DDW 2014 Note: How Common is Functional Dyspepsia in U.S. Adults? Findings From Our National Survey.

Functional dyspepsia (FD) is a common disorder characterized by symptoms that are often described as indigestion; unpleasant sensations in the middle of the abdomen, uncomfortable fullness after eating, and sometimes inability to eat normal-size meals. FD is a much-researched disorder, but surprisingly, no nationwide studies have been done in the U.S. to evaluate what proportion of adults actually meet formal criteria for FD as defined by the current Rome III diagnostic criteria. Moreover, little is known about how rates of dyspepsia differ among race or ethnic groups or between different age group in the American population.

Today (May 3, 2014) I presented in poster format at Digestive Disease Week 2014 in Chicago the results of statistical analyses that our research team carried out to estimate how common FD is in American adults. We used for this purpose data from the Rome Normative Gastrointestinal Symptom Survey that we conducted last year, and which was sponsored by the Rome Foundation. In this secure online survey, we obtained responses from a large group of adults across every state in the U.S. The survey included questions about the responders’ demographics, health history, and the whole Rome III Diagnostic Questionnaire that diagnoses all functional gastrointestinal disorders. To minimize bias due to the possibility that people with GI symptoms might be more interested than others in participating and therefore be over-represented in our sample, invitations to participate described the study as a physical symptoms survey but did not mention gastrointestinal symptoms. We also controlled how many participants in different demographic categories could participate, in order to ensure equal gender proportions and get enough minority participation for our sample to be similar to the U.S. population.
A total of 1,665 individuals ranging in age from 18-94 years completed our survey, but we then eliminated from our analysis dataset people who showed evidence of inconsistent survey answers (we included three repeat questions in the survey for quality-check purposes), leaving us with responses from 1,277 people suitable for analysis. We have used that sample to estimate how common different functional gastrointestinal disorders are in the U.S. population and whether they have different frequency in various subgroups of the population (like males vs. females or older individuals versus young). In today’s presentation we only reported such findings for FD, but we will also be presenting our results for IBS and fecal incontinence separately here at DDW on Tuesday. We found that 11.4% of the people who completed our survey met Rome III criteria for FD. However, to get a more accurate estimate of the national dyspepsia prevalence, we statistically adjusted (weighted) our calculations to make the sample match the national adult age, gender and race/ethnicity distribution in the 2010 U.S. Census. Doing this only altered our numbers slightly, resulting in an estimated overall national U.S. FD rate of 11.9%.

We also found that functional dyspepsia tended to be more common in women than men (13.0% versus 9.9%) but this actually did not quite reach statistical significance, so we cannot be confident about the sexes really being different in this regard. In both sexes, FD rates were lowest in the youngest and oldest age groups, and significantly higher at mid-life; see the Figure below. Dyspepsia prevalence was not significantly different in white (12.3%) hispanic (12.9%) and black (9.6%) respondents in our survey.

FDrate

There are presently two recognized subtypes of FD, separated by difference in the symptom pattern. A surprising finding in our survey was that only 3 individuals in our whole sample (a mere 0.2%) met criteria for one of those sub-types, which is called Epigastric Pain Syndrome (defined primarily by pain in the upper gut, above the stomach). In contrast, most of the people (87%) in our survey who qualified for FD diagnosis based on their responses fit into the other subgroup, called Postprandial Distress Syndrome (meaning that they mostly have uncomfortable fullness after eating).
In summary, our analyses of responses to the FD diagnostic questions in this large nationwide survey give a clear picture for the first time of the prevalence of this disorder overall in the U.S. and in population subgroups, as it is defined by current Rome symptom criteria. Our results indicate that about 12% of American adults have this disorder, which makes it one of the most common of all gastrointestinal problems in the U.S.

Presentation:

Sa1335. Olafur S. Palsson, Miranda A. Van Tilburg, Brennan M. Spiegel, Jan F. Tack, Robin C. Spiller, Lynn S. Walker, Yunsheng Yang, William E. Whitehead. Uninvestigated Dyspepsia in the U.S. General Population: Results From the ROME Normative Gastrointestinal Symptoms Survey (RNGSS). Center for Functional GI and Motility Disorders, University of North Carolina, Chapel Hill, NC; Digestive Diseases, VA/UCLA, Los Angeles, CA; TARGID, University Hospitals of Gasthuisberg, Leuven, Belgium; Nottingham Digestive Diseases Centre Biomedical Research Unit, University of Nottingham, Nottingham, United Kingdom; Adolescent Medicine, Vanderbilt Children’s Hospital, Nashville, TN; Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, Beijing, China.

Advertisements

DDW 2013 Note: Self-perceived Poor Health in IBS is Mostly Due to Other Things Than Bowel Symptoms

Disease and illness are two different phenomena that overlap to a widely varying degree1. Disease is a problem with the structure or function of an organ or organ system in the body. Illness, in contrast, refers to the behavioral, emotional and cognitive reactions or consequences of that disease (for example, the behavior of lying in bed, feeling lousy and considering oneself to be unhealthy are all very common illness consequences of having the viral disease influenza). It is of course, possible to have disease without any illness if there are no troublesome symptoms. And conversely, it is possible for people to feel ill without any physical disease, for example because of psychological upset, physical over-exertion, or extreme fatigue. However, most disease produces some physical symptoms that in turn result in some degree of illness. How much a given amount of disease results in the patient being ill and perceiving himself/herself to be in poor health varies a lot from person to person, though. And in chronic diseases, where physical symptoms are present frequently over time, the degree to which people feel in poor health and have illness with their disease is of major importance, for it will likely affect their entire life outlook and functioning.

When I was the Director of a Behavioral Medicine Clinic at Eastern Virginia Medical School, where we treated a large number individuals with IBS, we had this standard questions on our health history intake form: “How would you rate your overall health?”. The were four answer options: Poor, Fair, Good, and Excellent. I found it very intriguing to see that sometimes we would get IBS patients with severe bowel symptoms who rated their overall health on this four-point scale as “Excellent” at the very time that they were coming to us seeking help for a disease that was causing them considerable trouble and suffering. And conversely, IBS patients in our clinic with only mild bowel symptoms would sometimes rate their health as “Poor” even though they did not report any other serious medical problems. In short, it became clear to me that self-perceived health of IBS patients was commonly not very closely tied to the status of the bowel symptoms that define the disorder. Many people who work a lot with IBS or other chronic illness have noted similar discrepancy between disease severity and sense of health, but what other factors than disease determines how much illness is associated with a disease has generally been poorly understood.

Today at Digestive Disease Week 2013 in Orlando, Lackner and colleagues presented an interesting analysis of this in IBS that sheds some light on this matter. They studied 235 IBS patients who had no other gastrointestinal disease. The patients completed a whole battery of questionnaires to measure their self-rated health (using a 5-point rating scale) along with psychological symptoms, general (non-gastrointestinal) physical symptoms, quality-of-life impact of the IBS symptoms, and social functioning. The investigators found that the actual severity of IBS symptoms (measured on the validated IBS Severity Scale) and how much the IBS affected life functioning only predicted self-ratings of poor health to a very minor degree (even though it was statistically significant in this large sample). Instead, a whole group of other factors that had nothing to do with bowel symptoms were more substantially associated with poor health, including fatigue, the amount of general non-gastrointestinal body symptoms or non-GI diagnoses, negative social interactions, and feeling anxious or depressed. Because so many different variables correlated with poor self-rated health, the investigators simplified their explanatory model by picking the statistically strongest contributing factors, and found in the end that three separate variables — fatigue, somatization (that is, the amount of general non-GI symptoms) and negative social interactions — added together in predicting self-ratings of poor health, and added together to produce a sense of poor health. Together, these three variables explained a total of 35% of the variability in health self-ratings.

Assuming that the three key variables identified in this study to be associated with poor self-perceived health hold up in analysis of other patient samples, these observations have clear implications for treatment of IBS (and perhaps for other chronic disease conditions as well). They confirm that IBS bowel symptoms actually play a relatively minor role in patients’ personal sense of health, and point instead to specific other aspects of IBS functioning that should be addressed to improve this important aspect of personal well-being. It seems likely that some fine-tuning or shift in emphasis in the adjunctive psychological and educational interventions that are widely used to help IBS patients could accomplish this, because the tools for addressing each of these three variables that seem to contribute substantially to a sense of poor health already exist: Cognitive behavioral therapy is ideal for addressing and neutralizing the impact of negative social interactions; hypnosis treatment reduces somatization in IBS (and cognitive behavioral therapy does so as well to some extent); and teaching patients methods that improve sleep (something that in my opinion far too often neglected in IBS, which is a disorder notorious for impaired sleep) is already done in some places and could be done much more routinely and systematically.

What is missing now, of course — even in spite of these new insights — is to explain what accounts for the rest of the variability in how healthy or ill IBS patients feel (more than half of it is still unexplained). Further research will hopefully add those missing pieces in the future, but this is a great start and a valuable addition to the research literature.

Presentation:

Sa1326 “Psychosocial Predictors of Self Ratings of Health in Moderate to Severe IBS Patients: What’s Involved in Feeling Healthy Besides the Severity of GI Symptoms?” Jeffrey M. Lackner, Gregory D. Gudleski, Laurie Keefer, Darren M. Brenner, Travis J Stewart, Gary Iacobucci, Rebecca Firth, Camille Simonetti, Christopher Radziwon, Susan S. Krasner, Michael D. Sitrin, Leonard A. Katz, Sarah Quinton and Elyse Sklar. University at Buffalo, SUNY, Buffalo, NY; Northwestern University, Chicago; Wayne State University, Detroit, MI

Presented at Digestive Disease Week in San Diego, May 18, 2013.

    References:

Helman CG. Disease versus illness in general practice. J R Coll Gen Pract. 1981 September; 31(230): 548–552

.Lackner_2

Jeffrey Lackner, Ph.D., Associate Professor of Medicine at the University of Buffalo, SUNY, and Principal Author of this Study Report, in the Poster Session at Digestive Disease Week 2013 Today.