The gastro-esophageal refl ux disease questionnaire using Indonesian language: a language validation survey

Background: The aims of this study were to test the usefulness of the Gastro-esophageal Refl ux Disease Questionnaire (GERDQ) in the diagnosis of GERD, to validate the GERDQ written in Indonesian language, and to evaluate the reliability of the GERDQ for use in Indonesian-speaking GERD patients (Virginia study). Methods: This was a prospective survey of 40 patients diagnosed with GERD, based on an endoscopic examination, in 3 cities in Indonesia (Jakarta, Bandung, and Surabaya) from 15 January to 15 May 2009. Patients were asked to complete the GERDQ, and the validity and reliability of the questionnaire were assessed. Results: The percentages of respondents who reported symptoms lasting 4–7 days were as follows: 68% had a burning sensation behind the breastbone (heartburn); 65% had stomach content (fl uid) move upwards to the throat or mouth (regurgitation); 70% had a pain in the centre of the upper abdomen; 58% had nausea; 63% had diffi culty sleeping because of the heartburn and/or regurgitation; and 63% took additional medication for heartburn and/or regurgitation. Cronbach’s alpha was 0.83, indicating that all of the questions in the Indonesian-language GERDQ are valid and reliable for Indonesian GERD patients. Conclusions: This study achieved the primary objectives and showed that the GERDQ is valid and reliable for use with Indonesian-speaking GERD patients. The results were consistent with those of the DIAMOND study, which showed that the GERDQ can be used to diagnose GERD on the basis of the reported symptoms. (Med J Indones 2011; 20:125-30) Key word: GERD, GERDQ, Reliability test, Validity test, Virginia study Correspondence email to: [email protected] Gastro-oesophageal refl ux disease (GERD) is a condition that develops when refl ux of the stomach’s contents causes troublesome symptoms or complications.1 GERD is a chronic disease and causes persistent symptoms in 79–87% of patients. Although the disease itself is benign and the prevalence of complications and severe GERDrelated morbidity is low, GERD can severely reduce a patient’s quality of life.2,3 GERD is common but its prevalence varies between different parts of the world. GERD is highly prevalent in Western countries,1,3 affecting 10–30% of the population. In Singapore, the prevalence of GERD symptoms increased from 1.6% of the population in 1994 to 10.6% in 2001. 1,4-6 The prevalence of GERD in Hong Kong was 35% of the population in 2003.7 Simadibrata et al. 126 Med J Indones Endoscopy and oesophageal 24-h pH monitoring were initially proposed as the gold standards for the diagnosis of GERD.8,9 However, it is estimated that up to 70% of patients with typical symptoms of GERD have normal oesophageal mucosa on upper endoscopy (non-erosive refl ux disease) or endoscopy-negative refl ux disease.9 Oesophageal 24-h ambulatory pH monitoring is not sensitive enough to serve as a diagnostic criterion. A Chinese GERD study group found that only 63 of 102 GERD patients were endoscopy positive and only 84 of 115 patients had a positive pH test result.9 Therefore, about 25% of patients cannot be diagnosed using this method. Furthermore, endoscopy and pH testing are expensive and are not available in small hospitals or clinics. Because there is no gold standard for diagnosing and evaluating GERD, the valid assessment of symptoms is especially important.8-11 Although a combination of symptom scoring and endoscopy has been shown to diagnose GERD with high specifi city, it is increasingly accepted that management of GERD in primary care is best addressed on the basis of the patient’s report of his or her symptoms.12 Several communication tools are used to help the physician make appropriate management decisions. In 2001, Shaw et al.2 developed a brief, simple 12-item questionnaire called the Refl ux Disease Questionnaire (RDQ), which is reproducible and reliable for the diagnosis of GERD. Although the specifi city is low (50%), the RDQ has high sensitivity (94.12%), good psychometric properties, is responsive to changes in health, and is well suited for use in both primary care settings and epidemiological studies. Jones et al. developed and tested the GERD Impact Scale (GIS), a short questionnaire to aid patient–doctor communication. The GIS is a 1-page questionnaire that asks GERD patients about their symptoms and how these affect their everyday lives. It has been validated in a study involving 205 primary care patients with a new or existing diagnosis of GERD. The GIS demonstrated good psychometric properties in newly diagnosed GERD patients and those already receiving treatment. This simple communication tool is a useful aid for managing primary care patients with GERD.12 Indonesian people have many ethnics and languages, so it is very diffi cult to translate the GERD symptoms uniformly due to the expression variations. Current GERD monitoring instruments are not appropriate because they do not assess daily symptoms, are not suffi ciently responsive to short-term changes in health status, or have not been validated. To address these problems, the conceptual and psychometric requirements for a GERD symptom assessment ques tionnaire were identifi ed used to create the GERD Questionnaire (GERDQ).3 The GERDQ was created from 3 different validated questionnaires evaluated in the DIAMOND study.13 The GERDQ is a simple communication tool developed for physicians to identify and manage patients with GERD. The aim of this survey was to test whether the GERDQ is effective in diagnosing GERD, to validate the GERDQ written in Bahasa Indonesia, and to evaluate its reliability when used with Indonesian-speaking GERD patients (Virginia study = validated Survey of GERDQ in Indonesia).