Surgical Procedure Infections in California

$179 / year

This dataset contains the Surgical Site Infections (SSI) collected data from the California Department of Public Health (CDPH) Healthcare Associated Infections (HAI) for surgical procedures performed during 2014. The surgical infection ratio (SIR) is used to identify the SSI and it was calculated the number of predicted infections, the calculations were risk-adjusted.


This dataset shows the Centers for Disease Control and Prevention National Healthcare Safety Network (NHSN) risk adjusted standardized infection ratios (SIR) for surgical site infections (SSIs) reported by hospitals for 24 operative procedures that are listed in the Data Dictionary. The SIR is calculated by dividing the number of observed infections by the number of predicted infections. The number of predicted infections is calculated using SSI probabilities estimated from multivariate logistic regression models constructed from NHSN data during a baseline time period 2006 through 2008, which represents a reference population’s SSI experience. To enforce a minimum precision criterion, an SIR is calculated only if the number of observed infections is at least one.

SIRs are based on the date of procedure, not the date of the SSI event. All procedure and infection data entered before May 1, 2015 for surgical procedures performed between January 1 and December 31, 2014 were downloaded from NHSN for this dataset. The SIR used for this dataset is a risk adjusted SIR that considers only complex SSI identified during hospital admission or readmission to the same hospital following inpatient surgeries. The procedure counts and infection counts submitted by each hospital are displayed along with an SIR, the 95 percent confidence interval for the SIR, and the statistical comparison as follows: No difference – no difference in number of observed and predicted infections, High – more infections than predicted, or Low – fewer infections than predicted.

Reporting of SSI data by California general acute care hospitals to CDPH and public reporting of hospitals’ risk-adjusted SSI rates by CDPH‘s HAI Program were mandated by Health and Safety Code 1288.55 (a)(3), (b)(2), and (c)(1). The frequency of SSIs varies depending on modifiable risk factors, such as surgical technique and infection prevention measures, and non-modifiable risk factors, such as underlying patient illnesses, whether the surgery was an emergency, and whether the wound was contaminated prior to surgery. The distribution of non-modifiable risk factors among patients, referred to as patient case mix, can vary widely among different hospitals. To report SSI rates that allow for meaningful comparisons between hospitals, it is critical to adjust for the differences in patient case mix. Instead of a risk-adjusted SSI rate, NHSN produces a standardized infection ratio (SIR) that compares the number of SSIs reported by a hospital to the number that is predicted based on a surgical procedure category-specific algorithm derived from national data reported to NHSN from 2006 through 2008.

NHSN produces two SIRs for each surgical category, one that includes all SSIs (including superficial incisional) and the second, the Complex A/R SIR, that includes only deep incisional and organ/space SSI identified during the index hospital admission or on readmission to the same hospital that performed the inpatient surgery. For this dataset, data was extracted from CDPH that used only the Complex A/R SIR, hereafter referred to as SIR. Ten surgical procedure categories were selected for presentation based on the number of SIRs generated. SIRs were generated more frequently for high volume surgical procedure categories, surgeries that have a higher predicted number of infections, or both. As such, these were the surgical procedure categories where infection prevention strategies would have the largest impact. These ten surgical procedure categories, abdominal hysterectomy, cesarean section, coronary artery bypass graft, colon surgery, hip prostheses, knee prostheses, open reduction of fracture, spinal fusion, small bowel surgery and bile duct, liver and pancreatic surgery, account for 66% of SIRs for all the risk-adjusted SP categories. The data was collected through reports from hospitals in California for 24 common procedures plus 5 procedures without risk adjusted comparisons: heart transplant, kidney surgery, ovarian surgery, pacemaker surgery, and spleen surgery.

The datasets used from CHHS Open Data Portal has been modified.

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California, United States


John Snow Labs; California Health and Human Services Open Data Portal;

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Post-operative Infections, SSI Wound Infections, Surgical Site Infections, Infected Wounds, Post Surgery Infections, Surgical Procedure Complications, Surgical Infection Ratio

Other Titles

Surgical Procedures Site Infections in California by County, Infections After Surgical Procedures in California by County

CountyCalifornia county where surgical infection occurredstring-
YearYear when the cases occurreddate-
Operative_ProcedureType of surgerystring-
Facility_IDIdentification number of the hospitalintegerlevel : Nominal
Facility_NameName of the hospitalstring-
Procedure_CountNumber of times the procedure was performed in the hospitalintegerlevel : Ratio
Infection_CountNumber of procedures that had infection complicationintegerlevel : Ratio
Predicted_Infection_CountSurgical infection estimated probability calculated from a multivariate logistic regression model based on Prevention National Healthcare Safety Network (NHSN) datanumberlevel : Ratio
Standardized_Infection_RatioCenters for Disease Control and Prevention National Healthcare Safety Network (NHSN) risk adjusted standardized infection ratio (SIR); division of the number of observed infections by number of predicted infectionsnumberlevel : Ratio
ComparisonStatistical comparison between the number of observed and predicted infections; Higher = more infections than predicted and Lower = fewer infections than predictedstring-
CI_LowerSurgical SIR 95% Confidence interval lower limit for percentnumberlevel : Ratio
CI_UpperSurgical SIR 95% Confidence interval upper limit for percentnumberlevel : Ratio
NotesSSI SIR was calculated by CDPH if the predicted number of infections was less than 1 and greater than or equal 0.2 (this SIR and its comparison are not as accurate as SIRs based on a larger number of predicted infections); if a hospital is not in the table, the hospital may be reporting data combined with another hospitalstring-
CountyYearOperative ProcedureFacility IDFacility NameProcedure CountInfection CountPredicted Infection CountStandardized Infection RatioComparisonCI LowerCI UpperNotes
Orange2013 Abdominal Aortic Aneurysm Repair60000002AHMC Anaheim Regional Medical Center, AnaheimSSI SIR was calculated by CDPH
San Diego2013 Abdominal Aortic Aneurysm Repair90000013Alvarado Hospital Medical Center, Campus #1, San DiegoSSI SIR was calculated by CDPH
Los Angeles2013 Abdominal Aortic Aneurysm Repair930000008Antelope Valley Hospital, LancasterSSI SIR was calculated by CDPH
San Bernardino2013 Abdominal Aortic Aneurysm Repair240000100Arrowhead Regional Medical Center, ColtonSSI SIR was calculated by CDPH
Kern2013 Abdominal Aortic Aneurysm Repair120001330Bakersfield Heart HospitalSSI SIR was calculated by CDPH
Kern2013 Abdominal Aortic Aneurysm Repair120000338Bakersfield Memorial HospitalSSI SIR was calculated by CDPH
San Francisco2013 Abdominal Aortic Aneurysm Repair220000022California Pacific Medical Center, Pacific Campus Hospital, SFSSI SIR was calculated by CDPH
Los Angeles2013 Abdominal Aortic Aneurysm Repair930000004Cedars-Sinai Medical Center, Los AngelesSSI SIR was calculated by CDPH
Madera2013 Abdominal Aortic Aneurysm Repair40000129Children's Hospital Central California, MaderaSSI SIR was calculated by CDPH
Alameda2013 Abdominal Aortic Aneurysm Repair140000014Childrens Hospital and Research Center at OaklandSSI SIR was calculated by CDPH