This data release on Clostridium difficile (C. difficile) infections (CDI) in California general acute care hospitals is the third by the California Department of Public Health (CDPH) and the second using information submitted by California hospitals to the Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN). Data were reported from January 1, 2011 through December 31, 2011. The data presented in this release are based on laboratory identification of CDI cases. Each case is categorized by whether illness onset occurred in a hospital or in the community. Hospital-related cases of CDI are identified as “hospital-onset” or “hospital-associated.” Hospital-onset (HO) cases are those for which the positive stool sample for CDI was obtained on day four or later during the hospital stay. Hospital-associated (HA) cases are HO cases plus cases in which a patient who was discharged from the same hospital within the previous four weeks is readmitted to that hospital with a new positive stool sample for CDI during the first three days of the current admission. For HA cases, the CDI could have occurred as a result of the recent hospitalization or could be related to other exposures outside of the hospital.
Long-term acute care (LTAC) hospitals have longer patient lengths of stay and length of stay is an established risk factor for CDI. An LTAC hospital is a licensed general acute care hospital defined by the Centers for Medicare & Medicaid Services (CMS) as providing care for patients with medically complex conditions requiring an average length of stay for all patients of greater than 25 days. For this reason, we present HO and HA incidence rates for LTAC hospitals separately from all other general acute care hospitals.
We included in this report whether a hospital uses polymerase chain reaction (PCR) to detect C. difficile. The sensitivity of the PCR test, i.e. the ability of the test to detect C. difficile when present, can be as much as two times greater than other laboratory methods. Rates for hospitals that use PCR have not been adjusted to account for this difference in laboratory test sensitivity; therefore, we do not group or stratify hospitals by PCR use.
Although reporting CDI data to NHSN allows for accurate classification of CDIs, it does not allow the data to be used to compare hospitals with each other or with a state average. Hospital CDI rates are not comparable, as the rates are unadjusted for other risk factors associated with CDI (e.g., hospital type, characteristics of patient population, and community onset rates). Hospital rates for C. difficile infection may differ because patient populations have different risks for infection that are beyond the control of the hospital. The rate of community onset cases has also been shown to affect the rate of hospital onset infections. These data serve as a basis to evaluate CDI rates in California hospitals over time. Definitions, including methods associated with this release are summarized in Technical Notes.
What’s in key findings? This document summarizes the key findings from this data release including introduction, important results, and key public health actions and messages.
The data in this report is presented in the following tables. CDI incidence rates are provided for all hospitals that reported 12 months of data for the reporting period.
What is in the technical notes? The Technical Notes contain information on the data sources, definitions, quality assurance and control, data presentation and statistical analyses associated with this data release.
For more information on Clostridium Difficile Infection (CDI), see CDI Information