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Applied Research Brief: Measurement Issues; Nutrition
Reliability and Validity of the Turkish Version of the Situational Self-Efficacy Scale for Fruit and Vegetable Consumption in Adolescents Hasibe Kadioglu, PhD, RN; Saime Erol, PhD, RN; Ayse Ergun, PhD, RN
Abstract Purpose. The purpose o f this research was to examine the psychometric properties o f the Turkish version o f the situational self-efficacy scale fo r vegetable and fru it consumption in adolescents. Design. This was a methodological study. Setting. The study was conducted in fo u r public secondary schools in Istanbul, Turkey. Subjects. Subjects were 1586 adolescents. Measures. Content and construct validity were assessed to test the validity o f the scale. The reliability was assessed in terms o f internal consistency and test-retest reliability. Analysis. For confirmatory factor analysis, f statistics plus other fit indices were used, including the goodness-offit index, the adjusted goodness-of-fit index, the nonnormed f i t index, the comparative f i t index, the standardized root mean residual, and the root mean square error o f approximation. Pearson’s correlation was used fo r test-retest reliability and item total correlation. The internal consistency was assessed by using Cronbach a. Results. Confirmatory factor analysis strongly supported the three-component structure representing positive social situations (a = .81), negative effect situations (a = .93), and difficult situations (a = .78). Psychometric analyses o f the Turkish version o f the situational self-efficacy scale indicate high reliability and good content and construct validity. Conclusion. Researchers and health professionals will fin d it useful to employ the Turkish situational self-efficacy scale in evaluating situational self-efficacy fo r fru it and vegetable consumption in Turkish adolescents. (Am j Health Promot 2015;29[4]:273-275.) Key Words: Self-efficacy, Reliability, Validity, Adolescent, Prevention Research. Manuscript format: research; Research purpose: instrument development; Study design: content analysis; Outcome measure: behavioral; Setting: school; ffealth focus: nutrition; Strategy: skill building/behavior change; Target population age: youth; Target population circumstances: geographic location
Hasibe Kadioglu, PhD, RN; Saime Erol, PhD, RN; and Ayse Ergun, PhD, RN, are with the Department o f Community Health Nursing, Faculty of Health Science, Marmara University, Istanbul, Turkey. Send reprint requests to Hasibe Kadioglu, PhD, RN, Marmara Universitesi Hemsirelik Bolumu, HaydarpasaYerleskesi, Tibbiye cad. No: 40, Haydarpasa-Istanbul 81326, Turkey; e-mail: hasibek® gmail.com. This manuscript was submitted December 3, 2013; revisions were requestedJanuary 14 and January 30, 2014; the manuscript was accepted for publication February 3, 2014. Copyright © 2013 by American Journal of Health Promotion, Inc. 0890-11 71/13/$ 3.00 + 0 DOI: 10.4278/ajhp. 131203-ARB-611
American Journal of Health Promotion
PU R PO SE
Increasing fruit and vegetable (FV) consumption is one of the most sig nificant and effective interventions for decreasing the risk of various illness. The transtheoretical model (TTM) is widely used to modify health behav iors such as FV c o n s u m p tio n ,p h y s ical activity,'1 and smoking.' The TTM consists of four domains: stages of change, decisional balance, situational self-efficacy, and processes of change.8 Situational self-efficacy shows a per son’s self-confidence in being able to continue a specific healthy attitude (eating FV, for example) in the face of difficult conditions.9 In Turkey, daily FV intake in adoles cents is less than five portions.10 A valid and reliable self-efficacy scale for FV intake in adolescents may be useful in future studies. To our knowledge, there is no instrument in the literature that measures FV consumption-related situational self-efficacy among Turkish adolescents. The purpose of this study was to examine the psychometric properties of the Turkish version of the situational self-efficacy scale (SSES) for FV intake in adolescents. M ETH O D S Participants and Procedure
A total of 2150 students in four secondary schools were asked to join in this study. These schools were located in metropolitan Istanbul, Turkey. The students were adolescents in grades six (age 11) through eight (age 15). Data were collected in the spring of 2011. The retest was performed ap-
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proximately 2 weeks after the first data collection (n = 310).
Table Model Fit Indices of the Turkish Version of SSES
Instrument
The SSES was developed by Di Noia et al.3 The SSES contains 17 items that are rated on a 5-point Likert scale ranging from 1 (not at all confident) to 5 (completely confident). The SSES contains three subscales: positive social situations (PSS; 4 items), negative effect situations (NES; 8 items), and difficult situations (DS; 5 items). The total SSES score ranges from 17 to 85. Translation Procedures
A back-translation technique for translation of the SSES was used. The original and back-translated English forms of the SSES were examined and found to be highly similar in meaning. Content Validity Procedure
Content validity of the SSES was assessed by nine experts. The experts were then asked to rate each item on a 4-point scale, based on relevance ranging from 1 (not relevant) to 4 (highly relevant). They were also asked to give advice on how to correct the items. Data Analysis
Statistical analyses were assessed us ing by the Statistical Package for Social Sciences Version 17 for Windows and the LISREL 8.0. The content validity index was evaluated at both the item level and scale level. As suggested by Lynn,11 the individual content validity index (ICVI) was calculated as the number of experts giving a rating of 3 or 4 divided by the total number of ex perts. Overall content validity index (S-CVI) was computed by averaging all I-CVIs.12 Construct validity of the SSES was assessed by using confirmatory factor analysis (CFA). For CFA, y2 statistics plus other fit indices were used, in cluding the goodness-of-fit index (GFI), the nonnormed fit index (NNFI), the adjusted goodness-of-fit index (AGFI), the standardized root mean residual (SRMR), the compara tive fit index (CFI), and the root mean square error of approximation (RMSEA). The internal consistency of the SSES was assessed using Pearson’s correlation (corrected item-total cor
274
American Journal of Health Promotion
Model Fit Indices
Value
1225.48
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Applied Research Brief: Measurement Issues; Nutrition
Reliability and Validity of the Turkish Version of the Situational Self-Efficacy Scale for Fruit and Vegetable Consumption in Adolescents Hasibe Kadioglu, PhD, RN; Saime Erol, PhD, RN; Ayse Ergun, PhD, RN
Abstract Purpose. The purpose o f this research was to examine the psychometric properties o f the Turkish version o f the situational self-efficacy scale fo r vegetable and fru it consumption in adolescents. Design. This was a methodological study. Setting. The study was conducted in fo u r public secondary schools in Istanbul, Turkey. Subjects. Subjects were 1586 adolescents. Measures. Content and construct validity were assessed to test the validity o f the scale. The reliability was assessed in terms o f internal consistency and test-retest reliability. Analysis. For confirmatory factor analysis, f statistics plus other fit indices were used, including the goodness-offit index, the adjusted goodness-of-fit index, the nonnormed f i t index, the comparative f i t index, the standardized root mean residual, and the root mean square error o f approximation. Pearson’s correlation was used fo r test-retest reliability and item total correlation. The internal consistency was assessed by using Cronbach a. Results. Confirmatory factor analysis strongly supported the three-component structure representing positive social situations (a = .81), negative effect situations (a = .93), and difficult situations (a = .78). Psychometric analyses o f the Turkish version o f the situational self-efficacy scale indicate high reliability and good content and construct validity. Conclusion. Researchers and health professionals will fin d it useful to employ the Turkish situational self-efficacy scale in evaluating situational self-efficacy fo r fru it and vegetable consumption in Turkish adolescents. (Am j Health Promot 2015;29[4]:273-275.) Key Words: Self-efficacy, Reliability, Validity, Adolescent, Prevention Research. Manuscript format: research; Research purpose: instrument development; Study design: content analysis; Outcome measure: behavioral; Setting: school; ffealth focus: nutrition; Strategy: skill building/behavior change; Target population age: youth; Target population circumstances: geographic location
Hasibe Kadioglu, PhD, RN; Saime Erol, PhD, RN; and Ayse Ergun, PhD, RN, are with the Department o f Community Health Nursing, Faculty of Health Science, Marmara University, Istanbul, Turkey. Send reprint requests to Hasibe Kadioglu, PhD, RN, Marmara Universitesi Hemsirelik Bolumu, HaydarpasaYerleskesi, Tibbiye cad. No: 40, Haydarpasa-Istanbul 81326, Turkey; e-mail: hasibek® gmail.com. This manuscript was submitted December 3, 2013; revisions were requestedJanuary 14 and January 30, 2014; the manuscript was accepted for publication February 3, 2014. Copyright © 2013 by American Journal of Health Promotion, Inc. 0890-11 71/13/$ 3.00 + 0 DOI: 10.4278/ajhp. 131203-ARB-611
American Journal of Health Promotion
PU R PO SE
Increasing fruit and vegetable (FV) consumption is one of the most sig nificant and effective interventions for decreasing the risk of various illness. The transtheoretical model (TTM) is widely used to modify health behav iors such as FV c o n s u m p tio n ,p h y s ical activity,'1 and smoking.' The TTM consists of four domains: stages of change, decisional balance, situational self-efficacy, and processes of change.8 Situational self-efficacy shows a per son’s self-confidence in being able to continue a specific healthy attitude (eating FV, for example) in the face of difficult conditions.9 In Turkey, daily FV intake in adoles cents is less than five portions.10 A valid and reliable self-efficacy scale for FV intake in adolescents may be useful in future studies. To our knowledge, there is no instrument in the literature that measures FV consumption-related situational self-efficacy among Turkish adolescents. The purpose of this study was to examine the psychometric properties of the Turkish version of the situational self-efficacy scale (SSES) for FV intake in adolescents. M ETH O D S Participants and Procedure
A total of 2150 students in four secondary schools were asked to join in this study. These schools were located in metropolitan Istanbul, Turkey. The students were adolescents in grades six (age 11) through eight (age 15). Data were collected in the spring of 2011. The retest was performed ap-
March/April 2015, Vol. 29, No. 4
273
proximately 2 weeks after the first data collection (n = 310).
Table Model Fit Indices of the Turkish Version of SSES
Instrument
The SSES was developed by Di Noia et al.3 The SSES contains 17 items that are rated on a 5-point Likert scale ranging from 1 (not at all confident) to 5 (completely confident). The SSES contains three subscales: positive social situations (PSS; 4 items), negative effect situations (NES; 8 items), and difficult situations (DS; 5 items). The total SSES score ranges from 17 to 85. Translation Procedures
A back-translation technique for translation of the SSES was used. The original and back-translated English forms of the SSES were examined and found to be highly similar in meaning. Content Validity Procedure
Content validity of the SSES was assessed by nine experts. The experts were then asked to rate each item on a 4-point scale, based on relevance ranging from 1 (not relevant) to 4 (highly relevant). They were also asked to give advice on how to correct the items. Data Analysis
Statistical analyses were assessed us ing by the Statistical Package for Social Sciences Version 17 for Windows and the LISREL 8.0. The content validity index was evaluated at both the item level and scale level. As suggested by Lynn,11 the individual content validity index (ICVI) was calculated as the number of experts giving a rating of 3 or 4 divided by the total number of ex perts. Overall content validity index (S-CVI) was computed by averaging all I-CVIs.12 Construct validity of the SSES was assessed by using confirmatory factor analysis (CFA). For CFA, y2 statistics plus other fit indices were used, in cluding the goodness-of-fit index (GFI), the nonnormed fit index (NNFI), the adjusted goodness-of-fit index (AGFI), the standardized root mean residual (SRMR), the compara tive fit index (CFI), and the root mean square error of approximation (RMSEA). The internal consistency of the SSES was assessed using Pearson’s correlation (corrected item-total cor
274
American Journal of Health Promotion
Model Fit Indices
Value
1225.48
