Reliability and validity of the PedsQL™ Multidimensional Fatigue Scale in Japan

Parents underestimate fatigue in younger children aged 5-7 years with asthma but not in older children

AIM

To assess fatigue in children aged 2-17 years with asthma from both child and parent perspectives and describe associated factors.

METHODS

Fatigue scores were self-reported by children aged 5-17 years old and proxy-reported by parents or carers for all children. The Pediatric Quality of Life Inventory Multidimensional Fatigue Scale was used. Fatigue scores ranged from 0 to 100, higher scores meant less fatigue.

RESULTS

There were 527 children and parents enrolled. The mean overall fatigue score by self-report was 72.7 ± 15.8 and by proxy report was 75.8 ± 16.3. Self-reported fatigue score was lower in children aged 5-7 years (71.5 ± 15.9) compared to proxy-reported score (76.3 ± 15.5). Proxy and self-reported fatigue scores were similar between parents and older children. Fatigue scores were lower in association with poor asthma control and receipt of social support. Lower self-reported, but not proxy-reported, fatigue score was related to asthma severity. Lower proxy-reported, but not self-reported, fatigue score was related to the child being older and having shortness of breath.

CONCLUSION

Parents underestimated the fatigue of younger children aged 5-7 years, but fatigue scores were similar between parents and older children. Both clinical and social factors are associated with fatigue in children with asthma.

Prospective Associations of Susceptibility-Weighted Imaging Biomarkers with Fatigue Symptom Severity in Childhood Traumatic Brain Injury

Fatigue may be among the most profound and debilitating consequences of pediatric traumatic brain injury (TBI); however, neurostructural risk factors associated with post-injury fatigue remain elusive. This prospective study aimed to evaluate the independent value of susceptibility-weighted imaging (SWI) biomarkers, over-and-above known risk factors, to predict fatigue symptom severity in children with TBI. Forty-two children were examined with structural magnetic resonance imaging (sMRI), including a SWI sequence, within eight weeks post-injury. The PedsQL Multi-Dimensional Fatigue Scale (MFS) was administered 24 months post-injury. Compared with population expectations, the TBI group displayed significantly higher levels of general fatigue (Cohen d = 0.44), cognitive fatigue (Cohen d = 0.59), sleep/rest fatigue (Cohen d = 0.37), and total fatigue (Cohen d = 0.63). In multi-variate models adjusted for TBI severity, child demographic factors, and depression, we found that subacute volume of SWI lesions was independently associated with all fatigue symptom domains. The magnitude of the brain-behavior relationship varied by fatigue symptom domain, such that the strongest relationships were observed for the cognitive fatigue and total fatigue symptom scales. Overall, we found that total subacute volume of SWI lesions explained up to 24% additional variance in multi-dimensional fatigue, over-and-above known risk factors. The subacute SWI has potential to improve prediction of post-injury fatigue in children with TBI. Our preliminary findings suggest that volume of SWI lesions may represent a novel, independent biomarker of post-injury fatigue, which could help to identify high-risk children who are likely to benefit from targeted psychoeducation and/or preventive strategies to minimize risk of long-term post-injury fatigue.

Reliability and Validity of the Japanese Pediatric Version of Memorial Symptom Assessment Scale

CONTEXT

Few instruments in Japanese assess health-related quality of life in pediatric cancer patients.

OBJECTIVES

To translate the Memorial Symptom Assessment Scale (MSAS) into Japanese pediatric and proxy versions (MSAS-J 7-12, MSAS-J 13-18, and MSAS-J-Proxy) and assess validity and reliability.

METHODS

Phase I comprised forward-backward translation and pilot testing in 13 children and 16 guardians. Phase II consisted of psychometric testing of the three MSAS-J versions in 162 children and 238 guardians. Internal consistency, test-retest reliability, and construct and known-group validity of the MSAS-J were assessed.

RESULTS

Cronbach's alpha coefficients for the total and subscale scores were over 0.70, excluding the psychological symptom (PSYCH) subscale score of the MSAS-J 7-12. Most MSAS-J scores significantly inversely correlated with two versions of the Pediatric Quality of Life Inventory. A strong child-guardian correlation was shown in the total and subscale scores (ICC range 0.66-0.83). Kappa estimates showed acceptable child-guardian symptom agreement. MSAS-J 7-12 and proxy differentiated patients according to clinical status.

CONCLUSION

MSAS-J is a reliable and valid instrument to assess symptoms among Japanese children with cancer.

Psychometric properties of Pediatric Quality of Life multidimensional fatigue scale in Italian paediatric cancer patients: A multicentre cross-sectional study

OBJECTIVE

The original Pediatric Quality of Life-Multidimensional Fatigue Scale (PedsQL-MFS) developed in 2002 in the English language is a frequently used tool in paediatric oncology. It has been translated into several languages, and the aim of this study was to test the psychometric properties of the Italian version of this scale in paediatric patients with cancer.

METHODS

This was a cross-sectional validation multicentre study.

RESULTS

Acceptability was 100% for patients and 99.2% for parents. Confirmatory factor analysis of the three-factor model of the original scale yielded poor fit indices. A three-factor solution was found through exploratory structural equation modelling, with good fit indices. The internal consistency, evaluated through the Cronbach's alpha coefficient, ranged 0.71-0.92 for the total sample, both in the self-report and in the proxy-report questionnaire.

CONCLUSION

The Italian version of the PedsQL-MFS for children and adolescents with cancer shows adequate psychometric characteristics of both the self- and proxy-report. Further research with larger samples is needed ensuring all age groups are appropriately represented.

Analysis of daily energy, protein, fat, and carbohydrate intake in citrin-deficient patients: Towards prevention of adult-onset type II citrullinemia

Patients with citrin deficiency during the adaptation/compensation period exhibit diverse clinical features and have characteristic diet of high protein, high fat, and low carbohydrate. Japanese cuisine typically contains high carbohydrate but evaluation of diet of citrin-deficient patients in 2008 showed a low energy intake and a protein:fat:carbohydrate (PFC) ratio of 19:44:37, which indicates low carbohydrate consumption rate. These findings prompted the need for diet intervention to prevent the adult onset of type II citrullinemia (CTLN2). Since the publication of the report about 10 years ago, patients are generally advised to eat what they wish under active dietary consultation and intervention. In this study, citrin-deficient patients and control subjects living in the same household provided answers to a questionnaire, filled-up a maximum 6-day food diary, and supplied physical data and information on medications if any. To study the effects of the current diet, the survey collected data from 62 patients and 45 controls comparing daily intakes of energy, protein, fat, and carbohydrate. Food analysis showed that patient's energy intake was 115% compared to the Japanese standard. The confidence interval of the PFC ratio of patients was 20-22:47-51:28-32, indicating higher protein, higher fat and lower carbohydrate relative to previous reports. The mean PFC ratio of female patients (22:53:25) was significantly different from that of male patients (20:46:34), which may explain the lower frequency of CTLN2 in females. Comparison of the present data to those published 10 years ago, energy, protein, and fat intakes were significantly higher but the amount of carbohydrate consumption remained the same. Regardless of age, most patients (except for adolescents) consumed 100-200 g/day of carbohydrates, which met the estimated average requirement of 100 g/day for healthy individuals. Finally, patients were generally not overweight and some CTLN2 patients were underweight although their energy intake was higher compared with the control subjects. We speculate that high-energy of a low carbohydrate diet under dietary intervention may help citrin-deficient patients attain normal growth and prevent the onset of CTLN2.

Simple change in logistic procedure improves response rate to QOL assessment: a report from the Japan Children's Cancer Group

Background

Reducing non-completion of quality-of-life assessment in clinical trials is an important challenge in obtaining accurate data and unbiased interpretation of patients’ quality-of-life for each regimen. We evaluated the effect of changing our questionnaire distribution procedure in a multicenter phase II/III trial on the response rate to a quality-of-life questionnaire.

Methods

In the trial, we distributed 1767 questionnaires and 1045 were returned. We adopted a regression discontinuing design and estimated the change in response rate between pre-intervention (quality-of-life questionnaires were sent to each center soon after patient registration) and post-intervention (a set of tailored questionnaires was sent just before the first quality-of-life assessment).

Results

The post-intervention response rate was higher (odds ratio = 1.62) than the pre-intervention response rate.

Conclusions

A simple logistic intervention reduced the non-completion of QOL assessment in this case, suggesting that a simple change can contribute to improving clinical trial accomplishment.

Translation of the Frailty Paradigm from Older Adults to Children with Cardiac Disease

Children and adolescents with cardiac disease (CCD) have significant morbidity and lower quality of life. However, there are no broadly applicable tools similar to the frailty score as described in the elderly, to define functional phenotype in terms of physical capability and psychosocial wellbeing in CCD. The purpose of this study is to investigate the domains of the frailty in CCD. We prospectively recruited CCD (8-17.5 years old, 70% single ventricle, 27% heart failure, 12% pulmonary hypertension; NYHA classes I, II and III) and age and gender matched healthy controls (total n = 56; CCD n = 34, controls n = 22; age 12.6 ± 2.6 years; 39.3% female). We measured the five domains of frailty: slowness, weakness, exhaustion, body composition and physical activity using developmentally appropriate methods. Age and gender-based population norms were used to obtain Z scores and percentiles for each measurement. Two-tailed t-tests were used to compare the two groups. The CCD group performed significantly worse in all five domains of frailty compared to healthy controls. Slowness: 6-min walk test with Z score -3.9 ± 1.3 vs -1.4 ± 1.3, p < 0.001; weakness: handgrip strength percentile 18.9 ± 20.9 vs 57.9 ± 26.0, p < 0.001; exhaustion: multidimensional fatigue scale percentile 63.7 ± 13.5 vs 83.3 ± 14.4, p < 0.001; body composition: height percentile 43.4 ± 29.5 vs 71.4 ± 25.2, p < 0.001, weight percentile 46.0 ± 36.0 vs 70.9 ± 24.3, p = 0.006, BMI percentile 48.4 ± 35.5 vs 66.9 ± 24.2, p = 0.04, triceps skinfold thickness 41.0 ± 24.0 vs 54.4 ± 22.1, p = 0.04; physical activity: pediatric activity questionnaire score 2 ± 0.6 vs 2.7 ± 0.6, p < 0.001. The domains of frailty can be quantified in children using developmentally appropriate methods. CCD differ significantly from controls in all five domains, supporting the concept of quantifying the domains of frailty. Larger longitudinal studies are needed to study frailty in CCD and examine if it predicts adverse health outcomes.Clinical Trial Registration: The ClinicalTrials.gov identification number is NCT02999438. https://clinicaltrials.gov/ct2/show/NCT02999438.

Reliability and validity of the turkish translation of pedsqlTM multidimensional Fatigue scale in Duchenne Muscular Dystrophy

OBJECTIVE

To perform the Turkish translation, reliability, and validity study of the PedsQLTM-3.0 Multidimensional Fatigue Scale (PedsQL-MFS) in patients with Duchenne Muscular Dystrophy (DMD).

METHODS

This prospective, cross-sectional, observational study was held in Hacettepe University, Faculty of Physical Therapy and Rehabilitation between January 2016-August 2018. Turkish translation of the PedsQL-MFS was conducted based on the steps addressed in the translation manual of the original research. The psychometric features of the Turkish version of PedsQL-MFS including feasibility, internal consistency, and test-retest reliability, construct, and criterion-related validity as well as parent/child agreement were investigated on a total of 71 children and their parents.

RESULTS

The mean age of boys with DMD included in the study was 102.94+/-23.23 months with a mean 17.15+/-2.98 BMI. Internal consistencies of Child Self Report General Fatigue, Sleep/rest Fatigue, and Cognitive Fatigue items were 0.74, 0.65, and 0.83 while, 0.89, 0.84, and 0.91 in Parent Proxy Report. The ICC values of Child Self Report and Parent Proxy Report were 0.87 and 0.91, respectively. Parent Proxy Report succeded more acceptable fit indices than Child Self Report. A statistically significant correlation was found between PedsQL-MFS and PedsQL-Neuromuscular Module (p<0.05). Moderate agreement was detected between parent and child.

CONCLUSION

The Turkish version of PedsQL-MFS was determined to be a reliable and valid tool to evaluate fatigue in 5-12 years old, ambulant children with DMD.

Current treatment for citrin deficiency during NICCD and adaptation/compensation stages: Strategy to prevent CTLN2

Identification of the genes responsible for adult-onset type II citrullinemia (CTLN2) and citrin protein function have enhanced our understanding of citrin deficiency. Citrin deficiency is characterized by 1) neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD); 2) adaptation/compensation stage with unique food preference from childhood to adulthood; and 3) CTLN2. The treatment of NICCD aims to prevent the progression of cholestasis, and it includes medium chain triglycerides (MCT) milk and lactose-free milk, in addition to medications (e.g., vitamin K₂, lipid-soluble vitamins and ursodeoxycholic acid). Spontaneous remission around the age of one is common in NICCD, though prolonged cholestasis can lead to irreversible liver failure and may require liver transplantation. The adaptation/compensation stage (after one year of age) is characterized by the various signs and symptoms such as hypoglycemia, fatty liver, easy fatigability, weight loss, and neuropsychiatric symptoms. Some poorly-controlled patients show failure to thrive and dyslipidemia caused by citrin deficiency (FTTDCD). Diet therapy is the key in the adaptation/compensation stage. Protein- and fat-rich diet with a protein: fat: carbohydrate ratio being 15-25%: 40-50%: 30-40% along with the appropriate energy intake is recommended. The use of MCT oil and sodium pyruvate is also effective. The toxicity of carbohydrate is well known in the progression to CTLN2 if the consumption is over a long term or intense. Alcohol can also trigger CTLN2. Continuous intravenous hyperalimentation with high glucose concentration needs to be avoided. Administration of Glyceol® (an osmotic agent containing glycerol and fructose) is contraindicated. Because the intense treatment such as liver transplantation may become necessary to cure CTLN2, the effective preventative treatment during the adaptation/compensation stage is very important. At present, there is no report of a case with patients reported having the onset of CTLN2 who are on the diet therapy and under the appropriate medical support during the adaptation/compensation stage.

Health-related quality of life in Japanese children with acute lymphoblastic leukemia during and after chemotherapy

BACKGROUND

Quality of life (QOL) as a treatment outcome has not yet been evaluated among patients receiving a specific treatment regimen by treatment phase in a consistent manner. This exploratory cross-sectional study evaluated the QOL of children with acute lymphoblastic leukemia (ALL) receiving one of the most popular treatment regimens in Japan (Japan Association of Childhood Leukemia Study ALL-02 revised protocol).

METHODS

Children aged 5-18 years with newly diagnosed B-cell precursor ALL were included. The Pediatric Quality of Life Inventory^™ 4.0 Generic Core Scales (PedsQL-J) were completed by children with ALL and their siblings, as well as by age- and sex-matched healthy controls. PedsQL Cancer Module (PedsQL-C) scores were also collected from children with ALL.

RESULTS

QOL in children with ALL of the consolidation phase group was significantly decreased compared with that of healthy controls, except in the area of emotional functioning. Regarding the maintenance phase group, QOL impairment was noted in the physical and school functioning, but no differences were noted in social functioning. The off-treatment group had a large effect size only for physical functioning, and the social functioning score was even better in children with ALL than in matched controls. QOL of children with ALL differed with treatment phase. Effect size varied with function and treatment phase.

CONCLUSIONS

QOL may change with the progression of treatment, and the timing of these changes varied according to function and problem.

Objective assessment of sleep status and its correlates in hospitalized children with cancer: Exploratory study

BACKGROUND

Children with cancer are known to have sleep problems. Although hospitalization and psychosocial factors are considered to be the factors affecting children's sleep, few studies have confirmed these effects. The aims of this study were to describe the sleep status of hospitalized children with cancer and to explore the correlates.

METHODS

The sleep status of 11 hospitalized children (aged 2-12 years) with cancer was measured using actigraph and sleep diary during hospitalization and a short home stay. Possible correlates were assessed using a questionnaire.

RESULTS

The participants had significantly longer sleep onset latency, earlier bedtime, and poorer self-evaluated sleep quality during hospitalization than the short home stay. They had shorter total sleep time, longer wake time after sleep onset, and less sleep efficiency at home, compared with healthy historical controls. Children's age, symptoms, hospitalization period, Cognitive Fatigue, Procedural Anxiety, Treatment Anxiety, Social Anxiety, and Separation Anxiety, as well as caregiver anxiety, Receptive and Focused Attitude, and Regimented Attitude were significantly correlated with sleep variables.

CONCLUSIONS

Hospitalization decreased self-evaluated sleep quality, and difficulty falling asleep. The sleep of the participants at home was disturbed compared with that of healthy children. Hospitalization, patient characteristics, disease-related, and some psychosocial factors were associated with sleep variables. Medical professionals should develop a favorable environment for falling asleep in hospital for individual children. Children with cancer in the early period of hospitalization need increased care to facilitate good sleep.

Interrelations between siblings and parents in families living with children with cancer

Having a child diagnosed with cancer is a stressful event for the family. This exploratory multimethod study utilized both quantitative and qualitative multiinformant methodologies to investigate the relationships between parental family functioning and siblings' health-related quality of life (HRQOL) and to describe interrelations between the experiences of parents and siblings of children with childhood cancer. A total of 14 Japanese families participated in the quantitative study, and 4 families of the 14 participated in the qualitative study. In-depth, semistructured interviews revealed three family-unit stages during the time course of the ill child's treatment that included particular parent-sibling interrelations. We also found strong correlation between parental family functioning and siblings' HRQOL in the quantitative study. The results suggest the importance of family nursing interventions directed to individual family members and the family unit that focus on strengthening the parent-sibling relationship and supporting families who are experiencing childhood cancer.

High validity and reliability of the PedsQL™ Multidimensional Fatigue Scale for Brazilian children with cancer

Among the main factors that affect patients' quality of life, fatigue is a significant symptom experienced by children during treatment. Despite the high incidence, there has been no validated scale to evaluate fatigue in children with cancer in Brazil. The purpose of this study was to examine the psychometric properties of the PedsQL™ Multidimensional Fatigue Scale, using self-reports of Brazilian children, 8 to 18 years of age, and proxy reports. A cross-sectional method was used to collect data from 216 subjects over an 18-month period. Reliability ranged from .70 to .90 except for sleep/rest fatigue, self-report (α = .55). No floor or ceiling effects were found in any dimension. Convergent validity was higher than .40 and divergent validity had 100% adjustment. The root mean square error of approximation was acceptable. The comparative fit index was lower than expected. The agreement between self and proxy responses was weak and moderate. The results demonstrate the reliability and validity of the Brazilian version in children with cancer. This is the first validated scale that assesses fatigue in Brazilian children and adolescents with cancer.

Fatigue in children with juvenile idiopathic arthritis: reliability of the "Pediatric Quality of Life Inventory-Multidimensional Fatigue Scale"

The aim of the study was (1) to translate the "Pediatric Quality of Life Inventory-Multidimensional Fatigue Scale" (PedsQL-Fatigue) into Brazilian Portuguese language and culture and evaluate its reliability and (2) to measure fatigue among patients with juvenile idiopathic arthritis (JIA): (1) Translation of the PedsQL-Fatigue by two bilingual researchers; (2) Backtranslation into English assessed by the authors of the original version; (3) Pilot study with five patients followed in the Pediatric Rheumatology Outpatient Clinic and their parents; and (4) Field study and assessment of measurement properties (internal consistency, reproducibility, and construct validity). In this stage, the scale was administered to 67 patients with JIA and 63 healthy individuals, aged from 2 to 18 years old, matched by age (from 2 to 4, 5 to 7, 8 to 12, and from 13 to 18 years old). Cronbach's alpha coefficient ranged from 0.6 to 0.8 for children and parents, indicating the instrument's good internal consistency. The scale's construct validity was confirmed by a satisfactory Spearman's coefficient between the PedsQL-Fatigue and the generic PedsQL 4.0 (0.840 for the children and 0.742 for the parents). Reproducibility was also adequate (0.764 for the children and 0.938 for the parents). No differences were found between the scores obtained by the JIA group and control group, though lower scores were observed among patients with clinically active JIA when compared to those without clinical activity. The PedsQL-Fatigue is a valid and reliable tool, and that can be used to measure fatigue among patients with JIA.

PedsQL™ Multidimensional Fatigue Scale in sickle cell disease: feasibility, reliability, and validity

BACKGROUND

Sickle cell disease (SCD) is an inherited blood disorder characterized by a chronic hemolytic anemia that can contribute to fatigue and global cognitive impairment in patients. The study objective was to report on the feasibility, reliability, and validity of the PedsQL™ Multidimensional Fatigue Scale in SCD for pediatric patient self-report ages 5-18 years and parent proxy-report for ages 2-18 years.

PROCEDURE

This was a cross-sectional multi-site study whereby 240 pediatric patients with SCD and 303 parents completed the 18-item PedsQL™ Multidimensional Fatigue Scale. Participants also completed the PedsQL™ 4.0 Generic Core Scales.

RESULTS

The PedsQL™ Multidimensional Fatigue Scale evidenced excellent feasibility, excellent reliability for the Total Scale Scores (patient self-report α = 0.90; parent proxy-report α = 0.95), and acceptable reliability for the three individual scales (patient self-report α = 0.77-0.84; parent proxy-report α = 0.90-0.97). Intercorrelations of the PedsQL™ Multidimensional Fatigue Scale with the PedsQL™ Generic Core Scales were predominantly in the large (≥0.50) range, supporting construct validity. PedsQL™ Multidimensional Fatigue Scale Scores were significantly worse with large effects sizes (≥0.80) for patients with SCD than for a comparison sample of healthy children, supporting known-groups discriminant validity. Confirmatory factor analysis demonstrated an acceptable to excellent model fit in SCD.

CONCLUSIONS

The PedsQL™ Multidimensional Fatigue Scale demonstrated acceptable to excellent measurement properties in SCD. The results demonstrate the relative severity of fatigue symptoms in pediatric patients with SCD, indicating the potential clinical utility of multidimensional assessment of fatigue in patients with SCD in clinical research and practice.

Fatigue and quality of life in citrin deficiency during adaptation and compensation stage

Citrin-deficient children and adolescents between adult-onset type II citrullinemia and neonatal intrahepatic cholestasis by citrin deficiency do not have clear clinical features except for unusual diet of high-fat, high-protein, and low-carbohydrate food. The aims of the present study are to characterize fatigue and quality of life (QOL) in citrin-deficient patients during adaptation and compensation stage, and to define the relationship between fatigue and QOL. The study subjects were 55 citrin-deficient patients aged 1-22years (29 males) and 54 guardians. Fatigue was evaluated by self-reports and proxy-reports of the PedsQL Multidimensional Fatigue Scale. QOL was evaluated by the PedsQL Generic Core Scales. Both scale scores were significantly lower in child self-reports (p<0.01 and p<0.05, respectively) and parent proxy-reports (p<0.01 and p<0.01, respectively) than those of healthy children. Citrin-deficient patients with scores of 50 percentile or less of healthy children constituted 67.5% of the sample for the Fatigue Scale and 68.4% for the Generic Core Scales. The PedsQL Fatigue Scale correlated with the Generic Core Scales for both the patients (r=0.56) and parents reports (r=0.71). Assessments by the patients and their parents showed moderate agreement. Parents assessed the condition of children more favorably than their children. The study identified severe fatigue and impaired QOL in citrin-deficient patients during the silent period, and that such children perceive worse fatigue and poorer QOL than those estimated by their parents. The results stress the need for active involvement of parents and medical staff in the management of citrin-deficient patients during the silent period.

Factorial invariance of pediatric patient self-reported fatigue across age and gender: a multigroup confirmatory factor analysis approach utilizing the PedsQL™ Multidimensional Fatigue Scale

OBJECTIVES

In order to compare multidimensional fatigue research findings across age and gender subpopulations, it is important to demonstrate measurement invariance, that is, that the items from an instrument have equivalent meaning across the groups studied. This study examined the factorial invariance of the 18-item PedsQL™ Multidimensional Fatigue Scale items across age and gender and tested a bifactor model.

METHODS

Multigroup confirmatory factor analysis (MG-CFA) was performed specifying a three-factor model across three age groups (5-7, 8-12, and 13-18 years) and gender. MG-CFA models were proposed in order to compare the factor structure, metric, scalar, and error variance across age groups and gender. The analyses were based on 837 children and adolescents recruited from general pediatric clinics, subspecialty clinics, and hospitals in which children were being seen for well-child checks, mild acute illness, or chronic illness care.

RESULTS

A bifactor model of the items with one general factor influencing all the items and three domain-specific factors representing the General, Sleep/Rest, and Cognitive Fatigue domains fit the data better than oblique factor models. Based on the multiple measures of model fit, configural, metric, and scalar invariance were found for almost all items across the age and gender groups, as was invariance in the factor covariances. The PedsQL™ Multidimensional Fatigue Scale demonstrated strict factorial invariance for child and adolescent self-report across gender and strong factorial invariance across age subpopulations.

CONCLUSIONS

The findings support an equivalent three-factor structure across the age and gender groups studied. Based on these data, it can be concluded that pediatric patients across the groups interpreted the items in a similar manner regardless of their age or gender, supporting the multidimensional factor structure interpretation of the PedsQL™ Multidimensional Fatigue Scale.

Fatigue in survivors of childhood acute lymphoblastic and myeloid leukemia in Japan

BACKGROUND

Fatigue in cancer survivors is a serious problem in pediatric oncology, but reports on this issue are limited, especially in Asian countries.

METHODS

Sixty-three patients with acute lymphoblastic leukemia and 18 patients with acute myeloid leukemia who attended a follow-up outpatient clinic were enrolled. Participants were required to be >8 years of age, in remission, and without any cancer treatment for at least the previous 1 year. A control group consisted of 243 subjects whose age and gender were matched with the patient group. A questionnaire consisting of 12 items was devised for fatigue measurement.

RESULTS

Principal factor analysis identified three dimensions, defined as physical fatigue, decreased function, and altered mood. The mean total and the three fatigue dimension scores tended to be higher in the control group, but significant differences between the scores were seen only in the total and physical fatigue scores. Multiple regression analysis indicated an association of present older age or shorter duration after completion of treatment with total and physical fatigue, and an association of presence of total body irradiation with decreased function.

CONCLUSION

Pediatric leukemia survivors in Japan experience equal or less fatigue compared with that of controls in different fatigue dimensions. Elucidation of underlying mechanisms of cancer-related fatigue including the differences of cultural background among different countries is necessary for future study of this issue.