Protocol: i-stat Cardiac Troponin I Performance Verification GENERAL INFORMATION Introduction The i-stat cardiac troponin I (ctni) cartridge, used in conjunction with the i-stat 1 Analyzer, is an in vitro diagnostic product for the measurement of ctni in whole blood patient samples. Measurements of ctni are used in the diagnosis and treatment of acute myocardial infarction (AMI) and as an aid in the risk stratification of patients with acute coronary syndromes (ACS) with respect to their risk of mortality. Purpose The intent of this protocol is to provide an efficient, statistically valid means to demonstrate that the i-stat ctni test performs in accordance with published performance claims and typical performance data. A comparison of methods, imprecision testing, and calibration verification are evaluated. Note: For the verification protocol, i-stat Corporation recommends modified versions of the NCCLS guidelines. Additionally, a performance verification is a recommendation, not a CLIA requirement, for a facility to verify a manufacturer s published performance claims and typical performance data. Modifications may be applied to this protocol adhering to an institution s policy related to verifying new test methodologies. Training It is important that the individuals conducting the tests be thoroughly familiar with the operation, maintenance, and quality control procedures of both the i-stat 1 Analyzer and the comparative method system before starting the protocol. Equipment /consumables The four i-stat 1 Analyzers required to perform the verification protocol will be provided. The required consumables include: Cartridges: A minimum of 169 i-stat ctni cartridges are required (100 for the method comparison, 60 for imprecision, and 9 for calibration verification). Controls: 1 box each level i-stat Cardiac Markers Control (,, and ) Calibration Verification Set: 1 box i-stat Cardiac Markers Calibration Verification Control Set. METHOD COMPARISON STUDY Samples Patients in any hospital department (e.g., emergency department [ED], ICU, CCU, general ward) that present with acute, severe, and prolonged chest pain are eligible to be included in the study. Fifty (50) samples from patients who are experiencing acute, severe, and prolonged chest pain will be included in the study. Up to three (3) samples, drawn at different times, can be taken from any one patient, each within 48 hours of presentation. Thirty of these samples should demonstrate ctni results greater than the cutoff on the comparative method, and 20 samples should demonstrate results less than or equal to the cutoff on the comparative method. Attempts should be made to include samples which cover as much of the i-stat ctni reportable range (0.00 50.00 ng/ml) as possible.
Stockpiling samples ahead of time In order to assure there are sufficient numbers of troponin positive samples included in the study and still allow the performance verification to take place over a reasonable amount of time, plasma samples can be frozen and stored during the days/weeks preceding the start of the verification study. Sample analysis Each sample will be analyzed in duplicate on two i-stat 1 Analyzers. The same sample will be analyzed, in duplicate, on the comparative method. Even if the sample had been previously analyzed on the comparative method, if it had been frozen, it should be analyzed in duplicate again on the comparative method. The results from the i-stat and comparative methods will be logged on provided data forms. Data analysis Deming regression and percent concordance statistics will be used to estimate the agreement between the i-stat and comparative systems. IMPRECISION STUDY Samples One box of each of three levels of control materials is provided for the imprecision component of the verification protocol. Each box contains 6 vials of a single level. Each vial can be used for a minimum of 4 tests. Storage of control materials The controls should be handled and analyzed according to the instructions included with this protocol. The controls should be stored at 18 C in a non-defrosting freezer until approximately 15 minutes before use. The controls are thawed for 15 minutes at room temperature prior to use. Once thawed, the controls are stable for four hours when capped and stored at 2-8 C. Analysis of control materials On each of five occasions, during the course of the performance verification, the following should happen: one vial of each level of control should be removed from the freezer, thawed and handled per the instructions for use (three vials total). the contents of each vial should be used to run 4 cartridges (12 cartridges total). Once this has been done on five occasions, there should be twenty results for each level of control. Data analysis The twenty results for each level will be used to calculate mean, standard deviation, and coefficient of variation at the three levels. CALIBRATION VERIFICATION Samples One box containing two vials of each of the three levels of calibration verification material will be provided. Storage of cal. ver. materials The calibration verification materials are stored and handled exactly the same as the control materials.
Analysis of calibration verification materials During the course of the performance verification, one vial of each level of calibration verification material should be removed from the freezer, thawed and handled per the instructions for use. The contents of each vial should be used to run 3 i-stat ctni cartridges (9 cartridges total). Data analysis The means of the 3 results for each level will be compared to the published acceptable range for each level.
i-stat Cardiac Troponin I Performance Verification Attn: i-stat Representative: To have a verification report produced, please complete this form and the attached worksheets. Return the forms and worksheets to the i-stat Clnical Affairs Department, attention Ann Parsons. Facility Name Mailing Address City, State, Zip Start date: Completion date: Analyzer Software Rev. i-stat Cartridge Lot number: Comparative Method: Control Lot numbers: Calibration Verification Lot number: Procedural notes - describe any modifications to the i-stat-recommended protocol: Completed Report Please send copies to the attention of Address: i-stat representative submitting Data Collection Sheets: Name: VM # Please send a copy to my home address: yes no
Sample ID i-stat 1 i-stat 2 comparative 1 comparative 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 ctni Method Comparision
Sample ID 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 ctni Calibration Verification ctni Imprecision