Study reference

Study characteristics

Patient characteristics

Index test

(test of interest)

Reference test

Follow-up

Outcome measures and effect size

Comments

Ashorn, 2009

Type of study: Prospective cohort

Setting: Hospital for Children and Adolescents Helsinki

Country: Finland

Conflicts of interest: not reported

Inclusion criteria: children and adolescents examined for suspicion of IBD

Exclusion criteria: not reported

N= 73

Prevalence IBD (CD/UC/IBD-U)): 80% (18/36/6)

Mean age ± SD:

IBD: 13.8 yrs (2.7-19.9), Non-IBD: 8.1 yrs (5.8 – 14.9)

Sex: 45% F

Other important characteristics:

Describe index test: FCP measured by enzyme immunoassay (PhiCal) in fecal samples.

Cut-off point(s): FCP level higher than 100 mg/g was considered elevated.

Comparator test^[1]: Serological tests; anti-I2 and anti-OmpW, IgA, ASCA for both IgG and IgA isotypes

Cut-off point(s): Equivocal/borderline results were interpreted as negative. Results exceeding 25 U for IgG and/or IgA ASCA were regarded as positive.

Describe reference test^[2]: Upper GI endoscopy, colonoscopy and histology

Cut-off point(s): The presence and degree of inflammation were determined in the upper gastrointestinal biopsies using the modified Sydney system.

Time between the index test en reference test: FCP levels were assessed at the time of diagnosis

For how many participants were no complete outcome data available?

N=18 (25%), there were only 55 patients samples available for FCP analysis.

Reasons for incomplete outcome data described? Nine patients diagnosed 5.3yrs (2.0-12.8yrs) before first available serum or feces sample.

Outcome measures and effect size (include 95%CI and p-value if available)⁴: FCP levels were elevated more frequently in IBD patients (89%, 39/44) compared to non-IBD cases (9%, 1/11, P < 0.001)

Canani, 2006

Type of study: Prospective cohort study

Setting: Pediatric Gastroenterology Unit, University Federico II of Naples

Country: Italy

Conflicts of interest: Not reported

Inclusion criteria: All children referred to the paediatric gastroenterology unit for initial assessment of suspected IBD.

Exclusion criteria: Patients with symptoms or signs (right-lower quadrant mass or perianal disease or hematochezia) mandating a complete work-up for IBD were excluded.

N= 49

Prevalence: 60% (27/45) IBD (CD:UC = 63:37)

Mean age ± SD: Non-IBD 11,0 yrs (2.2), CD 14.5yrs (5.1), UC 11.0yrs (5.0)

Sex: 53% M / 47% F

Other important characteristics:

Describe index test: FCP values were analysed by a commercial enzyme linked immunosorbent assay (ELISA) (Calprest, Eurospital Trieste, Italy)

Cut-off point(s): 95.3 μg/g

Comparator test: Cellobiose and mannitol were measured; The IgA and IgG ASCA were determined by a commercially available ELISA assay according to the instruction manuals (Medizym ASCA, ALIFAX, MEDIPAN Diagnostic, Selchow, Germany); To detect pANCA, an indirect immunofluorescence method was performed on commercially available slides (Bios GmbH, Munchen, Germany).

Describe reference test: Endoscopy with biopsies.

Cut-off point(s): final diagnosis of IBD or non-IBD according to the presence or absence of previously reported clinical, radiographic, endoscopic and histopathologic criteria.

Time between the index test en reference test: FCP test was performed in all patients at the time of initial assessment.

For how many participants were no complete outcome data available?

N=4

Reasons for incomplete outcome data described? Withdrawn consent.

Outcome measures and effect size (include 95%CI and p-value if available): Median FCP concentration in the IBD group was significantly higher compared with that of the non-IBD group (p < 0.001) without differences between CD and UC patients or between patients with and without small intestine involvement.

Fagerberg, 2005

Type of study: prospective cohort study

Setting: Department of Gastroenterology, Astrid Lindgren Children’s Hospital, Stockholm, and the Department of Pediatrics, Central Hospital, Vasteras.

Country: Sweden

Conflicts of interest: not reported

Inclusion criteria: children (age between 6 and 17 years old) with gastrointestinal symptoms who were scheduled for colonoscopy to rule out IBD.

Exclusion criteria: bacterial gastroenteritis detectable by fecal culture or serology and having any other chronic inflammatory disease.

N=36

Prevalence IBD: 56%

Age range: 6.5-17.8yrs

Sex: 17 M / 19 F (53% F)

Other important characteristics:

Describe index test: FCP measured by Calprest, Europsital, Trieste, Italy

Cut-off point(s): 50 μg/g

Comparator test:

Cut-off point(s):

Describe reference test: Complete ileocolonoscopy with histopathologic evaluations of mutlitple tissue samples.

Cut-off point(s):

Accepted conventional criteria for diagnosis of IBD

Time between the index test en reference test: median 3 days (range 0-37)

For how many participants were no complete outcome data available?

N=4

Reasons for incomplete outcome data described?

Two delivered fecal sample after colonoscopy and in two children, assessment of colonic inflammation was not possible because of incomplete colonoscopy with normal findings.

Outcome measures and effect size (include 95%CI and p-value if available):Median FCP concentration was 349 μg/g (95% CI 213-440 μg/g) in the group with colonic inflammation compared with 16.5 μg/g (95%CI 6.9-28.2 μg/g) in the group without inflammation. The difference in median FCP concentrations was highly significant (p<0.00001). All children with IBD and the child with juvenile colon polyposis had FCP concentrations > 50 μg/g.

Pre-selected group

Sidler, 2008

Type of study: prospective cohort study

Setting: gastroenterology outpatient clinic at Syndey Children’s Hospital, Randwick

Country: Australia

Conflicts of interest: not reported

Inclusion criteria: Children and adolescents presenting with GI symptoms suggestive of an organic gut disease and required further investigation based on clinical assessment.

Exclusion criteria: previously established diagnosis of an organic gastrointestinal disease, infectious gastroenteritis, having used NSAID agents, antibiotics or corticosteroids in the preceding 2 weeks.

N=61

Prevalence IBD: 51% (CD:UC 97:3)

Age range: 2.2 -16.0

Sex IBD: 61% M / 39% F

Sex non-IBD: 57% M / 43 F

Other important characteristics:

Describe index test: FCP level using PhiCal test (Nycomed, Oslo, Norway)

Cut-off point(s): 50 ug/g

Comparator test: Fecal S100A12 measured by an in-house ELISA using a previously published protocol.

Cut-off point(s):

Describe reference test: All children underwent upper gastrointestinal endoscopy and complete ileocolonoscopy including multiple biopsies for histopathological verification. In addition to ileocolonoscopy, the small bowel was assessed by a small bowel follow-through.

Cut-off point(s):

Time between the index test en reference test: stool sample collection prior to admission for GI endoscopy and colonoscopy, before the bowel preparation.

For how many participants were no complete outcome data available?

N 0 (%)

Reasons for incomplete outcome data described? Not applicable.

Outcome measures and effect size (include 95%CI and p-value if available): Children diagnosed with IBD (n=31) had elevated fecal s100A12 (median 55.2mg/kg) and calprotectin (median 1265 mg/kg) levels compared with the children without IBD (n=30; s100A12: median 1.1mg/kg, P<0.0001; calprotectin:median 30.5mg/kg;P<0.0001)

Vd Vijver, 2012

Type of study: prospective cohort study

Setting: outpatient clinics for general paediatrics and one tertiary care hospital (UMCG)

Country: the Netherlands

Conflicts of interest: not reported

Inclusion criteria: children and teenagers between 6 and 18 years of age with abdominal complaints were eligible for participation.

Exclusion criteria: children < 6 years of age

N=117

Prevalence confirmed IBD: 42 (36%) (24 CD, 17 UC, 2 IBDU)

32 functional abdominal pain.

Mean age: 14yrs (range 6-18)

Sex: 57 M / 60 F

Other important characteristics:

Describe index test: FCP measurement by CALPRO ELISA test (ALP); Calpro AS, Lysaker, Norway.

Cut-off point(s): positive FCP test when >50ug/g.

Comparator test:

Cut-off point(s):

Describe reference test: Confirmation of IBD was obtained after endoscopic and histologic evaluation (n=68) according to the Porto criteria.

Diagnosis of non-IBD was made when other test results gave a convincing explanation of symptoms, or when symptoms had completely resolved at 6-month follow-up.

Cut-off point(s):

Time between the index test en reference test: median time between FCP sampling and endoscopy was 22 days (range 0-79) in the confirmed IBD group and 42 days (0-164) in the non-IBD group (p=0.105)

For how many participants were no complete outcome data available?

N 49

Reasons for incomplete outcome data described?

Choice of physician to not do an endoscopy.

Outcome measures and effect size (include 95%CI and p-value if available): Pretest probability of IBD in the study population was 36%. Calpro (cutoff 50ug/g) was elevated in all children and teenagers with IBD (sens 100%, 95% CI 92-100%), and in 20 out of 75 patients without IBD (spec 73%, 95% CI 62-83%)

Basing referral on a positive FCP test result in the absence of GI infection would have resulted in 22% negative ileocolonoscopies and no missed IBD cases. The reduction of negative endoscopies is significant (p=0.001)

Holtman, 2016

Type of study: prospective cohort study

Setting: primary care practices and 4 general hospitals and 3 academic centers

Country: the Netherlands

Conflicts of interest: not reported

Inclusion criteria: Children aged 4 to 18 years who sought care for chronic diarrhea, recurrent abdominal pain, or both were eligible.

Exclusion criteria: Previous diagnosis of chronic organic gastroin- testinal disease; evaluation with endoscopy or FCP for gastrointestinal symptoms in 6 months before this study; difficulty in understanding questionnaires; children with long-term

use (>3 months) of antibiotics, nonsteroidal anti- inflammatory drugs, or oral corticosteroids in the past 6 months, as well as those aged younger than 4 years.

N=204 (114 primary care cohort en 90 referred cohort)

Prevalence confirmed IBD: 8% (17/204)

Mean age (range): Primary care chort: 9 (6-12) yrs. Referred cohort: 11 (7-15) yrs.

Sex: 37% F (75/204)

Other important characteristics:

Describe index test: FCP measurement by PhiCal (Calpro AS, Lysaker, Norway)

Cut-off point(s): 50ug/g.

Comparator test:

Cut-off point(s):

Describe reference test: Endoscopic assessment (esophagogastroduodenoscopy, ileocolonoscopy, and histopathologic examination) or 1-year follow-up

Cut-off point(s): according to the Porto criteria. A negative endoscopy was defined as the absence of endoscopic and histo- pathologic findings of IBD. Children were considered not to have IBD if, after 12 months, the attending phy- sician found no red flags or the pediatric gastroenter- ologist decided that red flags were not related to IBD.

Time between the index test en reference test: 4 days and 8 days for children with IBD and without IBD, respectively


For how many participants were no complete outcome data available?

In total, values were missing for 11 children (9.6%) in the primary care cohort and 5 (5.5%) in the referred cohort.

Reasons for incomplete outcome data described?

Choice of physician to not do an endoscopy.

Outcome measures and effect size (include 95%CI and p-value if available): The speci city of FCP in the primary care cohort was 0.87 (95% CI, 0.80-0.92). Among the 90 children in the referred cohort, 17 (19%) ultimately received a diagnosis of IBD. The sensitivity of FCP in the referred cohort was 0.99 (95% CI, 0.81-1.00).

Study reference

FCP Cut-off value (mg/g)

TP

FP

TN

FN

Sensitiviteit (95% BI)

Specificiteit (95% BI)

PPV

NPV

Fagerberg, 2005

50

20

2

14

0

97,6% (71,3 – 99,9)

85,3% (60,2 – 95,7)

90,1%

100%

Canani, 2006

95.3

25

2

16

2

92.6% (74,8 – 98,1)

88.9% (64,8 – 97,2)

92,6%

88,9%

Sidler,

2008

50

31

10

20

0

98,4% (79,4 – 99,9)

66,1% (48,1 – 80,4)

75,6%

100%

Ashorn, 2009

100

39

1

10

5

88,6% (75,5 – 95,2)

90,9% (56,1 – 98,7)

97,5%

66,7%

van de Vijver, 2012

50

42

20

55

0

98,8% (84 – 99,9)

73% (62 – 81,8)

67,7%

100%

Holtman, 2016

50

16

24

162

1

94,1% (68 – 99,2)

87,1% (81,5 – 91,2)

40%

99,4%

Study reference

Patient selection

Index test

Reference standard

Flow and timing

Comments with respect to applicability

Ashorn, 2009

Was a consecutive or random sample of patients enrolled?

Unclear

Was a case-control design avoided?

Unclear

Did the study avoid inappropriate exclusions?

Yes

Were the index test results interpreted without knowledge of the results of the reference standard?

/Unclear

If a threshold was used, was it pre-specified?

Yes

Is the reference standard likely to correctly classify the target condition?

Yes

Were the reference standard results interpreted without knowledge of the results of the index test?

Unclear

Was there an appropriate interval between index test(s) and reference standard?

Unclear

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

Yes

Were all patients included in the analysis?

No

Are there concerns that the included patients do not match the review question?

Yes/No/Unclear

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

Yes/No/Unclear

Are there concerns that the target condition as defined by the reference standard does not match the review question?

Yes/No/Unclear

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: UNCLEAR

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: UNCLEAR

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: UNCLEAR

CONCLUSION

Could the patient flow have introduced bias?

RISK: HIGH

Canani, 2006

Was a consecutive or random sample of patients enrolled?

Yes

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Yes

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

Yes

Is the reference standard likely to correctly classify the target condition?

Unclear

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

Unclear

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

Unclear

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

Yes/No/Unclear

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

Yes/No/Unclear

Are there concerns that the target condition as defined by the reference standard does not match the review question?

Yes/No/Unclear

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: LOW

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: UNCLEAR

CONCLUSION

Could the patient flow have introduced bias?

RISK: UNCLEAR

Fagerberg, 2005

Was a consecutive or random sample of patients enrolled?

No

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Unclear

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

Yes

Is the reference standard likely to correctly classify the target condition?

Yes

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

Yes

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

No

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

Yes/No/Unclear

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

Yes/No/Unclear

Are there concerns that the target condition as defined by the reference standard does not match the review question?

Yes/No/Unclear

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: /HIGH

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: LOW

CONCLUSION

Could the patient flow have introduced bias?

RISK: HIGH

Sidler, 2008

Was a consecutive or random sample of patients enrolled?

Yes

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Unclear

Were the index test results interpreted without knowledge of the results of the reference standard?

Unclear

If a threshold was used, was it pre-specified?

No

Is the reference standard likely to correctly classify the target condition?

Yes

Were the reference standard results interpreted without knowledge of the results of the index test?

Unclear

Was there an appropriate interval between index test(s) and reference standard?

Unclear

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

Yes

Were all patients included in the analysis?

Unclear

Are there concerns that the included patients do not match the review question?

Yes/No/Unclear

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

Yes/No/Unclear

Are there concerns that the target condition as defined by the reference standard does not match the review question?

Yes/No/Unclear

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: UNCLEAR

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: HIGH

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: UNCLEAR

CONCLUSION

Could the patient flow have introduced bias?

RISK: UNCLEAR

Vd vijver, 2012

Was a consecutive or random sample of patients enrolled?

Yes

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Yes

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

Yes

Is the reference standard likely to correctly classify the target condition?

Unclear

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

Yes

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

No

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

Yes/No/Unclear

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

Yes/No/Unclear

Are there concerns that the target condition as defined by the reference standard does not match the review question?

Yes/No/Unclear

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: LOW

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: UNCLEAR

CONCLUSION

Could the patient flow have introduced bias?

RISK: HIGH

Holtman, 2016

Was a consecutive or random sample of patients enrolled?

No

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Yes

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

Yes

Is the reference standard likely to correctly classify the target condition?

Yes

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

Yes

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

No

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

Yes/No/Unclear

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

Yes/No/Unclear

Are there concerns that the target condition as defined by the reference standard does not match the review question?

Yes/No/Unclear

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: HIGH

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: LOW

CONCLUSION

Could the patient flow have introduced bias?

RISK: HIGH