Translation and Validation of the Khasi version of European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C-30) and Oesophageal Cancer module (EORTC QLQ-OES-18)

INTRODUCTION

Oesophageal carcinoma (OC) is the seventh most prevalent malignancy worldwide and sixth in terms of cancer-related mortality.^[1] OC is the fifth most prevalent malignancy in India and fifth in terms of cancer-related mortality according to Global Cancer Observatory (GLOBOCAN) 2020.^[2] OC is characterised by poor prognosis, a significant reduction in Quality of Life (QoL) and requirement for morbid treatment with a 5-year overall survival rate rarely exceeding 40%.^[3] The highest age-adjusted rate of OC incidence in India was seen in the East Khasi Hills district of Meghalaya [75.4/100000 men], being 10 times the national average, according to the data from the Population-based Cancer Registry, National Centre for Disease Informatics and Research, and Indian Council of Medical Research.^[4,5]

OC in India commonly presents in the locally advanced stage, wherein neoadjuvant therapy followed by surgery is the mainstay of treatment. The alternative is chemoradiation; however, there have been few studies directly comparing these two multimodal treatment options. Since both are associated with significant morbidity and mortality, patient-reported outcomes are important in clinical decision-making for patients and their treating physicians alike.^[6] Mauer et al. and Gotay et al. in their studies demonstrated that combining QoL scores with clinical outcomes may enhance survival prediction.^[7,8]

The European Organisation for Research and Treatment of Cancer (EORTC) Core QoL questionnaire and the OC-specific module EORTC QLQ-OES-18 have been commonly utilised to evaluate the reliability and validity of the tool in the Khasi language, QoL of cancer patients across various countries. However, the reliability and validity of the Khasi language, spoken in Meghalaya, has not yet been established. In addition, there is a lack of research focusing on the QoL of OC patients in this region. The purpose of this study was to develop and validate Khasi translations of the EORTC QLQ-C-30 Version 3.0(QLQ-C-30) and EORTC QLQ-OES-18 (QLQ-OES-18) questionnaires for use in Khasi-speaking populations.

MATERIALS AND METHODS

RESULTS

A total of 123 patients were included in the final analysis. In our cohort, 81.3% patients presented with locally advanced disease. The sociodemographic details, risk behaviour and clinical history are described in Table 1.

Correlation between QLQ-C-30 and QLQ-OES-18

Correlation coefficient values for each scale between QLQ-C-30 and QLQ-OES-18 ranged from 0.001 to 0.557. Most of the QLQ-OES-18 scales correlated weakly (r < 0.40) with QLQ-C-30. An exception was the oesophageal module pain scale which correlated moderately with QLQ-C-30 module’s pain scale (r = 0.557) and physical functioning scale (r = 0.447). Furthermore, oesophageal module eating scale correlated moderately with QLQ-C-30 module’s QoL scale (r = 0.452) and pain scale (r = 0.540) [Figures 1 and 2].

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Figure 1:

Correlation between QLQ-C-30 and multi-item scales of QLQ-OES-18. QOL: Global health scale/QOL scale, PF: Physical functioning, RF: Role functioning, EF: Emotional functioning, SF: Social functioning, FA: Fatigue, NV: Nausea and vomiting, PA: Pain, DY: Dyspnoea, SL: Insomnia, AP: Appetite, CO: Constipation, DI: Diarrhoea, FI: Financial difficulties, OESDYS: Dysphagia, OESEAT: Eating, OESRFX: Reflux, OESPA: Pain. *=P<0.05, **=P<0.01.

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Figure 2:

Correlation between QLQ-C-30 and single-item scales of QLQ-OES-18. QOL: Global health scale/QOL scale, PF: Physical functioning, RF: Role functioning, EF: Emotional functioning, SF: Social functioning, FA: Fatigue, NV: Nausea and vomiting, PA: Pain, DY: Dyspnoea, SL: Insomnia, AP: Appetite, CO: Constipation, DI: Diarrhoea, FI: Financial difficulties, OESSV: Trouble swallowing saliva, OESCH: Choked when swallowing, OESDM: Dry mouth, OESTA: Trouble with taste, OESCO: Trouble with coughing, OESSP: Trouble with talking. *=P<0.05, **=P<0.01.

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DISCUSSION

The QoL of OC patients remain incompletely understood, primarily due to a lack of specific assessment tools. This is particularly true for patients from Meghalaya, where the highest incidence of OC was reported in India. The Khasi versions of QLQ-C-30 and QLQ-OES-18 were found to have good psychometric properties in our study, which is similar to such efforts for various other languages.^[16-18] This research holds significance for three primary reasons. First, the predominant histological type of OC in Meghalaya (squamous carcinoma) differs from that found in most European nations, where the QLQ-OES-18 was initially designed. Second, several cultural distinctions exist between the study setting (Meghalaya, India) and the countries where this was first developed. Third, the dietary practices in Meghalaya contrast with those in European countries.

All scales demonstrated high internal consistency, with Cronbach’s alpha coefficients exceeding 0.70. The QLQ-C-30 showed strong correlations with their respective scale and showed good internal consistency, with Cronbach’s alpha ranging from 0.708 to 0.976. Zahid et al., in their translation and validation study found internal consistency of 0.46–0.83 for QLQ-C-30.^[19] The QLQ-OES-18 items exhibited stronger correlations with their respective scales compared to other scales. Blazeby et al’s findings revealed that 60% of Cronbach’s alpha coefficients surpassed 0.7, with reflux and pain scales showing the lowest value (0.58–0.71) and eating and dysphagia scales displaying higher coefficients.^[12] A study by Chie et al.^[20] in Taiwan confirmed the strong reliability of QLQ-OES-18. Their internal consistency analysis revealed satisfactory Cronbach’s alpha coefficients ranging from 0.77 to 0.82, with the pain component approaching satisfactory levels at 0.67.^[20] Another study yielded comparable findings, affirming QLQ-OES-18’s robust reliability. However, minor discrepancies in data were observed across the three studies.^[21] These variations might be attributed to differences in sample size, cultural factors or the specific conditions of the enrolled patients.

According to studies by Blazeby et al., and Chie et al., most scales in the oesophageal module showed weak correlations with the QLQ-C-30.^[12,20] However, Blazeby et al.,^[12] research revealed an exception: The oesophageal ‘pain’ item demonstrated a moderate correlation (r = 0.58) with the QLQ-C-30 ‘pain’ item. In addition, the QLQOES-18 ‘eating’ item exhibited moderate correlations with ‘fatigue’ and ‘social function’ of QLQ-C-30. Chie et al.^[20] also found low to moderate correlation between the scales of QLQ-C-30 and QLQ-OES-18 except the correlation between ‘appetite’ and ‘eating’ which exceeded 0.70. Our experimental findings largely align with these two studies. The absolute values of correlation coefficients for each scale between both questionnaires showed low correlations. The ‘eating’ scale of QLQ-OES-18 correlated moderately with QLQ-C-30 module’s global health scale (r = 0.452) and pain scale (r = 0.540). These associations are not unexpected, given the important role of eating in social life. The QLQOES-18’s pain scale which correlated moderately with QLQC-30’s pain scale (r = 0.557) and physical functioning scale (r = 0.447) could be explained by the fact that the majority of patients present at advanced stages of the disease, impairing their physical functioning.

To assess clinical validity, this study examined the correlation between clinical parameters (that affect QoL of OC patients) with multi-item and single-item scales of both questionnaires. Stage of cancer and intent of treatment showed significant correlation with some of the scales. Hence, further comparison of mean scores of subgroups of these clinical parameters was done to know about the baseline variation of QoL in the said groups. There are some studies that showed deterioration of many scales of QoL following treatment, whereas disease-specific benefit with treatment is also demonstrated.^[12,22]

The limitations of this study include a relatively small sample size and the heterogeneity, in terms of the different clinical stages of cancer and the varied treatments that the patients received. Furthermore, we did not conduct a test-retest reliability analysis to evaluate stability as the cross-sectional design prevented us from observing the variation of QoL over time. Nevertheless, our research paves the way for further assessment of QoL in the region which reports the highest incidence of OC in India. The baseline QoL assessed using this validated tool has been published separately,^[23] and the QoL of all OC patients treated in our centre is being collected prospectively.

CONCLUSION:

The Khasi versions of the QLQ-C-30 and QLQ-OES-18 demonstrate good psychometric properties, proving to be a reliable and culturally appropriate valuable tool for assessing QoL in OC patients in the Khasi-speaking population of North-East India. Its use may enhance the understanding of PRO and the impact of treatment in this high-incidence region. We recommend incorporating this validated tool into routine clinical practice to monitor QoL throughout treatment.