Quantitative validation of central line-associated bloodstream infections (CLABSI) in Oregon intensive care units (ICU) 2009 Zintars Beldavs Manager HAI Program, Acute and Communicable Disease Section, Oregon Public Health Division, Oregon Health Authority June, 2012

Central Line-Associated Bloodstream Infection (CLABSI) Deadly: 18% mortality 14,000 deaths/ year in ICU patients Prolong hospitalization by mean of 7 days Expensive: $3,700 - $29,000/episode Preventable: hand hygiene, barrier precautions, skin antisepsis, catheter site selection Pittet D, Tarara D, Wenzel RP. Nosocomial bloodstream infection in critically ill patients. Excess length of stay, extra costs, and attributable mortality. JAMA. 1994;271:1598-1601. Soufir L et al. Infect Control Hosp Epidemiol 1999 Jun;20(6):396-401.

Mandated Reporting in Oregon Reportable as of 1/1/2009 CLABSIs in ICU SSI knee prostheses and coronary artery bypass grafts More reportable surgical site infections as of 1/1/11 Colon surgery Hip prosthesis Laminectomy Abdominal hysterectomy Rationale behind CLABSI: high morbidity and mortality Behnd CABG: cardiac prodedures also high-risk Behind KPRO: consequences of an infection are severe...(i.e. Getting your knee opened up again!). Also, this allows for inclusion of a reasonable number of facilities; orthopedic procedures done at more facilities than cardiacs SCIP-1: antibiotic received 1-hour prior to surgical incision SCIP-2: prophylactic antibiotic selection SCIP-3: prophylactic antibx discontinued < 24 hours after surgery end

2009 Oregon CLABSI Pathogens Charts indicate primary organism associated with for each (~4 true pos cases had secondary and tertiary orgs). This is statewide aggregate data. “other” = 1 Moraxella (gram neg diplococcus),1 Stenotrophomonas, 1 Veillonella. All but 2 “other yeast” are non- albicans Candida spp.

CLABSI Rate 2009-2011

CLABSI Rate Change 2009-2011

CLABSI Count by Hospital Size

Validation for Accurate Data Concern: surveillance definitions applied inconsistently by IPs Poor inter-rater reliability: kappas .30 to .58 Previous validation studies: potentially > half of cases not reported (Connecticut) Oregon hospitals:Lin MY, et al., SHEA 2010. % of 661 positive blood cultures considered CLABSIs: Infection Preventionists: 21% Standardized review: 35% Electronic algorithm: 57 Kappa values 0.43, 0.30, 0.58 Mayer J, et al., SHEA 2010: 120 VAMC records, 18 IPs compared to electronic algorithm Overall kappa 0.42, range 0.30–0.50 Individual IPs varied up to 2-fold in CLABSI assessments Backman et al: 23 of 48 (48%) CLABSI reported

Objectives Evaluate quality of reported data Assess under- and over-reporting Gauge the reliability and consistency of surveillance case definitions Provide feedback to facilities on surveillance case definitions and reporting methods

Methods Study period: 2009 Included: 44 acute care hospitals 28 with < 50 beds 10 with > 200 beds Median central line days 210, range 4-4956 OPHD validation team: HAI Program Manager Epidemiologist EIS Officer/Physician 3 public health nurses 58 total hospitals. 14 excluded because they had no ICU or no more than 10 patients with CL annually. Map: Oregon Association of Hospitals and Healthcare Systems, oahhs.org

Methods All blood culture (+) Drawn in ICU or up to 48 hours after and Organism not isolated in 14 days before admit

Methods Unit of analysis: Single bacteremia episode More than one CLABSI/patient possible

All (+) culture reviewed Methods 37 Hospitals 7 Hospitals All reported CLABSI and random sample 60 (+) culture not reported as CLABSI All (+) culture reviewed March 2010 - April 2011: on-site hospital visit for chart review Retrospective record review by 2-4 reviewers At 37 hospitals: all ICU pts. blood culture (+) At 7 largest hospitals: all reported CLABSI plus random sample of 60 patients with ICU blood-culture(+) not reported as CLABSI Validators blinded as to whether cases reported as CLABSI Reviewers blind as to reported CLABSI status

Methods Adjudication Discussion NHSN Hospital Determination Validator Determination After visit, all cases with discordant CLABSI determinations (suspected false positives or false negatives) adjudicated by phone with hospital staff Participants Hospital IP staff Hospital physician OPHD validators OPHD physician Review of all findings for final CLABSI determination If no consensus reached, case referred to CDC staff

Methods 1926 (+) cultures received on line lists 1204 from 7 highest volume facilities 722 from 41 facilities < than 60 (+) cultures

Methods 1199 medical records reviewed 477 sampled at 7 highest-volume facilities 722 at small- and medium- volume facilities

817 included in final analysis Results 817 included in final analysis Hospitals included cultures not requested: (+) blood cultures obtained prior admit or > 48 hours after discharge from ICU 382 of 1199 reviewed censored

Results Discordant Cases 35 records with disagreement 18 (51%) adjudicated as CLABSI 17 (49%) adjudicated as not CLABSI Hospital correct in 13 (37%) OPHD correct in 22 (63%) 4 required NHSN consult (2 CLABSI)

Reasons for discrepancies Reason for discrepancy for under-reported CLABSI No. episodes % No clearly discernible reason determined 7 44 Misattributed CLABSI to other infection Recognized CLABSI failed to attribute ICU 1 6 Misclassified CLABSI as present on admit Total 100 Reason for discrepancy for over-reported CLABSI No. episodes % Infection attributable to other site 2 33 Infection not attributable to ICU Single blood culture for probable contaminant 1 16.5 Unknown why reported CLABSI Total 6 100 For CLABSI “just missed”: at some facilities, IP staff had changed since 2009 and current staff unaware of rationale for previous reporting decisions.

Results Validation outcome, unadjusted CLABSIs among All ICU Patients with Positive Blood Cultures, by Initial Hospital Report — Oregon, 2009 CLABSI Final determination Present Absent Total Hospital report 70 (TP) 6 (FP) 76 16 (FN) 725(TN) 741 86 731 817

Example Calculation to Adjust for Sampling Fraction 60 Records sampled at hospital 142 Total BSI 2 BSI reported as CLABSI Sampling fraction: 60/140=.43 True positive and false positive remain (all reported CLABSI reviewed) False negative and true negative results divided by sampling fraction Final Determination CLABSI Present CLABSI Absent Hospital 1 True Positive False Positive “Overreport” 2 (Estimate: 2/.43=4.7) False Negative “Underreport” 42 (Estimate: 42/.43=98) True Negative

Results Estimated # of CLABSI adjusted for sampling fraction Estimated CLABSIs among All ICU Patients with Positive Blood Cultures, by Initial Hospital Report — Oregon, 2009 CLABSI Final determination Present Absent Total Hospital report 70 (TP) 6 (FP) 76 27a (FN) 1089a (TN) 1116 97 1095 1192 72% of true CLABSIs had been reported (Sensitivity = 0.72) 99% of true non-CLABSI were correctly not reported (Specificity = 0.99) 92% of CLABSIs reported were true CLABSI (Positive predictive value = 0.92) 98% of cases not reported CLABSI were not CLABSI (Negative predictive value = 0.98) 8% of positive cultures were CLABSIs (Prevalence = 0.08 )

Validation Impact on CLABSI Rate Validation increased the statewide ICU CLABSI rate from 1.21 (95% CI: 0.95–1.51) to 1.54 (95% CI: 1.25–1.88) CLABSI per 1,000 central-line days Change after validation in CLABSI rate No. hospitals % Rate decreased 0.70 1 2 No change 33a 75 0.01–0.50 higher 5 0.51–1.00 higher >1.00 higher 6b 14 Total 44 100 1 hospital reported 2 CLABSIs and these were later deemed non CLABSI: rate change .7 to 0. > 1 rate change: 4 to 146 bed. 4 of 6 with >1 smaller census hospitals reported 1 collectively but validation found 8. 2 Sampled hospitals reported 28 but were found to have estimated 40. a 23/33 had no CLABSI identified either before or after the validation. b 3/6 had no CLABSI before the validation.

Importance of Inter-Agency Follow-up Discussion Of 27 unreported cases identified as CLABSI by OPHD, 16 (59%) true CLABSI Sensitivity of reporting: 72% based on follow-up adjudication vs. 60% based on OPHD review alone (P= 0.07), closer to some previous validation efforts

Limitations Denominator data not rigorously assessed Did not adjudicate cases when reviews concordant with reported data Unbiased 3rd party not involved in adjudication discussions

Conclusions Validating hospital CLABSI reporting improves accuracy of hospital-based CLABSI surveillance Discussing discordant findings improves the quality of validation

Future Work Currently completing coronary artery bypass graft validation of all 14 hospitals Similar adjudication procedure Sampling higher duration procedures Given funding: comprehensive baseline and yearly sampled validation other HAIs

Acknowledgments Questions? OPHD HAI program staff and others assisting Paul Cieslak – Public Health Physician Ann Thomas – Public Health Physician Margaret Cunningham – HAI Epidemiologist Diane Roy – HAI Administrative Assistant John Oh – EIS Officer Steve Moore – Public Health Nurse Jennifer Tujo – Infection Preventionist Valerie Ocampo – HAI Public Health Nurse Oregon Patient Safety Commission Office for Oregon Health Policy and Research Association of Professionals in Infection Control, Oregon-SW Washington Chapter Questions? 971-673-1111 zintars.g.beldavs@state.or.us

Questions?