Psychometric evaluation of Oral Mucositis Daily Questionnaire: A cross-cultural adaptation of the Malay version in multiethnic adult autologous stem cell transplant.

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Introduction

Autologous stem cell transplant (SCT) is considered one of the most important treatment modalities for hematological cancers, with potential for cure. Exposure to high-dose chemotherapy during this procedure predisposes patients to mucositis, which involves both the upper oral and lower gastrointestinal (GI) regions. The former is characterized by erythema, pain and ulceration, 1 whereas the latter is distinguished by ulceration or loss of villi structure and function, manifesting as cramping and/or diarrhea. 2

Malaysia represents a unique multiethnic, multicultural and multilingual Asian country. 3 Among all the complications of SCT, patients viewed mucositis as the single most debilitating complication. 4 Even mild mucositis pain is a cause for serious concern among patients and caregivers. 5 Nonetheless, patients still recorded in their dairies that there was no or only slight pain relief from mucositis pain treatment in a pilot study. 6 These findings could indicate challenges ascribed to culturally-related factors among Asians, distorting pain reporting to healthcare professionals and subsequently affecting pain management. 7

The main focus of studies reporting patient-related outcomes in mucositis has largely focused on the oral region. 8 However, lower GI mucositis is increasingly being recognized as an important toxicity with equally important impact of patient-reported outcomes. 9 Despite that, there is an evident lack of literature especially in the area of transplant, as reflected by paucity of data on the lower GI mucositis. This could present as an obstacle as there is increasing interests to deliver autologous SCT in the outpatient setting. 10 Hence, patient self-assessment, complementary to clinician-based assessment, is imperative as a form of continued evaluation of this procedure outcome. 11

Multiple self-reporting tools for the assessment of mucositis are available. 12 , 13 , 14 The Oral Mucositis Daily Questionnaire (OMDQ) 14 is a patient self-report tool that has been validated in both adult and pediatric populations. 14 , 15 , 16 , 17 , 18 It is a 10-item questionnaire containing quality of life assessment on oral mucositis, diarrhea, and other daily functions such as sleeping and talking. 14 This questionnaire has been translated to other languages, 15 , 19 , 20 indicating its global cultural adaptability and suitability for clinical use. Despite demonstrating adequate validity and reliability, exploratory- and confirmatory factor analyses (EFA and CFA) have not been performed, neither on the original nor translated adaptations of OMDQ. Translations into the Malay language, which is the national language of the country, have also not been performed.

Hence, this research aimed to conduct a cross cultural adaptation of OMDQ into Malay language (OMDQ-Mal) and to evaluate its psychometric properties of validity and reliability which include (1) internal consistency, (2) reproducibility, (3) criterion validity, (4) discriminative validity, and (5) construct validity.

Methods

Patient population

Patients scheduled for autologous SCT between April 2019 and December 2020 at the national hematology center in Malaysia were recruited using convenience sampling and followed-up longitudinally during the period of hospital admission. Inclusion criteria were aged at least 18 years old; diagnosed with hematological cancer; and understand, speak, and write in Malay. Exclusion criteria included oral soreness or erythema, diarrhea, nausea or vomiting during baseline assessment, or mental incapacity. Based on the subject-to-variable ratio of no lower than 5, EFA was conducted in a previous SCT population of 62 samples collected using the same questionnaire (patient characteristics described in Supplementary Table S1 ). For CFA, a minimum sample size of at least 100 participants is generally required, equivalent to a subject-to-variable ratio of 10:1. 21 , 22 Written informed consent was obtained from all individual participants included in this study. Participants were assessed daily from conditioning regimen until discharged. 23

Data collection

Cross-cultural adaptation

The original questionnaire was forward-translated by a bilingual healthcare professional and a nonmedical professional translator whose native languages were Malay. 24 Both translated versions were synthesized to produce a “common forward translation” by both translators and a researcher. The synthesized translation was then back-translated by two nonmedical professional translators who were fluent in English and not involved in the initial translation process. Both documents were compared to the original questionnaire by a bilingual hematology consultant and two researchers, in consultation with the forward- and back-translators. All steps were performed with conceptual equivalence and cultural applicability considered. A final version was reached and cognitive debriefing was pretested in 15 autologous SCT patients who were native speakers of the Malay language. Participants were asked to comment on words and sentences that were difficult to comprehend. A group of five experts fluent in both Malay and English (hematology consultant, nurse, academician, experienced clinical research officer, and pharmacist) assessed the comments and final questionnaire for satisfactory face, operational, conceptual, semantic, and item equivalence as detailed in Herdman's framework. 25

Participant self-assessment

Participants completed the oral mucositis daily questionnaire Malay version (OMDQ-Mal), independently or with the assistance of their caregiver, without intervention from any healthcare professional. Prior to commencement of recording, participants received training on how to fill in the questionnaire. The OMDQ-Mal is a 10-item tool consisting of overall health (one question), mouth and throat soreness (MTS) (two questions), effects of MTS pain on functional states (five questions), and diarrhea (two questions) status. Identical to the original questionnaire, worsening conditions were graded with higher scores, except for the overall health status question, which was on an inverse scale. 14

Healthcare practitioner assessments

Trained healthcare professionals accessed participant's oral mucosa according to the World Health Organization (WHO) Oral Toxicity Scale 1 and diarrhea status (as one of a surrogate indicator of lower GI mucositis) according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5. 26 Interrater agreement between assessors met minimum set criteria of 0.80 using a mean rating, absolute agreement, two-way mixed model intraclass correlation coefficient (ICC). 27 The WHO and CTCAE scales are among the most widely utilized and current standards for grading of treatment-related adverse effects. The WHO scale consists of five grades, describing the progressive extent of mouth ulcers, erythema, pain and soreness, as well as oral intake, whereas the CTCAE scales consists of six grades, ranging from Grade 0 (none) to Grade 5 (death-related to adverse event).

Data analysis

Internal consistency reliability within the questions were determined by Cronbach alpha. Interitem correlation matrix values of 0.70–0.95 and a corrected item–total correlation of > 0.3 were accepted as good measures for internal consistency. 28

Reproducibility was demonstrated by using ICC to determine the test–retest reliability between paired days 0 and 1, and days 7 and 8 for each OMDQ-Mal question. Those days were chosen as it represented the least day-to-day variation among participants, who were discharged at a median (interquartile range, IQR) of 11 (10–13) days post-transplant. ICC estimates and their 95% confidence intervals were calculated using a mean rating, absolute agreement, two-way mixed model. Based on the 95% confident interval of the ICC estimate, a moderate reliability of > 0.50 was accepted as satisfactory. 27

Spearman correlation was employed for criterion validity to correlate the ordinal scores of daily corresponding MTS-related questions with WHO oral mucositis scores, and diarrhea-related questions with CTCAE diarrhea scores. We hypothesized a priori that items in OMDQ-Mal would have at least have a moderate correlation of > 0.50 with other measures of mucositis. 18 , 43

Discriminative validity was determined by comparing the MTS-related scores between participants with mild (WHO grade 1–2) and severe mucositis (WHO grade 3–4) using the Mann–Whitney U test for ordinal data on day+6. Similarly, diarrhea-related scores between participants with mild (CTCAE grade 1–2) and severe diarrhea (CTCAE grade 3–5) were compared. Day+6 was chosen as it represented the midpoint between the mean onset and resolution of mucositis. A medium effect size of > 0.3 was accepted as satisfactory. 29

Construct validity was assessed using EFA and CFA. The Kaiser–Meyer–Olkin (KMO) > 0.6 and a statistically significant ( P < 0.05) Bartlett's test of sphericity were accepted as adequate correlation among the items for the possibility of EFA. 30 The extraction method used was principal component analysis, and rotation method was varimax with Kaiser normalization. An initial eigen value > 1 as criterion for factor extractions, and factor loadings > 0.4 as a practically significant loading were selected. 31 CFA was determined with the partial least squares structural equation modeling (PLS-SEM). 32 Loading factors (LF) > 0.5, composite reliability (CR) > 0.7, and average variant extracted (AVE) ≥ 0.5 were indicative of adequate convergent validity. 33 Heterotrait–monotrait ratio (HTMT) < 0.85, and Fornell–Larcker criterion (FLC) demonstrating a higher value than its correlation with another construct, were indicative of adequate divergent validity. 34 , 35

Overall health scores were reversed, to align to higher values reflecting worsening condition, for the purpose of statistical analyses. Missing data were excluded from the analysis. SPSS version 24 (IBM Corp., Armonk, New York) was employed for statistical analyses, and SmartPLS 3 version 3.3.3 (SmartPLS GmbH, Boenningstedt) was employed for CFA. 35

Results

Table 1 shows the demographic and clinical characteristics of participants. A total of 142 participants were screened pretransplant, where a total of 114 participants who completed the OMDQ-Mal were assessed (15 did not meet inclusion criteria, 10 did not consent, and 3 diaries were untraceable). Participant's age ranged from 19 to 65 years old (40.6 ​± ​13.6) and 50.0% were males, with Malay ethnicity forming the majority of participants (70.2%). The Malay language is the national language and was understood by all participants independent of their ethnic background. Participants who experienced oral mucositis were 67.5% and 66.7% by physician and participant self-reported scores, respectively, whereas participants who experienced diarrhea were 98.2% and 82.5% by physician and participant self-reported scores, respectively.

Cross-cultural adaptation

Pretesting in a variable age group of participants revealed adequate comprehension of the OMDQ-Mal. All participants found that the language was generally easily understood and the layout was orderly. The questionnaire format, instructions, mode of administration, time requirement and measurement methods were acceptable to the participants. The expert group discussed comments and unclear items identified by the participants. Final adjustments were made based on the subjective judgment of the expert group. The expert group ascertained that the final version of OMQD-Mal was conceptually and culturally suitable for the intended population.

Internal consistency reliability

Overall Cronbach alpha indicated an acceptable reliability (α ​= ​0.874). Table 2 shows the corrected item–total correlation and Cronbach alpha if item is deleted for each item. The corrected item–total correlation values were above 0.3 and ranged between 0.476 and 0.832. Cronbach alpha for most items decreased if an item was deleted, indicating their relevance to the questionnaire, except for the overall health and overall diarrhea item which would increase the alpha to α ​= ​0.891 and α ​= ​0.877, respectively. Interitem correlation matrix among MTS-related items ranged from α ​= ​0.708 to 0.928, and between diarrhea past 24 hours and overall diarrhea was α ​= ​0.915 ( Supplementary Table S2 ).

Test–retest reliability (reproducibility)

Based on the 95% confident interval of the ICC estimate, test–retest reliability results between paired days were moderate to excellent and ranged between 0.676 and 0.953 ( Supplementary Table S3 ).

Criterion validity

Table 3 shows that all MTS items and diarrhea questions in OMDQ-Mal had a significantly moderate to strong correlation with the WHO oral mucositis (0.503–0.721) and CTCAE diarrhea scores (0.652–0.654), respectively.

Discriminative validity

Discriminative validity by the Mann–Whitney U test is shown in Supplementary Table S4 . It is demonstrated that the participant-reported scores were significantly distinct between the groups with mild and severe conditions (ie., mucositis and diarrhea), where the mean rank values were significantly higher in the severe groups. Effect sizes were medium for all items (0.30–0.45).

Construct validity

EFA was conducted based on Bartlett's test of sphericity (χ 2 ​= ​19,967, P ​< ​0.001) and KMO ​= ​0.888. Two principal components were extracted and accounted for 81.8% of the cumulative variance. The first compartment comprised of all the MTS items (7 items; loading ​= ​0.851–0.938), whereas the second component comprised of all the diarrhea items and overall health (diarrhea-overall health) (3 items; loading ​= ​0.526–0.952).

As illustrated in Fig. 1 , CFA of the two-compartment model was conducted and indicated that the LF ranged from 0.868 to 0.952 for MTS and from 0.708 to 0.904 for diarrhea-overall health items. CR and AVE were above the minimal threshold for both MTS (CR ​= ​0.974, AVE ​= ​0.841) and diarrhea-overall health (CR ​= ​0.879, AVE ​= ​0.710) items. The results revealed that convergent validity and construct reliability existed within the constructs of this study.

Adequate divergent validity was established, as demonstrated by the HTMT ratio between the MTS with diarrhea-overall health constructs (0.528). FLC indicated that the diarrhea-overall health construct (0.843) was discriminant from the MTS (0.467) constructs. Supplementary Table S5 shows that all the factor loadings are greater than the cross loadings among items within the OMDQ-Mal.

Discussion

This study provides a patient self-assessed mucositis tool in the Malay language, which is the national language of multiethnic, multicultural Malaysia, and also spoken worldwide. 3 In this study, we found that OMDQ-Mal exhibited conceptual and cultural equivalence to the original version. Psychometric analysis demonstrated acceptable internal consistency, test–retest reliability, criterion validity, and discriminative validity. To the best of our knowledge this is the first study correlating diarrhea items in the OMDQ with physician-scored diarrhea assessment. This is also the first study performing a PLS-SEM CFA on the OMDQ-Mal. The hypothesized two-component measurement model demonstrated construct validity exhibited by adequate convergent and divergent validity.

All items in the OMDQ-Mal met the minimum acceptable criteria for internal consistency as demonstrated by the corrected item–total correlation. When comparing the interitem correlation matrix, the “diarrhea past 24 ​hours” item was found to be highly correlated with “overall diarrhea” (α ​= ​0.915) ( Supplementary Table S2 ), similar to the Korean and English versions 14 , 19 despite differing statistical tests employed in the latter. This correlation value was still within our predefined threshold of α ​= ​0.70–0.95. However, a more conservative cutoff of α ​= ​0.90 has been proposed by other authors. 36 A very high correlation should be interpreted with caution, as it could signify minor wording variants between each item rather than being truly representative measures of the constructs it represents. 37 Contrary to MTS items, the “overall diarrhea” item had a slight improvement in Cronbach alpha if this item was deleted, suggesting that this item or the suitability of its translation could be reconsidered.

Similar to prior publications, 14 , 15 , 17 reproducibility measures indicated that the OMDQ-Mal yielded adequately consistent results over time, with little external, psychological, and methodological influence, and suggests that it is appropriate for use to capture quality of life measures in studies such as in SCT to investigate longitudinal outcomes.

Research into mucositis often addresses oral and lower GI mucositis separately, and the issues are rarely investigated in its entirety. 38 Distinct from prior publication where all items in the OMDQ were compared to physician-scored mucositis of the oral region, 17 , 18 comparison of the diarrhea items in OMDQ-Mal with physician-scored CTCAE diarrhea which was undertaken in this study showed moderate to strong correlation. Exploring the diarrhea component of OMDQ-Mal as a surrogate indicator for GI mucositis allows for a step toward more comprehensive assessment of mucositis of the entire alimentary tract. The good correlation between OMDQ-Mal items with physician scores in this study provides strong justification for the use of this tool as a patient-reported outcome measure even in the out-patient setting, circumventing the need to involve healthcare professionals in this process.

Discriminative validity was demonstrated in MTS items between two contrasting groups of WHO graded oral mucositis severity, in agreement with the original author of the questionnaire. 14 Similarly, this was also demonstrated by other authors although participants were segregated according to patient-reported oral mucositis severity. 15 The performance of the diarrhea component to discriminate between two contrasting groups of severity according to physician diarrhea scores further supports the use of OMDQ-Mal to assess this symptom.

EFA indicated that the questionnaire belonged to two components, and was verified by CFA. Interestingly, overall health was found to be in the same domain as diarrhea items. While this observation might be context specific, it does provide insights that any attempt to mitigate the symptoms of diarrhea in this patient population could have significant impact on improving overall quality of life.

This study provides a patient self-assessed mucositis tool in the Malay language, which gives a voice to the majority of the population in the country. This language is used by 13.5 and 19 million people in the country and worldwide, respectively. 3 The strong correlation of OMDQ-Mal items with physician scores indicate support for the use of this tool as a patient self-reported outcome measure, independent of healthcare professional assessment in this multiethnic, multicultural population. This is significant in an Asian population, where cultural barriers in communication about pain with healthcare professionals are more prominent compared to Western populations. 39 The use of patient self-assessment tools in replacement of healthcare professional assessments would allow for reoptimization of time spent by nurses and physicians in the overall healthcare management of patients. Furthermore, in circumstances where direct assessment is unfeasible such as with the increasing interest to deliver autologous SCT as an outpatient service, patients can confidently take up the shared responsibility in the assessment of oral and GI mucositis. This would preclude the need for intensive nursing monitoring of oral and GI mucositis, and enable monitoring to be done remotely. The use of an objective scale would also increase the clarity of communication between nursing staff and patients.

The study utilized EFA and a structural equation modeling for CFA, which have not been published to the best of our knowledge. The information obtained highlights cultural differences in our population where diarrhea was found to be in the same component as overall health. This emphasizes patient's viewpoint on the high significance of diarrhea side effects on their overall quality of life. Hence, future studies interrogating patient's well-being in autologous SCT should include the diarrhea component as an integral aspect in the perceived quality of life.

Additionally, this study substantiates the use of OMDQ-Mal as a potential comprehensive tool for mucositis assessment of the entire alimentary tract. Allowing patients to self-report their condition enables them to be included as a contributing “expert” in their treatment, and be potentially involved in healthcare decision making that aligns with their values. 40 The results obtained also serve as a basis for further research into oral and GI mucositis in other high-risk mucositis conditions such as in the use of total body irradiation, where mucosal injury follows a different pathophysiology of damage in contrast to chemotherapy insult. 41 Future research on adequacy of pain control and diarrhea management, as well as quality-of-life studies, could also draw baseline information from this current work.

Limitations and recommendation

There were several limitations to the study. First, this study was conducted at a single center. However, being the national hematology referral center, participants recruited were from nationwide referrals. Thus, the disadvantages of poor generalizability from recruitment at a single center were minimized. Furthermore, this study was conducted in a real-world setting, increasing its generalizability in the autologous stem cell setting elsewhere. Second, although both participant and healthcare professional scales were employed, the results were still exposed to experimental bias. To minimize response bias, emphasis on the importance of honest documentation reflecting genuine viewpoint was relayed to participants prior to diary recording and intermittently during the study period. Furthermore, intensive longitudinal methods employed in this research with daily follow ups enabled the study of intra- and interindividual changes while minimizing recall bias and provide real-world data. 42

Conclusions

In conclusion, the results of this study demonstrated that the OMDQ-Mal questionnaire was a valid and reliable two-component model instrument for the assessment of both oral and GI mucositis (diarrhea) in individuals undergoing autologous SCT in a multiethnic, multicultural population.

Acknowledgments

The authors would like to thank all the staffs of the Haematology Department, Hospital Ampang, and Immunotherapeutics Laboratory, Universiti Malaya for their invaluable contribution towards this project. We would like to thank the Director General of Health Malaysia for his permission to publish this article.

Footnotes

Supplementary data to this article can be found online at https://doi.org/10.1016/j.apjon.2022.100180

CRediT author statement

Shu Ping Wong: Conceptualization, Methodology, Formal analysis, Visualization, Writing – Original draft, Funding acquisition. Sen Mui Tan: Resources, Review and Editing. Mahmoud Danaee: Methodology, Formal analysis, Visualization. Khairunnajwa Muhamad: Investigation, Data curation. Munirah Jamal: Investigation, Data curation. Farida Islahudin: Validation, Supervision. Faizah Khairudin: Investigation, Data curation. Syed Carlo Edmund: Investigation, Data curation. Kian Meng Chang: Resources, Supervision, Validation. Muhd Zanapiah Zakaria: Validation, Supervision. Yvonne Ai Lian Lim: Writing – Review and editing, Funding acquisition. Reena Rajasuriar: Writing - Review and editing, Funding acquisition. All authors had full access to all the data in the study, and the corresponding author had final responsibility for the decision to submit for publication. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.

Declaration of competing interest

The authors declare that they have no conflicts of interest.

Funding

This work was supported by Research and Technical Support, Ministry of Health Malaysia (Grant No. NMRR-18-2946-44954); and the Malaysian Society of Haematology (Grant No. 2019-005). The funders had no role in the study design, data acquisition, analysis, report writing, and/or decision to submit the article for publication. All authors were not precluded from accessing data in the study, and they accept responsibility to submit for publication.

Ethics statement

The questionnaire and methods of the study was approved by the Medical Research and Ethics Committee, Ministry of Health Malaysia (IRB No. NMRR-18-2946-44954). All procedures were performed in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. All participants provided written informed consent.

Data availability ​statement

The data that support the findings of this study are available from the corresponding author, RR, upon reasonable request.

Supplementary data

The following are the supplementary data to this article.

Multimedia component 1

References

1. World Health Organization (WHO) World Health Organization; Geneva: 1979. WHO Handbook for Reporting Results of Cancer Treatment.

2. Keefe D.M.K. Gastrointestinal mucositis: a new biological model. Support Care Cancer. 2004;12(1):6–9. doi: 10.1007/s00520-003-0550-9.

3. Eberhard D.M., Simons G.F., Fennig C.D. Ethnologue: languages of the world. Ethnologue. 2021. https://www.ethnologue.com/country/MY

4. Bellm L.A., Epstein J.B., Rose-Ped A., Martin P., Fuchs H.J. Patient reports of complications of bone marrow transplantation. Support Care Cancer. 2000;8(1):33–39. doi: 10.1007/s005209900095.

5. Ethier M.C., Regier D.A., Tomlinson D., et al. Perspectives toward oral mucositis prevention from parents and health care professionals in pediatric cancer. Support Care Cancer. 2012;20(8):1771–1777. doi: 10.1007/s00520-011-1274-x.

6. Wong S.P., Islahudin F. A pilot study on effectiveness of oral mucositis pain control in hematopoietic stem cell transplant patients. J Appl Pharmaceut Sci. 2019;9(3):27–32. doi: 10.7324/JAPS.2019.90305.

7. Institute of Medicine . The National Academics Press; Washington, DC: 2011. Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research.

8. Bowen J.M., Wardill H.R. Advances in the understanding and management of mucositis during stem cell transplantation. Curr Opin Support Palliat Care. 2017;11(4):341–346. doi: 10.1097/SPC.0000000000000310.

9. Bowen J.M., Gibson R.J., Coller J.K., et al. Systematic review of agents for the management of cancer treatment-related gastrointestinal mucositis and clinical practice guidelines. Support Care Cancer. 2019;27(10):4011–4022. doi: 10.1007/s00520-019-04892-0.

10. Khouri J., Majhail N.S. Advances in delivery of ambulatory autologous stem cell transplantation for multiple myeloma. Curr Opin Support Palliat Care. 2017;11(4):361–365. doi: 10.1097/SPC.0000000000000305.

11. Quinn B., Potting C.M.J., Stone R., et al. Guidelines for the assessment of oral mucositis in adult chemotherapy, radiotherapy and haematopoietic stem cell transplant patients. Eur J Cancer. 2008;44(1):61–72. doi: 10.1016/j.ejca.2007.09.014.

12. Cheng K.K.F., Leung S.F., Thompson D.R., et al. New measure of health-related quality of life for patients with oropharyngeal mucositis: development and preliminary psychometric evaluation. Cancer. 2007;109(12):2590–2599. doi: 10.1002/cncr.22730.

13. Kushner J.A., Lawrence H.P., Shoval I., et al. Development and validation of a patient-reported oral mucositis symptom (PROMS) scale. J Can Dent Assoc. 2008;74(1) 59-59j PMID: 18298885.

14. Stiff P.J., Erder H., Bensinger W.I., et al. Reliability and validity of a patient self-administered daily questionnaire to assess impact of oral mucositis (OM) on pain and daily functioning in patients undergoing autologous hematopoietic stem cell transplantation (HSCT) Bone Marrow Transplant. 2006;37(4):393–401. doi: 10.1038/sj.bmt.1705250.

15. Cheng K.K.F., Ip W.Y., Lee V., Li C.H., Yuen H.L., Epstein J.B. Measuring oral mucositis of pediatric patients with cancer: a psychometric evaluation of Chinese version of the Oral Mucositis Daily Questionnaire. Asia Pac J Oncol Nurs. 2017;4(4):330–335. doi: 10.4103/apjon.apjon_39_17.

16. Elting L.S., Keefe D.M., Sonis S.T., et al. Patient-reported measurements of oral mucositis in head and neck cancer patients treated with radiotherapy with or without chemotherapy: demonstration of increased frequency, severity, resistance to palliation, and impact on quality of life. Cancer. 2008;113(10):2704–2713. doi: 10.1002/cncr.23898.

17. Manji A., Tomlinson D., Ethier M.C., Gassas A., Maloney A.M., Sung L. Psychometric properties of the Oral Mucositis Daily Questionnaire for child self-report and importance of mucositis in children treated with chemotherapy. Support Care Cancer. 2012;20(6):1251–1258. doi: 10.1007/s00520-011-1211-z.

18. Tomlinson D., Ethier M.C., Judd P., et al. Reliability and construct validity of the oral mucositis daily questionnaire in children with cancer. Eur J Cancer. 2011;47(3):383–388. doi: 10.1016/j.ejca.2010.09.018.

19. Choi S.E., Kim H.S. Reliability and validity of patient self-reported daily questionnaire on oral mucositis in acute leukemic patients under chemotherapy. J Korean Biol Nurs Sci. 2010;12(3):148–156. https://www.koreascience.or.kr/article/JAKO201016450253353.page

20. Kamulegeya A., Nakanjako D., Orem J., Kizza H. Translation and determination of the comprehensibility of a Luganda version of oral mucositis daily questionnaire. East Afr Med J. 2021;98(3):3599–3607. https://www.researchgate.net/publication/352056493_Translation_and_determination_of_the_comprehensibility_of_a_Luganda_version_of_oral_mucositis_daily_questionnaire

21. MacCallum R.C., Widaman K.F., Zhang S., Hong S. Sample size in factor analysis. Psychol Methods. 1999;4(1):84–99. doi: 10.1037/1082-989X.4.1.84.

22. Arrindell W.A., van der Ende J. An empirical test of the utility of the observations-to-variables ratio in factor and components analysis. Appl Psychol Meas. 1985;9(2):165–178. doi: 10.1177/014662168500900205.

23. Vagliano L., Feraut C., Gobetto G., et al. Incidence and severity of oral mucositis in patients undergoing haematopoietic SCT-results of a multicentre study. Bone Marrow Transplant. 2011;46(5):727–732. doi: 10.1038/bmt.2010.184.

24. Beaton D.E., Bombardier C., Guillemin F., Ferraz M.B. Guidelines for the process of cross-cultural adaptation of self-report measures. Spine. 2000;25(24):3186–3191. doi: 10.1097/00007632-200012150-00014.

25. Herdman M., Fox-Rushby J., Badia X. A model of equivalence in the cultural adaptation of HRQoL instruments: the universalist approach. Qual Life Res. 1998;7(4):323–335. doi: 10.1023/a:1024985930536. PMID: 9610216.

26. U.S. Department of Health and Human Services . 2017. Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0. https://ctep.cancer.gov/protocolDevelopment/electronic_applications/docs/CTCAE_v5_Quick_Reference_5x7.pdf November 2017.

27. Koo T.K., Li M.Y. A guideline of selecting and reporting intraclass correlation coefficients for reliability research. J Chiropr Med. 2016;15(2):155–163. doi: 10.1016/j.jcm.2016.02.012.

28. Terwee C.B., Bot S.D.M., de Boer M.R., et al. Quality criteria were proposed for measurement properties of health status questionnaires. J Clin Epidemiol. 2007;60(1):34–42. doi: 10.1016/j.jclinepi.2006.03.012.

29. Cohen J. 2nd ed. Lawrence Erlbaum Associates; Hillsdale, New York: 1988. Statistical Power Analysis for the Behavioral Sciences.

30. Field A. Discovering Statistics Using IBM SPSS Statistics. 5th ed. SAGE Publications; Thousand Oaks, CA: 2017.

31. Osborne J.W. CreateSpace Independent Publishing; Scotts Valley, CA: 2014. Best Practices in Exploratory Factor Analysis.

32. de Vet H.C.W., Adèr H.J., Terwee C.B., Pouwer F. Are factor analytical techniques used appropriately in the validation of health status questionnaires? A systematic review on the quality of factor analysis of the SF-36. Qual Life Res. 2005;14(5):1203–1218. doi: 10.1007/s11136-004-5742-3.

33. Hoyle R.H., editor. Structural Equation Modeling: Concepts, Issues, and Applications. Sage Publications; Thousand Oaks: 1995.

34. Henseler J., Ringle C.M., Sarstedt M. A new criterion for assessing discriminant validity in variance-based structural equation modeling. J Acad Market Sci. 2015;43(1):115–135. doi: 10.1007/s11747-014-0403-8.

35. Ringle C.M., Wende S., Becker J.M. 2015. SmartPLS 3. http://www.smartpls.com

36. Nunnally J.C., Bernstein I.H. 3rd ed. McGraw-Hill; New York: 1994. Psychometric Theory.

37. Garson G.D. Statistical Associates Publisher; North Carolina: 2016. Partial Least Squares: Regression and Structural Equation Models. Asheboro.

38. Keefe D.M.K., Gibson R.J., Hauer-Jensen M. Gastrointestinal mucositis. Semin Oncol Nurs. 2004;20(1):38–47. doi: 10.1053/j.soncn.2003.10.007.

39. Chen C.H., Tang S.T., Chen C.H. Meta-analysis of cultural differences in Western and Asian patient-perceived barriers to managing cancer pain. Palliat Med. 2012;26(3):206–221. doi: 10.1177/0269216311402711.

40. Wickramasekera N., Taylor S.K., Lumley E., Gray T., Wilson E., Radley S. Can electronic assessment tools improve the process of shared decision-making? A systematic review. Health Inf Manag J. 2020:1–15. doi: 10.1177/1833358320954385.

41. Pearlman R., Hanna R., Burmeister J., Abrams J., Dominello M. Adverse effects of total body irradiation: a two-decade, single institution analysis. Adv Radiat Oncol. 2021;6(4):1–11. doi: 10.1016/j.adro.2021.100723.

42. Bolger N., Laurenceau J.P. Guilford Press; 2013. Intensive Longitudinal Methods: An Introduction to Diary and Experience Sampling Research.

43. Colton T. 1st ed. Little, Brown and Company; Boston: 1974. Statistics in Medicine.

Associated Data

Supplementary Materials

Multimedia component 1

Data Availability Statement

The data that support the findings of this study are available from the corresponding author, RR, upon reasonable request.