1. Russ Olmsted olmstedr@trinity-health.org
Principles of Epidemiology & Surveillance of Health care-Associated Infection
Russ Olmsted

2. Some “real world” definitions of Epidemiology
“the worst taught course in medical school”
Medical student, U of M
"the science of making the obvious obscure”
Clinical Faculty, MSU
“the science of long division”
Statistician , Grand Valley State U
"the study of skin diseases“
New CDC Epidemic Intelligence Service Officer, Atlanta

3. The Real Definition
epidemiology is "the study of the distribution and determinants of health-related states in specified populations, and the application of this study to control health problems." - smarty pants epidemiologist during a cocktail party

4. Goals of Infection Prevention/Control (IP/C) & Epidemiology Programs
Surveillance:
systematic collection, analysis, & reporting of data from surveillance system to prevent disease & improve health
Principal Goals:
Protect the patient;
Protect health care personnel, visitors, & others
Accomplish these in a cost effective manner whenever possible
Scheckler WE. AJIC 1998;26:47-60

5. Surveillance Definition:
Function: noun Etymology: French, from surveiller to watch over, from Latin vigilare, from vigil watchful
close watch kept over someone or something (as by a detective)
Application:...ongoing, systematic collection, analysis, interpretation, and dissemination of data regarding a health-related event...
Purpose: to reduce morbidity and mortality and to improve health
CDC. Surveillance system guideline. MMWR 2001;50(RR13)

6. Comparing & Contrasting Surveillance vs. Individual Patient Care
Surveillance is:
Population-based
Incidence and prevalence rates versus raw numbers – trending
Risk stratification (age, disease, complexity of surgery, etc.)
Systematic and improvement oriented
Measurement to improve patient safety.
Surveillance is NOT:
Clinical diagnosis of infection
Clinical determination of antibiotic use
Based on subjective criteria “Gut feeling”
Based on definitions of from your facility’s medical director

7. Early Evidence of Efficacy of Surveillance; using data for patient safety
Power of performance measurement: feedback loop of surgeon-specific SSI rates, NY Roosevelt Hospital,
Year Overall SSI Rate
% (baseline)
(1st yr. SSI data provided)
Brewer GE. JAMA 1915

8. Keys for the Elimination of Healthcare-associated Infections
Collect data and disseminate results
transparency with consumers
Engaging direct care providers
Full adherence to best practices
Recognize excellence
Identify and respond to emerging threats
Improve science for prevention through research
Cardo D, et al. ICHE 2010

9. Efficacy of Surveillance Data + Prevention Strategies at the Bedside

10. Using HAI Data for Comparing Performance Between Providers
National Surgical Quality Improvement Program (NSQIP)

11. Uses of HAI Surveillance Data: Nationwide

12. Impact of C. difficile infection (CDI)
Hospital-acquired, hospital-onset: 165,000 cases, $1.3 billion in excess costs, and 9,000 deaths annually
Hospital-acquired, post-discharge (up to 4 weeks): 50,000 cases, $0.3 billion in excess costs, and 3,000 deaths annually
Nursing home-onset: 263,000 cases, $2.2 billion in excess costs, and 16,500 deaths annually
Campbell et al. Infect Control Hosp Epidemiol. 2009:30: Dubberke et al. Emerg Infect Dis. 2008;14:
Dubberke et al. Clin Infect Dis. 2008;46: Elixhauser et al. HCUP Statistical Brief #

13. Using HAI Data to Assess Efficacy of an Intervention; Preop Skin Prep
Table 2. Proportion of Patients with Surgical-Site Infection, According to Type of Infection (Intention-to-Treat Population).
Reference:
Darouiche RO et al. NEJM: 2010; 362:18-26.
Darouiche RO et al. N Engl J Med. 2010;362:18-26.

14. Klevens, et al. Pub Health Rep 2007;122:160-6
Snapshot of Relative Distribution of Health Care-Associated Infections (HAIs) in U.S. hospitals, 2002; 1.7 M/yr; 100,000 deaths
SSI
20%
BSI
11%
UTI
36%
PNEU
Other
22%
133,368
424,060
263,810
129,519
274,098
-967
-21
-28,725
244,385
TOTAL
HRN
WBN
Non-newborn ICU
= SSI
Klevens, et al. Pub Health Rep 2007;122:160-6
HRN = high risk newborns WBN -= well-baby nurseries ICU = intensive care unit SSI = surgical site infections BSI – bloodstream infections UTI = urinary infections PNEU = pneumonia
Comment: relative proportion of this Pie for
UTI is less in 2012 = change to SUTI. SSI is #1 14

15. Updated Distribution of HAIs, U.S., 2012
SSIs are now most prevalent site of HAI
Reason:
Change in criteria for UTI by NHSN, 2009
Complexity of Prevention of SSIs; multiple risk factors
Magill SS, et al. ICHE 2012; 33:
SSI -surgical site infection; Pneu -pneumonia; UTI –urinary tract infection;
BSI –bloodstream infection; GI – gastrointestinal infection

16. Steps Involved in Managing Information
Surveillance of HAIs Lee TB, et al. AJIC 2007;35:
Needs
Assessment
Assess Pt.
Population
Planning &
Design
Select
Indicators
Report & Use
Findings
Display &
Disseminate
Capturing
& Reporting
Apply Surv.
Definitions
Analyze
Data
Process
& Analyze
Storing &
Retrieving
Collect Data
Apply risk
stratification
JC. CAMH, 2007

17. How Much Time is Spent on Surveillance by Infection Preventionists (IPs) in NY?
IPs surveyed from 222/224 acute care hospitals, NY
Scope of responsibility for “average IP” 1.0 FTE:
151 pt. Beds
1.3 ICUs
21 LTCF beds
0.6 Dialysis ctrs
0.5 ASC
4.8 Amb. Care
1.3 PCP offices
capacity
responsibilities
In balance?
infrastructure

18. Conceptual Model for Performance Improvement: Have we created a culture of safety?
Process
Outcome
Structure
Have we reduced the likelihood of harm?
How often do we do what we are supposed to?
How often do we harm?
Adapted from: Donabedian A. Evaluating the quality of medical care. Milbank Memorial Fund Quarterly 1966;44:166–206.

19. Using Process Data to Improve Antibiotic Stewardship
Multidisciplinary team, IP+ID+Geriatrician visited and surveyed use of Abx to Prevent UTIs in all LTC units, Central Finland
Results:
Most (80%) Abx use for UTI
Significant drop in Use overall 13 to 6%;acute+ LTC
59% of units used urine odor as reason for culture
Rummukainen ML, et al. AJIC 2012

20. Ensuring Quality of Surveillance
Written Plan: risk assessment, goals, objectives, & elements
Maintain thoroughness and intensity over time; e.g. what happens to rate of VAP if ICP leaves a position and it is not filled for 6 months?
Organization leaders need to provide adequate resources for surveillance program
Re-evaluate efficacy of surveillance program at least annually

21. Validation of HAI Surveillance: Precision & Quality of the Information
20 ICUs, 4 Medical Centers
Median CLABSI rates:
IP = 3.3
Computer algorithm = 9.0
Medical Ctr C had the lowest rate
by IP (2.4) however the highest
rate by computer algorithm (12.6)
Lin MY, et al. JAMA 2010

22. Step 1 – Assess population and environment
Patient demographics (age, gender, socioeconomic status)
Patient clinical characteristics (most frequent diagnoses and co-morbidities, most frequent and most rarely performed procedures, medical treatments)
Characteristics of HCP (knowledge and training)
Facility characteristics (physical size, age, condition, single or shared rooms, geographic location)
Do you have existing surveillance data?
Lee TB, et al. AJIC 2007

23. Step 2 – Select Indicators/Metrics to Measure: Process, Outcome…
Use facility-specific risk assessment
Search the literature for relevant studies that apply to your patient population
What are most likely HAI issues?
Frequency, cost, reg./accred. requirement, PI project
Examples:
Process: % residents & HCP rec’d flu vax., CMS survey tool for ASC, % Abx use for ASB, Hand hygiene adherence
Outcome: CLABSI, CAUTI, SSI rates; incidence of CDI/10,000 patient days
Lee TB, et al. AJIC 2007

24. Step 3 – Use Valid, Reproducible Surveillance Criteria
Acute & Ambulatory Care: CDC’s National Healthcare Safety Network (NHSN); ww.cdc.gov/nhsn
Long Term Care: Revised McGeer;Stone ND, et al. Infect Control Hosp Epidemiol 2012;33:965-77
Home Care & Hospice: APIC-HICPAC, Available from
Consider performing a “Point or period Prevalence” or even simple line listing to establish baseline frequency if existing data are not available
Lee TB, et al. AJIC 2007

25. NHSN Surveillance Criteria
HAI: localized or systemic condition resulting from an adverse reaction to the presence of an infectious agent(s) or its toxin(s) that was not present on admission to the acute care facility
…all elements of a CDC/NHSN site-specific infection criterion were first present together on or after the 3rd calendar day of admission to the facility (the day of hospital admission is day 1).

26. NHSN Surveillance Criteria: example of application

27. Present on Admission (POA)
If all of the elements of an infection definition are present during the two calendar days before the day of admission, the first day of admission (day 1) and/or the day after admission (day 2) and are documented in the medical record, the infection would be considered POA
Urine Cx
>105 E. coli
Fever = 102 F
This infection = POA

28. Location, Location, Location… key variable for NHSN surveillance

29. Key Terms & Concepts Term Definition HAI
An infection is considered an HAI if all elements of a CDC/NHSN site-specific infection criterion were first present together
on or after the 3rd hospital day (day of hospital admission is day 1). For an HAI, an element of the infection criterion may
be present during the first 2 hospital days as long as it is also present on or after day 3. All elements used to meet the
infection criterion must occur within a timeframe that does not exceed a gap of 1 calendar day between elements.
Device-associated infection
An infection meeting the HAI definition is considered a device-associated HAI if the device was in place for >2 calendar
days when all elements of a CDC/NHSN site-specific infection criterion were first present together. HAIs occurring on the
day of device discontinuation or the following calendar day are considered device-associated HAIs if the device had been
in place already for >2 calendar days.
Date of Event
For an HAI (excludes VAE), the date of event is the date when the last element used to meet the CDC/NHSN site-specific
infection criterion occurred

30. Key Terms & Concepts Term Definition Transfer Rule
If all elements of an HAI are present within 2 calendar days of transfer from one inpatient location to another in the same facility (i.e., on the day of transfer or the next day), the HAI is attributed to the transferring location.
Likewise, if all elements of an HAI are present within 2 calendar days of transfer from one inpatient facility to another, the HAI is attributed to the transferring facility. Receiving facilities should share information about such HAIs with the transferring facility to enable reporting.

31. Step 4 – Collect HAI Data
Run…don’t walk to your PC/Mac, fire up your browser, and take training on use of NHSN – AC & LTC
Lee TB
AJIC 2007

32. New LTCF – specific Modules Now Available from
NHSN.
For Details see:

33. New HCP Vaccination Module Now Available at NHSN
See:

34. Step 5 – Analyze HAI Data Line Listing CAUTI Rate Table
Bar Graph & Pie Charts

35. Step 6 – Apply Risk Stratification to Data
NHSN
Location: ICU, non-ICU, Hem-Onc
Standardized Infection Ratio (SIR)
Summary measure to compare HAI data among one or more groups of patients to that of a standard population’s (e.g. NHSN)
Accounts for differences in incidence of HAI by patient groups
SSI: ASA score, duration of surgery, wound class > 3
NICU: birthweight category
Others:
SSI rates; inpatients only vs inpt. + post-discharge
Fall injury risk scoring scheme
Stratify receipt of influenza vaccine by job class and department

36. Step 7 – Reporting & Using HAI Surveillance Data
Incorporate HAI data into health system monthly patient safety quality reporting dashboard
Reporting data to MDCH Sharp Unit & CMS
Permit access to MI-Specific HAI experience
Fulfills incentive-based reimbursement from CMS
Be consistent in timelines for reporting to key personnel and other entities
The most important step in the surveillance process – data for improvement at the local level is first step in improving care

37. Keystone ICU Project: The Results
66% reduction in Central Line Bloodstream Infections (CLBSI)
Interventions:
Hand hygiene
Max. barrier prec. during insertion
CHG antiseptic on insertion site
Avoid femoral CLs
Remove CL when not needed
Pronovost P, et al. NEJM 2006;355:
Rate
Per
1,000 CL
Days

38. Use of Surveillance Technology to Improve Efficiency of IPC Program
M. Moyhla – Holy Cross Hospital

39. Improving Surveillance Skills: Case Studies in AJIC & Available online at cdc.gov/nhsn