New York State Department of Health: Mandatory Reporting of Clostridium difficile via National Healthcare Safety Network LabID Event – Evaluating the Validity of the Proxy Measure vs. Infection Surveillance

Background:

In 2009, the Center for Disease Control (CDC) introduced a module in the National Healthcare Safety Network (NHSN) allowing reporting of Clostridium difficile (C. diff). In July 2009, New York State (NYS) began using the LabID Event reporting function to report facility-wide C. diff at all NYS hospitals as part of the mandatory public reporting law. 30 NYS facilities were also collecting C. diff infection data as part of a prevention collaborative.

Objective:

Compare LabID case status with infection surveillance definitions requiring chart review¹.

Methods:

30 facilities reporting both LabID and clinical infection surveillance data were evaluated via on-site audit by NYS staff. LabID case status (CO – community onset; CO-HCFA – community onset-healthcare facility associated; HO – hospital onset) was assigned by the NHSN and compared to the case status assigned by the facilities (NFA – not facility associated; PFA – possibly facility associated; FA – facility associated).

Results:

Table 1: C. diff Event – Case Status Match
Hospital	NHSN LabID
	CO	CO-HCFA	HO	Recurrent
NFA	576 (22.1%)	84	232	7
PFA	53	218 (8.4%)	129	4
FA	20	27	1063 (40.7%)	7
Recurrent	28	29	54	78 (3.0%)

(Table 1) The overall case status match was 74.2% (1935/2609), ranging from 53.8% to 90.2% by facility. The NHSN classified 95.2% (1063/1117) of the FA cases reported by hospitals as HO, however only 71.9% (1063/1478) of HO cases were considered FA by the hospital. 232 HO cases were called NFA, accounting for the largest proportion of the discrepancies. The NHSN overestimates the facility incidence (HO & CO-HCFA) by 21.7% (range 5.7-42.7% by facility).

Conclusions:

In addition to the definition differences with regard to day 3 vs. day 4 onset, a significant proportion of the 232 NHSN HO cases classified as NFA by the facilities were due to clinical and laboratory information obtained from other facilities.

Despite these variations and definition differences, there is fair overall case status match. The LabID will continue to be used as a proxy measure for 2010 mandatory state reporting in NYS and its utility will continue to be evaluated. The definitions are applied uniformly across facilities, and the surveillance is much less labor intensive than conducting infection surveillance.

Acknowledgement: GNYHA & UHF C. difficile Prevention Collaborative and participating hospitals

¹McDonald LC, Coignard B, Dubberke E, et al. Recommendations for Surveillance of Clostridium difficile-Associated Disease. Infect Control Hosp Epidemiol 2007; 28:140-145.