Cross-Cultural Adaptation and Validation of European Organization for Research and Treatment of Cancer Quality of Life Questionnaire – Oral Health 15 into Hindi Version for Cancer Patients

INTRODUCTION

As a leading cause of death globally, cancer presents a significant challenge to increasing life expectancy worldwide.^[1] In 2018, the World Health Organization estimated that cancer was responsible for 9.6 million deaths, accounting for approximately 1 in 6 deaths globally. Low- and middle-income countries, like India, face greater challenges due to limited healthcare access and low health insurance coverage.^[2] The GLOBOCAN 2022 data indicated 20 million new cases of cancer alongside 9.7 million deaths, with projections of 35 million new cases of cancer by 2050.^[3]

Cancer patients often experience numerous and severe oral health issues, including xerostomia, altered salivary flow, taste abnormalities, caries, infections, jaw pain, mucosal inflammation, ulceration, candidiasis and bleeding.^[4,5] These complications significantly affect their quality of life (QoL), with oral complications expected in 40–70% of cancer patients due to the disease or its treatment.^[6] Although well-researched in head and neck cancer patients, oral health issues are often underreported in patients with other malignancies, leading to insufficient symptom management and reduced QoL.^[7]

The multifaceted concept of QoL is increasingly crucial in cancer treatment and research, encompassing the physical, mental and social impacts of cancer therapy.^[8] Patient-reported QoL outcomes are essential in cancer care due to the various symptoms and functional limitations patients experience, such as activity restrictions, dietary changes and altered relationships.^[9] The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-C30 is a widely used, valid and comprehensive QoL measure for cancer patients, developed by the European Organisation for Research and Treatment of Cancer (EORTC).^[9-11] The quality of life questionnaire oral health15 (QLQ-OH15) module, used alongside the core QLQ-C30, focuses on oral health issues affecting QoL in cancer patients.^[12]

Adapting existing tools culturally, rather than creating new ones, offers numerous advantages, such as standardsed measures and cross-cultural comparability.^[10] In India, the cross-cultural adaptation of the EORTC QLQ-OH-15 has not yet been undertaken, highlighting the need for this research to translate and adapt the questionnaire into Hindi, ensuring its reliability and validity for Indian cancer patients.

MATERIALS AND METHODS

The cross-cultural adaptation and validation of the EORTC QLQ-OH-15 questionnaire were conducted among patients with heterogeneous cancer at the Radiotherapy Department, J Awaharlal Nehru Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, India, from June 2019 to May 2021. Permission for adaptation and translation was obtained from the EORTC QLQ group, and ethical clearance was obtained from the Institutional Ethical Review Board, Faculty of Medicine, Aligarh Muslim University, Aligarh. Permission was obtained from the respective authorities of the Department of Radiotherapy, Aligarh. Patients who agreed to participate in the research provided informed consent.

RESULTS

Initially, 161 cancer patients were evaluated to see if they qualified for the trial. A total of 147 patients who fulfilled the eligibility requirements were extended an invitation to take part, and 140 of them were accepted, yielding a 95.23% response rate. Only two patients marked samvedansheelata (sensitivity) as confusing or difficult to answer. Therefore, the final version of the questionnaire was left unchanged. The raw data obtained from the study were compiled, tabulated and subjected to statistical analysis.

The data were not normally distributed, as indicated by statistically significant findings (P < 0.01) from the Kolmogorov–Smirnov and Shapiro–Wilk tests. As per Lawshe’s 1975 study on content validity ratio, the initial items of the measure yielded agreement ratings higher than the suggested threshold of 0.75. Satisfactory internal consistency was indicated by the overall scale score of 0.75, which varied from 0.71 for soreness to 0.86 for pain and discomfort. The ICC estimates varied from 0.731 for soreness to 0.959 for pain and discomfort indicating high reliability. Details of reliability statistics are provided in Table 1.

An additional assessment of construct validity was conducted using EFA. Details of factor analysis are provided in Table 2. The sample size used for the validation was sufficient (140), as indicated by the Kayser–Meyer–Olkin measure of sampling adequacy (0.717), and Bartlett’s test of sphericity showed that the correlation matrix differed from an identity matrix (P < 0.001), indicating the factorability of the correlation matrix. The majority of the values in the correlation matrix were more than 0.3, indicating that factor analysis was appropriate. Five factors outperformed Eigenvalue by more than one, according to the results, and 74.86% of the variation was explained collectively. To make their interpretation easier, a rotational solution was then produced, and only loading factors >0.40 were deemed significant in accordance with sample size requirements. The parameters had loaded to five factors with substantial coefficients when looking at the component matrix. Since all six items were substantially correlated with the first factor – pain and discomfort – the scale has been called the ‘Pain and discomfort’ scale. The ‘Information’ scale comprised two items entered into the second component, while the ‘Soreness’ scale comprised two items loaded into the third element. The ‘Denture’ scale comprised two components that were loaded into the fourth factor. Three parameters loaded to the fifth factor named ‘Xerostomia’. The EORTC committee recommended a linear transformation for symptom scales and items, which was applied to the scores to convert them to a 0–100 scale. Greater ratings demonstrated a greater number of problems or symptoms.

All of the scaling predictions have been verified by multi-trait scaling analysis. Details of the same are provided in Table 3. Every item in every scale had its item convergent validity validated; all values were over 0.4 and there were no scaling mistakes observed. Queries Have you had gum pain? Have you experienced gum bleeding? Have you experienced dental issues? Have you experienced oral soreness? Has food and drink caused any sensitivity in your mouth? Have you had unusual tastes for food or drink? All these were connected with the subscale of pain and discomfort.

The queries have you heard anything concerning potential oral or dental issues? And how satisfied were you with the quantity of information you were given on potential oral or dental issues? Had a correlation with the subscale of information. Queries did you ever get lip sores? And do you have any history of mouth sores in the corners? Were associated with the subscale of soreness. Queries have you ever worn dentures? Do you have any history of denture fitting issues? Were associated with the subscale for dentures. Queries Has your mouth felt dry? Did you ever have sticky saliva? and Do you have any trouble consuming solid food? Had a correlation with the subscale of xerostomia. They were all statistically significant correlations.

All of the items’ correlation coefficients for the other scales were lower than their own scales, indicating discriminant validity.

There were statistically significant associations between Hindi EORTC QLQ-OH15 scores and three proxy measures: Perceived oral health (P = 0.000), perceived satisfaction with the mouth (P = 0.000) and perceived dental treatment need (P = 0.001).

Details of criteria validity are provided in Table 4. The findings showed that oral health-related quality of life (OHRQoL) was considerably higher in patients who reported better oral well-being and were satisfied with their mouth than in patients who reported poor oral health and mouth dissatisfaction (P < 0.01). Individuals who felt they needed dental care had significantly lower overall OHRQoL contrasted to others who did not feel they needed any care (P < 0.01).

DISCUSSION

Cancer prognosis traditionally relies on survival rates and disease-free life expectancy, but assessing health-related quality of life (HRQOL) is increasingly crucial, impacting work, psychological well-being and social interactions.^[14,15] Cancer treatments often detrimentally affect oral health, with 40–70% of patients experiencing issues such as mucositis, dental problems and pain, which significantly affect QoL.^[16,17]

In developing countries like India, HRQOL research is sparse due to literacy and poverty challenges, complicating QoL assessment. Most QoL questionnaires are not culturally adapted for India’s diverse population. The EORTC QLQOH15 module was translated into Hindi to assess its feasibility and psychometric properties for Indian cancer patients, representing its first validation in this context. Successful validation would facilitate nationwide multicentric research, enhancing the evaluation of OHRQOL in Indian cancer patients.

Translating the validated EORTC QLQ-OH15 into Hindi was efficient and aligned with EORTC guidelines, benefiting from widespread English proficiency in India. A pilot test involving 15 patients confirmed the acceptability of the translated version, which was approved by the EORTC QoL group’s translation office.^[13]

CONCLUSION

The Hindi version of the QLQ-OH15 questionnaire, adapted for use in Indian cancer patients, proves to be a valid and reliable tool for evaluating OHRQoL. It effectively captures differences in QoL among various demographic and clinical groups, highlighting its utility in clinical practice and research. The study underscores the importance of integrating QoL assessments into multidisciplinary patient care to improve therapeutic outcomes and mitigate oral side effects associated with cancer treatments. This validated tool now supports future clinical investigations and multicentric research endeavours aimed at enhancing cancer patient care in India.