Utility of Fecal Calprotectin in Evaluation of Chronic Gastrointestinal Symptoms in Primary Care

Management of children with non-acute abdominal pain and diarrhea in Dutch primary care: a retrospective cohort study based on a routine primary care database (AHON)

OBJECTIVE

To describe the testing, prescription, referral, and follow-up management by general practitioners (GPs) for children presenting with non-acute abdominal pain and/or diarrhea in primary care.

DESIGN

Retrospective cohort study with one-year follow-up.

SETTING

Registry data from a Dutch primary care database (AHON) between 2015 and 2019.

SUBJECTS

Children aged 4-18 years old who presented by face-to-face consultation in primary care for non-acute abdominal pain and/or diarrhea (>7 days).

MAIN OUTCOME MEASURES

We recorded the proportions of children who received (1) diagnostic testing, medicine prescriptions, follow-up consultations, and referrals at their first visit and (2) repeat consultations and referrals by one-year of follow-up.

RESULTS

Among the 2200 children (median age, 10.5 years; interquartile range, 7.0-14.6) presenting to a GP with non-acute abdominal pain and/or diarrhea, most reported abdominal pain (78.7%). At the first visit, GPs performed diagnostic testing for 32.2%, provided a prescription to 34.5%, and referred 2.5% to secondary care. Twenty-five percent of the children had a follow-up consultation within four weeks and 20.8% had a repeat consultation between four weeks and one year. Thirteen percent of the children were referred to secondary care by one year. However, only 1% of all children had documentation of an organic diagnosis needing management in secondary care.

CONCLUSION

One-third of children received diagnostic testing or a medicine prescription. Few had a follow-up consultation and >10% was referred to pediatric care. Future research should explore the motivations of GPs why and which children receive diagnostic and medical interventions.

Effect of faecal calprotectin testing on referrals for children with chronic gastrointestinal symptoms in primary care: study protocol for a cluster randomised controlled trial

INTRODUCTION

Children with chronic gastrointestinal symptoms are frequently seen in primary care, yet general practitioners (GPs) often experience challenges distinguishing functional gastrointestinal disorders (FGID) from organic disorders. We, therefore, aim to evaluate whether a test strategy that includes point-of-care testing (POCT) for faecal calprotectin (FCal) can reduce the referral rate to paediatric specialist care among children with chronic gastrointestinal symptoms. The study findings will contribute to improving the recommendations on FCal use among children in primary care.

METHODS AND ANALYSIS

In this pragmatic cluster randomised controlled trial, we will randomise general practices into intervention and control groups. The intervention group will use FCal-POCT when indicated, after completing online training about its indication, interpretation and follow-up as well as communicating an FGID diagnosis. The control group will test and treat according to Dutch GP guidelines, which advise against FCal testing in children. GPs will include children aged 4-18 years presenting to primary care with chronic diarrhoea and/or recurrent abdominal pain. The primary outcome will be the referral rate for children with chronic gastrointestinal symptoms within 6 months after the initial assessment. Secondary outcomes will be evaluated by questionnaires completed at baseline and at 3- and 6-month follow-up. These outcomes will include parental satisfaction and concerns, gastrointestinal symptoms, impact of symptoms on daily function, quality of life, proportion of children with paediatrician-diagnosed FGID referred to secondary care, health service use and healthcare costs. A sample size calculation indicates that we need to recruit 158 GP practices to recruit 406 children.

ETHICS AND DISSEMINATION

The Medical Research Ethics Committee (MREC) of the University Medical Center Groningen (The Netherlands) approved this study (MREC number: 201900309). The study results will be made available to patients, GPs, paediatricians and laboratories via peer-reviewed publications and in presentations at (inter)national conferences.

TRIAL REGISTRATION NUMBER

The Netherlands Trial Register: NL7690 (Pre-results).

Optotheranostic Nanosystem with Phone Visual Diagnosis and Optogenetic Microbial Therapy for Ulcerative Colitis At-Home Care

Ulcerative colitis (UC) is a relapsing disorder characterized by chronic inflammation of the intestinal tract. However, the home care of UC based on remote monitoring, due to the operational complexity and time-consuming procedure, restrain its widespread applications. Here we constructed an optotheranostic nanosystem for self-diagnosis and long-acting mitigations of UC at home. The system included two major modules: (i) A disease prescreening module mediated by smartphone optical sensing. (ii) Disease real-time intervention module mediated by an optogenetic engineered bacteria system. Recombinant Escherichia coli Nissle 1917 (EcN) secreted interleukin-10 (IL-10) could downregulate inflammatory cascades and matrix metalloproteinases; it is a candidate for use in the therapeutic intervention of UC. The results showed that the Detector was able to analyze, report, and share the detection results in less than 1 min, and the limit of detection was 15 ng·mL^-1. Besides, the IL-10-secreting EcN treatment suppressed the intestinal inflammatory response in UC mice and protected the intestinal mucosa against injury. The optotheranostic nanosystems enabled solutions to diagnose and treat disease at home, which promotes a mobile health service development.

Test accuracy of faecal calprotectin for inflammatory bowel disease in UK primary care: a retrospective cohort study of the IMRD-UK data

OBJECTIVE

To estimate the test accuracy of faecal calprotectin (FC) for inflammatory bowel disease (IBD) in the primary care setting using routine electronic health records.

DESIGN

Retrospective cohort test accuracy study.

SETTING

UK primary care.

PARTICIPANTS

5970 patients (≥18 years) without a previous IBD diagnosis and with a first FC test between 1 January 2006 and 31 December 2016. We excluded multiple tests and tests without numeric results in units of µg/g.

INTERVENTION

FC testing for the diagnosis of IBD. Disease status was confirmed by a recorded diagnostic code and/or a drug code of an IBD-specific medication at three time points after the FC test date.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative predictive values for the differential of IBD versus non-IBD and IBD versus irritable bowel syndrome (IBS) at the 50 and 100 µg/g thresholds.

RESULTS

5970 patients met the inclusion criteria and had at least 6 months of follow-up data after FC testing. 1897 had an IBS diagnosis, 208 had an IBD diagnosis, 31 had a colorectal cancer diagnosis, 80 had more than one diagnosis and 3754 had no subsequent diagnosis. Sensitivity, specificity, and positive and negative predictive values were 92.9% (88.6% to 95.6%), 61.5% (60.2% to 62.7%), 8.1% (7.1% to 9.2%) and 99.6% (99.3% to 99.7%), respectively, at the threshold of 50 µg/g. Raising the threshold to 100 µg/g missed less than 7% additional IBD cases. Longer follow-up had no effect on test accuracy. Overall, uncertainty was greater for specificity than sensitivity. General practitioners' (GPs') referral decisions did not follow the anticipated clinical pathways in national guidance.

CONCLUSIONS

GPs can be confident in excluding IBD on the basis of a negative FC test in a population with low pretest risk but should interpret a positive test with caution. The applicability of national guidance to general practice needs to be improved.

Primary care faecal calprotectin testing in children with suspected inflammatory bowel disease: a diagnostic accuracy study

OBJECTIVE

To determine the diagnostic accuracy of calprotectin to diagnose inflammatory bowel disease (IBD) in children in whom general practitioners (GPs) suspected IBD.

DESIGN

Prospective observational cohort study of a new calprotectin-based primary care referral pathway.

SETTING

48 GP practices and gastroenterology secondary care services at the Royal Devon and Exeter NHS Foundation Trust in the South-West of England, UK.

PATIENTS

195 children aged between 4 and 18 years referred on the pathway between January 2014 and August 2017 for investigation of gastrointestinal symptoms were included.

INTERVENTIONS

Primary-care-driven faecal calprotectin testing. Primary and secondary care records over 12 months from the point of calprotectin testing were used as the reference standard.

MAIN OUTCOME MEASURES

Diagnostic accuracy of calprotectin testing to detect IBD.

RESULTS

7% (13/195) tested patients were diagnosed with IBD. Using our prespecified cut-off of 100 µg/g, calprotectin had a diagnostic accuracy of 91% (95% CI 86% to 95%) with a sensitivity for distinguishing IBD from non-IBD of 100% (95% CI 75% to 100%), a specificity of 91% (95% CI 85% to 94%), a positive predictive value of 43% (95% CI 25% to 63%) and a negative predictive value of 100% (95% CI 98% to 100%). Calprotectin testing had no effect on the time to diagnosis, but a negative test contributed to saved referrals and was associated with fewer diagnostic tests in secondary care.

CONCLUSIONS

Calprotectin testing of children with suspected IBD in primary care accurately distinguishes IBD from a functional gut disorder, reduces secondary care referrals and associated diagnostic healthcare utilisation.

Diagnostic accuracy of faecal calprotectin in a symptom-based algorithm for early diagnosis of inflammatory bowel disease adjusting for differential verification bias using a Bayesian approach

BACKGROUND

Diagnostic delay in IBD is a major problem and diagnosis is frequently arrived when irreversible damage has already occurred. This study evaluated accuracy of faecal calprotectin (fCAL) integrated with diagnostic criteria for early diagnosis of IBD in a primary care setting.

METHODS

General practitioners (GPs) were trained to recognize alarm symptoms for IBD classified as major and minor criteria. Fulfilment of one major or at least two minor criteria was followed by free fCAL testing and a visit by an IBD specialist and follow-up over 12 months. All patients with positive fCAL testing, i.e., ≥70 μg/g underwent colonoscopy. The diagnostic accuracy of fCAL was estimated after adjusting for differential-verification bias following a Bayesian approach.

RESULTS

Thirty-four GPs participated in the study and 133 patients were tested for fCAL between July 2016 and August 2017. Positivity of fCAL was seen in 45/133 patients (34%) and a final IBD diagnosis was made in 10/45 (22%). According to the threshold of 70 μg/g, fCAL achieved a sensitivity of 74.8% (95%CI: 39.10-96.01%), a specificity of 70.4% (95%CI: 61.76-78.16%) and an overall diagnostic accuracy of 70.6% (95%CI: 61.04-78.37%). As for prognostic accuracy, despite positive predictive value being low, 21.9% (95%CI: 11.74-35.18%), the negative predictive value was definitely higher: 96.2% (95%CI: 84.96-99.51%).

CONCLUSIONS

fCAL with a threshold set at 70 μg/g seems to represent a potentially reliable negative test to be used in primary care settings for patients with symptoms suggestive of IBD.

Teenager With Abdominal Pain and Decreased Appetite

A 16-year-old girl presented to her primary care physician with a one-month history of decreased appetite and abdominal pain. She had normal bowel movements and no vomiting, but her periumbilical pain limited her ability to finish most meals. She had gradual weight loss over the previous 2 years, and during the previous 4 years, she intermittently received counseling for depression after the loss of her mother. Her initial physical examination and laboratory evaluation were unremarkable. She was referred to a nutritionist, adolescent medicine, and pediatric gastroenterology. Her presentation evolved over time, which ultimately led to a definitive diagnosis.

Fecal Calprotectin in Combination With Standard Blood Tests in the Diagnosis of Inflammatory Bowel Disease in Children

Introduction: Fecal calprotectin (FC) is a useful non-invasive screening test but elevated levels are not specific to inflammatory bowel disease (IBD). The study aimed to evaluate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FC alone or FC in combination with other standard blood tests in the diagnosis of IBD. Methods: Children aged <17 years who had FC (normal range <50 μg/g) measured and underwent endoscopy over 33 months in Christchurch, New Zealand were identified retrospectively (consecutive sampling). Medical records were reviewed for patient final diagnoses. Results: One hundred and two children were included; mean age was 12.3 years and 53 were male. Fifty-eight (57%) of the 102 children were diagnosed with IBD: 49 with Crohn's disease, eight with ulcerative colitis and one with IBD-unclassified. FC of 50 μg/g threshold provided a sensitivity of 96.6% [95% confident interval (CI) 88.3-99.4%] and PPV of 72.7% (95% CI 61.9-81.4%) in diagnosing IBD. Two children with IBD however were found to have FC <50 μg/g. Sensitivity in diagnosing IBD was further improved to 98.3% (95% CI 90.7-99.1%) when including FC >50 μg/g or elevated platelet count. Furthermore, PPVs in diagnosing IBD improved when FC at various thresholds was combined with either low albumin or high platelet count. Conclusion: Although FC alone is a useful screening test for IBD, a normal FC alone does not exclude IBD. Extending FC to include albumin or platelet count may improve sensitivity, specificity, PPV and NPV in diagnosing IBD. However, prospective studies are required to validate this conclusion.

Recurrent Abdominal Pain in Children: Is Colonoscopy Indicated?

Recurrent abdominal pain (RAP) in children is common, with most functional in origin. Colonoscopy has sometimes been performed to exclude pathology but its role is unclear. Our aim therefore was to assess the diagnostic yield and role of colonoscopy in these children. Retrospective review of consecutive colonoscopies in a tertiary pediatric hospital between November 2011 and October 2015 was undertaken. Only those with RAP as an indication for procedure were included. Chart review of patients with pain was undertaken to ensure they fulfilled Rome IV criteria. Patient demographics, indication for procedure, and adjunct preprocedure tests were noted. Statistical analyses were performed with SPSS software. A total of 652 colonoscopies were performed, of which 68 (10%) had abdominal pain as one of the indications, and was the sole indication in 15 (2%) patients. All 68 patients had preprocedure serum inflammatory markers measured and 53% (36/68) had stool calprotectin. Positive histology was found in 10% (7/68) including Crohn disease (n = 3), polyps (n = 2), and microscopic colitis (n = 2). The remaining 61 patients had normal colonoscopy and ileocolonic biopsies. Of the 36 patients 5 had raised fecal calprotectin, and all had abnormal histology. Serum inflammatory markers were raised in 4 patients and all also had abnormal calprotectin. No patient with isolated abdominal pain had positive histology. Rectal bleeding was the only associated indication to predict abnormal histology (P = 0.019). Colonoscopy is likely not warranted in children with RAP without bleeding, weight loss, or altered bowel habit. Fecal calprotectin is useful in helping predict positive findings.