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Article

Brazilian Validation of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group (QLG) Computerised Adaptive Tests (CAT) Core

1
Department of Radiation Oncology, Hospital Sírio-Libanês, Rua Dona Adma Jajet 115, Sao Paulo 01308-050, Brazil
2
Latin America Cooperative Oncology Group (LACOG), Porto Alegre 90619-900, Brazil
3
Academic Trials Promoting Team, Institut Jules Bordet, l’Université Libre de Bruxelles (U.L.B), 1210 Brussels, Belgium
4
Radiation Oncology Unit, Santa Maria University Hospital (UFSM), Santa Maria 97105-900, Brazil
5
Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry II, A-6020 Innsbruck, Austria
6
Dendrix Research, Sao Paulo 04534-000, Brazil
7
Palliative Care Research Unit, Department of Geriatrics and Palliative Medicine GP, Bispebjerg & Frederiksberg Hospital, University of Copenhagen, 2400 Copenhagen NV, Denmark
*
Author to whom correspondence should be addressed.
Curr. Oncol. 2021, 28(5), 3373-3383; https://doi.org/10.3390/curroncol28050291
Received: 21 May 2021 / Revised: 6 August 2021 / Accepted: 26 August 2021 / Published: 31 August 2021

Abstract

Background: This study aimed to validate the Brazilian version of EORTC CAT Core and compare the Brazilian results with those from the original European EORTC CAT Core validation study. Methods: After validated translation, 168 cancer patients from Brazil receiving radiation therapy with or without chemotherapy was assessed. Translated EORTC CAT Core and all QLQ-C30 items were administered to patients using CHES (Computer-Based Health Evaluation System) before (T0) and after (T1) treatment initiation. The association between QLQ-C30 and CAT scores and ceiling/floor effects were estimated. Based on estimates of relative validity (cross-sectional, known-group differences and changes over time), relative sample-size requirements for CAT compared to QLQ-C30 were estimated. Results: Correlation coefficients between CAT and QLQ-C30 domains ranged from 0.63 to 0.93; except for dyspnoea, all coefficients were >0.82 (corresponding figures were 0.81–0.93 in the European study). On average across domains, floor/ceiling was reduced by 10% using CAT (9% in the European study) corresponding to a relative reduction of 32% (37% in the European study). Analyses of known-group validity and responsiveness indicated that, on average across domains, the sample-size requirements may be reduced by 17% using CAT rather than QLQ-C30, without loss of power (28% in the European study). The Brazilian sample had less symptom/quality of life impairment than the European sample, which likely explains the lower sample-size reduction using CAT when comparing with the European sample. Conclusions: The results in the Brazilian cohort were generally similar to those from the European sample and confirm the validity and usefulness of the EORTC CAT Core.
Keywords: health-related quality of life; treatment; patient-reported outcome measures; computerized adaptive test health-related quality of life; treatment; patient-reported outcome measures; computerized adaptive test

1. Introduction

The patient-reported outcome measures (PROMs) evaluating health-related quality of life (HRQoL) are usually not assessed using dynamic questionnaires. With the instruments typically used, an identical set of items structured in the same sequence is presented to all persons in order to ensure that results are comparable among patients. The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group has developed computerized adaptive tests (CATs) covering the 14 symptom and functional domains of the EORTC Quality of Life Core Questionnaire, the QLQ-C30 [1]. The EORTC CAT Core was developed to measure the same domains as the QLQ-C30 but with improved measurement accuracy, relevance to patients, and flexibility [2,3,4,5,6,7]. Another possible advantage is that, being an instrument with improved measurement precision, CAT requires a relatively smaller patient sample when compared with a static questionnaire while maintaining an equivalent level of statistical power [4,5,8,9,10].
The development and the comprehensive results of specific EORTC CAT item banks have been reported by the EORTC Quality of Life Group. Of note, initial validation studies during the construction of the item banks showed that CAT measures conceptually are similar and comparable to the QLQ-C30 instrument [4,5,6,7,8,9,10,11,12,13].
Recently, Petersen et al. reported the first international validation of the EORTC CAT Core, including 699 cancer patients from seven European countries. Based on this study, it was demonstrated that CAT, when compared with the QLQ-C30, largely simplified the assessment of these PROMs with the use of smaller samples and no loss of power, thus being a suitable instrument for general use [8].
Despite all this evidence in favour of the EORTC CAT Core utilisation, before its wider use globally, it is important to generate further evidence to support the use of this instrument. This study aimed to validate the Brazilian version of the EORTC CAT Core and compare the Brazilian results with those from the European EORTC CAT Core validation study.

2. Methods

2.1. Instruments and Translation Procedure

The EORTC CAT Core has been described previously [13]. In brief, it consists of 14 item banks covering the symptom and functional domains of the QLQ-C30 (see the list of domains in Table 1). Each item bank comprises between 7 and 34 items, with a total of 260 items. The CAT scores are on a so-called T-score metric, scaled so that the European general population has a mean of 50 and a standard deviation of 10 for all domains [14].
The EORTC CAT Core was translated to Portuguese according to the EORTC Quality of Life Group recommendations. All the translation phases (preparation stage, forward translations, reconciliation, back translations, back translation report, proofreading, pilot-testing, and final translation) were performed [15].
The EORTC QLQ-C30 consists of 30 items covering the same 14 domains as the EORTC CAT Core plus overall health/quality of life. The QLQ-C30 scales range from 0 to 100 and were scored according to the official QLQ-C30 scoring manual [16]. For both CAT and QLQ-C30, a higher score indicates better functioning for the functional domains and worse symptoms for the symptom domains.

2.2. Study Design and Selection Criteria

To allow direct comparison of results of the current study with those of the original European validation of the EORTC CAT Core, the study design and inclusion criteria followed those of the original validation study [8].
Patients from one Oncology Centre in Sao Paulo (Brazil) were included in this prospective survey. The inclusion criteria used in the study were: age 18 years or older; histological confirmation of cancer; planned radiation therapy and/or systemic therapy; having Portuguese as native language; and having the capacity to understand and complete the EORTC CAT Core.
The EORTC CAT Core instrument was presented to the patients twice: at baseline (0 to 14 days before treatment initiation) and on follow-up (6 to 14 days after chemotherapy initiation or 1 to 8 days after completion of radiation therapy). At each assessment, patients completed CATs consisting of 5 to 9 items for each domain.
A web-based platform for collecting data was used. The EORTC CAT Core and all QLQ-C30 items were applied to patients using CHES (Computer-Based Health Evaluation System—https://ches.pro/index.php/ches, accessed on at the same time. All patients completed their assessments at the hospital where they underwent their oncological treatment using a personal computer (tablet or desktop).

2.3. Statistical Analyses

The statistical analyses generally followed those of the original validation study [8]. The applied analyses are summarised as follows. Further details about the statistical analyses are available from Petersen et al [8].
The association between QLQ-C30 and EORTC CAT Core scores were quantified through Pearson correlation coefficients, and the ceiling and floor effects were estimated.
To estimate the relative precision of the CAT scores compared to the QLQ-C30 scores, the ratio of the CAT score to the QLQ-C30 score information functions (a measure of precision [17]) were calculated.
The relative sensitivity, i.e., ability to detect expected cross-sectional group differences, of the EORTC CAT Core compared to the QLQ-C30 sum scales was evaluated by estimating relative validities (RVs). The RVs are calculated as the ratio of test statistics (TestCAT/TestC30) for testing expected group differences formed based on variables available at baseline T0. RV > 1 indicates greater power to detect differences using the CAT. Based on RV estimates, relative sample-size requirements for future studies using the EORTC CAT Core were calculated and compared with the corresponding requirements using QLQ-C30. A comparison of the Brazilian results with those from the European EORTC CAT Core validation study [8] was also performed. Although no formal sample-size calculation was performed for the current study, the initial aim was to have 100 evaluable patients for analysis (similar to the aim per country in the European validation); therefore, a larger sample size was required in order to account for potential loss to follow-up after the baseline assessment. SAS Enterprise Guide 7.1 software was used for analysis.

2.4. Ethics Approval

The study was approved by the ethics committee (Hospital Sírio-Libanês) and was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki. Informed consent was obtained from all individual participants included in the study.

3. Results

3.1. Patient Characteristics

Between February 2018 and June 2019, 168 patients were included. Data were collected for all patients at baseline and for 107 (63.7%) patients on follow-up. Median age was 60.2 years, and the most common cancer type was breast cancer. All patients received both radiation therapy and systemic therapy. Table 2 presents the patient characteristics (sociodemographic and clinical) from the Brazilian cohort as well as selected information about the participants from the European EORTC CAT Core validation study [8].

3.2. Brazilian Data

Table 1 summarizes the EORTC CAT Core and QLQ-C30 scores at T0 and T1 for Brazilian participants. The CAT scores at both T0 and T1 were close to the European general population mean of 50; most were within five points (0.5 SD). The only exception was the overall quality of life (QL), for which the Brazilian patients scored 12 points higher (better) than the European general population.
T1-T0 score differences for both instruments are displayed in Table 3. Positive differences indicate more symptoms or better functioning at T1. Differences reflecting better scores (i.e., <0 for symptoms and >0 for functional scores) at T1 are highlighted in bold type. Generally, the changes from T0 to T1 were minor. For the EORTC CAT, the changes for all domains were within five points.
The relative information precision of EORTC CAT Core compared with QLQ-C30 scores at and baseline (T0) is shown in the Table 4. Across the domains, the EORTC CAT Core provides mean = 5.5/median = 3.7 times as much information as the QLQ-C30 scores. Results for follow-up (T1) are similar to T0, with mean = 5.6/median = 3.7 times as much information across domains (details not shown).

3.3. Comparison between Brazilian and European Data

The comparison of QLQ-C30 scores at T0 between Brazilian and European participants are presented in the Supplementary Material Table S1. Overall, fewer symptoms/impairments were seen in the Brazilian sample, particularly regarding lack of appetite, dyspnoea, fatigue, role functioning, social functioning, and overall quality of life.
Table 5 demonstrates the correlations between EORTC CAT Core and QLQ-C30 scores and differences in correlation coefficients between Brazil and Europe. The relatively low correlation for dyspnoea in the Brazilian sample is likely because most participants (87%) answered “not at all” to the QLQ-C30 item, but when asked about more demanding tasks (like walking up one flight of stairs), some (approximately 20%) responded “a little” or “quite a bit” dyspnoea. Hence, the relatively low correlation is mainly a result of a low sensitivity of the original item for individuals with little dyspnoea. Otherwise, the correlations between EORTC CAT Core and QLQ-C30 scores in the Brazilian sample were high and comparable to those found in the European cohort; for the comparisons between the two cohorts at T0, the median difference between correlation coefficients across all domains is <0.01.
Overall, the floor/ceiling are on average reduced by 10% using EORTC CAT Core (9% in European study), corresponding to a relative reduction of 32% (37% in European). For least symptoms/best functioning (i.e., floor for symptom domains and ceiling for functional domains), the reduction in Brazil is 18% (59% to 41%). The floor/ceiling reductions are generally similar in the Brazilian and European samples (Table 6).
Mean RV for each domain is shown in Supplementary Material Table S2. An extreme RV value was observed for dyspnoea in the Brazilian sample, reflecting that the C30 dyspnoea scale has low sensitivity in this sample, with few dyspnoea problems resulting in non-significant differences for the QLQ-C30 scale, while the CAT score results in significant differences. Otherwise, most differences found were small (8 of 14 RVs are <1.1), with a median RV across domains of 1.1, indicating average savings in sample-size requirements using the EORTC CAT Core versus QLQ-C30 of about 17%. Most RVs (10 of 14) are lower in the Brazilian sample than observed in the original European validation, and in the original validation, the average sample savings across domains were estimated to be 28%.

4. Discussion

Historically, information on patients’ HRQoL comes from PROMs that are usually obtained using standardised, static questionnaires for which all responders need to answer the same set of items to create comparable scores. Of note, conventional PROMs frequently involve a considerable number of items, oftentimes more than might be reasonable to request patients to answer, to accomplish accurate measurements for patients at diverse levels of HRQoL [18].
CATs have the exceptional feature that permits the questionnaire to be adjusted to the individual patient without impairing the measurement of scores and the direct comparison across patients. For each patient, CATs select the most relevant items based on answers to previous items and can thereby optimise the measurement assessment. In this way, CAT increases measurement accuracy by focusing on questions of relevance to individual patients; increases flexibility, since the instrument can be adapted to each study; and allows real-time feedback of results due to the features of automatic device reporting. [18,19]
Due to the clear benefits of CAT, the EORTC Quality of Life Group have been developing the CAT PROM for cancer patients since 2005. Considering that EORTC QLQ-C30 is one of the most used instruments worldwide both for clinical assessment and cancer research, much effort has been put into developing the psychometric properties of this novel instrument [18,20,21,22]. In the studies that led to the development of CAT, collection and calibration of data for all domains evaluated by the EORTC QLQ-C30 allowed respecting the conceptual framework of the EORTC QLQ-C30, guaranteeing the highest possible compatibility with and ability to replace the original tool. Therefore, results of studies using EORTC CAT Core and the EORTC QLQ-C30 are comparable to each other. The EORTC CAT Core consists of 14 item banks, each including 7 to 34 items, resulting in a total of 260 items. This instrument was created considering different aspects, including interviews with cancer patients, expert recommendations, literature searches, and psychometric analyses. Furthermore, the EORTC CAT Core was developed transnationally, incorporating different cultures and languages, which supports it as an appropriate instrument across patient groups [1,18,23].
Despite the enthusiasm for developing the EORTC CAT Core that may have more accurate measurement compared with standard instruments, such as the QLQ-C30, and the existing data supporting this prospect, the efficacy of EORTC CAT Core benefits from confirmation in independent cohorts. The international validation study assessed the psychometric properties of the EORTC CAT Core in an independent sample and confirmed that the EORTC CAT Core has higher precision and measures the same HRQoL domains as the QLQ-C30 in the European perspective [8].
The present study is the first to address the evaluation of EORTC CAT Core in Latin America (Brazil). After being translated into Portuguese according to the EORTC Quality of Life Group recommendations, the EORTC CAT Core was prospectively applied to cancer patients. The Brazilian sample generally had less symptoms/impairment compared with the European sample. Of note, the Brazilian study was conducted in a privately held cancer centre, and perhaps for this reason, participants were generally wealthier and had a higher education level than was reported for the European sample. Additionally, the Brazilian patients generally deteriorated less from baseline T0 to follow-up T1. Nevertheless, the results in the Brazilian sample are comparable to the findings in the European sample except for a few differences, generally confirming the validity and applicability of the EORTC CAT Core in a non-European setting as well. Importantly, most correlations with QLQ-C30 and floor/ceiling are similar in comparison with the results from the European study. Likewise, for the estimates of relative validity of EORTC CAT Core compared with those from QLQ-C30, they were generally slightly lower in the Brazilian sample than among patients from Europe, which is in line with the former sample having less symptom/impairment and the fact that EORTC CAT Core particularly improves measurement for patients having symptom/impairment.
Our study has certain limitations. All patients are from the same centre, and it would be valuable to expand the validation to other centres in Brazil. However, as a strength, since the study used a broad mixed sample of patients (in gender, different ages, different cancer stage, etc.), our findings probably well represent the Brazilian population.
In conclusion, overall, the validation indicates that the EORTC CAT Core works well in the Brazilian sample and is comparable to the performance in the European sample.

Supplementary Materials

The following are available online at https://www.mdpi.com/article/10.3390/curroncol28050291/s1, Table S1: QLQ-C30 mean scores at T0 in Brazil and the difference between Brazilian and European mean scores. Table S2: Mean relative validity/sensitivity (ability to detect cross-sectional differences) of the EORTC CAT Core compared to the QLQ-C30.

Author Contributions

All authors contributed to the study conception and design. Material preparation, data collection, and analysis were performed by G.N.M., T.Y.T.d.S., A.R.N.d.S.e.S., A.P.A.P., D.R.F.N., R.N.A., F.A.M.D., M.A.P., G.N.-M., M.F.d.S., E.D.S., B.H., R.G. and S.A.H. The first draft of the manuscript was written by G.N.M. and M.A.P. All authors commented on previous versions of the manuscript. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

The study was approved by the ethics committee (Hospital Sírio-Libanês 2.520.830) and was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki.

Informed Consent Statement

Informed consent was obtained from all individual participants included in the study.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author (G.N.M.) upon reasonable request.

Conflicts of Interest

All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript. The authors have no financial or proprietary interests in any material discussed in this article.

References

  1. Aaronson, N.K.; Ahmedzai, S.; Bergman, B.; Bullinger, M.; Cull, A.; Duez, N.J.; Filiberti, A.; Flechtner, H.; Fleishman, S.B.; De Haes, J.C.; et al. The European Organization for Research and Treatment of Cancer QLQ-C30: A Quality-of-Life Instrument for Use in International Clinical Trials in Oncology. J. Natl. Cancer Inst. 1993, 85, 365–376. [Google Scholar] [CrossRef]
  2. Petersen, M.A.; Giesinger, J.; Holzner, B.; Arraras, J.I.; Conroy, T.; Gamper, E.-M.; King, M.T.; Leeuw, I.V.-D.; Young, T.; Grønvold, M. Psychometric evaluation of the EORTC computerized adaptive test (CAT) fatigue item pool. Qual. Life Res. 2013, 22, 2443–2454. [Google Scholar] [CrossRef] [PubMed]
  3. Dirven, L.; Groenvold, M.; Taphoorn, M.J.; Conroy, T.; Tomaszewski, K.A.; Young, T.; Petersen, M.A. Psychometric evaluation of an item bank for computerized adaptive testing of the EORTC QLQ-C30 cognitive functioning dimension in cancer patients. Qual. Life Res. 2017, 26, 2919–2929. [Google Scholar] [CrossRef]
  4. Petersen, M.A.; Aaronson, N.K.; Arraras, J.I.; Chie, W.-C.; Conroy, T.; Costantini, A.; Giesinger, J.M.; Holzner, B.; King, M.T.; Singer, S.; et al. The EORTC computer-adaptive tests measuring physical functioning and fatigue exhibited high levels of measurement precision and efficiency. J. Clin. Epidemiol. 2013, 66, 330–339. [Google Scholar] [CrossRef] [PubMed]
  5. Gamper, E.; Grønvold, M.; Petersen, M.A.; Young, T.; Costantini, A.; Aaronson, N.; Giesinger, J.; Meraner, V.; Kemmler, G.; Holzner, B.; et al. The EORTC emotional functioning computerized adaptive test: Phases I–III of a cross-cultural item bank development. Psycho-Oncology 2013, 23, 397–403. [Google Scholar] [CrossRef] [PubMed]
  6. Thamsborg, L.H.; on behalf of the EORTC Quality of Life Group; Petersen, M.A.; Aaronson, N.K.; Chie, W.-C.; Costantini, A.; Holzner, B.; Leeuw, I.M.V.-D.; Young, T.; Groenvold, M. Development of a lack of appetite item bank for computer-adaptive testing (CAT). Support. Care Cancer 2015, 23, 1541–1548. [Google Scholar] [CrossRef] [PubMed]
  7. Giesinger, J.M.; Petersen, M.A.; Groenvold, M.; Aaronson, N.K.; Arraras, J.I.; Conroy, T.; Gamper, E.M.; Kemmler, G.; King, M.T.; Oberguggenberger, A.S.; et al. Cross-cultural development of an item list for computer-adaptive testing of fatigue in oncological patients. Health Qual. Life Outcomes 2011, 9, 19. [Google Scholar] [CrossRef]
  8. Petersen, M.A.; on behalf of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group; Aaronson, N.K.; Conroy, T.; Costantini, A.; Giesinger, J.M.; Hammerlid, E.; Holzner, B.; Johnson, C.D.; Kieffer, J.M.; et al. International validation of the EORTC CAT Core: A new adaptive instrument for measuring core quality of life domains in cancer. Qual. Life Res. 2020, 29, 1405–1417. [Google Scholar] [CrossRef] [PubMed]
  9. Petersen, M.A.; Gamper, E.-M.; Costantini, A.; Giesinger, J.M.; Holzner, B.; Johnson, C.; Sztankay, M.; Young, T.; Grønvold, M. An emotional functioning item bank of 24 items for computerized adaptive testing (CAT) was established. J. Clin. Epidemiol. 2016, 70, 90–100. [Google Scholar] [CrossRef] [PubMed]
  10. Petersen, M.A.; Grønvold, M.; Aaronson, N.K.; Chie, W.-C.; Conroy, T.; Costantini, A.; Fayers, P.; Helbostad, J.; Holzner, B.; Kaasa, S.; et al. Development of computerized adaptive testing (CAT) for the EORTC QLQ-C30 physical functioning dimension. Qual. Life Res. 2011, 20, 479–490. [Google Scholar] [CrossRef] [PubMed]
  11. Gamper, E.-M.; on behalf of the EORTC Quality of Life Group; Petersen, M.A.; Aaronson, N.; Costantini, A.; Giesinger, J.M.; Holzner, B.; Kemmler, G.; Oberguggenberger, A.; Singer, S.; et al. Development of an item bank for the EORTC Role Functioning Computer Adaptive Test (EORTC RF-CAT). Health Qual. Life Outcomes 2016, 14, 72. [Google Scholar] [CrossRef] [PubMed]
  12. Dirven, L.; Taphoorn, M.J.; Groenvold, M.; Habets, E.J.; Aaronson, N.K.; Conroy, T.; Reijneveld, J.C.; Young, T.; Petersen, M.A.; EORTC Quality of Life Group; et al. Development of an item bank for computerized adaptive testing of self-reported cognitive difficulty in cancer patients. Neurooncol. Pract. 2017, 4, 189–196. [Google Scholar] [CrossRef] [PubMed]
  13. Petersen, M.A.; Aaronson, N.K.; Chie, W.-C.; Conroy, T.; Costantini, A.; Hammerlid, E.; Hjermstad, M.J.; Kaasa, S.; Loge, J.H.; Velikova, G.; et al. Development of an item bank for computerized adaptive test (CAT) measurement of pain. Qual. Life Res. 2016, 25, 1–11. [Google Scholar] [CrossRef]
  14. Liegl, G.; Petersen, M.; Groenvold, M.; Aaronson, N.; Costantini, A.; Fayers, P.; Holzner, B.; Johnson, C.; Kemmler, G.; Tomaszewski, K.; et al. Establishing the European Norm for the health-related quality of life domains of the computer-adaptive test EORTC CAT Core. Eur. J. Cancer 2019, 107, 133–141. [Google Scholar] [CrossRef]
  15. Kulis, D.; Bottomley, A.; Velikova, G.; Greimel, E.; Koller, M. EORTC Quality of Life Group Translation Procedure, 4th ed.; European Organization for Research and Treatment of Cancer: Brussels, Belgium, 2016. [Google Scholar]
  16. Fayers, P.M.; Aaronson, N.K.; Bjordal, K.; Groenvold, M.; Curran, D.; Bottomley, A. The EORTC QLQ-C30 Scoring Manual, 3rd ed.; European Organisation for Research and Treatment of Cancer: Brussels, Belgium, 2001. [Google Scholar]
  17. Reise, S.P.; Revicki, D.A. Handbook of Item Response Theory Modeling: Applications to Typical Performance Assessment; Routledge: New York, NY, USA, 2015. [Google Scholar]
  18. Petersen, M.A.; Aaronson, N.K.; Arraras, J.I.; Chie, W.-C.; Conroy, T.; Costantini, A.; Dirven, L.; Fayers, P.; Gamper, E.-M.; Giesinger, J.M.; et al. The EORTC CAT Core—The computer adaptive version of the EORTC QLQ-C30 questionnaire. Eur. J. Cancer 2018, 100, 8–16. [Google Scholar] [CrossRef] [PubMed]
  19. Wainer, H. Computerized Adaptive Testing: A Primer; Lawrence Erlbaum Associates, Inc.: Mahwah, NJ, USA, 2000. [Google Scholar]
  20. Fayers, P.; Bottomley, A.; EORTC Quality of Life Group and of the Quality of Life Unit. Quality of life research within the EORTC-the EORTC QLQ-C30. European Organisation for Research and Treatment of Cancer. Eur. J. Cancer 2002, 38 (Suppl. 4), S125–S133. [Google Scholar] [CrossRef]
  21. Marta, G.N.; Moraes, F.Y.; Leite, E.T.T.; Chow, E.; Cella, D.; Bottomley, A. A critical evaluation of quality of life in clinical trials of breast cancer patients treated with radiation therapy. Ann. Palliat. Med. 2017, 6, S223–S232. [Google Scholar] [CrossRef] [PubMed]
  22. Marta, G.N.; Saad, E.D. Assessment of quality of life in phase III trials of radiotherapy in localized or locally advanced head and neck cancer over the past 17 years. Ann. Palliat. Med. 2017, 6, 73–80. [Google Scholar] [CrossRef] [PubMed]
  23. Petersen, M.A.; Groenvold, M.; Aaronson, N.K.; Chie, W.-C.; Conroy, T.; Costantini, A.; Fayers, P.; Helbostad, J.; Holzner, B.; Kaasa, S.; et al. Development of computerised adaptive testing (CAT) for the EORTC QLQ-C30 dimensions—General approach and initial results for physical functioning. Eur. J. Cancer 2010, 46, 1352–1358. [Google Scholar] [CrossRef] [PubMed]
Table 1. Brazilian data. The EORTC CAT Core and QLQ-C30 scores at baseline (T0) and follow-up (T1) for Brazilian participants.
Table 1. Brazilian data. The EORTC CAT Core and QLQ-C30 scores at baseline (T0) and follow-up (T1) for Brazilian participants.
DomainNMeanStandard DeviationMedianMinimumMaximum
Baseline (T0)
EORTC CAT Core
AP16850.29.643.943.987.8
CF16851.510.453.215.462.3
CO16849.811.041.141.187.3
DI16847.28.143.843.892.2
DY16847.18.044.040.482.0
EF16850.58.951.119.263.9
FA16844.99.443.334.382.1
FI16853.49.750.642.187.4
NV16848.98.145.845.8106.1
PF16845.29.245.59.866.3
PA16846.09.139.439.478.7
RF16848.210.348.816.558.8
SF16848.59.450.417.757.6
SL16850.110.148.636.975.6
QL16862.012.867.220.077.4
QLQ-C30
AP16811.522.80.00.0100.0
CF16885.321.3100.00.0100.0
CO16814.326.20.00.0100.0
DI1686.016.80.00.0100.0
DY1686.017.60.00.0100.0
EF16874.722.875.00.0100.0
FA16818.721.011.10.0100.0
FI16817.929.20.00.0100.0
NV1685.012.80.00.0100.0
PF16882.417.286.70.0100.0
PA16815.125.00.00.0100.0
RF16885.225.2100.00.0100.0
SF16881.226.2100.00.0100.0
SL16827.233.80.00.0100.0
QL16874.421.783.30.0100.0
Follow-up (T1)
EORTC CAT Core
AP10752.711.343.943.987.8
CF10752.310.054.122.762.3
CO10750.510.447.541.178.4
DI10749.39.843.843.882.9
DY10748.38.647.640.468.5
EF10753.67.655.634.763.9
FA10747.99.046.834.374.3
FI10752.99.450.642.187.4
NV10751.09.545.845.899.8
PF10744.67.745.326.566.3
PA10744.97.939.439.467.1
RF10747.48.746.027.558.8
SF10748.58.650.429.857.6
SL10747.79.943.136.975.6
AP10762.110.862.129.077.4
QLQ-C30
AP10718.129.10.00.0100.0
CF10787.219.4100.00.0100.0
CO10717.427.60.00.0100.0
DI10710.623.60.00.0100.0
DY1079.018.10.00.066.7
EF10783.616.991.725.0100.0
FA10724.722.422.20.0100.0
FI10717.827.60.00.0100.0
NV1078.614.90.00.0100.0
PF10782.915.186.733.3100.0
PA10712.923.50.00.0100.0
RF10781.223.683.316.7100.0
SF10782.621.083.316.7100.0
SL10718.729.40.00.0100.0
QL10774.618.175.016.7100.0
Note: AP, lack of appetite; CO, constipation; DI, diarrhoea; DY, dyspnoea; FI, financial difficulties; SL, insomnia; NV, nausea/vomiting; PA, pain; FA, fatigue; CF, cognitive functioning; RF, role functioning; SF, social functioning; EF, emotional functioning; PF, physical functioning; and QL, overall quality of life.
Table 2. Clinical and sociodemographic characteristics at baseline of the included patients (Brazil) and for comparison in the original European validation study.
Table 2. Clinical and sociodemographic characteristics at baseline of the included patients (Brazil) and for comparison in the original European validation study.
Brazil N (%) *European Countries N (%) **
Baseline assessment168 (100.0%)694 (99.3%)
Follow-up assessment107 (63.7%)446 (63.8%)
Age, mean (SD)60.2 (13.8)60.6 (12.0)
Gender
Female91 (54.2%)391 (55.9%)
Male 63 (37.5%)296 (42.4%)
Cancer stage
I–II83 (49.4%)207 (29.6%)
III–IV61 (36.3%)360 (51.5%)
Cancer site
Breast65 (38.7%)213 (30.5%)
Lung9 (5.4%)83 (11.9%)
Prostate29 (17.3%)45 (6.4%)
Ovary2 (1.2%)38 (5.4%)
Other48 (28.6%)256 (36.7%)
Treatment
Systemic therapy168 (100.0%)639 (91.4%)
Radiation therapy168 (100.0%)60 (8.6%)
Highest level of education
Less than compulsory2 (1.2%)27 (3.9%)
Compulsory10 (6.0%)178 (25.5%)
Post compulsory below university19 (11.3%)268 (38.4%)
University level or above121 (72.0%)185 (26.5%)
Household income
<40,000 euro47 (28%)206 (29.5%)
40,000–79,999 euro49 (29.2%)63 (9.0%)
80,000–119,999 euro20 (11.9%)32 (4.6%)
≥120,000 euro10 (5.9%)16 (2.3%)
Do not know/want to disclose27 (16.1%)330 (47.3%)
Employment status
Retired42 (25.0%)280 (40.1%)
Working79 (47.0%)288 (41.2%)
Other32 (19.1%)91 (13.0%)
Note: * Some percentages sum to less than 100% because of missing data; **: Results of the European study originally presented in: Petersen MA, Aaronson NK, Conroy T, Costantini A, Giesinger JM, Hammerlid E, et al. International validation of the EORTC CAT Core: a new adaptive instrument for measuring core quality of life domains in cancer. Qual Life Res. 2020;29:1405–17.
Table 3. Differences between follow-up (T1) and baseline (T0) scores of the EORTC CAT Core and QLQ-C30 for Brazilian participants.
Table 3. Differences between follow-up (T1) and baseline (T0) scores of the EORTC CAT Core and QLQ-C30 for Brazilian participants.
DomainNMeanStandard DeviationMedianMinimumMaximum
EORTC CAT Core
AP1074.011.30.0−22.739.8
CF1071.28.90.0−21.725.3
CO1070.711.40.0−29.232.8
DI1072.110.10.0−26.939.1
DY1071.97.20.0−17.523.4
EF1073.07.12.3−19.419.4
FA1073.68.22.2−13.926.4
FI107−1.06.00.0−20.217.8
NV1072.79.60.0−30.637.1
PA107−0.19.00.0−19.327.6
PF107−1.16.1−0.1−27.322.9
QL107−0.813.10.0−39.237.2
RF107−2.09.20.0−28.121.4
SF107−0.68.70.0−26.027.8
SL107−2.69.70.0−38.727.5
QLQ-C30
AP10710.331.20.0−66.7100.0
CF1071.919.30.0−66.783.3
CO1072.230.10.0−100.0100.0
DI1074.424.30.0−66.7100.0
DY1072.820.00.0−66.766.7
EF1078.019.38.3−66.766.7
FA1077.920.80.0−55.688.9
FI107−0.619.40.0−66.766.7
NV1074.516.30.0−50.0100.0
PA1070.825.30.0−66.7100.0
PF107−1.211.70.0−40.026.7
QL107−1.222.20.0−66.766.7
RF107−7.525.50.0−66.766.7
SF107−1.126.00.0−66.7100.0
SL107−8.735.90.0−100.0100.0
Note: AP, lack of appetite; CO, constipation; DI, diarrhoea; DY, dyspnoea; FI, financial difficulties; SL, insomnia; NV, nausea/vomiting; PA, pain; FA, fatigue; CF, cognitive functioning; RF, role functioning; SF, social functioning; EF, emotional functioning; PF, physical functioning; QL, overall quality of life. Differences reflecting better scores (i.e., <0 for symptoms and >0 for functional scores) at T1 are highlighted in bold and color type.
Table 4. Brazilian data. Relative precision of the EORTC CAT Core compared to QLQ-C30 scores (information(CAT)/information(C30)).
Table 4. Brazilian data. Relative precision of the EORTC CAT Core compared to QLQ-C30 scores (information(CAT)/information(C30)).
VariableNMeanStandard DeviationMedianQuartile RangeMinimumMaximum
AP1684.301.104.300.003.0016.40
CO1685.802.407.103.502.8020.50
DI1682.602.202.200.002.2028.30
DY16719.007.8025.7014.104.3025.70
FI1685.102.004.603.903.3017.20
SL16813.1016.104.208.203.2047.70
NV1683.602.802.300.002.3012.10
PA1682.301.101.501.901.507.80
FA1683.300.403.100.502.805.10
CF1684.501.104.202.502.905.80
RF1683.700.403.900.801.804.10
SF1682.400.802.000.201.707.00
EF1682.500.602.400.801.704.30
PF1685.001.404.802.202.808.00
Across domains 5.56.83.72.81.547.7
Note: AP, lack of appetite; CO, constipation; DI, diarrhoea; DY, dyspnoea; FI, financial difficulties; SL, insomnia; NV, nausea/vomiting; PA, pain; FA, fatigue; CF, cognitive functioning; RF, role functioning; SF, social functioning; EF, emotional functioning; PF, physical functioning.
Table 5. Correlations between EORTC CAT Core and QLQ-C30 scores in Brazil and differences in correlations between Brazil and Europe.
Table 5. Correlations between EORTC CAT Core and QLQ-C30 scores in Brazil and differences in correlations between Brazil and Europe.
DomainBrazil (T0)Brazil (T1)Brazil-Europe (T0)Brazil-Europe (T1)
AP0.8630.920−0.0350.022
CF0.8670.8800.0070.002
CO0.8530.804−0.018−0.081
DI0.9000.8970.020−0.003
DY0.6340.701−0.200−0.115
EF0.8780.7950.005−0.060
FA0.8790.862−0.004−0.034
FI0.8210.8750.0070.058
NV0.9020.8800.003−0.014
PF0.8660.8640.007−0.039
PA0.9340.9100.015−0.025
RF0.8370.783−0.032−0.125
SF0.8500.844−0.020−0.033
SL0.8790.908−0.0040.010
QL1.0001.0000.0010.001
Median0.8670.8750.001−0.025
Note: AP, lack of appetite; CO, constipation; DI, diarrhoea; DY, dyspnoea; FI, financial difficulties; SL, insomnia; NV, nausea/vomiting; PA, pain; FA, fatigue; CF, cognitive functioning; RF, role functioning; SF, social functioning; EF, emotional functioning; PF, physical functioning; QL, overall quality of life.
Table 6. Floor and ceiling at T0 for the QLQ-C30 and the EORTC CAT Core, the differences in floor and ceilings between the two instruments, and the difference of this to the difference found in Europe.
Table 6. Floor and ceiling at T0 for the QLQ-C30 and the EORTC CAT Core, the differences in floor and ceilings between the two instruments, and the difference of this to the difference found in Europe.
Brazil QLQ-C30Brazil CATBrazil CAT-QLQ-C30Brazil-Europe Difference
AP, floor75.0%66.1%8.9%0.2%
AP, ceiling2.4%0.6%1.8%−2.1%
CF, floor1.8%1.8%0.0%−0.6%
CF, ceiling53.6%32.7%20.8%0.2%
CO, floor71.4%52.4%19.0%1.6%
CO, ceiling4.2%1.2%3.0%1.1%
DI, floor86.9%82.7%4.2%−1.6%
DI, ceiling0.6%0.6%0.0%1.0%
DY, floor86.9%50.0%36.9%14.0%
DY, ceiling1.8%0.6%1.2%−1.3%
EF, floor1.8%0.6%1.2%0.5%
EF, ceiling17.3%13.7%3.6%−0.6%
FA, floor32.7%23.2%9.5%6.0%
FA, ceiling0.6%0.6%0.0%−4.1%
FI, floor66.7%23.8%42.9%−0.6%
FI, ceiling5.4%0.6%4.8%2.3%
NV, floor81.0%78.0%3.0%0.7%
NV, ceiling0.6%0.6%0.0%0.0%
PA, floor62.5%57.1%5.4%−1.9%
PA, ceiling3.0%0.6%2.4%0.9%
PF, floor0.6%0.6%0.0%−0.1%
PF, ceiling20.8%4.2%16.6%−5.0%
RF, floor1.8%1.2%0.6%−2.3%
RF, ceiling66.1%35.7%30.4%16.3%
SF, floor3.0%1.8%1.2%−5.8%
SF, ceiling52.4%39.3%13.1%4.0%
SL, floor53.0%17.3%35.7%4.8%
SL, ceiling8.9%1.2%7.7%4.6%
Mean30.8%21.0%9.8%1.1%
Note: AP, lack of appetite; CO, constipation; DI, diarrhoea; DY, dyspnoea; FI, financial difficulties; SL, insomnia; NV, nausea/vomiting; PA, pain; FA, fatigue; CF, cognitive functioning; RF, role functioning; SF, social functioning; EF, emotional functioning.
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