The Hospital Says Use a Nasal Swab for Detection Preop: Any - - PowerPoint PPT Presentation

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

The Hospital Says Use a Nasal Swab for Detection Preop: Any Science? Cost Effective?

David J. Mayman, MD

Assoc iate Pr

• fe ssor

in Or thopae dic Sur ge r y Hospital for Spe c ial Sur ge r y Ne w Yor k, NY USA

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Disclosures

Consultant: Smith and Nephew OrthAlign Stock Options Imagen Stock Options

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More Important Disclosure

• I am not an epidemiologist
• I am not an ID doc

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Background: PJI

• Prosthetic joint infection

– Preventable – Morbid – Costly to patients, hospitals, society – PJI prevalence varies

• By center
• By subpopulation

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Background

• By 2020, an estimated 70,000 patients will require

revision TJA due to PJI at a cost of $1.62 billion

• annually. 1
• Patients that are nasal carriers of S. aureus have

up to a nine times higher risk of postoperative infection compared to a non-carrier. 2–4

• Methicillin-resistant Staphylococcus Aureus

(MRSA) colonization is thought to be a risk factor for developing a PJI following TJA. 5,6

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Background: Prevention

• How do we prevent PJI?

– Patient selection – Pre-operative measures – Intra-operative practices – Post-operative care

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Background: S. aureus

• 30-40% of humans

are colonized with MSSA or MRSA

• Colonization

increases infection risk

– Orthopedic, thoracic, and abdominal surgery – Intensive care

Perl TM. Ann Pharmacother 1998;32:S7 Safdar N. Am J Med. 2008 Apr;121(4):310 Wenzel RP. J Hosp Infect 1995;31:13-24

Anterior Nares Pharynx Axillae Groin

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Background: Decolonization

• Does decolonization actually work?

– Studies differ. RCT data mostly lacking. – Methods vary (PCR vs culture, decolonization methods) – ID and Surgical preoperative guidelines don’t commit:

Bratzler DW. Surg Infect (Larchmt) 2013;14:73 AAOS Clinical Practice Guidelines. http://www.aaos.org/guidelines/?ssopc=1 Mangram AJ. Infect Control Hosp Epidemiol 1999;20:250 Parvizi J. J Arthroplasty. 2014;29(7):1331

IDSA CDC AAOS MSIS

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At our hospital:

• Preoperative decolonization =

– Five days of

• Chlorhexidine gluconate 4% liquid once daily
• Mupirocin 2% ointment to nose twice daily

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Cost Effectiveness of Staphylococcus aureus Decolonization Strategies in High- Risk Total Joint Arthroplasty Patients

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Objectives

• To compare the cost-effectiveness of different

strategies among high-risk arthroplasty patients

– Using cost effectiveness decision analysis – From different payer viewpoints – Across a range of

• Baseline PJI rates
• Decolonization effectiveness levels

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Methods

• TreeAge software: analytic model
• 5 strategies compared

Strategy Practice Do Nothing No Screening, No treatment Treat All All patients decolonized 1S Nasal screening only 2S Nasal + 1 site 4S Nasal, pharynx, axillae, groin

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Model Inputs

• 1. Baseline prevalence

– Swab data from 1,418 patients – 28-34% rate of colonization – ~21% relative increase with four swabs – 33% (+) cultures were MRSA 28 31 34

20 25 30 35 40

1 2 4

Number of Swabs

% Staph prevalence detected

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Model Inputs

• 2. PJI incidence rates: literature1 estimates

– 1.3% in decolonized carriers after decolonization – 0.6% in non-carriers

• (3.4% in untreated S. aureus carriers)
• 3. Costs:

– $95 for mupirocin/chlorhexidine – $60 per swab culture ( = $240 for four cultures)

• 1. Hacek DM, et al, CORR 2008;466:1349

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Results

Effective Treat All, and 4S Cost Effective for Patient 2 swab strategy $4,773 /PJI prevented Cost Effective for Hospital Treat All $0 Cost Effective for Society Treat All $14,229

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1 10 100 1000 10000 100000 1000000 10000000 100000000 1E+09

Incremental Cost Effectiveness Ratio

PSSInotreat

Sensitivity Analysis: Societal Perspective

Treat All Nare + Pharynx Nare Do Nothing 4 Swabs

$ to prevent a PJI Increasing Baseline PJI Rate 

Less Cost-Effective 

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Conclusions

• More swabs = find more S. aureus.
• More swabs ≠ more cost effectiveness.
• Universal decolonization, as effective as 4S, is

more cost effective from a society/payer perspective.

• Cost effectiveness of decolonization increases

when PJI rates increase.

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Limitations

• Regional variations not reflected.
• Other strategies not evaluated.
• Definitions of ‘high-risk’ vary.
• Consequences and costs of excessive use of

antiseptics not measured.

– Bacterial resistance – Lack of MRSA monitoring

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Take Home Points

• Different strategies differ in cost effectiveness.
• In our model, universal decolonization was

broadly cost effective.

• Universal decolonization could be highly cost

effective in hospitals and among patient subgroups with average or higher PJI rates.

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What Are We Doing Today?

• Everyone gets a screening questionnaire
• If they have had an MRSA infection, have a

history of MRSA colonization or have a relative with a history of MRSA infection or colonization they get swabbed

• If they are positive they get decolonization

protocol before surgery

• Even after decolonization they get dual antibiotic

prophylaxis (Vancomycin and Ancef)

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Thank you

Special thank you to the following for their contribution to this talk: Andy O. Miller, MD Devin M. Williams, MPH Michael W. Henry, MD Geoffrey Westrich, MD Hassan M.K. Ghomrawi, PhD MPH