Factor Analysis Defines Distinct Upper and Lower Gastrointestinal Symptom Groups Compatible With Rome IV Criteria in a Population-based Study.

The Rome IV criteria define functional gastrointestinal (GI) disorders by specific combinations of symptoms. It is possible to empirically evaluate these symptom combinations by factor analysis (a statistical procedure that groups variables that correlate). However, this analysis has not been performed for the Rome IV criteria, and factor analyses based on the previous versions of the Rome criteria did not use population-based data. We therefore investigated symptom grouping by the Rome IV questionnaire using factor analysis of a population-based sample. The Rome IV questionnaire was completed online in English by 5931 respondents from the United Kingdom, United States, and Canada (49% female, age range, 18-92 years). We performed an exploratory factor analysis on the Rome IV questions. Next, we performed a confirmatory factor analysis to compare the exploratory factor result to that of the Rome IV criteria. The exploratory factor analysis identified 8 factors that accounted for 45% of the variance in response: constipation, diarrhea, irritable bowel syndrome, abdominal pain, heartburn, nausea or vomiting, globus, and other upper GI symptoms. Most factors corresponded to distinct functional GI disorders defined by the Rome IV criteria-exceptions included abdominal pain and upper GI symptoms. In confirmatory factor analysis, the exploratory model fitted slightly better than that based on the Rome IV criteria (root mean square error of approximation, 0.063 vs 0.077). We used factor analysis to identify distinct upper and lower GI symptom groups that are compatible with the Rome IV criteria. Our findings support the use of the Rome IV criteria in research and clinical practice as a basis for development of diagnostics and management of patients.

Clevers E ，Whitehead WE ，Palsson OS ，Sperber AD ，Törnblom H ，Van Oudenhove L ，Tack J ，Simrén M ... -  《-》

Factor Analysis of the Rome IV Criteria for Major Disorders of Gut-Brain Interaction (DGBI) Globally and Across Geographical, Sex, and Age Groups.

The Rome criteria are widely accepted for diagnosing disorders of gut-brain interaction, but their global applicability has been debated. This study aimed to evaluate the validity of the Rome IV criteria by factor analysis globally, across geographical regions, by sex, and by age groups. Data were collected in 26 countries using the Rome IV questionnaire. Forty-nine ordinal variables were used in exploratory factor analysis (EFA) to identify clusters of inter-correlated variables (factors) within the data set. Confirmatory factor analysis with predefined factors of the disorders of gut-brain interaction was compared with the factors in the EFA. Analyses were performed globally, for each geographical region (North and Latin America, Western and Eastern Europe, Middle East, Asia), sex, and age groups (18-34, 35-49, 50-64, ≥65). A total of 54,127 people were included. The EFA identified 10 factors accounting for 57% of the variance: irritable bowel syndrome, constipation, diarrhea, upper gastrointestinal symptoms, globus, regurgitation/retching, chest pain, nausea/vomiting, and 2 right upper quadrant pain factors. Most factors had close correspondence to a Rome IV criteria diagnosis, but notably, functional dysphagia and heartburn symptoms were often included in the same factor and/or in upper gastrointestinal symptoms. Most factors were consistent across geographical regions, sex, and age groups, and compatible to the global results. All prespecified factors in the confirmatory analysis had a loading ≥0.4, indicating validity of the Rome IV criteria. The results indicate that the Rome IV criteria for irritable bowel syndrome, functional dyspepsia, functional constipation, globus, and biliary pain are globally valid and represent universal diagnostic entities that are similar across sex and age groups.

Hreinsson JP ，Törnblom H ，Tack J ，Drossman DA ，Whitehead WE ，Bangdiwala SI ，Sperber AD ，Palsson OS ，Simrén M ... -  《-》

Prevalence of Rome IV Functional Bowel Disorders Among Adults in the United States, Canada, and the United Kingdom.

Little is known about the population prevalence or demographic distributions of Rome IV functional bowel disorders (FBDs) or their effects on quality of life. We examined these in a multinational survey. We analyzed data from a population-based survey of adults in the United States, Canada, and United Kingdom (5931 valid responders; 49.2% female; mean age, 47.4 years; range, 18-92 years). The survey included the Rome IV Diagnostic Questionnaire, Rome III irritable bowel syndrome (IBS) and constipation questions, and the SF-8 quality of life questionnaire. The prevalence values of census-adjusted Rome IV FBDs were similar among the 3 countries; ranges were: 4.4%-4.8% for IBS, 7.9%-8.6% for functional constipation, 3.6%-5.3% for functional diarrhea, 2.0%-3.9% for functional bloating or distention, 1.1%-1.9% for opioid-induced constipation, 7.5%-10.0% for unspecified FBDs, and 28.6%-31.7% for any Rome IV FBD. FBDs were less common in older individuals, and all except functional diarrhea were more common in women. IBS was only half as prevalent by Rome IV as by Rome III criteria (4.6% vs 9.0% overall), primarily due to higher Rome IV minimum pain frequency. Functional diarrhea and functional constipation were more prevalent by Rome IV than Rome III criteria. Subjects with FBD had significant reductions in quality of life and reported more gastrointestinal doctor consultations than other subjects. More than 1 in 4 adults in the general population meet the Rome IV criteria for FBDs. These disorders affect quality of life and increase use of gastrointestinal health care. The switch from Rome III to Rome IV criteria reduces the prevalence of IBS by half, but increases the prevalence of functional constipation and functional diarrhea.

Palsson OS ，Whitehead W ，Törnblom H ，Sperber AD ，Simren M ... -  《-》

Epidemiology, clinical characteristics, and associations for symptom-based Rome IV functional dyspepsia in adults in the USA, Canada, and the UK: a cross-sectional population-based study.

The population prevalence, clinical characteristics, and associations for Rome IV functional dyspepsia are not known. Following the publication of the Rome IV criteria for functional gastrointestinal disorders, we aimed to assess the prevalence, characteristics, and associations for symptom-based Rome IV functional dyspepsia in adults across the USA, Canada, and the UK. We sent an internet-based cross-sectional health survey to adults in the general population of three English-speaking countries: the USA, Canada, and the UK. We used quota-based sampling to generate demographically balanced and population-representative samples. Individuals were invited to complete an online questionnaire on general health, without mention that the purpose of this survey was to examine gastrointestinal symptoms. We excluded participants who failed two attention-test questions or were excessively inconsistent on the three gastrointestinal questions that were presented twice in the survey for this particular purpose. The survey enquired about demographics, health-care visits, medications, somatisation, quality of life, and symptom-based criteria for Rome IV functional dyspepsia as well as for irritable bowel syndrome (IBS) and functional heartburn. We made subsequent comparisons between participants with Rome IV functional dyspepsia and controls without dyspepsia. The primary objective was to identify participants who fulfilled symptom-based criteria for Rome IV functional dyspepsia and categorise them into postprandial distress syndrome, epigastric pain syndrome, or overlapping subtypes. 6300 general population adults completed the health survey; 2100 each from the USA, Canada, and the UK. 369 responses were deemed inconsistent, leaving data for 5931 adults. Rome IV functional dyspepsia was significantly more prevalent in the USA (232 [12%] of 1949) than in Canada (167 [8%] of 1988) and the UK (152 [8%] of 1994; p<0·0001). The subtype distribution was 61% postprandial distress syndrome, 18% epigastric pain syndrome, and 21% overlapping variant with both syndromes; this pattern was similar across the countries. Participants with functional dyspepsia had significantly greater health impairment and health-care usage than those without dyspepsia. Participants with the overlapping variant showed greater somatisation and poorer quality-of-life scores than did individuals with either postprandial distress syndrome or epigastric pain syndrome alone. In multivariate analysis, independent factors associated with all functional dyspepsia subtypes included worsening quality of life and the presence of symptoms compatible with functional heartburn and IBS, with functional heartburn and IBS having the strongest association with overlapping postprandial distress syndrome and epigastric pain syndrome. Notably, somatisation showed a positive association with postprandial distress syndrome and the overlapping variant, and use of antidepressants showed a negative association with postprandial distress syndrome. Approximately 10% of the adult population fulfils symptom-based criteria for Rome IV functional dyspepsia and incurs considerable associated health impairment. The functional dyspepsia subtypes show differing associations, suggesting differences in pathophysiological processes or influences. The Rome Foundation, the US National Institute of Diabetes and Digestive and Kidney Diseases, the Swedish Medical Research Council, AFA Insurance, Ferring Pharmaceuticals, and the Faculty of Medicine, University of Gothenburg, Gothenburg, Sweden.

Aziz I ，Palsson OS ，Törnblom H ，Sperber AD ，Whitehead WE ，Simrén M ... -  《The Lancet Gastroenterology &amp; Hepatology》

Validation of Rome II criteria for functional gastrointestinal disorders by factor analysis of symptoms in Asian patient sample.

It has been unclear as to whether the Rome II criteria could be applied to patients in the Asia region with functional gastrointestinal (GI) diseases. The aim of the present study was to determine if symptoms of Asian patients with functional gastrointestinal disorders formed groups which corresponded to the Rome II diagnostic criteria. A modified English version of Talley's bowel disease questionnaire was developed in collaboration with various research teams in accordance with the Rome II criteria. This instrument was translated into the local languages of the following nine Asian regions: China, Hong Kong, Indonesia, Korea, Malaysia, Singapore, Taiwan, Thailand and Vietnam. From September to December 2001, newly enrolled outpatients attending 14 GI or medical clinics in these regions were invited to complete the questionnaire. From these respondents, patients with functional gastrointestinal disorders fulfilling the '12 weeks out of 12 months' criteria were separated for further analysis. Principal component factor analysis with varimax rotation was used to identify symptom clusters or factors. These factors were compared with the existing classification of functional GI diseases derived from the Rome II criteria. Factor analysis of symptoms from 1012 functional GI patients supported the Rome II classification of the following groups of functional GI disorders: diarrhea-predominant irritable bowel syndrome, functional constipation, functional dyspepsia, functional abdominal pain syndrome, functional heartburn, and functional vomiting. Functional diarrhea was combined with functional anorectal disorders, and globus merged with functional dysphagia into one factor. Some of the functional dyspepsia, abdominal bloating and belching symptoms were loaded into one factor. Factor analysis of symptoms from a sample of Asian patients with functional GI disorders partially supported the use of the Rome II classification.

Kwan AC ，Bao T ，Chakkaphak S ，Chang FY ，Ke M ，Law NM ，Leelakusolvong S ，Luo JY ，Manan C ，Park HJ ，Piyaniran W ，Qureshi A ，Long T ，Xu GM ，Xu L ，Yuen H ... -  《JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY》