PHLT 8270 Week 4 Surveillance System Evaluation Example

One Question for the Whole Evaluation: Does a Composite State's Surveillance of Carbapenemase-Producing Organisms Get Each Confirmed Case the Containment Response It Exists to Trigger?

Student Name

Walden University

PHLT 8270: Health Informatics and Surveillance

Instructor Name

Month Day, Year

One Question for the Whole Evaluation: Does a Composite State's Surveillance of Carbapenemase-Producing Organisms Get Each Confirmed Case the Containment Response It Exists to Trigger?

Why One Question

Evaluations that grade a surveillance system on every attribute tend to produce long tables and few conclusions. CDC's revised framework for appraising surveillance systems advises focusing an evaluation on the questions that matter to the people who will use it (German et al., 2001). The composite state's surveillance of carbapenemase-producing Enterobacterales exists mainly to trigger containment: when a confirmed case appears in a hospital or nursing home, the health department works with the facility to screen patients who shared the unit, review infection control and alert facilities that receive the patient. This evaluation therefore asks one question: does the system get confirmed cases that response, and quickly enough to matter? All figures are composite.

Describing the System

Clinical laboratories report carbapenem-resistant isolates electronically or by fax. Isolates are referred to the state public health laboratory for carbapenemase testing when the clinical laboratory does not test them itself. When a carbapenemase producer is confirmed, the state's healthcare-associated infections team contacts the facility, recommends screening of contacts and contact precautions, and follows up until screening is complete. The system's stakeholders include laboratories, infection preventionists, facility administrators and the state team. Most reported isolates come from urine cultures of older patients with recent health care exposure, the pattern seen in national surveillance (Guh et al., 2015), so the facilities that matter most are hospitals, long-term acute care hospitals and nursing homes.

Focusing the Evaluation

Given the question, three attributes matter most. Timeliness is measured from specimen collection to the start of a containment response. Completeness is measured as the share of carbapenem-resistant isolates tested for mechanism, since an untested isolate cannot trigger a response. Usefulness is measured as the share of confirmed cases that received a response. Other attributes, such as simplicity, flexibility and acceptability, matter for the system's long-term health but are not needed to answer this question and are set aside, as the guidelines allow.

The Evidence

Two gaps stand out. A third of resistant isolates were never tested for mechanism, so any carbapenemase producers among them could not trigger a response. And of the 64 confirmed cases, 23 received no response. Review of those 23 found three reasons: in 11, the patient had already been discharged home with no ongoing exposure to other patients; in 7, the state learned of the confirmation more than a month after the specimen was collected, usually because the isolate was shipped late; and in 5, the facility could not be reached or declined.

Table 1

Containment Responses for Confirmed Carbapenemase Producers in One Year (Composite Figures)

Note. Composite figures. A containment response means the state contacted the facility and screening of contacts was recommended.

Timeliness in Context

A median of nine days from specimen to response leaves time for spread. In national containment work, screening of contacts after a novel resistance mechanism was identified identified carriers in roughly 11% of those tested (Woodworth et al., 2018), and carriers who move between facilities extend the chain before anyone knows. Most delay in the composite state occurred before the state was notified, in the shipment of isolates and the laboratory's turnaround, rather than after.

Gathering Credible Evidence

The guidelines ask evaluators to use evidence that stakeholders will find credible, and for this question the evidence came from three sources. Case records in the surveillance database supplied dates and response status. The state laboratory's referral log supplied shipment and testing dates for isolates sent for mechanism testing. And brief interviews with infection preventionists at eight facilities that had confirmed cases supplied their view of whether the response arrived in time and was useful. The interviews added context the records could not: two preventionists said the state's call came after the patient had moved to another facility, and one said screening supplies arrived before the facility knew why they were needed. Interviews alone could not answer the evaluation's question, but combined with the records they explained several of the delays.

Limits of the Evaluation

The evaluation covered one year and a modest number of confirmed cases, so its estimates of timeliness and response rates are imprecise. It could not measure whether containment actually prevented transmission, since the system does not track what would have happened without a response. And it relied on the database's own response status field, which staff complete inconsistently. None of these limits overturns the central result, that delays arise before the state hears of a case, though they argue for repeating the evaluation after changes are made. A second evaluation a year after laboratories begin testing all resistant isolates would show whether the share of confirmed cases receiving a response, and the speed of that response, improved as expected. It would also test whether the shorter delays this evaluation predicts actually appear once isolate shipment is faster.

Conclusions

The system does trigger containment for most confirmed cases it learns about promptly, and once notified, the state acts quickly. It falls short in two places: it confirms mechanism for too few resistant isolates, and confirmation often arrives too late for a response to matter. Neither problem lies in the state team's work. Both lie upstream, in testing practices and isolate shipment.

Recommendations

Ask clinical laboratories to test all carbapenem-resistant isolates for carbapenemase production or to ship every such isolate within two business days. Track the share of resistant isolates tested and the time from collection to state notification as routine performance measures. For cases discharged home, define a minimal follow-up, such as notifying the primary care provider, rather than recording no response. Share the findings with laboratories and facilities, consistent with the guidelines' final step of ensuring the evaluation is used.

References

German, R. R., Lee, L. M., Horan, J. M., Milstein, R. L., Pertowski, C. A., & Waller, M. N. (2001). Updated guidelines for evaluating public health surveillance systems: Recommendations from the Guidelines Working Group. MMWR Recommendations and Reports, 50(RR-13), 1-35.

Guh, A. Y., Bulens, S. N., Mu, Y., Jacob, J. T., Reno, J., Scott, J., Wilson, L. E., Vaeth, E., Lynfield, R., Shaw, K. M., Vagnone, P. M. S., Bamberg, W. M., Janelle, S. J., Dumyati, G., Concannon, C., Beldavs, Z., Cunningham, M., Cassidy, P. M., Phipps, E. C., . . . Kallen, A. J. (2015). Epidemiology of carbapenem-resistant Enterobacteriaceae in 7 US communities, 2012-2013. JAMA, 314(14), 1479-1487. https://doi.org/10.1001/jama.2015.12480

Woodworth, K. R., Walters, M. S., Weiner, L. M., Edwards, J., Brown, A. C., Huang, J. Y., Malik, S., Slayton, R. B., Paul, P., Capers, C., Kainer, M. A., Wilde, N., Shugart, A., Mahon, G., Kallen, A. J., Patel, J., McDonald, L. C., Srinivasan, A., Craig, M., & Cardo, D. M. (2018). Vital signs: Containment of novel multidrug-resistant organisms and resistance mechanisms, United States, 2006-2017. MMWR. Morbidity and Mortality Weekly Report, 67(13), 396-401. https://doi.org/10.15585/mmwr.mm6713e1