Clinical trial NCT02727075: Performance Value of Research of Occult Gastrointestinal Bleeding by Immunoassay in the Diagnostic Process of Iron Deficiency Anemia in Patients Over 75 Years
Official title: Performance Value of Research of Occult Gastrointestinal Bleeding by Immunoassay in the Diagnostic Process of Iron Deficiency Anemia in Patients Over 75 Years
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Occult Gastrointestinal Bleeding
Keywords: Occult Gastrointestinal Bleeding
Iron Deficiency Anemia
Aged 75 Years and Older
Lead sponsor: Assistance Publique - Hôpitaux de Paris
Sponsor class: OTHER
First posted: 2016-04-04
Enrollment: 79
Sex: ALL
Minimum age (years): 75
Standard ages: OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: 200 people at least 75 years old.

Brief summary: This study aims to characterize the diagnostic performance of immunological testing of occult gastrointestinal bleeding in stool in the population aged over 75 years with iron deficiency anemia.

As secondary objectives, the study aims to:

* determine a threshold of positivity optimizing the immunoassay performance for the study population, in accordance with the probabilities of error (false positives, false negatives) and weights (defined by expert consensus) allocated to these errors.
* Assess the benefit of a double measure of bleeding (two stools) by immunoassay compared to a single measure.

Detailed description: Immunological testing will be performed systematically for each patient.

Research of blood in fecal sample will be based on 2 methods: one based on a qualitative immunochromatographic method (such as HemSign4 technique, Servibio, France; or all other techniques used at AP-HP) and another quantitative immunoturbidimetric method (OC-Sensor, Eiken, Japan). They will be performed systematically with two fresh fecal samples for each patient, before coloscopy examination.

Treating physicians will not be provided with the testing result. The diagnosis of reference will be established by experts based on the result of explorations (colonoscopy, coloscanner) and the patient's progression, blinded to the result of immunoassay.

The intrinsic characteristics of the immunoassay (sensitivity, specificity...) will be determined with reference to this reference diagnosis, using a positivity threshold defined using expert consensus on the weights to be allocated to potential errors.

2 modeling scenarios (without vs with immunological testing) using decision trees based on prevalence and diagnostic performance observed and stochastic simulations.

Eligibility criteria: Inclusion Criteria:

* Physical status score 3 or 4, aged 75 and older patient, (patients under guardianship may be included).
* Iron deficiency anemia (Hb≤120 g/l for a woman or Hb≤130 g/l for a man), and nonregenerative anemia with reticulocytes \<120 000/mm3.
* Patient who has indication for colonoscopy and / or colonography examination, whatever the results of gastroscopy if performed.
* Have a health insurance.
* Informed consent signed.

Exclusion Criteria:

* Hematemesis or melena
* Life expectancy inferior to 12 months
* Patient has difficulty in follow-up of study.

Primary outcomes:
measure: Sensitivity of immunological test with OC-SENSOR supplies
timeFrame: At baseline
measure: Specificity of immunological test with OC-SENSOR supplies
timeFrame: At baseline
measure: Likelihood ratios of immunological test with OC-SENSOR supplies
timeFrame: At baseline
Secondary outcomes:
measure: Diagnostic Performance
timeFrame: At baseline
measure: Comparing scenarios using decision trees
timeFrame: At baseline
measure: Performance of the test when used with an optimized positivity threshold
timeFrame: At baseline
Other outcomes:
Locations:
city: Boulogne-Billancourt
country: France
facility: Service Hépato-Gastroentérologie, Hôpital Ambroise Paré
state: Hauts-de-Seine
Study officials:
affiliation: Service Hépato-Gastroentérologie, Hôpital Ambroise Paré
name: Dominique Lamarque, MD, PhD
role: STUDY_DIRECTOR
References: