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Celiac Disease Serology and Irritable Bowel Syndrome: Does the Relationship Merit Further Evaluation?: In Response

      We appreciate Sanders and Azmy's comments and their interest in our article.
      • Locke III, GR
      • Murray JA
      • Zinsmeister AR
      • Melton III, LJ
      • Talley NJ
      Celiac disease serology in irritable bowel syndrome and dyspepsia: a population-based case-control study.
      We wish to clarify that our study design was different than inferred by Sanders and Azmy. The patients in our study were identified by the symptoms they reported on a survey mailed to a random sample of the community. Hence, ours was a population-based sample, not a sample of primary care patients. The study consisted of minimal-risk interventions, and thus the patients did not undergo small bowel biopsy as part of the study protocol. The results of celiac serologic testing were unknown at the time of the physician interview and did not play a role in any decisions about patient care.
      Sanders and Azmy discuss the possibility of endomysial antibody-negative celiac disease. We recognize that it can occur and may be more common than has been appreciated previously.
      • Prasad S
      • Thomas P
      • Nicholas DS
      • Sharer NM
      • Snook JA
      Adult endomysial antibody-negative coeliac disease and cigarette smoking.
      • Dickey W
      • Hughes DF
      • McMillan SA
      Reliance on serum endomysial antibody testing underestimates the true prevalence of coeliac disease by one fifth.
      However, we believe that it is important to highlight that false-negatives are a lesser issue in populations with a low prevalence of disease. Even if all the patients who were TTg-positive and endomysial antibody-negative in our study were considered to have celiac disease, the differences between the cases and controls are minimal.
      Although Sanders and Azmy were also concerned about the power of our study to detect clinically relevant differences, we believe that the order of magnitude of the prevalence rates must be emphasized. Some may argue that the difference of 4% in patients with IBS and 2.6% in controls is clinically important. However, a study of 2700 subjects per group would be needed to detect this size difference (with 80% power at an a level of .05). Our goal was to estimate the importance of celiac disease in explaining why IBS symptoms are so common in the community. We did not mean to imply that there is no association between celiac disease and IBS or dyspepsia in the community. Our findings, however, support the conclusion that the vast majority of people with functional bowel symptoms in the community do not have occult celiac disease.

      REFERENCES

        • Locke III, GR
        • Murray JA
        • Zinsmeister AR
        • Melton III, LJ
        • Talley NJ
        Celiac disease serology in irritable bowel syndrome and dyspepsia: a population-based case-control study.
        Mayo Clin Proc. 2004; 79: 476-482
        • Prasad S
        • Thomas P
        • Nicholas DS
        • Sharer NM
        • Snook JA
        Adult endomysial antibody-negative coeliac disease and cigarette smoking.
        Eur J Gastroenterol Hepatol. 2001; 13: 667-671
        • Dickey W
        • Hughes DF
        • McMillan SA
        Reliance on serum endomysial antibody testing underestimates the true prevalence of coeliac disease by one fifth.
        Scand J Gastroenterol. 2000; 35: 181-183

      Linked Article

      • Medicare Reform Needed for Home-Based Low-Molecular-Weight Heparin Therapy
        Mayo Clinic ProceedingsVol. 79Issue 9
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          To the Editor: Similar to its policy regarding parenteral antibiotics, Medicare currently reimburses for the administration of low-molecular-weight heparin (LMWH) in office, clinic, and emergency department settings but does not pay for homebased treatment. Individual Medicare patients must provide out-of-pocket payment for home-based LMWH treatment or choose to remain in the hospital or go to a nursing home to complete intravenous heparin therapy. Paradoxically, if Medicare patients who are homebound and receiving home health care nursing receive outpatient (office- or clinic-based) LMWH therapy, they become ineligible for home nursing benefits.
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