Quantitative validation of central line- associated bloodstream infections (CLABSI) in Oregon intensive care units (ICU) 2009 Zintars Beldavs Manager HAI.

Quantitative validation of central line-associated bloodstream infections

(CLABSI) in Oregon intensive care units (ICU) 2009

Zintars BeldavsManager HAI Program, Acute and Communicable Disease Section,

Oregon Public Health Division, Oregon Health AuthorityJune, 2012

Central Line-Associated Bloodstream Infection (CLABSI)

Deadly: 18% mortality14,000 deaths/ year in ICU patientsProlong 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

2009 Oregon CLABSI Pathogens

Candida albicans14%

Candida non-albicans15%

Yeast NOS2%

Enterococcus spp.13%Gram-neg bacilli

15%

Staphylococcus aureus15%

Coagulase-neg Staphy-lococcus spp.

22%

Other bacteria 5%

2009

-01

2009

-02

2009

-03

2009

-04

2009

-05

2009

-06

2009

-07

2009

-08

2009

-09

2009

-10

2009

-11

2009

-12

2010

-01

2010

-02

2010

-03

2010

-04

2010

-05

2010

-06

2010

-07

2010

-08

2010

-09

2010

-10

2010

-11

2010

-12

2011

-01

2011

-02

2011

-03

2011

-04

2011

-05

2011

-06

2011

-07

2011

-08

2011

-09

2011

-10

2011

-11

2011

-12

0

0.5

1

1.5

2

2.5

ICU CLABSI per 1,000 central line-daysAll reporting Oregon hospitals (Note only 2009 data

validated)

CLABSI Rate 2009-2011

Rate increased by 1.01 or more*2%

Rate increased by 0.01-1.0

9%

No change in rate (no CLABSI in 2009 or in

2011)53%

Rate decreased by 0.01- 1

15%

Rate decreased by 1.01 or more**

21%

*The only Oregon hospital with a rate increase of more than 1 CLABSI per 1000 central line-days reported one CLABSI in 2011 (vs. zero in 2009).**Six of the ten hospirals reporting decreases of more than 1 CLABSI per 1000 central line-days reported zero CLABSI for 2011.

CLABSI Rate Change 2009-2011

CLABSI Count by Hospital Size

2009 2010 2011

1 30

3 3 1

20

7 5

62

34

40

Number of beds<=25 26-100 101-200 >200

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)

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

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

Methods

All (+) culture reviewe

d

All reported CLABSI and random sample 60 (+) culture

not reported as CLABSI

37 Hospitals

7 Hospitals

Reviewers blind as to reported CLABSI status

Methods

Hospital Determinati

on

ValidatorDeterminati

on

Adjudication Discussion

NHSN

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

Results

817 included in final analysis

382 of 1199 reviewed censored

Hospitals included cultures not requested:

(+) blood cultures obtained prior admit or > 48 hours after discharge from ICU

ResultsDiscordant 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

For CLABSI “just missed”: at some facilities, IP staff had changed since 2009 and current staff unaware of rationale for previous reporting decisions.

Reason for discrepancy for under-reported CLABSI No. episodes %

No clearly discernible reason determined 7 44

Misattributed CLABSI to other infection 7 44

Recognized CLABSI failed to attribute ICU 1 6

Misclassified CLABSI as present on admit 1 6

Total 44 100

Reason for discrepancy for over-reported CLABSI No. episodes %

Infection attributable to other site 2 33

Infection not attributable to ICU 2 33

Single blood culture for probable contaminant 1 16.5

Unknown why reported CLABSI 1 16.5

Total 6 100

ResultsValidation outcome, unadjusted

CLABSIs among All ICU Patients with Positive Blood Cultures, by Initial Hospital Report — Oregon, 2009

CLABSIFinal determination

Present Absent Total

Hospital

report

Present 70 (TP) 6 (FP) 76

Absent 16 (FN) 725(TN) 741

Total 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 DeterminationCLABSI Present

Final DeterminationCLABSI Absent

HospitalCLABSI Present

1True Positive

1False Positive“Overreport”

Hospital CLABSI Absent

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

CLABSIFinal determination

Present Absent Total

Hospital

report

Present 70 (TP) 6 (FP) 76

Absent 27a (FN) 1089a (TN) 1116

Total 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 )

Change after validation in CLABSI rate No. hospitals %

Rate decreased 0.70 1 2

No change 33a 75

0.01–0.50 higher 2 5

0.51–1.00 higher 2 5

>1.00 higher 6b 14

Total 44 100

a 23/33 had no CLABSI identified either before or after the validation.b 3/6 had no CLABSI before the validation.

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

Validation Impact on CLABSI Rate

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

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

[email protected]

Questions?