Brazilian-Portuguese Validation Assessment of the Gastrointestinal Quality of Life Index for Patients After Laparoendoscopic Cholecystectomy

Abstract

Background:

Cholelithiasis is currently one of the most common diagnosis in Brazil. The aim of this study was to validate the Gastrointestinal Quality of Life Index (GIQLI) as a quality-of-life (QoL) assessment among the Brazilian population with syntomatic gallstone.

Materials and Methods:

The questionnaire was translated and culturally adapted after the linguistic validation process determined by the international methodology. Sixty-three patients who underwent laparoscopic cholecystectomy responded to the GIQLI-Brazil and Short-Form Health Survey (SF-36) instruments. For the evaluation of reproducibility, 30 patients responded to GIQLI-Brazil two more times after 2 and 4 weeks. After the University of São Paulo Ethics Commitee Board approval (UNIFESP/CEP: 1270/2019), the study was carryed out between May 2019 and February 2020 at the Gastroenterology outpatient clinic of Hospital São Paulo-Federal University of São Paulo (UNIFESP). Cronbach's alpha, the calculation of the intraclass correlation coefficient (ICC), and Spearman's correlation were used to assess the validity and reproducibility of the instrument translated into Portuguese, and to measure correlation between the domains of the GIQLI-Brazil and SF-36 (P < .05).

Results:

Seven questions were modified during the process of translation and cultural adaptation. The Brazilian version of the instrument presented a Cronbach's alpha of 0.89, and excellent reproducibility through the ICC, with the following variation between domains: meteorism (ICC = 0.918; P < .001) and gastrointestinal function (lower tract) (ICC = 0.956; P < .001). The dimensions of the GIQLI-Brazil and SF-36 demonstrated a significant correlation (P < .001), except between the domains: functional aspects of the SF-36 and gastrointestinal function (lower tract) of the GIQLI-Brazil (r = 0.211).

Conclusion:

The GIQLI was translated and validated for Portuguese-Brazil and can be used to assess the QoL of adult patients with gastrointestinal diseases and/or disorders.

Introduction

Gastrointestinal (GI) diseases affect ∼70 million people in the United States, resulting in an estimated annual cost of US$142 billion. In 2004, >4.6 million Americans were hospitalized, 72 million visited ambulatory care, and >236,000 deaths were attributed to GI diseases, being cholelithiasis with cholecystitis the second principal discharge diagnosis from hospital admissions.¹ According to the United European Gastroenterology (2016), the cost of absenteeism from work in Europe owing to GI diseases and distress was estimated in €1 billion in 2014.^2,3

In Brazil, GI diseases have contributed to long work leave periods, early retirement owing to disability, and high medication and treatment costs to the social security system.⁴

The burden caused by GI diseases and distress may impact patient's quality of life (QoL) owing to some long-term treatments, surgeries, and frequent medical follow-up. Therefore, QoL evaluation has been adopted more frequently to measure the success of a medical intervention.^5,6

Unfortunately, there are few available instruments translated and validated into Brazilian-Portuguese to evaluate the QoL of patients diagnosed with specific GI conditions.^7–11

A reliable instrument, specifically developed to evaluate the QoL of patients with GI diseases and distress, not only assessing GI symptoms but also physical and mental well-being is crucial to help physicians to decide the best treatment for their patients.

Gastrointestinal Quality of Life Index (GIQLI), is an easy and fast self-administrated questionnaire with 36 items, divided into five domains comprising questions that evaluate patient's physical well-being, large bowel function, emotional well-being, upper GI tract function, and meteorism in one single instrument. Originally developed in German, the instrument has been translated and validated into English and other languages.^12–16 This instrument has been applied in patients with general and specific GI diseases and distress in several studies.¹²

Based on the limited availability of instruments comprising general and specific questions to evaluate the impact of GI diseases and distress in patients' QoL in Brazil, this study aimed to translate and validate a Brazilian-Portuguese version of the GIQLI questionnaire.

Materials and Methods

This cross-cultural validation study was approved by the Universidade Federal de São Paulo Ethics Committee (CEP/UNIFESP: 1270/2019) and was conducted in accordance with the Declaration of Helsinki and the Declaration of Istanbul 2008. All patients, older than 18 years, and assisted at the gastroenterology outpatient clinic of Hospital São Paulo, signed a written informed consent after the procedures had been fully explained. Patients younger than 18 years, with no ability to understand the questionnaires' questions and presence of psychiatric disorders were excluded.

The GIQLI linguistic validation process was priorly authorized by Mapi Research Trust–ePROVIDE™ and the questionnaire developer Ernst Eypasch. This study was conducted between May 2019 and February 2020.

Survey instruments

Developed by Eypasch et al.,¹² the GIQLI is a self-administered 36-item questionnaire that evaluates the patient's physical and emotional well-being associated with GI diseases and distress on a Likert scale ranging from worst to best condition (0–4) . The GIQLI total score ranges from worst to best (0–144), and can also be divided into five domains and its components: physical well-being (0–44), large bowel function (0–24), emotional well-being (0–32), upper GI tract function (0–32), and meteorism (0–12). The instrument generates a total and each domain scores.

The Short-Form Health Survey (SF-36) is a QoL generic instrument with eight domains comprising physical function, role functioning—physical problems, bodily pain, general health, vitality, social functioning, role functioning—emotional problems, and mental health. Total score ranged from 0 (worst) to 100 (best). This instrument was previously translated and validated into Brazilian-Portuguese.¹⁷

Translation and cultural adaptation

The English version of the GIGLI questionnaire was translated into Brazilian-Portuguese by two local Brazilian-Portuguese native speakers and independent professional translators, bilingual in the English language. After the two translations were compared, a first version of the instrument in Brazilian-Portuguese was produced taking into account the two translated versions. This version was back translated into English by one local independent translator, English native speaker, bilingual in Brazilian-Portuguese language who did not have access to the original questionnaire.

The back-translated version was evaluated by a multidisciplinary committee composed of health professionals with experience in GI diseases and distress. After a consensus, a prefinal version of the Brazilian-Portuguese instrument was obtained maintaining the original questionnaire essential characteristics.

The prefinal version was administrated to 25 patients by one experienced psychologist, one specialist in health care QoL, and one gastroenterologist to test the language structure and comprehension of the items. All patients expressed their opinion and suggested necessary changes, when required. The final version of the Brazilian-Portuguese instrument was obtained after a final consensus, and proofreading by a Brazilian-Portuguese language arts professor (Supplementary Data S1).

The translation of the GIQLI questionnaire into Brazilian-Portuguese language respected the ©Mapi Research Trust–ePROVIDE™ linguistic validation process (Fig. 1).

FIG. 1.

Flow chart of the ©Mapi Research Trust linguistic validation process for the Gastrointestinal Quality of Life Index (GIQLI) instrument.

The questionnaire acronym was maintained to be identified by the scientific community.

Psychometric evaluation

After translation and cultural adaptation, the final version of the instrument was tested for reliability among 30 patients and for construct validity among 63 patients, which comprised the 30 patients together with 33 different patients (Fig. 2). Patients diagnosed with gallstones who were submitted to laparoscopic cholecystectomy, patients with no intercurrences, and patients for whom 6 months or more had elapsed since surgery were recruited for the reliability and validity tests. The 63 patients did not participate in the cultural adaptation of the instrument.

FIG. 2.

Flow diagram of the study's initial recruited participants and final samples.

Owing to the SARS-COVID-19 pandemic, all psychometric interviews were conducted using the Google Forms platform after explaining the study aims to the patients by telephone.

Test-retest reliability

For the test-retest analysis, 30 patients were retested with the GIQLI Brazilian-Portuguese version after a 2- and 4-week interval. The interview intervals were determined long enough to ensure patients did not recall their previous answers.^18,19

Construct validity

Construct validity was tested assessing 63 patients who answered the GIQLI Brazilian-Portuguese questionnaire along with the validated SF-36.^20,21

Statistical analysis

The analysis was conducted using the SPSS—Statistical Package for Social Sciences (v25.0).

Internal consistency of the GIQLI Brazilian-Portuguese questionnaire was calculated using Cronbach's alpha and values were classified as: poor (0–0.21), reasonable (0.21–0.40), moderate (0.41–0.60), adequate (0.61–0.80), and excellent (0.81–1.0).²²

For instrument reproducibility, intraclass correlation coefficient (ICC) was used. ICC values were classified as follows: poor (<0.4), reasonable (0.4–0.6), good (0.6–0.75), and excellent (0.75–1.0).²³ Intraclass correlation was assessed by comparing the scores of respondents (n = 30) at three different time intervals.

Spearman correlation was used to verify the GIQLI Brazilian-Portuguese version and the SF-36 domain correlation. Values of P < .05 were considered statistically significant.

As the purpose of the cultural adaptation was to evaluate the questionnaire translation, clear interpretation and comprehension in the Brazilian-Portuguese language, the 25 patients who participated in the cultural adaptation were not included in the statistical analysis.

Results

Study population

The Brazilian-Portuguese GIQLI questionnaire final version was administered to a convenience sample of patients (n = 88) of both sexes (Fig. 2). No patient declined to participate.

Most patients were women 87.5% (n = 77); 12.5% (n = 11) were men; 25.0% (n = 22) had completed high school education, and 39.8% (n = 35) had completed college or higher education. Mean age was 45.1 ± 13.8 years.

Cultural adaptation

In the cultural adaptation phase, seven questions showed a level of >15% misunderstanding in the pretest. After review, a final translation was defined (Supplementary Data). The patients had no doubts about the questionnaire and found it easy to answer. The mean time to respond to the questionnaire was 10 minutes.

Reliability

Internal consistency

The final version of the Brazilian-Portuguese GIQLI for the total questionnaire domains (n = 63) expressed by Cronbach's alpha correlation coefficients for internal consistency was 0.89, which was considered excellent.²² All domains favorably contributed to the internal consistency of the scale (Table 1).

Table 1.

Internal Consistency (Cronbach's Alpha) of the Brazilian-Portuguese GIQLI Questionnaire (n = 63)

Items—Cronbach's alpha = 0.89	Mean	SD	Corrected item—total correlation	Cronbach's alpha if item deleted
Physical well-being	30.41	6.67	0.74	0.85
Large bowel function	16.90	5.26	0.69	0.86
Emotional well-being	18.97	3.98	0.77	0.85
Upper gastrointestinal tract function	20.70	6.29	0.83	0.82
Meteorism	6.98	3.29	0.71	0.87

GIQLI, Gastrointestinal Quality of Life Index; n, number of patients; SD, standard deviation.

Test-retest

Test-retest reliability was tested in 30 patients at three different time intervals after 2 and 4 weeks, respectively. The Brazilian-Portuguese GIQLI questionnaire demonstrated excellent ICC. The intraclass correlation domains ranged from 0.918 (95% confidence interval [CI] = 0.850–0.958; P < .001) for meteorism to 0.956 (95% CI = 0.920–0.978; P < .001) for large bowel function (Table 2).

Table 2.

Test-Retest Reliability (Intraclass Correlation Coefficient) Values of the Brazilian-Portuguese GIGLI Version (n = 30)

Reliability	ICC	95% CI	P
Physical well-being	0.937	0.884–0.968	<.001^*
Large bowel function	0.956	0.920–0.978	<.001^*
Emotional well-being	0.944	0.897–0.971	<.001^*
Upper gastrointestinal function	0.944	0.897–0.971	<.001^*
Meteorism	0.918	0.850–0.958	<.001^*
Score total	0.957	0.922–0.978	<.001^*

P < .001.

GIQLI, Gastrointestinal Quality of Life Index; n, number of patients; ICC, intraclass correlation coefficient; CI, confidence interval.

Validation

The Brazilian-Portuguese GIQLI and the SF-36 subscale scores demonstrated significant correlations, except for the low correlation between the SF-36 social functioning and the Brazilian-Portuguese GIQLI large bowel function subscales (r = 0.211). The Brazilian-Portuguese GIQLI total score showed significant correlation with all SF-36 subscale scores (Table 3).

Table 3.

Results of the Spearman Correlation Test (Represented by Rho Coefficient) Between the Brazilian-Portuguese GIQLI and the SF-36 Questionnaires (n = 63)

Variables	Physical well-being	Large bowel function	Emotional well-being	Upper gastrointestinal function	Meteorism	Brazilian-Portuguese GIQLI total
SF-36 physical functioning	0.440^**	0.393^**	0.496^**	0.557^**	0.349^**	0.533^**
SF-36 role functioning—physical	0.417^**	0.408^**	0.499^**	0.566^**	0.314^*	0.526^**
SF-36 bodily pain	0.439^**	0.500^**	0.460^**	0.513^**	0.424^**	0.554^**
SF-36 general health	0.447^**	0.464^**	0.552^**	0.482^**	0.445^**	0.563^**
SF-36 vitality	0.531^**	0.484^**	0.626^**	0.667^**	0.475^**	0.673^**
SF-36 social functioning	0.432^**	0.211	0.486^**	0.441^**	0.338^**	0.441^**
SF-36 role functioning—emotional	0.327^**	0.387^**	0.471^**	0.480^**	0.334^**	0.468^**
SF-36 mental health	0.580^**	0.560^**	0.599^**	0.650^**	0.538^**	0.703^**

P < .05.

P < .01.

GIQLI, Gastrointestinal Quality of Life Index; SF-36, Short-Form Health Survey; n, number of patients; Spearman correlation coefficient (rho).

Discussion

Based on our results, the Brazilian-Portuguese version of the GIQLI questionnaire demonstrated high reliability and validity, supporting the importance of this instrument for assessing the impact of the general and specific GI diseases and distress on health-related QoL.

To ensure the quality of the cultural adaptation of the GIQLI into Brazilian-Portuguese, ^©Mapi Research Trust–ePROVIDE™ linguistic validation process guidelines were followed (Fig. 1). In the translation and back-translation process of this study, appropriate language terminology was considered to cover the entire Brazilian territory to avoid regional adaptation. All patients found the questionnaire easy and fast to be self-administrated.

Psychometric results of the Brazilian-Portuguese GIQLI were similar to those found in the validations conducted by Eypasch et al.¹² in the English version of the GIQLI, and in the Swedish, Spanish, Chinese-Taiwan, and Chinese versions.^13–16

Internal consistency for the Brazilian-Portuguese GIQLI total Cronbach's alpha score (0.89) given in Table 3 demonstrated strong reliability. This result was comparable with the English (0.93), Swedish, and Chinese-Taiwan (0.92), and Chinese (0.89) validation versions of the GIQLI questionnaire.^12,13,15,16

The reproducibility evaluation (test-retest reliability) ICC showed overall excellent results (0.95) and in its five domains. The Brazilian-Portuguese GIQLI version total score ICC had higher results compared with other language-validated versions corroborating with its reliability.^12,13,15,16 The instrument longitudinal responsiveness confirmed the ability to identify clinical change over time.

To assess construct validity, the Brazilian-Portuguese GIQLI questionnaire had significant Spearman correlation with the SF-36 subscales, except for the SF-36 social functioning and the Brazilian-Portuguese GIQLI lower bowel function domain (r = 0.21; P < .01). This result might be related to patients' complaint on having frequent diarrhea postcholecystectomy interfering with social functioning.²⁴

The significant correlation among all other Brazilian-Portuguese GIQLI domains and the SF-36 subscales suggests that the cholecystectomy procedure might have an important impact on patients' QoL (P > .05).

Other questionnaires related to GI systems in Brazil used the SF-36 for validation, the Gastrointestinal Symptom Rating Scale (GSRS),⁹ and the Inflammatory Bowel Disease Questionnaire (IBDQ).¹⁰ Although both questionnaires demonstrated overall good to moderate correlations with the SF-36, a stronger correlation in the Brazilian-Portuguese GIQLI questionnaire was observed.

Developing a questionnaire assessing patients' QoL regarding GI diseases and distress has been the aim of several authors.⁵ In the literature review, few questionnaires translated and validated into Brazilian-Portuguese to assess the impact of the GI diseases and distress in patients' QoL were found.^7–10,25 Although those instruments evaluated the GI system, they do not comprise generic and specific questions to evaluate patients' upper GI tract function, large bowel function, emotional well-being, physical well-being, and meteorism in one single questionnaire.

The Gastrointestinal Quality of Life Index (GIGLI) questionnaire was named as a modular questionnaire, combining disease-specific and generic instruments, including emotional and physical well-being, demonstrating robust psychometrical reliability to evaluate the QoL of patients suffering from different GI diseases.²⁶ The instrument was considered reliable by other authors to investigate the impact of specific diseases, distress, symptoms, and treatments on patient's QoL such as GI cancer, gallstones, gastroesophageal reflux and dyspepsia, irritable bowel syndrome.^27–30

Study limitations

Not conducting face-to-face interviews for the psychometric evaluation owing to the SARS-COVID-19 pandemics may be considered a limitation of this study.

Conclusion

The GIQLI was validated into Brazilian-Portuguese showing excellent internal consistency and reliability. The questionnaire was considered to be easily understood and fast to be answered by the patients.

With relevant reproducibility (test-retest) and construct validity results, the Brazilian-Portuguese GIQLI questionnaire is now available to be used to measure the impact of GI diseases and distress in the Brazilian population's QoL. Further studies with the validated version of the Brazilian-Portuguese GIQLI may be conducted by researchers to evaluate the effectiveness of the cholecystectomy in patient's QoL as a short, middle, and long-term treatment option.

Footnotes

Acknowledgment

The authors thank all patients who contributed to this study, and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).

Authors' Contribution

K.R.P.: conception, design, data acquisition, data analysis and interpretation, drafting, writing and work review; C.T.M.: data acquisition, data analysis, interpretation, and review; J.P.T.: data analysis, interpretation, drafting, writing and work review; E.M.C.Jr.: conception, design, data acquisition, and work review; M.B.F.: data analysis, interpretation, drafting, and work review. M.J.A.B.R.: conception, design, drafting, and work review; G.J.L.F.: data analysis, interpretation, drafting, and work review; M.M.L.: conception, design, data acquisition, data analysis and interpretation, drafting, writing and work review.

All the authors approved the final version of this article before submission, and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Author Disclosure Statement

No competing financial interests exist.

Funding Information

This study was funded by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES-109723).

Supplementary Material

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Supplementary Material

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