Health Economics of IBS
07/05/05 03:01 PM
Loc: Seattle, WA
Health Economics of IBS -- Clinical Implications
Brooks D. Cash, MD, FACP
Irritable bowel syndrome (IBS) is a chronic gastrointestinal (GI) disorder characterized by impaired regulation of GI function (motility and secretion) and altered visceral sensitivity, resulting in the typical physical manifestations of abdominal pain, bloating, and abnormal bowel habits. IBS is a highly prevalent disorder, and although it does not have a significant impact on mortality, there remains no definitive curative therapy. Thus, patients with this condition may suffer from debilitating symptoms for prolonged periods. The burden of illness on patients, the healthcare industry, and employers that is directly attributable to IBS has only recently begun to be realized. This article summarizes the scope of the economic burden associated with IBS and examines potential targets for cost containment through directed education, recognition, and effective treatment of patients with IBS.
Economic Burden of IBS
IBS is extremely common, with population-based prevalence estimates ranging from 10% to 15% in North America.[1-2] Approximately 12% of patients in the primary care setting and 28% of patients seeking subspecialty gastroenterology care will be diagnosed with IBS.[3-4] Several patterns of healthcare seeking have been identified in patients with IBS. Although IBS affects both sexes, it is largely considered a women's health issue. Epidemiologic data suggest that the female:male ratio of IBS sufferers in the community is 2-3:1, although estimates differ depending on the practice setting from which such assessments are generated. Generally, however, two thirds of IBS sufferers in North America who seek medical care are women.[5,6] Although the minority (25%) of individuals with typical symptoms of the disorder actually do seek medical care, the high prevalence of IBS translates into a sizable absolute number of patients.[2,7] Recent reports estimate physician visits attributable to IBS to be as high as 3.5 million visits annually.[8-10] Additionally, it has been repeatedly demonstrated that patients with IBS are more likely to seek medical care for other, non-GI conditions or physical complaints, such as fibromyalgia or chronic pelvic pain. Because there are no discrete physical abnormalities or biochemical/serological markers that define IBS, this condition has historically been viewed by many clinicians as a diagnosis of exclusion. This view, coupled with the increasing number and cost of available diagnostic studies, can lead to extensive and unnecessary testing. An exhaustive exclusionary diagnostic evaluation, especially in patients with typical IBS symptoms without alarm features (age ≥ 50 years, fever, abnormal physical examination findings, hematochezia, unintentional weight loss, nocturnal symptoms, or a family history of organic GI disease), contributes to an increased burden on both patients and the medical system, and recently has been challenged regarding its usefulness in the management of such patients.
Direct vs Indirect Costs
When considering the economic burden of a condition, it is important to consider both direct and indirect costs. The direct costs (use of healthcare-related services such as physician visits, diagnostic tests, and prescription or over-the-counter medication) associated with IBS are substantial. Excluding prescription and over-the-counter medicines, direct costs have been estimated to range from $1.5 to $10 billion. The indirect costs of IBS, however, have been estimated to be much greater -- approaching $20 billion. Examples of indirect costs include expenses that are not directly associated with the procurement of healthcare resources, such as the loss of hourly wages resulting from missed work or diminished work productivity resulting from absences for physician visits or incapacitating symptoms. Although direct costs are relatively straightforward and measurable, indirect costs are much more difficult to quantify.
Indirect costs comprise 3 primary components -- absenteeism (time absent from work), presenteeism (decreased productivity at work), and diminished health-related quality of life (HRQoL) -- which, in turn, are intangible costs that may result in diminished productivity.[12,14-16] The economic impact of absenteeism is fairly straightforward to gauge because most employers maintain adequate records of employee absences for illness. It has been estimated that a minimum of one third of IBS patients are absent on average from 1 day of work or school per week because of their symptoms. Results of a recent survey indicate that patients with IBS were absent from work twice as many days per year due to illness as compared with healthy respondents. In 1998 the direct cost of treating an employee with IBS was nearly $4000 compared with $2350 for an employee without IBS. By comparison, indirect costs to the employer were approximately $470 higher for employees with IBS -- a likely underestimate because these indirect costs only included measures of absenteeism.
Presenteeism may represent a significantly larger and less appreciated component of indirect costs than absenteeism.[17-21] Results of a recent study that examined impaired work productivity and HRQoL in employees with IBS demonstrated that the disorder was associated with a 21% reduction in work productivity, the equivalent of working less than 4 days in a 5-day work week. Both absenteeism and presenteeism are growing concerns for both employers as well as interested consumers who are forced to bear the brunt of lost work productivity and subsidize employee healthcare costs. It is, therefore, critical for healthcare providers and managed care organizations to present solutions for employers on how best to manage the large, often unrecognized costs of IBS.
Finally, IBS has a significant negative impact on the HRQoL of affected patients[14,22-25] that is comparable to that of other chronic GI and non-GI disorders.[26-27] Reduction in HRQoL may result from several features of IBS that are also observed with other functional GI disorders. The multiple symptoms of IBS may wax and wane over time, leading patients to put off healthcare consultation, thus resulting in delayed diagnosis of, and extended time suffering from, the disorder.[12,28] Supporting this hypothesis is the observation that although multiple epidemiologic and clinical studies demonstrate that the symptoms of IBS typically appear between the ages of 15-30 years, most IBS patients do not seek their first healthcare consultation for the disorder until they are between the ages of 30 and 50 years, coinciding with peak employment ages. Last, as in other functional GI disorders, the historical absence of effective therapies addressing the multiple symptoms of IBS is also likely have a negative impact on the HRQoL of affected patients.
Clinical and Therapeutic Impact
What, then, can be done to mitigate some of the costs associated with IBS? Although it is not the focus of this column, accurate and timely diagnosis is an important consideration. For IBS, applying clinically proven symptom-based diagnostic criteria (Manning, Rome, Rome I, or Rome II) to make a positive, rather than exclusionary, diagnosis is an important step in the right direction to reduce overall costs. Previous analyses have demonstrated that in patients with suspected IBS who do not manifest alarm features, the pretest probability of organic disease is similar to that of the general population, suggesting that there is little to be gained by implementing exhaustive diagnostic evaluations in such patients.[11,31] Current recommendations for such patients are to initiate empiric therapy, reserving additional testing for nonresponsive patients. There is evidence that this "minimalistic" approach is gaining favor and that such an approach can reduce resource utilization involving diagnostic procedures and frequent office visits. The magnitude of the impact of this approach on the total costs associated with IBS, however, remains to be seen.
Regarding therapeutic interventions and minimization of the costs associated with IBS, it is becoming increasingly clear that the multiplicity of the symptoms may be as important a feature of the disorder as the severity of individual symptoms in terms of how patients report the "bothersomeness" or seriousness of their condition. A significant limitation of the so-called traditional therapies for IBS, such as bulking agents or antispasmodic medications, is that they only target single symptoms, a feature that may explain their absence of proven efficacy in randomized controlled trials. Alternatively, broader acting therapeutic agents or modalities that provide relief for the multiple symptoms of IBS would conceivably have promise in reducing multiple direct and indirect costs of this condition. In a study regarding the effects of psychotherapy in patients with severe IBS, Creed and colleagues demonstrated annual healthcare-related utilization savings of nearly $700 compared with usual care. In this trial, "usual care" was defined as whatever management was considered appropriate by the gastroenterologists or primary care physicians caring for the patients. Although not explicitly delineated in the text of the article, "usual care" in this case, consisted primarily of traditional IBS therapies (such as antispasmodic agents, antidiarrheals, and bulking agents). However, the generalizability of these results to the community setting is not known. Fortunately, physicians now have access to new and increasingly effective medical therapies for the management of the multiple symptoms of IBS in the form of the serotonergic agents, tegaserod and alosetron. It is widely accepted that these agents are effective therapies for IBS; both tegaserod and alosetron were the only agents to receive grade A recommendations as IBS therapies from the American College of Gastroenterology Functional GI Disorder Task Force, based on the high quality of published evidence supporting their global efficacy in IBS with constipation and IBS with diarrhea, respectively. However, although both tegaserod and alosetron are clinically effective, they have been associated with adverse effects. Tegaserod is reported to cause severe but transient diarrhea, whereas patients taking alosetron have reported episodes of ischemic colitis and severe constipation. Ischemic colitis has also been observed in the postmarketing experience with tegaserod, but the incidence rate of ischemic colitis in patients taking tegaserod appears to be similar to that observed in the general population and is actually lower than reported rates in IBS patients. Thus, a causal relationship between tegaserod and ischemic colitis has not been established.
Although the expense associated with these newer agents may result in an initial increase in the direct costs of IBS care, it is possible that they could, when clinically effective for appropriate individual patients, significantly reduce the long-term direct and indirect costs. Limited data exist regarding the use of these serotonergic agents and their actual impact on the costs of IBS. A study utilizing a decision-analysis model examined the benefits of symptom improvement vs the complications associated with alosetron therapy in the treatment of patients with IBS with diarrhea.[33-34] It showed that although the benefit-to-risk profile of alosetron was favorable, this treatment was associated with a potentially large cost per quality-adjusted life-year. Currently, alosetron therapy is limited to women with severe IBS with diarrhea that is refractory to traditional therapies. As a consequence, new or ongoing studies regarding the economic impact of this therapy on IBS are limited. (In order to prescribe alosetron, clinicians must be familiar with the current prescribing guidelines and be enrolled in the prescribing program administered by the manufacturer. Patients who are prescribed alosetron are given a patient information booklet to read and are asked to sign a patient-physician agreement indicating that they have both read and understand the effects of the medication and that they do desire to take it.)
Largely due to the limited availability of data concerning the economic impact of the serotonergic agents in the treatment of IBS, a series of articles addressing many of the issues discussed in this column was recently published in The American Journal of Managed Care .[14,35-39] [14,34-38] The authors of these articles explore the costs associated with IBS as well as treatment options, and provide readers with a comprehensive review of the epidemiology, prevalence, management, and economic impact of the disorder. (It should be noted that 3 of the 5 articles in this series deal with analyses focused on the effects of tegaserod. Given that alosetron administration is restricted, the applicability of additional cost analyses of alosetron-based intervention strategies may be limited. Tegaserod, however, is not restricted and actually has several indications for its use, so analyses of the economic effects of this medicine may be important in steering formulary decisions or benefit coverage.) In one of these studies, a budget-impact model was developed to assess the economic effect of adding tegaserod to the formulary of a managed care organization. This model estimated the economic impact for patients with IBS both 6 months before and 6 months after the initiation of tegaserod therapy. It was found that the total per-patient budget impact for all resources (including the cost of tegaserod) for a 6-month period was approximately $274 for women with IBS. Overall, 29% of the cost of tegaserod was offset by decreases in resource utilization (including pharmacy, inpatient, outpatient, endoscopic, and nonendoscopic resources). These results suggest that effective therapy can indeed decrease GI-related resource utilization, perhaps ultimately leading to a significant cost-offset percentage.
Also included in this issue of the journal was a retrospective, longitudinal study that evaluated the GI-related resource utilization (office visits, hospitalizations, emergency department visits, endoscopic and nonendoscopic procedures) in a managed care population consisting of tegaserod users and nonusers. It was found that GI resource utilization by tegaserod users for all comparisons before and after the initiation of therapy showed significant decrements in all utilization categories except for GI drug prescriptions. Matched nonusers did not show consistent decrements in GI resource utilization. Last, in an effort to illustrate the indirect costs associated with IBS and the potential cost savings that might accrue after effective therapeutic intervention, an economic model was designed to assess the indirect costs associated with tegaserod therapy in female patients with IBS. This model demonstrated that treatment resulted in gains of $1882 through avoided productivity losses per employee. The benefits of decreased amounts of work loss and the cost of therapy in this model predicted a very favorable benefit/cost ratio of 3.75, demonstrating the potential extrapolated value of effective therapy.
The symptoms of IBS and the impact of this chronic disorder on both patients and the healthcare system alike are substantial. Because IBS has such a high prevalence and predominantly affects adults of working age, it imposes a significant burden on the patient as well as the employer, third-party payers, and society through a variety of direct and indirect costs. Although estimates of the degree of this burden vary and may be difficult to ascertain or even recognize, it appears that the indirect costs associated with IBS (upwards of $20 billion annually) comprise the major component of total costs associated with the condition.
Strategies to reduce direct costs will necessarily be directed at recognition of the disorder and should include physician and patient education, paramedical-based education and therapy, lay support groups, optimization of the diagnostic approach to patients with suspected IBS, and implementation of IBS educational awareness and incentive programs similar to initiatives targeting other chronic disorders such as GERD, diabetes mellitus, and hypertension.[35,40] Additionally, there is emerging evidence that continued development and increasing use of clinically effective therapies that target the multiple symptoms of IBS appear to have the potential to facilitate significant reductions in both direct and indirect costs associated with this chronic disorder.
Supported by an independent educational grant from Novartis.
Brooks Cash, MD, FACP , Assistant Professor of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland; Chief, Gastroenterology Division and Colon Cancer Center Initiative, National Naval Medical Center, Bethesda, Maryland
Disclosure: Brooks Cash, MD, FACP, has disclosed that he has served as an advisor or consultant to Novartis and Wyeth.
Medscape Gastroenterology. 2005;7(1) ©2005 Medscape
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