasaran (1997); stated that a reliability coefficient, which may be considered sufficient, should be as close to as possible in a Likert-type measurement tool (26). (SDKHP, Cronbach's was 0.86, SDBHP, Cronbach's was 0.73). The analyses revealed that both scales were valid and reliable measurement tools with a single sub-dimension. For both scales, the dietary knowledge and behaviors are positively improved with higher scores. The test-retest reliability, which is performed to reveal the stability of an instrument over time, involves administration of a scale developed to the same group under the same conditions in a certain interval and looking at the relationship in between using the Pearson correlation. The correlation coefficient is expected to show a positive and high-level relationship. The test-retest correlation of our scale was high, indicating a good stability over time. This means that SDKHP and SDBHP can ensure similar measurement outcomes in repeated measurements and is consistent over time. The test-retest technique was administered to 40 patients one month after the start of the study. For both scales, the correlation coefficient was 0.95 and the p value was 0.001, which was significant to the highest degree. The analyses revealed that both scales were valid and reliable measurement tools with a single subdimension. For both scales, the dietary knowledge and behaviors are positively improved with higher scores. Conclusion Diet is an important part of the treatment for patients under hemodialysis therapy. Nurses should assess the patients knowledge and behavioral status before providing them with dietary training, and determine the training plan accordingly. Therefore, a measurement tool was developed to establish the knowledge and behavioral status based on the lack of such a tool. SDKHP and SDBHP are valid and reliable measurement tools for assessing the level of dietary knowledge and the dietary behaviors in hemodialysis patients. SDKHP and SDBHP can be used by doctors, nurses and other health professionals in developing personal dietary and fluid restriction methods before and after trainings on dietary and fluid restriction to be given to hemodialysis patients. Limitations of this Study A limitation of the study is that it cannot be generalized for the entire HD patients, because the study population includes only the HD centers that could be reached by the researchers in Istanbul. References 1) Cicolini G, Palmae E, Simonetta C, Di Nicola M. Influence of family carers on haemodialyzed patients adherence to dietary and fluid restrictions: an observational study. Journal of Advanced Nursing 2012; 68 (11): ) Denhaerynck K, Manhaeve D, Dobbels F, Garzoni D, Nolte C, and De Geest S. Prevalence and consequences of nonadherence to hemodialysis regimens. American Journal of Critical Care 2007; 16(3), ) Coşar-Albayrak A, Çinar-Pakyüz S. Scale development study: The Fluid Control in Hemodialysis Patients. Japan Journal of Nursing Science 2016; 13: ) Pace RC. Fluid management in patients on hemodialysis. Nephrology Nursing Journal. 2007; 34(5): ) Saran R, Bragg-Gresham JL, Rayner HC, Goodkin DA, Keen ML, vandijk PC, Port FK. Nonadherence in hemodialysis: Associations with mortality, hospitalization, and practice patterns in the DOPPS. Kidney International. 2003; (64): ) Sezer S, Ozdemir FN, Arat Z, Perim O, Turan M, & Haberal M. The association of interdialytic weight gain with nutritional parameters and mortality risk in hemodialysis patients. Renal Failure 2002; 24(1): ) Kim Y, Evangelista LS, Philips LR, Pavlish C, Koople JD. The End-Stage Renal Disease Adherence

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