how much do health care associated infections really cost?

i n s t i t u t e o f h e a l t h a n d b i o m e d i c a l i n n o v a t i o n ■

How much do health care associated infections really

cost?

CRICOS No. 00213J

cost? and does preventing them

save money?

Kate Halton [email protected]

Background

• HAI are costly & preventable

• Diminishing returns for prevention

• Zero risk not feasible

CRICOS No. 00213JCRICOS No. 00213J

• Patient safety politically important

Allocating resources to infection control

Big number & scaremongering

Withhold payments for perceived preventable infections


Economic evaluations that quantify important parameters

Important economic parameters for evaluating infection control

Cost outcomes Health outcomes

Cost of infection control

Infection treatment costs saved Infection related morbidity avoided


Infection diagnosis costs saved Infection related mortality avoided

Length of stay reduced

Cost-effectiveness plane

Cost($)


Health Benefit(QALYs)

driving this is the bed-days released by preventing infection

Estimating the role of infection in length of stay

adverse event

healthcare associated infection


dischargeadmission

How many days??What are they worth??

Estimating increases to length of stay

Estimation methods available

– Expert attribution

– Unadjusted comparison

– Matched study

– Regression model

15d

23d

13d


Feedback effectsInfection extends length of stay; BUTlonger patient is in hospital the higher their risk of infection

Multistate models

– Regression model

able to adjust for timing of infection

7d

What’s the impact of ignoring this bias?

CRICOS No. 00213J

Study

Compared multi-state model with regression model

Data

• 11 ICUs in Argentina

• 9,545 admissions

• 8.7% rate of infection

Results

Extra length of stay

11.23 days (RM)

1.35 days (MSM)

Example with QLD data

Nine Queensland hospitals

2.7 million admissions between 1 January 2005 and 31 December 2010

Multistate model to estimate risk of mortality & extra length of stay

Infection type Number of Number Hazard ratio Mean extra length of ICU stay

Barnett et al. work in progress


Infection type Number of

infections

Number

of deaths

Hazard ratio

in-hospital

death

Mean extra length of ICU stay

due to infection (95% CI)

Died Discharged

BSI

(gram positive)2,141 866 3.0 (2.6, 3.5) 3.9 (2.4, 5.4) 1.0 (0.4, 1.8)

BSI

(SAB)744 303 3.4 (2.6, 4.4) 1.8 (0.7, 8.4) 1.0 (0.2, 2.5)

BSI

(gram negative)2,044 880 2.1 (1.8, 2.5) 2.9 (1.6, 4.2) 0.6 (0.3, 0.9)

What’s the value of an ICU bed-day?

Opportunity cost (willingness-to-pay) for bed day

Influenced by


– demand levels (waiting lists)

– ability to utilise extra bed-days (staffing constraints)

– level of reimbursement for admitting extra patients (WEIS budgets)

– impact on consumable costs (1st days more costly)

– budgetary flexibility (closure)

– level of decision making (reallocate budgets, responsibilities)

Example with antimicrobial catheters


StudyPurpose: compare cost-effectiveness of antibiotic-coated catheters with non-coated catheters

Setting: Australian hospitals

Study design: economic decision model

Data: hospital databases, published literature

Results

Use of antibiotic catheters means:(per 1000 catheters)

15 infections avoided

32.8 ICU bed days released

$130,289 costs saved

1.64 QALYs gained

COST-SAVING

Outcomes per 1,000

catheters

Scenario Value of a bed day Change in costs

Change in QALYs

Willing to pay for extra $3,021 ICU / $843 ward - $130,289 1.64

Example with antimicrobial catheters cont...


Willing to pay for extra unit capacity

$3,021 ICU / $843 ward - $130,289 1.64

Interested only in cash savings

$335 ICU / $101 ward + $28,257 1.64

Example with antimicrobial catheters cont...

Cost

WTP $15,000 / QALY

WTP $64,000 / QALY


Health Benefit

WTP $15,000 / QALY

Take home messages

• Infection control unlikely to be cash-saving

• Value more likely to be efficiency gain – capacity that’s freed up

• Implications for decision makers in different levels/areas


• Implications for decision makers in different levels/areas

• Cost-effective doesn’t mean same as cost-saving

• Sometimes you have to invest to get better outcomes

Policy relevance

Scaremongering with big ($) numbers

knee jerk reactions

expectations raised inappropriately

an oversized stick


Good quality cost effectiveness models

may show moderate cost savings

may show low cost-effectiveness

higher credibility

Multidisciplinary teamEconomics

Statistics

Epidemiology

Maths

Evidence Synthesis

KateKat

Nick

Adrian


Evidence Synthesis

Psychology

Project management

Liz

Nick

Jim

HenryMeganKatie

CRICOS No. 00213J

how much do health care associated infections really cost?

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