Symptom-Based Criteria Accuracy for Diagnosis of IBS in Primary Care
Symptom-Based Criteria Accuracy for Diagnosis of IBS in Primary Care
Background: Despite the trend towards making a positive diagnosis of irritable bowel syndrome (IBS), many health care providers approach IBS as a diagnosis of exclusion.
Aim: To summarize available evidence on the diagnostic performance of symptom-based IBS criteria in excluding organic diseases, and of individual signs and symptoms in diagnosing IBS and to additionally assess the influence of sources of heterogeneity on diagnostic performance.
Methods: We searched PubMed and EMBASE and screened references. Studies were selected if the design was a primary diagnostic study; the patients were adults consulting because of non-acute abdominal symptoms; the diagnostic test included an externally validated set of IBS criteria, signs, or symptoms. Data extraction and quality assessment were performed by two reviewers independently. The review adhered to the most recent guidelines as described in the Cochrane Diagnostic Reviewers' Handbook.
Results: A total of 25 primary diagnostic studies were included in the review. The performance of symptom-based criteria in the exclusion of organic disease was highly variable. Patients fulfilling IBS criteria had, however, a lower risk of organic diseases than those not fulfilling the criteria.
Conclusions: With none of the criteria showing sufficiently homogeneous and favourable results, organic disease cannot be accurately excluded by symptom-based IBS criteria alone. However, the low pre-test probability of organic disease especially among patients who meet symptom-based criteria in primary care argues against exhaustive diagnostic evaluation. We advise validation of the new Rome III criteria in primary care populations.
Irritable bowel syndrome (IBS) is a chronic condition characterized by abdominal pain or discomfort associated with disordered bowel habit and is one of the most common gastrointestinal (GI) disorders. Prevalence estimates in Western general populations range from 10% to 26%. Despite the bothersomeness of its symptoms, only a minority (30%) of patients with IBS seek medical care, with most of them being managed in primary care. Given the high prevalence of IBS, this results in a large number of primary health care visits.
Roughly, two opposing approaches can be distinguished in establishing the diagnosis of IBS: IBS as a 'diagnosis of exclusion' vs. IBS as syndromic condition on its own. The first approach is characterized by more or less extensive diagnostic testing and invasive investigations to exclude possible organic causes, while the second approach is characterized by using symptom-based IBS criteria to establish a positive diagnosis of IBS. The symptom-based approach was initiated in 1978 with the design of the Manning criteria. The most recent criteria are the Rome III criteria.
Despite a growing trend towards making a positive diagnosis of IBS, many health care providers approach IBS as a diagnosis of exclusion. This practice is expensive, may increase patients' anxiety and is in conflict with several guidelines (e.g. AGA position Statement). Review articles conclude that the routine use of diagnostic tests to exclude organic GI disease is not recommended in patients fulfilling IBS symptom criteria without demonstrating alarm features, but may be indicated among those with alarm features. However, several of those reviews and other reviews on the diagnosis of IBS lack a systematic approach in collecting the evidence, do not assess its methodological quality, do not differentiate between settings of care or need updating.
In this systematic review, we first studied the diagnostic performance of several symptom-based IBS criteria in excluding organic GI diseases, investigating the probability of uncovering an organic cause of symptoms when people have a positive score on the IBS criteria. Secondly, we studied which individual signs and symptoms (including alarm features) are important in differentiating IBS from organic diseases. Finally, we assessed the influence of sources of heterogeneity like differences in setting, study population and study design on diagnostic performance.
Summary and Introduction
Summary
Background: Despite the trend towards making a positive diagnosis of irritable bowel syndrome (IBS), many health care providers approach IBS as a diagnosis of exclusion.
Aim: To summarize available evidence on the diagnostic performance of symptom-based IBS criteria in excluding organic diseases, and of individual signs and symptoms in diagnosing IBS and to additionally assess the influence of sources of heterogeneity on diagnostic performance.
Methods: We searched PubMed and EMBASE and screened references. Studies were selected if the design was a primary diagnostic study; the patients were adults consulting because of non-acute abdominal symptoms; the diagnostic test included an externally validated set of IBS criteria, signs, or symptoms. Data extraction and quality assessment were performed by two reviewers independently. The review adhered to the most recent guidelines as described in the Cochrane Diagnostic Reviewers' Handbook.
Results: A total of 25 primary diagnostic studies were included in the review. The performance of symptom-based criteria in the exclusion of organic disease was highly variable. Patients fulfilling IBS criteria had, however, a lower risk of organic diseases than those not fulfilling the criteria.
Conclusions: With none of the criteria showing sufficiently homogeneous and favourable results, organic disease cannot be accurately excluded by symptom-based IBS criteria alone. However, the low pre-test probability of organic disease especially among patients who meet symptom-based criteria in primary care argues against exhaustive diagnostic evaluation. We advise validation of the new Rome III criteria in primary care populations.
Introduction
Irritable bowel syndrome (IBS) is a chronic condition characterized by abdominal pain or discomfort associated with disordered bowel habit and is one of the most common gastrointestinal (GI) disorders. Prevalence estimates in Western general populations range from 10% to 26%. Despite the bothersomeness of its symptoms, only a minority (30%) of patients with IBS seek medical care, with most of them being managed in primary care. Given the high prevalence of IBS, this results in a large number of primary health care visits.
Roughly, two opposing approaches can be distinguished in establishing the diagnosis of IBS: IBS as a 'diagnosis of exclusion' vs. IBS as syndromic condition on its own. The first approach is characterized by more or less extensive diagnostic testing and invasive investigations to exclude possible organic causes, while the second approach is characterized by using symptom-based IBS criteria to establish a positive diagnosis of IBS. The symptom-based approach was initiated in 1978 with the design of the Manning criteria. The most recent criteria are the Rome III criteria.
Despite a growing trend towards making a positive diagnosis of IBS, many health care providers approach IBS as a diagnosis of exclusion. This practice is expensive, may increase patients' anxiety and is in conflict with several guidelines (e.g. AGA position Statement). Review articles conclude that the routine use of diagnostic tests to exclude organic GI disease is not recommended in patients fulfilling IBS symptom criteria without demonstrating alarm features, but may be indicated among those with alarm features. However, several of those reviews and other reviews on the diagnosis of IBS lack a systematic approach in collecting the evidence, do not assess its methodological quality, do not differentiate between settings of care or need updating.
In this systematic review, we first studied the diagnostic performance of several symptom-based IBS criteria in excluding organic GI diseases, investigating the probability of uncovering an organic cause of symptoms when people have a positive score on the IBS criteria. Secondly, we studied which individual signs and symptoms (including alarm features) are important in differentiating IBS from organic diseases. Finally, we assessed the influence of sources of heterogeneity like differences in setting, study population and study design on diagnostic performance.