Irritable bowel syndrome (IBS) is a highly prevalent condition with a large health economic burden of illness marked by impaired health-related quality of life (HRQOL), diminished work productivity, and high expenditures. Clinicians should routinely screen for diminished HRQOL by performing a balanced biopsychosocial history rather than focusing just on bowel symptoms. HRQOL decrements should be acknowledged and addressed when making treatment decisions.
Irritable Bowel Syndrome (IBS) is a multisymptom condition defined by abdominal pain, abdominal discomfort, and abnormalities in stool form and frequency. IBS is a highly prevalent condition that can affect patients physically, psychologically, socially, and economically. Understanding the IBS burden of illness serves several purposes. For patients, it emphasizes that they are not alone, and that many others suffer from IBS and share the same disease-related experiences. For health care providers, it offers an opportunity to improve their treatment of IBS patients, who comprise a large portion of their medical practice. By better understanding the IBS illness experience, providers are better equipped to intervene and implement treatments tailored to each patient’s symptoms and health-related quality of life (HRQOL) decrement. For researchers and drug-approval authorities, IBS is approached as a condition with a prevalence and HRQOL impact that matches other major diagnoses such as diabetes, hypertension, or kidney disease. For employers and health care insurers, the overwhelming direct and indirect expenditures related to IBS are revealed, providing a business rationale to ensure that IBS is treated effectively. This article will summarize data regarding the burden of illness of IBS, including: the prevalence of IBS and its subtypes, the age of onset and gender distribution, the effect on HRQOL, and the economic burden of IBS, including direct and indirect expenditures and related clinical predictors.
Prevalence of IBS
It is estimated that the prevalence of IBS in North America and Europe ranges from 1% to over 20%. This wide range indicates that IBS prevalence depends on many variables, including the case-finding definition employed (eg, Manning criteria vs Rome criteria), the characteristics of the source population (eg, primary care vs specialty clinic), and the study methods and sampling frame of the studies. To refine the prevalence estimate, it is worth evaluating the studies that specifically employ consensus-based Rome definitions (the gold standard) and draw upon patients from the general adult community (ie, not exclusively from primary or specialty care). Four eligible studies evaluating 32,638 North American subjects meet these criteria. When comparing these studies, the IBS prevalence varied from 5% to 10%, with a pooled prevalence of 7% (95% confidence interval [CI] 6% to 8%). Previous reviews indicate that IBS patients are divided evenly among the three major subgroups (IBS-diarrhea, IBS-constipation, and IBS-mixed). However, the true prevalence of IBS subtypes in North America remains unclear; one study suggested that IBS with diarrhea is the most common subtype, whereas another indicated that mixed-type IBS is most common.
Demographic predictors of IBS
Demographic predictors of IBS include gender, age, and socioeconomic status. The odds of having IBS are higher in women than men (pooled odds ratio [OR] 1.46; 95% CI 1.13 to 1.88). However, IBS is now recognized to be a key component of the Gulf War syndrome, a multisymptom complex affecting soldiers (a predominantly male population was engaged in the Gulf War). Patients under the age of 50 years are more commonly diagnosed with IBS, although 2% to 6% of patients are 50 years or older. These data suggest that the pretest likelihood for IBS is higher in younger patients, but that patients of all ages may be diagnosed with the condition. This review identified two studies that report IBS prevalence by income strata, both of which revealed a graded decrease in IBS prevalence with increasing income. Eight percent to 16% of people earning less than $20,000 annually carry the diagnosis, compared with only 3% to 5% of people earning greater than $75,000.
Demographic predictors of IBS
Demographic predictors of IBS include gender, age, and socioeconomic status. The odds of having IBS are higher in women than men (pooled odds ratio [OR] 1.46; 95% CI 1.13 to 1.88). However, IBS is now recognized to be a key component of the Gulf War syndrome, a multisymptom complex affecting soldiers (a predominantly male population was engaged in the Gulf War). Patients under the age of 50 years are more commonly diagnosed with IBS, although 2% to 6% of patients are 50 years or older. These data suggest that the pretest likelihood for IBS is higher in younger patients, but that patients of all ages may be diagnosed with the condition. This review identified two studies that report IBS prevalence by income strata, both of which revealed a graded decrease in IBS prevalence with increasing income. Eight percent to 16% of people earning less than $20,000 annually carry the diagnosis, compared with only 3% to 5% of people earning greater than $75,000.
HRQOL of IBS
Several studies have compared HRQOL in IBS patients with HRQOL in healthy controls or patients with non-IBS medical disorders, and these have been summarized in a previous systematic review. Data consistently reveal that patients with IBS score lower on all 8 scales of the SF-36 HRQOL questionnaire compared with normal non-IBS cohorts. IBS patients have the same physical HRQOL as patients with diabetes, and a lower physical HRQOL compared with patients who have depression or gastroesophageal reflux disease. Also, mental HRQOL scores on the SF-36 were lower in patients with IBS than in those with chronic renal failure, an organic condition characterized by considerable physical and psychological disability. The health utility of severe IBS, where utility is a measure of HRQOL on a scale of 0 (death) to 1 (perfect health), was found to be 0.7. This utility is similar to that of Class 3 congestive heart failure (CHF) and rheumatoid arthritis.
This HRQOL decrement in IBS patients can be severe enough to raise the risk of suicidal behavior is some cases. The relationship between IBS and suicidality appears to be independent of comorbid psychiatric diseases such as depression. However, studies examining this relationship were performed in tertiary care referral populations. Therefore, the HRQOL decrement and suicidality risk documented in these cohorts may not be applicable to community-based populations. Regardless, IBS unquestionably has a negative impact on HRQOL, and failing to recognize this impact could undermine the physician–patient relationship and lead to dissatisfaction with care. Given that HRQOL decrements are common in IBS, it is recommended that routine screening for diminished HRQOL in IBS patients be performed. Treatment of IBS should be initiated when the symptoms are found to reduce functional status and diminish overall HRQOL. Furthermore, clinicians should remain alert to the potential for suicidal behavior in patients with severe IBS symptoms, and initiate timely interventions if suicide forerunners are identified.
Accurate measurement of HRQOL requires a thorough and often time-consuming evaluation of biologic, psychologic, and social health domains. In the setting of a busy outpatient clinic, this may be a practical limitation. To help providers gain better insight into their patients’ HRQOL, a concise list of factors known to predict HRQOL in IBS might be helpful, which providers then could use to question patients routinely in a timely manner. Several studies have identified predictors of HRQOL in IBS, the most consistent of which is the severity of the predominant bowel symptom. Data from several studies indicate that in patients with IBS, HRQOL decreases in parallel with increasing symptom severity. Therefore, it is important to identify and gauge the severity of the predominant symptom of patients with IBS. Studies have shown that the impact of physical HRQOL symptoms in IBS is associated with an increase in the duration of symptom flares and the presence of abdominal pain (as opposed to discomfort). Mental HRQOL symptoms are associated with abnormalities in sexuality, mood, and anxiety. Each of these domains shares a common association with symptoms of chronic stress and vital exhaustion, including tiring easily, feeling low in energy, and experiencing sleep difficulties. Patients acknowledge that these symptoms prompt avoidance of socially vulnerable situations (eg, being away from restrooms) and activities (eg, eating out for dinner). In contrast, HRQOL is not strongly determined by the presence of specific gastrointestinal (GI) symptoms (eg, diarrhea, constipation, bloating, dyspepsia), degree of previous GI evaluation (eg, previous flexible sigmoidoscopy or colonoscopy), or common demographic characteristics (eg, gender, age, marital status).
These findings suggest that in addition to the physiologic epiphenomena used to gauge HRQOL (eg, stool frequency, stool characteristics, subtype of IBS), it may be more efficient to assess HRQOL by gauging global symptom severity, addressing symptom-related fears and concerns, and identifying and eliminating factors contributing to vital exhaustion in IBS. This process may occur through teaching coping mechanisms and relaxation skills, developing a greater sense of self-efficacy by encouraging control over IBS symptoms, promoting lifestyle modifications to reduce symptoms (ie, diet, exercise, quitting smoking), and encouraging patients to recognize their own limitations. When combined with standard medical therapies, these approaches yield improved overall HRQOL. In short, treating bowel-related symptoms of IBS is important, but may not be sufficient, to impact overall HRQOL. In addition to treating symptoms, providers should attempt to positively modify the cognitive interpretation of IBS symptoms (ie, acknowledge and address the emotional context in which symptoms occur).
Measuring HRQOL in IBS
Measuring HRQOL can provide useful information for various clinical and research purposes. For example, it can provide insight not only to a patient’s physical symptoms and burden of illness, but also provide information about emotional well being, social functioning, and other emotions and behaviors. Originally, the SF-36 questionnaire was used to measure HRQOL in IBS patients. However, given that the SF-36 is a generic instrument, the need for a syndrome-specific questionnaire arose. Multiple IBS-targeted HRQOL questionnaires have been developed and validated including the IBS-QOL, IBSQOL, and IBS HRQOL. Table 1 shows these instruments in comparison to the generic SF-36 questionnaire. The information provided across HRQOL domains could be useful to develop targeted therapy. For example, if an IBS patient has a low HRQOL related to poor emotional well being as measured by the IBS-QOL, then the clinician might address coping mechanisms or initiate pharmacotherapy with a selective serotonin reuptake inhibitor (SSRI) based on this information.
| Scales | HRQOL Measures | |||
|---|---|---|---|---|
| SF-36 | IBS-QOL | IBSQOL | IBS-HRQOL | |
| Physical functioning | 10 | 7 | 3 | 6 |
| Physical role limitations | 4 | 0 | 3 | 0 |
| Bodily pain | 2 | 0 | 0 | 0 |
| General health perception | 5 | 0 | 0 | 0 |
| Energy/fatigue | 4 | 0 | 3 | 6 |
| Social functioning | 2 | 7 | 3 | 0 |
| Emotional role limitations | 4 | 0 | 3 | 0 |
| Emotional well being | 5 | 8 | 3 | 6 |
| Sexual function | 0 | 2 | 3 | 0 |
| Food avoidance | 0 | 3 | 3 | 0 |
| Health worry | 0 | 3 | 3 | 0 |
| Body image | 0 | 4 | 0 | 0 |
| Bowel symptoms | 0 | 0 | 0 | 8 |
| Sleep | 0 | 0 | 3 | 0 |
Related posts:
Inflammation and Microflora
Therapies Aimed at the Gut Microbiota and Inflammation: Antibiotics, Prebiotics, Probiotics, Synbiotics, Anti-inflammatory Therapies
Centrally Acting Therapies for Irritable Bowel Syndrome
Inflammation and Microflora
The Role of Diagnostic Testing in Irritable Bowel Syndrome
Emerging Pharmacological Therapies for the Irritable Bowel Syndrome
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
