Trial Outcomes & Findings for Validation of the GenePOC CDiff Assay for the Detection of the Toxin B Gene From Toxigenic Clostridium Difficile Strains (NCT NCT02968758)

Results Overview

To establish the performance characteristics of the GenePOC CDiff System for its use in determining the presence of CDiff in liquid/unformed stool specimen obtained from patients suspected of having C. difficile infection (CDI). Sensitivity will be established as the proportion of positives that are correctly identified by the GenePOC CDiff System, when compared to the Reference Method. Specificity will be established as the proportion of negatives that are correctly identified by the GenePOC CDiff System, when compared to the Reference Method.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

2461 participants

Primary outcome timeframe

At the time of the results with Reference Method is confirmed, up to 3 months

Results posted on

2021-05-03

Participant Flow

Participant milestones

Participant milestones
Measure	Accuracy Testing - Fresh Specimen Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Fresh Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.	Accuracy Testing - Frozen Specimen Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Frozen Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.
Overall Study STARTED	797	1664
Overall Study COMPLETED	797	1664
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Gender information was not collected during the trial.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Accuracy Testing - Fresh Specimen n=797 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Fresh Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.	Accuracy Testing - Frozen Specimen n=1664 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Frozen Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.	Total n=2461 Participants Total of all reporting groups
Age, Categorical <=18 years	34 Participants n=797 Participants	80 Participants n=1664 Participants	114 Participants n=2461 Participants
Age, Categorical Between 18 and 65 years	399 Participants n=797 Participants	800 Participants n=1664 Participants	1199 Participants n=2461 Participants
Age, Categorical >=65 years	364 Participants n=797 Participants	784 Participants n=1664 Participants	1148 Participants n=2461 Participants
Sex/Gender, Customized All Genders	—	—	0 Participants Gender information was not collected during the trial.
Race and Ethnicity Not Collected	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Region of Enrollment Canada	79 participants n=797 Participants	0 participants n=1664 Participants	79 participants n=2461 Participants
Region of Enrollment United States	718 participants n=797 Participants	1664 participants n=1664 Participants	2382 participants n=2461 Participants

PRIMARY outcome

Timeframe: At the time of the results with Reference Method is confirmed, up to 3 months

To establish the performance characteristics of the GenePOC CDiff System for its use in determining the presence of CDiff in liquid/unformed stool specimen obtained from patients suspected of having C. difficile infection (CDI). Sensitivity will be established as the proportion of positives that are correctly identified by the GenePOC CDiff System, when compared to the Reference Method. Specificity will be established as the proportion of negatives that are correctly identified by the GenePOC CDiff System, when compared to the Reference Method.

Outcome measures

Outcome measures
Measure	Accuracy Testing - Fresh Specimen n=797 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Fresh Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.	Accuracy Testing - Frozen Specimen n=1664 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Frozen Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.
Performance Characteristics : Clinical Sensitivity (True Positive Rate) and Clinical Specificity (True Negative Rate) in Comparison to the Reference Method Sensitivity	95.5 percentage of specimens Interval 87.3 to 99.1	95.2 percentage of specimens Interval 90.8 to 97.9
Performance Characteristics : Clinical Sensitivity (True Positive Rate) and Clinical Specificity (True Negative Rate) in Comparison to the Reference Method Specificity	93.4 percentage of specimens Interval 91.4 to 95.1	95.3 percentage of specimens Interval 94.1 to 96.3

SECONDARY outcome

Timeframe: At the time of the results with Reference Method is confirmed, up to 3 months

To estimate the Positive and Negative Predictive Values (PPV and NPV) of the GenePOC CDiff System. PPV is the percentage of true positives out of all positive results (true positive/true positive + false positive). NPV is the percentage of true negatives out of all negative results (true negative/true negative +false negative.).

Outcome measures

Outcome measures
Measure	Accuracy Testing - Fresh Specimen n=797 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Fresh Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.	Accuracy Testing - Frozen Specimen n=1664 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Frozen Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.
Positive and Negative Predictive Values (PPV and NPV) PPV	82.0 percentage of specimens Interval 73.6 to 88.6	83.1 percentage of specimens Interval 77.7 to 87.7
Positive and Negative Predictive Values (PPV and NPV) NPV	96.8 percentage of specimens Interval 95.2 to 98.0	98.0 percentage of specimens Interval 97.2 to 98.7

SECONDARY outcome

Timeframe: At the time of the results with Reference Method is confirmed, up to 3 months

To estimate the rate of unresolved results for the GenePOC CDiff System due to Sample Processing control failure (unresolved sample results).

Outcome measures

Outcome measures
Measure	Accuracy Testing - Fresh Specimen n=797 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Fresh Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.	Accuracy Testing - Frozen Specimen n=1664 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Frozen Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.
Unresolved Sample Results	1.1 percentage of Unresolved Interval 0.52 to 2.13	0.8 percentage of Unresolved Interval 0.42 to 1.33

SECONDARY outcome

Timeframe: At the time of the results with Reference Method is confirmed, up to 3 months

To estimate the rate of indeterminate results for the GenePOC CDiff Test due to an Instrument failure (indeterminate sample results).

Outcome measures

Outcome measures
Measure	Accuracy Testing - Fresh Specimen n=797 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Fresh Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.	Accuracy Testing - Frozen Specimen n=1664 Participants Comparison between GenePOC PCR and Reference Method Comparison between GenePOC PCR and Reference Method: Frozen Stool specimen will be tested with the GenePOC CDiff test on the GenePOC Instrument. The results will be compared to Reference Method defined as direct and enriched culture method for observation of a toxigenic Clostridium difficile strain.
Indeterminate Sample Results	1.6 percentage of Indeterminates Interval 1.16 to 2.2	1.5 percentage of Indeterminates Interval 0.78 to 2.61

Adverse Events

Accuracy Testing

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr Keith Chiasson, PhD

GenePOC

Phone: 418-650-3535

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place