1

Hospital Epidemiology

What is it and what is it good for?

Edward O’Rourke, M.DHarvard University - Harvard Medical School

2

"It may seem a strange principle to

enunciate as the very first requirement

in a hospital that it should do the sick

no harm"

Florence Nightingale

3

Nosocomial infection =

Any infection that is not present or incubating at the time the patient is admitted to the hospital

4

History of infection control and hospital epidemiology

Pre 1800: Early efforts at wound prophylaxis 1800-1940: Nightingale, Semmelweis, Lister, Pasteur 1940-1960: Antibiotic era begins, Staph. aureus nursery outbreaks,

hygiene focus 1960-1970’s: Documenting need for infection control programs,

surveillance begins 1980’s: focus on patient care practices, intensive care units, resistant

organisms, HIV 1990’s: Hospital Epidemiology = Infection control, quality

improvement and economics 2000’s: ??Healthcare system epidemiology

modified from McGowan, SHEA/CDC/AHA training course

5

Why do we need hospital epidemiology??

Hospitals are complex institutions where patients go to have their health problem diagnosed and treated

But, hospitals and medical/surgical interventions introduce risks that may harm a patient’s health

6

Additional morbidity Prolonged hospitalization Long-term physical, developmental

and neurological sequelae Increased cost of hospitalization Death

Consequences of Nosocomial Infections

7

Challenges to the hospital epidemiologist

Make a hospital safe – Prevent harm to the patient and employees

• initial focus on infectious diseases• increasingly all adverse (harmful) events

are targets

Improve hospital efficiency– Eliminate unnecessary costs– Eliminate wasteful practices

8

What is hospital epidemiology?

The fundamental roles of hospital epidemiology are to:

– Identify risks

– Understand risks

– Eliminate or minimize risks

9

What is the role of hospital epidemiology?

Identify risks to patient’s health

Find nosocomial infections– surveillance

Identify and study risk factors for nosocomial infection– understand epidemiologic principles and methods

• case-control and cohort studies, bias, confounding

– understand nosocomial pathogens– what is it about hospitalization that increases risk?

10

What is the role of hospital epidemiology?

Eliminate or minimize risks to a patient’s health

organize care to minimize risk– eliminate risk factors– work around risk factors– develop improved policies and procedures

educate physicians and nurses regarding risks study risk factors to learn more about them and how

to eliminate them

11

Responsibilities of the Infection Control Program

Surveillance of nosocomial infections

Outbreak investigation Develop written policies for

isolation of patients Development of written policies to

reduce risk from patient care practices

Cooperation with occupational health

Cooperation with quality improvement program

Education of hospital staff on infection control

Ongoing review of all aseptic, isolation and sanitation techniques

Monitoring of antibiotic utilization

Monitoring of antibiotic resistant organisms

Eliminate wasteful or unnecessary practices

12

Areas of interest to a hospital epidemiologist

Surveillance for nosocomial infection– bloodstream infections– pneumonia– urinary tract infections– surgical wound infections

Patterns of transmission of nosocomial infections

Outbreak investigation Isolation precautions Evaluation of exposures

Employee health Disinfection and

sterilization Hospital engineering

and environment– water supply– air filtration

Reviewing policies and procedures for patient care

13

Areas of interest to a hospital epidemiologist

Antibiotic use Antibiotic resistant

pathogens Microbiology

support National

regulations on infection control

Infection control committee

Quantitative methods in epidemiology

14

Organizational topics in hospital epidemiology

Relationship of Hospital to External Agencies and Organizations

Personnel Who does the hospital

epidemiologist report to? Authority Resources

15

Authority of Infection Control Program

Accreditation mandates: Must meet for accreditation (example in USA: JCAHO)– Infection Control Program– Infection Control Committee– Authority statement

OSHA mandates: Safety regulations Infection Control Department reports to Hospital

Administration, not Medicine/Surgery or Nursing Enhanced authority through cooperation, mutual

respect, and shared goal of improving patient outcome

16

QI versus Regulatory Strategies in Infection Control

Regulatory approach External organizations

establish rules and regulations

Data collection for comparison with outside standards

Inspections for compliance

Penalties for non-compliance

TQM/QI approach Internal organization of

hospital staff to develop goals and methods

Data collection for internal review

Continuous efforts to improve

Failure belongs to the entire system, not an individual

17

Organizing for Infection Control

Requires cooperation, understanding and support of hospital administration and medical/surgical/nursing leadership

There is no simple formula:– Every hospital is different– Every hospital’s problems are different– Every hospital’s personnel are different

The hospital must develop its own unique program

18

Changes in Nosocomial Infection Rates in Hospitals with or without Effective Programs

Infection site andpatient risk

Hospitals with veryeffective programs

Hospitals withineffective programs

Surgical Wound % %High risk -48.0 +13.8Low risk -23.6 +21.3

Urinary TractHigh risk -35.8 +18.5Low risk -41.6 +30.7

PneumoniaSurgical patients -7.3 +9.3Medical patients -7.7 +10.0

BloodstreamAll patients -27.6 +25.5

SENIC Study, CDC

19

Essential Components of an Effective Infection Control Program (after SENIC)

One full time infection control practitioner per 250 beds– optimal ratio may be different

A physician with training and expertise in infection control

Surveillance and feedback of rates to clinicians Control activities (interventions, policies,

training)

20

Personnel Hospital Epidemiologist

– MD with clinical training– Usually part time salaried by the hospital for infection

control duties and part time as infectious diseases clinician– Training in infection control

Infection Control Practitioner– Usually a nurse but can be a microbiologist– Has clinical experience before entering infection control– Full time in infection control, no other clinical or

administrative duties– Training in infection control

21

Organizing for Infection Control

Main elements– Develop an effective surveillance system– Establish policies and regulations to reduce

risks• Develop with clinicians (physicians and

nurses)

– Develop and maintain a program of continuing education for hospital personnel

– Use scientific (epidemiologic) method to study problems and test hypotheses

22

Organizing for Infection Control

Additional elements of an effective program– Antibiotic monitoring and control– Microbiologic laboratory liaison– Antibiotic susceptibility data dissemination– Occupational health– Provide resource to other departments for

quality improvement study design and data analysis

23

Key elements of surveillance

Defining as precisely as possible the event to be surveyed (case definition)

Collecting the relevant data in a systematic, valid way

Consolidating the data into meaningful arrangements

Analyzing and interpreting the data Using the information to bring about

change

adapted from R. Haley

24

Infection Control Committee Purpose Advisory

– Review ideas from infection control team

– Review surveillance data

Expert resource– Help understand hospital systems and policies

Decision making– Review and approve policies and surveillance plans

– Policies binding throughout hospital

Education– Help disseminate information and influence others

25

Infection Control Committee

Committee Representatives

– Hospital Epidemiologist

– Infection Control Practitioners

– Administrator

– Ward, ICU and Operating room Nurses

– Medicine/Surgery/Obstetrics/Pediatrics

– Central Sterilization

– Hospital Engineer

– Microbiologist

– Pharmacist

26

Infection Control Committee

Qualifications to be on the committee– Interest– Represent group in hospital– Experts in their field– Diplomatic– Good communicators

27

Resources: Where to get more information or help Training Courses

– Society of Hospital Epidemiologists of America (SHEA)– Association of Professionals in Infection Control (APIC)– National courses and congresses

Books– Textbooks: Bennett and Brachman - Wenzel - Mayhall– APIC Curriculum and Guidelines– CDC Guidelines

Journals– Infection Control and Hospital Epidemiology– Journal of Hospital Infections– American Journal of Infection Control

Consulting services– National: CDC, Ministry of Health– Colleagues

28

What is Hospital Epidemiology good for?

Infection control Quality improvement Controlling costs

An effective hospital epidemiology program can help achieve all three goals

29

Risk factors for surgical wound infection

Age Obesity Malnutrition (low albumin) Diabetes Steroids/immunosuppression Prolonged pre-op

hospitalization

Infection at another site

Prolonged procedure Drains Urgency of surgery Foreign body Skill of surgeon

30

Strategies to develop effective patient care practices

Team collaboration Staff education Communication

31

Identify problems with polices and procedures Example: Pre- and Post-Operative Care

Skin shaved the night before surgery

Inappropriate peri-op antibiotic prophylaxis

Instruments used for dressing changes submerged disinfectant

Large containers of antiseptics, no routine for cleaning and refilling

Eliminate shaving of skin the night before surgery

Single dose peri-op antibiotic prophylaxis guidelines

Use individual sterile packs of wound care instruments

Use small containers of antiseptics; clean and dry containers before refilling

RecommendationProblem Area

32

Methods to reduce cost of nosocomial infections

Reduce incidence Reduce morbidity Shorten hospital stay Reduce costs of treating infections Reduce costs of preventative measures Stop ineffective control measures

33

Eliminate wasteExample: Unnecessary nursing techniques

Dressing change of aseptic wounds Daily dressing change of venous catheter

dressings Daily change of intravenous infusion sets Preoperative shaving Routine changing of urinary catheters Twice daily urinary catheter care Protective gowns except for care of infected

patients

Daschner, F. J Hosp Infect (1991) 18, 73-78)

34

Eliminate waste:Unnecessary microbiologic monitoring

Routine environmental cultures of walls, floors, air, sinks, or other hospital surfaces

Routine cultures of healthcare workers nose and hands

Clinical cultures which are not available to clinicians in time to help with decision making

Also: Failure to generate annual summary of culture data to provide clinicians with data for empirical selection of antibiotics

35

Cultures of Walls, Floors and Other Smooth Surfaces

All hospitals have some bacterial colonization of environment

What is the evidence that the environment directly infects the patient?– Hospitalized patients infect the environment

– Poor technique, poor handwashing, poor disinfection have all been shown to infect the patients but these are all related to poor practice not the environment directly

Floors, Walls, Tables, Beds etc. should be cleaned properly but not cultured

36

Environmental Culturing: U. of Wisconsin Hospital Experience

Old Hospital1979

New Hospital1979

New Hosptial1980

# Positive Cultures Nosocomial Infection Rate

While maintaining standard hygiene and cleaning, degree of environmental contamination had no effect on infection rate

37

Prolongation of Hospital Stay due to Nosocomial Infections in the USA

Infection Site Excess Days

Surgical Wound 6.0

Urinary tract 1.2

Pneumonia 4.0

Bacteremia 7.0

Other sites 4.2

Adapted from Dixon, Ann Int Med 89:749, 1978

38

Annual Costs and Benefits of Infection Control Program in a Hypothetical 250-bed Hospital

Estimated reduction of directcosts from infectionsprevented

$246,700

Estimated infection controlprogram expenses

$60,000

Hospital savings $186,700

Each $1000 invested in infection controlwill return $3000 in net direct cost savings

39

Annual Nosocomial Infection Cost Savings by Introducing Effective Infection Control Program to a 250-bed Hospital

Infection site Infectionswithout

anyprogram

Infectionswith

effectiveprogram

Infectionsprevented

Averagecost perinfection

$

Totalsavings

$

Surgical wound 186 120 66 1944 128,304Urinary tract 283 195 88 318 29,574Respiratory 74 58 16 1540 24,640Bacteremia 34 22 12 2268 15,216Other sites 136 92 44 1113 48,972

TOTAL 713 487 226 $246,706

40

Antibiotic Prophylaxis in Surgery

Potentially an important part of surgical wound infection prevention

May also be a significant expense for the hospital What is the cost-benefit of prophylactic antibiotics?

– What is cost of wound infection? In money? In suffering?

– How effective is prophylaxis?

– How much can we spend to prevent a case of wound infection ?

41

Cost of Surgical Prophylaxis with Cefonocid in a Boston Teaching Hospital

Assuming $10 per course:– $178 to prevent one breast infection– $539 to prevent one herniorrhaphy infection– $1,515 to prevent one readmission for breast

infection– $622 to prevent one readmission for

herniorrhaphy

From: Platt et al. NEJM 322:153, 1990.

42

Impact of Cefonocid Prophylaxis(per 1,000 patients)

Routine use for breast surgery would prevent– 56 infections– 23 definite wound infections– 16 UTIs

Routine use for herniorrhaphy would prevent:– 19 infections– 13 definite wound infections

from: Platt et al. NEJM. 322:153,1990.

43

Organization and support

A. Institutional support– Infection control as a department– Placement in the organization– Authority– Personnel– Other resources

44

Organization and support

B. Infection control committee– membership– support by the medical staff– participation by other disciplines– annual planning

45

Organization and support

C. Infection Control Program– quality assessment – information for clinicians– educational/informational resource– surveillance data– outbreak investigation– assurance of appropriate asepsis, sterilization, disinfection– minimize risk from invasive procedures/devices– use of isolation– occupational health