A Methodological Study: Validity and Reliability of the Turkish Version of the Attitudes towards Cancer Scale

Introduction: The 30-item Attitudes Towards Cancer Scale (ATC) internal consistency reliability of the T-ATC was examined with Cronbach’s alpha (α), Spearman Brown split-half value, inter-item correlation. Inter-item correlation of the T-ATC was examined by intraclass correlation coefficients (ICCs). Results: One-factor structure of the T-ATC was demonstrated by analysis with principal components extraction. As for, internal consistency of T-ATC, it was supported by Cronbach’s alpha (α=0.68), Spearman Brown split-half value (0.57 for the first half and 0.61 for the second half), inter-item correlation was ranged from 0.21-0.46. Conclusion: The T-ATC showed initial evidence of the reliability and validity that can be used in Turkish speaking countries in order to measure attitudes towards cancer and patients with cancer.


INTRODUCTION
Cancer as a disease is often associated with distressing images of treatments and of suffering and death [1]. Despite advances in cancer treatment and decreases in mortality rates, cancer is still seen by individuals, the first and foremost, as a death sentence [2]. A fear of possible impending death of their clients with cancer by health care professionals may influence their attitudes towards such clients when making contact with them. These attitudes may, on occasion, be manifested negatively towards the client by the health care Professional, consequently affecting his/her behaviour towards the client's management [3].
Especially, nurses are involved in caring for patients with cancer who are dying or have a terminal stage and are faced with the process of dying. Working with these patients and their families can be emotionally demanding and challenging [4]. Many cancer nurses describe their work as meningful and rewarding as well as emotionally draining. Despite the emotional demand of the caring process, however, oncology nurses cite other issues as major sources of stress in their work. Organizational variables to setting, staff relationships, available to supports are cited more often as major sources of stress. In particular, feeling inadequately prepared to meet the emotional demands of patients and their families are a significant source of stress for nurses [2]. Nurses' attitudes towards caring for patients that are terminally ill and dying are influenced by working with these patients on a daily basis. Nurses' attitudes may be positively or negatively influenced by demographic factors (for example age and years of experience in oncology), work satisfaction and the degree of support in the working environment. If one considers that the role of caring and compassionate nursing staff has consistently been recognised as contributing to improvements in functional adjustment and quality of life of the patient with cancer [5].
The International Council of Nurses, stress that the nurses' role is important when dealing with terminally ill patients in reducing suffering and improving the quality of life for patients and their families in the management of physical, social, psychological, spiritual and culturel needs. Nurses play an important role in developing a caring and supportive enviroment that acknowledges cancer in order to help patients and their family members to understand and deal with symptoms [4].
Nurses working with person who have cancer are part of society which regards the disease with fear and dread. As health professionals, they are expected to hold objective views and have the most up-to-date knowledge in order to give the best services possible to their clients. However, little is known about the attitudes of nurses working with cancer patients, in particular those working in medical and surgical wards of distrinct general hospitals. Although these nurses are not expected to have specialist knowledge and skills in cancer care, they must be sufficiently informed, aware and skilled in order to give optimum care and to know when and how to refer patients to appropriate specialist services [1]. Traditionally, oncology units were among the least favoured places for nurses to work in Turkey. Many general nurses have reported not wanting to work with cancer patients due to their negative view of cancer as terminal condition in addition to the comparative lack of support in general for clinical nurses in Turkey [6].
There wasn't any scale which was reliable and valid in Turkey so as to assess nurses' attitudes and general attitudes towards cancer patients. The Attitudes Towards Cancer Scale (ATC) was developed by Tichenor & Rundall (1977) in order to measure the attitudes towards patients with cancer. The ATC is self-administered that are widely used in English speaking countries [7]. The purpose of this study was to test the validity and reliability of the Attitudes Towards Cancer Scale (ATC) in Turkish language.

Research Design
It is a methodological study.

Participants, Eligibility and Sample Size
The study was conducted in University  The study purpose, procedural details, the participant's rights and potential benefits and risks of the study were explained and written consent forms were obtained from them.

Instuments
Nurses completed the following questionnaires:

A general socio-demographic questionnaire
A socio-demographic instrument was developed by the authors to capture personal information on age, gender, marital status, educational status, working years, work department, job satisfaction, participation in scientific meeting and in-service training about cancer, status of giving care patients with cancer.

The attitudes towards cancer scale
The Attitudes Towards Cancer Scale (ATC) was initially developed by Tichenor and Rundall (1977). ATC is used in Likert format and it consists of 30 statements expressing both positive and negative sentiments about a person with cancer. ATC consisted of 30 items with six responses (+1, +2, +3, -1, -2, -3) for each statement. The items were scored in such a way that a score of +3 indicated strong agreement and that of -3 indicated strong disagreements with statement. There was no neutral or zero point provided on the scale, so the respondent had to indicate to some extent either agreement or disagreement with each item [7].

Procedure
At the beginning of the study, Tichenor, one of the developers of the ATC, was interviewed via the Internet, and his permission and approval were obtained for the use of the scale in this study. Translation and cross-cultural adaptation of the ATC was performed in accordance with the established guidelines [8,9]. First, a forward translation of the original ATC into Turkish involving independent translations by a professional native Turkish translator and bilingual Turkish Professor Nursing was obtained. Then, an expert committee including specialists in oncology, internal medicine, and methodology, synthesized the two translations. Finally, two native English translators, who were uninformed about the nature of the study, completed backtranslations of the translated ATC; thereafter, the back-translations were sent to an expert committee to detect cultural bias. When the T-ATC was deemed free of cultural bias, it was considered complete and suitable for administration to participants. Afterwards examining the content validity, a pilot test for comprehensibility and clarity of the scales were carried out on a sample of 6 volunteer nurses (4 females, 2 males). The respondents were asked if they had any trouble understanding and replying to the items and if they had any suggestions for the questionnaire. The participants reported no specific problems with issues and 30-item Turkish version of the ATC (T-ATC) was finalized. The final stage of T-ATC was used to collect data in this study. The final stage of T-ATC was used to collect data in this study. Completion of the questionnaire took an average of 20 minutes. The data of the pilot study were not used in the statistical analysis of the research data.

Data Collection and Data Analysis
The data were collected by socio-demographic questionnaire and T-ATC. All statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS version 11.0) software. Afterwards the transmission of data to computer environment and necessary error controls were performed. Data were given as mean ± standard deviation (SD) and percentage (%). Feasibility: The feasibility of the T-ATC was determined by analyzing the number of unanswered questions. Validity: The content validity was reviewed by an expert committee. After examining the content validity, a pilot test for comprehensibility and clarity of the scales was conducted on a sample of 6 volunteer nurses (4 females, 2 males). Construct validity was established through an exploratory factor analysis with principal components extraction. The Kaiser criterion (eigenvalues >1.0) and scree plot were used to determine the number of factors. The value of 0.40 or higher on factor loadings was chosen as the significant criteria for assigning items to factors. The conceptual relevance on the basis of empirical evidence was concerned with assignment of items that had significant loadings on multiple factors [10]. Reliability: Internal consistency was measured with Cronbach's alpha and Spearman-Brown split half coefficients. Cronbach's alpha coefficients and Spearman-Brown split half coefficients were considered as high if above 0.80, moderate if between 0.60 and 0.80, and low if below 0.60. Inter-item correlation of the T-ATC was examined by intraclass correlation coefficients (ICCs). Repeatability was assessed by a test-retest method. ICCs between test and retest scores were calculated based on data from nurses (8 females, 6 males). ICCs were classified as high (above 0.60), moderate (between 0.60 and 0.30) or low (below 0.30) in reliability of the scales [11,12,13]. A two-tailed pvalue less than 0.05 were considered statistically significant.

Ethical Issues
This study was approved by the Research Ethics Committee of the Celal Bayar University Faculty of Medicine at Manisa, Turkey. Participants were informed that they could refuse or withdraw from the study at any time. Participants signed a consent form before questionnaires were administered.

Study Sample Characteristics
Of the 300 nurses, 263 were women, the majority of whom was married (62.7%). The average age of the nurses was Mean±SD=31.5±7.1 years. The demographic and other characteristics of nurses are shown in the Table 1.

Content validity
The content validity was reviewed by an expert committee. They determined that there was no difference between the meanings of the two versions. After examining the content validity, a pilot test for comprehensibility and clarity of the scales were performed on a sample of 6 volunteer nurses (4 females, 2 males). The respondents were asked if they had any trouble understanding and replying to the items and if they had any suggestions for the scale. The participants reported no specific problems with issues and 30-item the T-ATC was finalized.

Construct validity
Construct validity was established factor analysis with principal components extraction. Factor analysis with varimax rotation, using Kaiser criterion (eingenvalues > 1.0), and a scree plot revealed that the main component of the T-ATC consists of determinative a factor structure. The factor loading of the items were ranged from 0.86 to 0.98 (Table 2).

Reliability
The adequacy of internal consistency of the T-ATC was examined with Cronbach's alpha, Spearman Brown split-half value (0.57 for the first half) and (0.61 for the second half). We were able to recruit 14 nurses for a test-retest study. Test-retest reliability within eight week was shown to be excellent for T-ATC score (ICC=0.95 p<0.01), which suggests good reproducibility. Item-total correlation coefficients were found to being ranged form 0.21 to 0.46. Cronbach's alpha and ICC values for seperate 30-item T-ATC are presented Table 3. The mean score of the T-ATC was obtained to be Mean±SD=95.5±14.3.

DISCUSSION
The negative or positive attitudes toward cancer and cancer patients in the health care services have almost appread, according to recent studies. Some health professionals are likely to have negative attitudes towards patients with cancer. The personal beliefs and attitudes of nurses can have serious implications for their practices [14][15][16][17]. But there are still lack of studies on attitudes towards cancer and patients with cancer in general population and health professionals specifially in Turkey. There wasn't any scale which was reliable and valid in Turkey so as to assess nurses' attitudes and general attitudes towards cancer and cancer patients. The Attitudes Towards Cancer Scale (ATC) was developed by Tichenor & Rundall (1977) in order to measure attitudes towards cancer and patients with cancer. The ATC is self-administered that are widely used in English speaking countries. This scale was utilized in few studies [3,7]. In the current study, we aimed to translate ATC into Turkish language and to establish the validity and reliability of the Turkish language version of the ATC. This study demonstrated that the T-ATC has good validity and reliability. The content validity was approved by an expert committee and observed by pilot testing for cultural relevance. There is a well-documented sequential process of scale's adaptation to be used in different cultures and it is well known that translation must be validated to achieve an equivalent scale and to allow comparability of data [8].    For factor analysis, approximately 5-10 samples per item are considered adequate [18]. Therefore, considering 10 samples per item of the T-ATC with 30 items (i.e., 300 samples) minimum sample size should be 300. With regard to construct validity, we conducted a factor analysis and found that the factor structure. The results of factor analysis yielded that the T-ATC had one-factor structure like the original ATC. None of items of the T-ATC was omitted because the factor loading of the items were ranged from 0.86 to 0.98.
Cronbach's alpha was found to be moderate level. This is considered a satisfactory value capable to evidence the sound internal consistency of the T-ATC. Test-retest reliability within eight week was shown to be excellent for T-ATC score (ICC=0.95 p<0.01), which suggests good reproducibility. Item-total correlation coefficients were found to being ranged form 0.21 to 0.46. ICC values for T-ATC total score and separate items were found to be moderate level.

CONCLUSION
This is the first study, it has been performed in Turkey, to translate, and to test psychometric properties of the ATC for Turkish population. However, current study has limitations. The first limitation of study was conducted only nurses. The second limitation was that this study was performed in Manisa, Turkey (West Anatolian). Despite of these limitations, results of this study demonstrated T-ATC reliable and valid scale in order to assess of attitudes attitudes toward cancer and cancer patients in our population. Nevertheless, this study provides evidence to support the content and constuct validity as well as the internal consistency of the T-ATC. The findings of this study support the validity and reliability of the T-ATC as the instrument to assess of attitudes towards cancer and patients with cancer in Turkish population. Therefore, further studies confirm that our results is recommended. Our findings suggested that the T-ATC should be tested in other population (health professionals, public, etc.) in the way of attitudes towards cancer and cancer patients.