(155 days)
Smart-Read EZTest – Steam self-contained biological indicators (SCBI) are for monitoring the efficacy of saturated steam sterilization processes. Performance characteristics are established in accordance with USP 31 for the pre-vacuum 121°C steam process. Additional pre-vacuum saturated steam sterilization temperatures are also included in the Certificate of Analysis. Smart-Read EZTest – steam SCBIs are also appropriate for use in saturated steam processes of 132°C, 134°C and 135°C.
The biological indicator consists of a self-contained unit which includes: bacterial spores inoculated onto a paper carrier, a small glass ampoule containing sterile culture medium and color indicator, and a plastic vial that serves as the culture tube. This unit complies to the performance characteristics described in USP 31 and ANSI/AAMI/ISO 11138-1.
Acceptance Criteria and Device Performance Study for Smart-Read™ EZTest® - Steam Biological Indicator
This report describes the acceptance criteria and the study that proves the Smart-Read™ EZTest® - Steam biological indicator meets those criteria for reduced incubation time.
1. Table of Acceptance Criteria and Reported Device Performance
The core acceptance criterion for the reduced incubation time (RIT) study is that 97% of growth results observed at 7 days should be available at the RIT of 10 hours for the biological indicator (BI) that have been exposed to a partial sterilization cycle.
| Acceptance Criterion | Reported Device Performance (Growth at 10 hours vs. Growth at 7 days) |
|---|---|
| Reduced incubation time (10 hours) results must show a minimum of 97% concordance with the results obtained after a 7-day incubation period for BIs exposed to partial sterilization cycles. This is based on sets of 100 BIs exposed to a steam process that reduced the spore population to approximately 1 spore per BI, where 30-80 units demonstrated growth (indicating a partial kill). | Partial Cycle #1: 97.7% at 10 hours, 100% at 7 days (43/44 at 10h vs. 44/44 at 7d) |
| Partial Cycle #2: 97.8% at 10 hours, 100% at 7 days (44/45 at 10h vs. 45/45 at 7d) | |
| Partial Cycle #3: 97.3% at 10 hours, 100% at 7 days (71/73 at 10h vs. 73/73 at 7d) | |
| Partial Cycle #4: 97.5% at 10 hours, 100% at 7 days (78/80 at 10h vs. 80/80 at 7d) | |
| Partial Cycle #5: 100% at 10 hours, 100% at 7 days (52/52 at 10h vs. 52/52 at 7d) | |
| Partial Cycle #6: 100% at 10 hours, 100% at 7 days (23/23 at 10h vs. 53/53 at 7d when looking at the last full growth %) | |
| Partial Cycle #7: 100% at 10 hours, 100% at 7 days (73/73 at 10h vs. 73/73 at 7d) | |
| Partial Cycle #8: 100% at 10 hours, 100% at 7 days (48/48 at 10h vs. 48/48 at 7d) | |
| Partial Cycle #9: 97.8% at 10 hours, 100% at 7 days (45/46 at 10h vs. 46/46 at 7d) | |
| Partial Cycle #10: 98.3% at 10 hours, 100% at 7 days (59/60 at 10h vs. 60/60 at 7d) | |
| Partial Cycle #11: 98.4% at 10 hours, 100% at 7 days (60/61 at 10h vs. 61/61 at 7d) | |
| Partial Cycle #12: 97.5% at 10 hours, 100% at 7 days (78/80 at 10h vs. 80/80 at 7d) |
Overall, all partial cycles meet or exceed the 97% concordance requirement at 10 hours compared to 7 days, demonstrating the device's ability to achieve reduced incubation time. |
2. Sample Size Used for the Test Set and Data Provenance
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Sample Size for Test Set: The study involved multiple partial sterilization cycles, each using a varying number of biological indicators (BIs).
- Partial Cycle #1: 44 BIs
- Partial Cycle #2: 45 BIs
- Partial Cycle #3: 73 BIs
- Partial Cycle #4: 80 BIs
- Partial Cycle #5: 52 BIs
- Partial Cycle #6: 53 BIs
- Partial Cycle #7: 73 BIs
- Partial Cycle #8: 48 BIs
- Partial Cycle #9: 46 BIs
- Partial Cycle #10: 60 BIs
- Partial Cycle #11: 61 BIs
- Partial Cycle #12: 80 BIs
The total number of BIs tested across all partial cycles is 715.
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Data Provenance: The document does not explicitly state the country of origin but implies laboratory testing conducted by SGM Biotech, Inc., located in Bozeman, MT, USA. The study design is prospective as it involves controlled exposure of BIs to partial sterilization cycles. The report indicates that the test was performed with "four different spore crops and multiple lots of product from each crop", suggesting multiple batches of the device were evaluated.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The ground truth for this device is established through microbiological growth assessment. This does not typically involve interpretation by human "experts" in the same way clinical imaging studies do. The assessment of growth (yellow color change) or no growth (clear and purple) is an objective, binary outcome. Therefore, there were no "experts" with specific qualifications like radiologists establishing the ground truth in this context. The results are based on direct observation of the color change in the culture medium, which is an intrinsic characteristic of the biological indicator's function.
4. Adjudication Method for the Test Set
Adjudication methods like 2+1 or 3+1 are typically used for subjective clinical interpretations. For the Smart-Read EZTest, the outcome (growth or no growth as indicated by color change) is a direct, objective result. There is no indication of an adjudication method being used because the results are determined by the biological reaction rather than human interpretation requiring consensus.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, an MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic devices where human readers interpret results, and the AI's role is to assist in that interpretation. The Smart-Read EZTest is a biological indicator designed for a direct chemical and biological reaction, not requiring human interpretation beyond observing a color change. Therefore, assessing how human readers improve with AI assistance is not applicable.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
Yes, a standalone study was performed. The data presented demonstrates the performance of the biological indicator itself in detecting sterilization failure (survival of spores). The "device performance" refers to the BI's ability to accurately show growth within the reduced incubation time, independent of any human intervention beyond activating and incubating the device and observing the final color change.
7. Type of Ground Truth Used
The ground truth used is a biological outcome (microbial growth of Geobacillus stearothermophilus spores) directly observed through a color change in the culture medium. For the purpose of establishing reduced incubation time, the 7-day incubation period serves as the gold standard ground truth, against which the 10-hour incubation results are compared. The 7-day result is considered the definitive indicator of spore survival or death.
8. Sample Size for the Training Set
The document does not explicitly state a separate "training set" for the reduced incubation time study. The study describes the methodology for establishing the reduced incubation time, which implies a development and testing process (i.e., the presented data acts as the validation that the 10-hour time is effective). The "test was performed with four different spore crops and multiple lots of product from each crop," suggesting robust testing across various manufacturing iterations and spore batches.
9. How the Ground Truth for the Training Set Was Established
As noted above, a distinct "training set" in the context of an AI/algorithm is not directly applicable here. However, the process for establishing the ground truth (7-day incubation) for the development and validation of the 10-hour reduced incubation time is as follows:
The ground truth for spore survival or death (growth or no growth) is established by incubation for 7 days at 60 ± 2°C. This extended incubation period ensures the maximum opportunity for any surviving spores to proliferate and cause a color change. This 7-day incubation serves as the reference standard against which the performance of the shorter (10-hour) incubation time is evaluated. The principle is that if spores survive, they will show growth within 7 days. The study then aimed to demonstrate that the same growth would be observable reliably at 10 hours.
§ 880.2800 Sterilization process indicator.
(a)
Biological sterilization process indicator —(1)Identification. A biological sterilization process indicator is a device intended for use by a health care provider to accompany products being sterilized through a sterilization procedure and to monitor adequacy of sterilization. The device consists of a known number of microorganisms, of known resistance to the mode of sterilization, in or on a carrier and enclosed in a protective package. Subsequent growth or failure of the microorganisms to grow under suitable conditions indicates the adequacy of sterilization.(2)
Classification. Class II (performance standards).(b)
Physical/chemical sterilization process indicator —(1)Identification. A physical/chemical sterilization process indicator is a device intended for use by a health care provider to accompany products being sterilized through a sterilization procedure and to monitor one or more parameters of the sterilization process. The adequacy of the sterilization conditions as measured by these parameters is indicated by a visible change in the device.(2)
Classification. Class II (performance standards).