An observational study in Drug Monitoring, Anticoagulants and Factor Xa Inhibitors, sponsored by Istituti Clinici Scientifici Maugeri SpA. Completed at 2 sites in Italy. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by Istituti Clinici Scientifici Maugeri SpA · Observational
The goal of this observational study is to learn whether two laboratory tests give the same results when measuring blood levels of blood thinners. The study looked at adults who take direct oral anticoagulants (DOACs) and came to an emergency department. DOACs are blood thinners such as apixaban, dabigatran, edoxaban and rivaroxaban.
Doctors do not usually measure DOAC levels in the blood. In an emergency, though, knowing the level can help doctors decide on treatment. This matters, for example, when a person is bleeding or has a blood clot.
The main questions the study aims to answer are:
Participants:
Researchers measured the DOAC level in each sample with both tests. They also collected information from medical records, such as the reason for the visit and the time since the last DOAC dose.
At Emergency Department admission, a dedicated blood sample (plain tube, without anticoagulant or gel separator) was collected from each participant. DOAC concentration was measured with two methods:
Clinical data were collected from medical records using a dedicated case report form: demographics, medical history, concomitant medications, DOAC type, indication and daily dose, reason for ED access, time since last DOAC intake, routine laboratory tests (blood count, creatinine, AST, ALT, INR, PT, aPTT), treatment (including antidotes) and outcome of the acute episode. No follow-up was performed.
DOAC levels were classified as below, within or above the expected range for each drug. Agreement between methods was assessed with the intraclass correlation coefficient (ICC) with 95% confidence interval and Bland-Altman plots. Associations between DOAC level categories and ED access for coagulation-related problems were analyzed with chi-square or Fisher's exact test and univariable and multivariable logistic regression. The sample size was calculated to estimate an expected ICC of 0.75 with a 95% confidence interval width of 0.15.
Istituti Clinici Scientifici Maugeri SpA is the lead sponsor of 126 studies on the registry; 51 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Convenience sample of adults on chronic DOAC therapy who came to the Emergency Department of Fondazione IRCCS Policlinico San Matteo, Pavia, Italy, between June 2024 and 2025.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
People on chronic therapy with apixaban, dabigatran, edoxaban or rivaroxaban who came to the Emergency Department of Fondazione IRCCS Policlinico San Matteo for any reason. Each participant gave one blood sample at arrival, analyzed with both laboratory methods. Clinical care was not changed.
Agreement between DOAC plasma concentrations measured by chromogenic assay and by HPLC-MS/MS
Intraclass correlation coefficient (ICC, unitless, range 0 to 1) between DOAC plasma concentrations (ng/mL) measured in the same blood sample with a DOAC-specific chromogenic anti-factor IIa/anti-factor Xa assay and with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Higher values indicate better agreement.
Time frame: Day 1
DOAC plasma concentration measured by chromogenic assay
Plasma concentration (ng/mL) of apixaban, dabigatran, edoxaban or rivaroxaban measured with a DOAC-specific chromogenic anti-factor IIa (dabigatran) or anti-factor Xa (apixaban, edoxaban, rivaroxaban) assay.
Time frame: Day 1
DOAC plasma concentration measured by HPLC-MS/MS
Plasma concentration (ng/mL) of apixaban, dabigatran, edoxaban or rivaroxaban measured with a validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method.
Time frame: Day 1
Percentage of participants with DOAC plasma concentrations below, within or above the expected range
Percentage of participants whose DOAC plasma concentration, measured by HPLC-MS/MS, falls below, within or above the expected on-treatment range for the specific drug, dose and sampling time (peak or trough).
Time frame: Day 1
Percentage of participants with Emergency Department access for bleeding or thrombosis
Percentage of participants whose reason for Emergency Department access was a coagulation-related problem (major or minor bleeding, or thrombosis), as recorded in the medical record, reported by DOAC plasma concentration category (below, within or above the expected range).
Time frame: Day 1
Plan to share: No — Individual participant data will not be shared publicly, as the informed consent did not include data sharing and in compliance with the EU General Data Protection Regulation (GDPR). Aggregate results will be published in a peer-reviewed journal.
Ran from Jun 2024 to primary completion in Jun 2025, 11 months.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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