The Validity and Reliability of the Turkish Scale for the Assessment of Fatigue in Pediatric Oncology Patients Aged 7-18 in Russia

Background Fatigue is the most common complaint by children both during and after cancer treatment, but in Russia, there is no reliable method for assessing fatigue. Objective To develop a Russian version of the Turkish Scale for the Assessment of Fatigue in Pediatric Oncology Patients Ages 7-18. Design Our first step was to translate all the items of the Turkish questionnaire into Russian. Then, through discussion, we created a single proposition for each item. The next step was obtaining expert opinions to assess the validity. Once the expert estimates agreed, a pilot version of the questionnaire was formed. The next step was to collect a large sample of patients to study the reliability and validity of the questionnaire. Results As a result of factor analysis, three factors were identified. The first factor was "fatigue associated with actions;" the second was "fatigue as feeling;" and the third was "fatigue associated with sleep difficulties." The children's and parents’ versions had the same factor structure. Conclusions This study showed the possibility of using the questionnaire in a Russian sample. That’s why it is necessary to continue collecting and analyzing data in this direction. The reliability of the test was also assessed. The reliability of the parent version scored a Cronbach’s alpha of 0.91. The reliability of the children’s version showed a Cronbach’s alpha of 0.93.


Introduction
C ancer is a serious disease that occurs throughout the world Jemal, 2011;Stewart et al., 2019). It a ects both children and adults. In addition to the pain of the disease and treatment, patients su er emotional and behavioral disorders (Olson et al., 2008). e most common cancer complaint is fatigue (Curt et al., 2000). It is the most distressing symptom for patients, since it reduces their quality of life (Bower et al., 2000). However, patients who have completed treatment and are in remission also have symptoms of fatigue. Even a er their cancer is cured, patients have chronic illnesses due to their treatment (Oe nger et al., 2006). Fatigue remains with some patients for many years a er the completion of treatment (Bower et al., 2006). Many studies show that over 50% of adults treated for cancer have signs of fatigue a er nishing treatment (Richardson et al., 1998). Adult fatigue has psychological, physiological, and emotional components (Richardson et al., 1998;Akechi et al., 1999). e chronic fatigue syndrome of cancer survivors has not been studied. In the rst attempt at such a study, a survey was conducted of children with cancer, their parents, and the hospital sta who worked with the children. ere was children's group of 7-12 year-olds and one of 13-18 year-olds (Winningham et al., 1994). e children complained of fatigue and the lack of enough strength to even get up and open their eyes. ey had no desire to play and learn. ey wanted to lie down and do nothing, and their parents allowed them not to attend classes and school, because the children complained of fatigue as soon as they woke up. e task of a psychologist who wants to help such children is to help them cope with fatigue (Hockenberry-Eaton et al., 1998). To do this, however, you should rst determine the degree of fatigue. Fatigue can be alleviated, and therapy can improve patients' quality of life (Varni et al., 2005). In order to alleviate the symptoms of fatigue in children, joint work by the therapist, the parents, and the hospital sta is necessary (Miaskowski, 2006). e feeling of fatigue prevents children from leading active lives, as well as preventing them from getting an education. Children can be cognitively intact, but lack of strength does not allow them to e ectively solve problems. High degrees of fatigue prevent children from attending school, which leads to emotional deprivation and a decrease in social contact. In addition, the quality of home education may be lower than that at school (Wu et al., 2010). erefore, fatigue is a serious problem for cancer survivors. Since it a ects the quality of a patient's life, it's necessary to diagnose it as quickly as possible.
In order to assess fatigue, a reliable method is required. However, in Russia there is no such method for assessing fatigue in children who have survived cancer. Current methods for assessing fatigue are not reliable and valid (Miaskowski, 2006;Wu et al., 2010). Most o en, if a child complains of fatigue, he is permitted more rest and freed from any activities.
In world practice, however, fatigue is assessed using questionnaires. For example, in Turkey there is a national questionnaire for assessing fatigue. e Turkish Chronic Fatigue Questionnaire was developed for children 7-12 and 13-18 years of age, and their parents. is questionnaire has shown its reliability, validity, and consistency in Turkish samples (Gerceker & Yilmaz, 2012;Kudubes et al., 2014;. e aim of our study was to adapt the Turkish questionnaire measuring the Scale for the Assessment of Fatigue in Pediatric Oncology Patients Ages 7-12 and 13-18, for use with a Russian population.

Participants
Our sample included 295 children (Table 1). e mean age of their oncology diagnoses was 7.25 years (SD = 1.5 years). eir periods of remission ranged from 24 to 72 months, with most children having received that status by the age of 8.2. e older the child, the longer the remission period (for example, a 12 year-old child's remission period was 3.8 years; a 15 year-olds was 6.8 years). Mothers lled out the parent version of the questionnaire. Parents and children over 14 signed informed consent forms to participate in the study. An ID number was assigned to each patient to maintain anonymity. e children spent from seven to 32 days as patients at a rehabilitation center, and received various forms of rehabilitation depending on their needs. Some children underwent motor training and some cognitive training; some children saw a psychotherapist (individually or in a group). Also, all the children underwent physiotherapy, which included swimming. During admission to the center, the children received an invitation to participate in the study assessing chronic fatigue syndrome. So, their responses were not a ected by their presence in the center. Procedures can be di cult for a child and increase his fatigue.
Measures e original version of the Scale for the Assessment of Fatigue in Pediatric Oncology Patients had been developed in Turkey and consisted of a total of 27 items and 3 factors. e factor of general problems was measured by the rst eighteen items. is factor measured overall fatigue. e next factor measured fatigue associated with di culty sleeping (9-24 items). e last factor consisted of 25-27 items and evaluated fatigue during treatment procedures. We carried out the for the Assessment of Fatigue in Pediatric Oncology Patients (Gerceker et al., 2012;Kudubes et al., 2014;.
We used the scales presented by Aslı Akdeniz Kudubes (Gerceker et al., 2012;Kudubes et al., 2014;. e rst step was to translate all the items of the questionnaire into Russian. Eight psychologists, ve doctors, two biologists, and one translator took part. Each expert presented his version of the translation. en, through discussion, they created a single proposition for each item. is stage lasted a month and a half. e result was a list of items in Russian. e next step was an expert assessment, which took place in several stages. e pool of translated items was sent to several independent experts for improving the translation. e aim was to get an identical interpretation of the items a er reverse translation.
e experts studied the translated items and evaluated how each statement related to what we wanted to measure, and whether this a rmation was clear to the respondents. If the experts' assessments had signi cant di erences, the additional opinion of other experts in this eld was required.
Once the expert estimates were agreed upon, a pilot version of the questionnaire was created. Respondents were to grade each item on a Likert scale. e pilot version of the test was o ered to 20 patients. is was necessary in order to assess how clear the items were for the patients. At this stage, we also checked whether the patients understood the items correctly. Both parents and children lled out the questionnaires and a rmed that all the items were understandable and did not have di erent interpretations. en, the next step was to collect a large sample of patients to study the reliability and validity of the questionnaire.
To assess the coherence of our questionnaire with other valid questionnaires, we used the Achenbach Children Behavior Checklist for assessing emotional states. e Achenbach Children Behavior Checklist (CBCL) has three forms: one for parents, one for children, and one for teachers. In this study, we used only the ones for parents and children. e questionnaire was standardized in Russian, and described behavioral and emotional problems.

Construct Validity
e results of the assessment by the 16 experts were tested for accuracy. e consistency scores were determined to be 0.716. us, the estimates were considered consistent.
e Parent Form of the Scale for the Assessment of Fatigue in Pediatric Oncology Patients: Construct validity of the scales was tested by factor analysis, which showed the Kaiser-Meyer-Olkin coe cient (KMO) to be 0.931. e resulting factor structure di ered from the original. In our study, three factors were also highlighted, but the distribution of assertions varied. e rst factor can be called "fatigue associated with actions" (it included items 2, 8, 9, 10, 11, 12, 13, 15, 17, 25, 26, & 27); the factor loads were determined to be 0.42-0.68. e second factor was "fatigue as feeling" (it included items 1, 4, 5, 7,14, 16, 18, & 22); the factor loads were determined to be 0.42-0.72. e third factor was "fatigue associated with sleep di culties" (it included items 3, 6, 19, 20, 21, 23, & 24); the factor loads were determined to be 0.48-0.66. e "fatigue associated with actions" explained 38.3% of the total variance; the "fatigue as feeling" explained 38.3%; and the "fatigue associated with sleep di culties" explained 18.9%. e total of the three explained 94% (see Table 2 in the Appendix).
e Child Form of Scale for the Assessment of Fatigue in Pediatric Oncology Patients: As a result of the factor analysis, the Kaiser-Meyer-Olkin coe cient (KMO) was determined to be 0.888. e resulting factor structure di ered from the original. In our study, three factors were also highlighted, but the distribution of assertions varied.

Internal consistency analysis
One of the steps required to successfully adapt the questionnaire was to evaluate its internal consistency; that is, how much did each item in the test correspond to what the questionnaire measured? e reliability coe cients of the factors of the parent form showed a Cronbach's alpha of 0.91. e reliability coe cients of the factors of the child form showed a Cronbach's alpha of 0.93.

Relationship to other questionnaires
e coherence between the parent version of the questionnaire Scale for the Assessment of Fatigue in Pediatric Oncology Patients and the parent version of the Achenbach Child Behavior Checklist was evaluated; it amounted to p = 0.001. e relationship between the child version of the Scale for the Assessment of Fatigue in Pediatric Oncology Patients and child form of the Achenbach Child Behavior Checklist measured p = 0.001.

Discussion
In the present study, we completed the rst stage of the adaptation of the Turkish questionnaire Scale for the Assessment of Fatigue in Pediatric Oncology Patients for use in Russia. We showed that this questionnaire had validity and reliability. We as-sessed the validity of the questionnaire: it was translated with the help of experts from various elds who work with this cohort of patients. We also obtained expert opinions of psychologists. As a result, we created the rst version of the questionnaire, which was used for getting a large sample of patients.
Fatigue is a common complaint of cancer survivors. Fatigue prevents children from leading a standard lifestyle, communicating with peers, and attending educational institutions. O en, due to fatigue, children cannot cope with cognitive tasks. In this case, they don't have problems with cognitive functions, but they lack enough strength to solve cognitive tasks. Since fatigue is an obstacle to a full life, high-quality tools are needed to evaluate it.
We then carried out a factor and explanatory analysis. e goal of the factor analysis was to identify the structure of the relationship between the variables and highlight the factors describing them (Gozum & Aksayan, 2002;Ozdamar, 2005;Simsek, 2007). In the course of a factor analysis, from the rst rotation, the varimax structure was divided into three factors. e rst factor was "fatigue associated with actions;" the second was "fatigue as feeling;" and the third was "fatigue associated with sleep di culties. " e resulting factor structure di ered from the original. In our study, three factors were also highlighted, but the distribution of assertions was di erent.
Currently, in Russia, rehabilitation programs for cancer survivors are just beginning to be created. ese programs are based on correction of the children's cognitive and motor de cits, but don't take into account the emotional consequences of cancer. However, fatigue complaints are the most frequent. Adaptation of the Turkish tool will help professionals to assess the degree of fatigue and create a rehabilitation plan for each child. is study showed the possibility of using the Turkish questionnaire with the Russian sample. It is necessary to continue collecting and analyzing data in this direction.

Conclusion
As a result of our study, a questionnaire was created which assesses chronic fatigue syndrome in Russian children who survived cancer. is questionnaire showed high validity and reliability in the Russian sample. e advantage of this questionnaire is the presence of both a children's and parental version, because the subjective feelings of the child and the parent may di er; having both versions will be helpful for the doctor's diagnosis. While our sample was small, this study was only the rst step toward collecting extensive data. e questionnaire will be distributed to other children's centers in Russia for more extensive data collection. Our research has not yet presented data on test-retest reliability; this is the subject of further research.

Limitations
ere are possible issues with the ability to generalize the results, e.g., sample size and limited access to data.
One limitation is that the sample size was not very large. Another limitation is that the sample was not divided by oncological diagnoses. Additional research is needed on large samples of children with various diagnoses and di erent ages.
In the creation of the Russian version of the questionnaire, only a direct translation of the questionnaire into Russian was carried out. No back translation from Russian was made. Also, test-retest reliability was not evaluated.  Table 3 Factor structure of the Child Form of the questionnaire

Factor name Items included in factor Factor loads
Fatigue associated with actions I feel tired even if eating 0.617