Principles of Epidemiology &
Surveillance of Health careAssociated Infection
Russ Olmsted
Trinity Health
olmstedr@trinity-health.org
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
The Real Definition

epidemiology is "the study of the
distribution and determinants of healthrelated states in specified populations,
and the application of this study to
control health problems." - smarty
pants epidemiologist during a cocktail
party
Comparison of Definitions; Epidemiology vs
Population Health

CDC: Epidemiology –

“the study of the
distribution and
determinants of healthrelated states or events
in specified populations,
and the application of
this study to the control
of health problems”


Institute of Medicine:
Population Health “the health outcomes
of a group of
individuals, including
the distribution of
such outcomes within
the group” (Kindig
and Stoddart, 2003).
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
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,

Purpose: to reduce
systematic collection,
analysis, interpretation,
and dissemination of data
regarding a health-related
event...
morbidity and mortality
and to improve health
CDC. Surveillance system guideline.
MMWR 2001;50(RR13)
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
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, 18951914 Year
Overall SSI Rate
1895
39.0 % (baseline)
1896
9.0 (1st yr. SSI data provided)
1899
3.2
1912
2.4
1914
1.2
Brewer GE. JAMA 1915
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
How Big of a Problem are Healthcare Associated
Infections (HAIs)?


Point Prevalence Survey;
National Healthcare Safety
Network (NHSN) N=183
hospitals, 2011
Patients at risk = 11,282




452 (4.0%) with > one HAI
Distribution by site – see pie chart
C. difficile = 70% of GI infections
Nationwide estimates:

648,000 patients with 721,800
HAIs/year
% HAIs
Pneu
SSI
GI
UTI
BSI
ENT
LRI
SST
CV
Magill SS et al. NEJM 2014;370:1198-208
Efficacy of Surveillance Data + Prevention Strategies at
the Bedside
Who Gets HAIs? 1/25 on any given day in U.S.
hospitals; many are older adults
McGill SS, et al
HAIs in Long Term Care Setting
Schweon S, LTC Safety Project, HRET, Cohort 5, 9/2015
Impact of C. difficile infection
(CDI)

Hospital-acquired, hospitalonset: 165,000 cases, $1.3
billion in excess costs, and
9,000 deaths annually

Hospital-acquired, postdischarge (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. 2009:30:523-33.; Dubberke et al. Emerg Infect Dis.
2008;14:1031-8. ; Dubberke et al. Clin Infect Dis. 2008;46:497-504.;
Elixhauser et al. HCUP Statistical Brief #50. 2008.
Steps Involved in
Managing Information
Needs
Assessment
Lee TB, et al. AJIC 2007;35:427-40.
Assess Pt.
Population
Planning &
Design
Capturing
& Reporting
Surveillance of HAIs
Select
Indicators
Display &
Disseminate
Apply Surv.
Definitions
Process
& Analyze
Analyze
Data
Storing &
Retrieving
Collect Data
JC. CAMH, 2007
Report & Use
Findings
Apply risk
stratification
Conceptual Model for Performance
Improvement: Have we created a culture of
safety?
Structure
Have we reduced the
likelihood of harm?
Process
How often do we do
what we are
supposed to?
Outcome
How often do
we harm?
Adapted from: Donabedian A. Evaluating the quality of medical care.
Milbank Memorial Fund Quarterly 1966;44:166–206.
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
“In response to anecdotal reports of intentional nonreporting of infection data, CDC and CMS are jointly
issuing a reminder that addresses concerns about
healthcare facility non–reporting of healthcareassociated infections events. While there is no evidence
of a widespread issue, CDC and CMS want to emphasize
that accurate reporting to NHSN through strict
adherence to the NHSN definitions is critical… “
Issued: 10/7/2015
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
In balance?
infrastructure
responsibilities
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
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
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
 http://www.ncbi.nlm.nih.gov/pubmed
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
Step 3 – Use Valid, Reproducible
Surveillance Criteria




Acute & Ambulatory Care: CDC’s National Healthcare
Safety Network (NHSN); ww.cdc.gov/nhsn
Long Term Care: Stone ND, et al. Infect Control Hosp
Epidemiol 2012;33:965-77
Home Care & Hospice: APIC-HICPAC, 2008. Available
from http://www.apic.org
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
www.cdc.gov/nhsn
NHSN Surveillance Concepts
Healthcare-associated Infection (HAI); if the date of event of
the NHSN site-specific infection criterion occurs on or after the
3rd calendar day of admission to an inpatient location where
day of admission is calendar day 1.
Present on Admission (POA); if the date of event of the NHSN
site-specific infection criterion occurs during the POA time
period, which is defined as the day of admission to an
inpatient location (calendar day 1), the 2 days before
admission, and the calendar day after admission
Guide for Classification of Infection
Symptomatic UTI criteria 1a, CAUTI:
1. Indwelling urinary catheter in place >2 d
2. fever (>38.0°C), suprapubic tenderness, costovertebral
angle pain, urgency, frequency, or dysuria &
3. Urine culture detects ≥105 CFU/ml.
NHSN Key Concepts, cont.
NHSN Key Concepts, cont.
Application of Key Concepts
IWP, RIT, and secondary bloodstream infection
attribution period do apply to other sites, e.g. CAUTI,
CLABSI
NHSN Surveillance Criteria: Let’s
Practice




Ms. Jones admitted to 5 West on 1/15/2015
 New medical resident orders urine culture on admission
because he wants to know what’s in her bladder but Ms.
Jones shares she has no symptoms or fever.
 Indwelling urinary catheter inserted
 Culture reveals > 100,000 CFU/ml of E. coli
Day 9 of admission, 1/23/2015
 New temperature = 39°C (102.2 F)
 Repeat urine culture ordered and finds > 100,000
CFU/ml of E. coli.
Is this a UTI that was POA?
Should this be reported to NHSN as a SUTI (CAUTI)?
Locations & Transfers

Location: inpatient location (unit) where the patient
was assigned on the date of the HAI event, i.e. date
when the first element used to meet the event
criterion occurred.

Transfer rule: if date of event for a HAI is the day of
transfer or discharge, or the next day, the infection is
attributed to the transferring location.
Day of
admission,
3/20/15
3/23/15
3/24/15
Tranfer rule
Result
Unit A; MICU
Central line
inserted
Transfer to Unit
B; progressive
care unit
Unit C, medical
ward
New fever,
blood cx =
S. aureus
CLABSI attribute
to Unit B
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.
Deviceassociated
infection
An infection meeting the HAI definition is considered a deviceassociated 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.
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
Patient Safety Component
ModulesNHSN Structure
Patient Safety
Component
Patient
Safety
Deviceassociated
Module
Procedureassociated
Module
Medicationassociated
Module
Healthcare
Personnel
Biovigilance
Safety
MDRO & CDI
Module
Lee TB
Vaccination
Module2007
AJIC
Surveillance Modules available for Acute & Long
Term Care
For Details on LTC see:
http://www.cdc.gov/nhsn/LTC/index.html
LabID C. difficile event
LabID C. difficile event


Community-onset (CO) LabID Event: Date specimen
collected ≤ 3 calendar days after current admission to the
facility (i.e., days 1, 2, or 3 of admission)
Long-term Care Facility-onset (LO) LabID Event : Date
specimen collected > 3 calendar days after current
admission to the facility (i.e., on or after day 4)
 sub-classified futher into:
 Acute Care Transfer-Long-term Care Facility-onset (ACTLO): LTCF-onset (LO) LabID event with specimen
collection date ≤ 4 weeks following date of last transfer
from an Acute Care Facility (Hospital, Long-term acute
care hospital, or Acute inpatient rehabilitation facility
only)
New HCP Vaccination Module Now Available at
Denominator Categories
NHSN
Employee HCP
See: http://www.cdc.gov/nhsn/hps_Vacc.html
Non-Employee HCP: Licensed independent practitioners (physicians,
advance practice nurses, and physician assistants)
Non-Employee HCP: Adult students/trainees and volunteers
Healthcare Personnel Safety Component
HCP must Personnel
be physically
presentModule
in the facility for at least 30 working d
Healthcare
Vaccination
between
October
1 and March
31
Influenza
Vaccination
Summary
National Center for Emerging and Zoonotic Infectious Diseases
Division of Healthcare Quality Promotion
Example #1: Line List – Device-associated Infections
RESULTS
Step 5 – Analyze HAI Data
National Healthcare Safety Network
Line Listing for All ICU Device-Associated Events
As of: June 25, 2012 at 8:11 AM
Date Range: DA_EVENTS evntDateYM 2011M01 to 2011M06
Line Listing
Location=71ICU
Event ID
Patient ID
Age Gender
on
Event
Date
Fac
Admission
Date
Event Date
Days: Event Specific Location Secondary
Admit Type
Event
BSI?
to
Event
Example #2: CAUTI Rate Table
RESULTS
234794 12120380
0 F
01/05/2011 01/08/2011
4 UTI
234783 9782078
108 F
01/14/2011 01/17/2011
4 PNEU PNU1 71ICU N
234711 Healthcare
PKM7182647
68 F
National
Safety Network
234795
02320380
2011
CAUTI
Rates in ICUs 23 F
12/27/2010 01/28/2011
33 BSI
LCBI
71ICU
01/28/2011 01/29/2011
2 UTI
SUTI
71ICU N
02/03/2011
4 BSI
LCBI
71ICU
02/11/2011
3 UTI
ABUTI 71ICU Y
As
of: June 023840830
25, 2012 at 8:54 AM 57 F
234747
01/31/2011
Date Range: CAU_RATESICU_SCA summaryYr 2011 to 2011
34 M
02/09/2011
CAUTI
Rate
Table
234778 1281028301
52 M
02/20/2011
234793 120837
SUTI
71ICU N
02/25/2011
6 PNEU PNU2 71ICU N
Org ID=10018 CDC Location=IN:ACUTE:CC:M
Location
Months CA 85Urinary
CA03/05/2011
UTI NHSN Incidence
Incidence4 Patient
234791Summary
0137070
F
03/08/2011
PNEU Cath
PNU3 CathDU_Mean
71ICU N
234757
Yr
UTI Catheter
07089H56476 Count85 Days
F
234748 2810829
MICU
2011
12
234749 9820K081
Rate
CAU
03/06/2011
Pooled
Mean
Density
Density
Days
03/10/2011
p-value
Percentile5 BSI
41 F
03/15/2011 03/20/2011
6 3284 1.827
2.4 0.3086
36 M
03/18/2011 03/21/2011
234771 2970273120
54 F
03/20/2011 03/22/2011
Org
ID=10018
CDC Location=IN:ACUTE:CC:MS
234780
0389034987
18 M
03/22/2011 03/23/2011
Location Summary Months CA UTI
19067 1045
62
Yr
Count
158875 222331
55
6 BSI
LCBI
50 4943 0.664
4 BSI
LCBI
3 BSI
369369
735 F 277604/26/2011
2011
11
1.801
158869
111213
50
M
05/12/2011
MSICU
2011
11
5
2735 1.828
158841 696693
71 M
05/01/2011
Org
ID=10018
CDC
Location=IN:ACUTE:CC:S
158915 646566
68 M
05/01/2011
Location Summary Months CA UTI Urinary
19069 1051
62 M
Yr
Count
Catheter
LCBI
71ICU
71ICU
0.73
71ICU
Proportion Proportion
p-value
Percentile
0.0000
26
71ICU
2 PNEU PNU3 71ICU N
Urinary
CA UTI
NHSN
Incidence
Incidence
M
04/12/2011
BSI
Catheter 08/31/2000
Rate
CAU
Density 3877Density
Pooled
p-value
M Days 04/12/2011
04/23/2011
12Percentile
UTI
Mean
2158842
MSICU
Util
LCBI
Ratio
Patient
Cath
LCBI
Days 71ICU
Util
CathDU_Mean Proportion Proportion
p-value
Percentile
Ratio
ABUTI 71ICU
Y
Bar Graph & Pie0.73Charts
0.0000
05/10/2011
2.2
0.4154 15 BSI 50 LCBI
5919 71ICU
0.469
05/16/2011
5
UTI
SUTI
71ICU
2.2
0.4297
50 6066 0.451 Y
05/26/2011
26 BSI
LCBI 71ICU
05/29/2011
CA UTI
NHSN
Incidence
05/16/2011
06/03/2011
Rate
CAU
Density
0.73
0.0000
9
9
29 PNEU PNU1 71ICU N
Incidence
19Density
BSI
Patient
Cath Util
LCBI
Days 71ICU
Ratio
CathDU_Mean Proportion Proportion
p-value
Percentile
Step 5 – Analyze HAI Data
Standardized Infection Ratio (SIR)
Step 6 –
Apply Risk Stratification to Data

NHSN
 Location: ICU, non-ICU, Hem-Onc
 Standardized Infection Ratio (SIR)


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


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
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
Uses of HAI Data; CMS Hospital
Compare
CY 2014
Uses of HAI Data, Hospital
Compare, continued.
Using HAI Data for Comparing
Performance Between Providers
National Surgical Quality Improvement Program (NSQIP)
Uses of HAI Data; Keystone ICU
Project



66% reduction in Central
Line Bloodstream Infections
(CLBSI)
Interventions:
3.5
 Hand hygiene
3
 Max. barrier prec.
Rate
Per 2.5
during insertion
1,000
 CHG antiseptic on
2
CL
insertion site
Days
1.5
 Avoid femoral CLs
 Remove CL when not
1
needed
Pronovost P, et al. NEJM
2006;355:2725-32.
K-ICU CLBSI Prevention
Project
0.5
0
Before
All
Teach
After
Non
Teach
<200
B
>200
B
Use of Surveillance Technology to Improve
Efficiency of IPC Program
M. Moyhla – Holy Cross Hospital
Using HAI Data to Assess Efficacy of an
Intervention; Preop Skin Prep
Darouiche RO et al. N Engl J Med.
2010;362:18-26.
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