Surveillance of nosocomial infections Johnny, Courtesy, Brocolli.
-
Upload
bailey-bennett -
Category
Documents
-
view
221 -
download
5
Transcript of Surveillance of nosocomial infections Johnny, Courtesy, Brocolli.
Surveillance of nosocomial infections
Johnny, Courtesy, Brocolli
Nosocomial infections (NCI)
"nosus" = disease
"komeion" = to take care of
Infections that occur during hospitalization but are not present nor incubating upon hospital admission
Characteristics of hospitals
• Treatment is main focus• Many stakeholders• Shift work• A lots of data, easily defined cohorts• Different patient population• Variation of length of stay• Vulnerable patients• Community vs. hospital
The problem of NCI
USA– Urinary tract infections: 2.4 per 100 admissions– Pneumonia: 1 case per 100 admissions– Surgical site infections: 2.8 per 100 operations– NCI; one death every 6th minutes
Norway– One of 19 patients have a NCI
The problem of NCI
• Regional hospital, Zimbabwe:– 1 of 6 developed SSI
• 2 referral hospitals, Ethiopia:– 38.7% developed SSI
– 14 of 18 deaths attributed to SSI
Cost of NCI
England
• Average cost per NCI: 3.000 pounds
• Extra days:Urinary tract infections: 6
Pneumonia: 12
Surgical site infections: 7
Why surveillance?
• NCI cause of morbidity and mortality
• One third may be preventable
• Surveillance = key factor – an infection control measure
– overview of the burden and distribution of NCI
– allocate preventive resources
• Surveillance is cost-efficient!!
The surveillance loop
Event
Action
Data
Information
Health care system
Surveillance centre
Reporting
Feedback, recommendations
An
alysis, in
terpretation
Considerations when creating a surveillance system
• Goal of the surveillance system (why)
• Engage the stakeholders (who)
• Surveillance method (what, how, when)– definition
– what to collect
– how to collect (operation of system)
• Available resources
I may not have gone where I intended to go, but I think I have ended up
where I needed to be
Douglas Adams
Objectives
• Reducing infection rates• Establishing endemic baseline rates• Identifying outbreaks• Identifying risk factors• Persuading medical personnel• Evaluate control measures• Satisfying regulators• Document quality of care• Compare hospitals’ NCI rates
Who
• All hospitals?
• All departments?
• All specialties?
• Other health institutions?
…..
PublicHealth
instituteI
Directorat
MinistryOf health
Service dep.
Lab Patients
Surgicalward. 2
Surgicalwards
It-dep.
ICP
Local adm.
Centraladm.
Surveillance of surgical site infections
Stakeholders
Surveillance of one or more types of NCI
Urinary tract infections
Lower respiratory tract infections
Surgical site infections
Bloodstream infections
Conjunctivitis
Others…
Targeted surveillance
• Special patient population(surgical, medical, paediatric, intensive)
• Diagnostic and therapeutic procedures(endoscope, haemodialysis, catheterization,
blood transfusion)
• Specific pathogens(staphylococcus aureus, MRSA,
clostridium difficile, norovirus)
Variables • Administrative data
– Id, address, dates of admission, discharge..
• Patient related factors:– Age, sex, severity of underlying disease
• Procedures– Surgery– Devices (e.g. catheters)
• Treatment, diagnosis– Use of antibiotics
……
Stratification points, surgical site infections
Variables for stratification Risk index Stratification points
ASA score > 2 1
Duration of operation > 75 percentile 1
Wound classification Contamination class > 2 1
Endoscopic procedure -1
When?
• During hospital stay?– Frequency of data collection
• After discharge?– When and how?
How?
• Two main surveillance methods – incidence
– prevalence
• Variations within these methods
Incidence (cohort) studies marching towards outcomes
Cohort design
PAR = Population at Risk
T = Time period
PAR Study group
Exposed
Not exposed
NCI
Not NCIT
NCI
NCI
Not NCIT
Retrospective
Prospective
Measure
• Percentage– #NCI / # patients
• Incidence density– Patient-days as denominator
• Risk factorsRR= risk in patients exposed
risk in patients not exposed
Positive aspects
• Provide information on several risk factors
• Exposure measures before outcome
• Information on consequences of NCI
• Can identify outbreak
• Ongoing attention
Limitations
• Resource demanding
• Loss of follow-up
• Seldom NCI
• Confounding and bias is possible
Prevalence
• Measures number of current NCI
• Within a defined population at risk
• At a given time
• #NCI / #patients at risk *100
• Point or period prevalence
Time of survey 20.10 at 8 AM …………… Name of institution …Oslo hospital……..……………………………….. Contact person ……Hanne Eriksen……………………………… Phone………………22042625……………………
Fax …22330033………………………………………………..… E-mail……[email protected]……..….……………….. Region: Oslo………………………… Department Number of
patients at 8 AM
Number of patients operated
Number of urinary tract inf.
Number of pneumonia
Number of surgical site inf.
Number of bacteremia
Number of patients on antibiotic
Total prevalence (%)
Rehabilitation
50 15 1 1 0 0 25 4,0
Surgical unit
80 3 2 0 4 0 7 7,5
Medical unit
50 0 4 1 0 0 5 10
Paediatric unit
20 5 1 1 0 1 7
Total for institution
23 10 8 7 1 39
Use of prevalence surveys
• Show trends
• Estimate – distribution of NCI
– surveillance accuracy
– incidence from prevalence??
– antimicrobial usage patterns
• Rise awareness
Limitations
• Do not identify causes
• Duration of NCI affects the prevalence
• Not very suitable for small institutions
• Difficult to adjust prevalence
Prevalence survey
UTI n=6SSI n=2Incidence surveillance
Define method
Identify and review– Protocols used elsewhere e.g.
HELICS incidence, Norway's prevalence
– Literature
Minimum dataset
Methodological issues
• Definitions NCI– Cut off 48 or 72 hours?– Criterias from Centers for Disease Control and Prevention (hospital)– McGeer (long-term care facilities)Risk variables
• Case finding– Active or passive– By whom?– After discharge?– Prospective or retrospective?
Case finding
• Active: by surveillance personnel• Passive: by medical personnel• Laboratory or clinical based
• Source of data– Clinical examinations– Medical records, reports from laboratories – Forms or interviews
Ongoing systematic collection?
• Cohort– Continual?
– Periodical?
• Prevalence– Weekly?
– Yearly?
– Depends on objectives
Precision of estimate
Number of patients under surveillance
Number of NCI
Incidence (%) 95% confidence interval
50 3 6% (1,3% - 17%) 100 3 3% (0,6% - 8,5%) 100 5 5% (1,6% - 11%) 200 20 10% (6,2% - 15%)
1000 50 5% (3,7% - 6,5%) 3500 100 3% (2,3% - 3,5%) 8000 320 4% (3,6% - 4,5%)
Dummy table
Variable Insidence% 95% confidence interval
Relative risk
95% confidence interval
Relative risk
95% confidence interval
Antibiotic-prophylaxis
Yes 4,6% (300/6500)
(4,1% - 5,2%)
Reference Reference
No 10% (150/1500)
(8,8% - 12%) 2,2 (1,8-2,6) 2,1 (1,7-2,5)
Stratified points 1 5,0%
(350/7000) (4,5% - 5,5%)
Reference Reference
2 7,1% (50/700)
(5,9% - 8,4%)
6,0 (4,8 – 7,5) 6,2 (5,0 – 7,4)
3 16,7% (50/300)
(14%-19%) 10 (8,1 – 12) 9,4 (8,0 – 11)
Etc.
Implementing surveillance system
• Administrators responsibility• Involvement of stakeholders• Identify available resources
– Personnel– Money– Time– Equipment– It- solutions
• Realistic project plan– Organization map– Making forms and letters– It-solutions– Training– Use of data
Making surveillance work
• Support by the administrators
• Involve local experts
• Simple
• Minimize resources required by hospitals
• Training
• Feedback and use of data
• Flexibility
Training topics
• Why surveillance?
• How?– Definition
– Case finding
– Case studies
– It-solution
• Use of data
Quality controls
• Define acceptable loss of follow-up
• Make sure all patients are included
• Identify infections– Use several sources
– Compare data, conduct surveys
– Training
• “Clean” data– Completeness
– Logical values
Use of data
• Prevent NCI
• Ward audits
• Present data to hospitals, administrators, MoH, patients
• Argument for resource allocation
• Audits for medical personnel
• Raise awareness
Incidence of SSI over time
Conclusion
Hospital Pathogen Unhappypatients
Unhappydirector
Hospital Surveillance HappyPatients
Happydirector