Road to denial: patient safety and quality healthcare

June 1, 2009

The Deficit Reduction Act of 2005 reduced
Medicare overpayments due to medical errors. In October 2008, the
Centers for Medicare and Medicaid Services (CMS) began denying or
reducing payment for specific healthcare-associated infections (HAIs):
catheter-associated urinary-tract infections, mediastinitis following
coronary-artery bypass grafting, and vascular catheter-associated
bloodstream infections. CMS currently looks to expand the list of denied
HAIs to include ventilator-associated pneumonia, Clostridium
, and methicillin-resistant Staphylococcus aureus
(MRSA) bloodstream infections — the latter affects as many as 350,000
patients yearly in the United States.1

In 1993, there were fewer than 2,000 MRSA infections
recorded in U.S. hospitals.2 MRSA caused 368,600 infections
in U.S. hospitals in 2005. On average, hospital stays related to MRSA
infections are twice as expensive as all other hospital stays ($14,000
vs. $7,600, respectively)2; more than twice as long as all
other stays (10 days vs. 4.6 days, respectively)2; and more
than double the risk of hospital deaths (4.7% vs. 2.1%, respectively).2

The goal is not only to reduce or eliminate these
infections, but also to quickly determine the infection's source in
order to guide empiric therapy, leading to rapid recovery and lowered
costs. Unreimbursed expenses could financially ruin some U.S. hospitals.
Consider that HAIs account for up to 2 million infections, 90,000
deaths, and billions of dollars in healthcare costs.

A bundle of techniques and lab tests exist to both
prevent false-positive blood cultures and rapidly identify pathogens
from positive blood cultures. The bundle includes a blood-culture
collection and products, coupled with a molecular test that uses a
fluorescent-labeled probe. Results from this combination are available
in 2.5 hours, a contrast to typical lab cultures that identify the
causative organism in positive samples in 48 to 72 hours. This delay
often means patients are treated with broad-spectrum antimicrobial — in
some cases, with the wrong antimicrobial — which can cause adverse
patient events. This new solution removes guesswork from infection
determination and treatment, while averting denied reimbursements and
the cost of improper antimicrobial-drug treatment.

Improperly collected blood cultures may yield
positive results from blood-culture tests via the introduction of a skin
contaminant at the venipuncture site, while the patient, in fact, does
not have a systemic infection. If the culture becomes positive, a Gram
stain is performed to determine the colony morphology of the bacteria.
The report is called to the physician who will prescribe empiric therapy
if clinical signs and symptoms are consistent with a potential septic

Rigid infection-prevention protocols, with the help
of new technology, are proving effective in guaranteeing hospitals
receive full reimbursement when infections are not spread in the
healthcare setting. Thus, finding the right culture-collection kit is
critical. Ideal kit systems should be capable of of processing blood,
body fluids, and mycobacteria specimens all in the same instrument and
have a well-established reputation for ease of use, high-performance
detection of positive results, and a low false-positive rate. For speed
and accuracy, ideal systems remove all subjectivity by providing
colorimetric-sensor technology. In such a system, each culture bottle is
continuously monitored for microorganism growth by a highly sensitive
reflectometer. Any recognized changes are quickly reported.

The molecular-testing system relies on peptide
nucleic-acid (PNA) molecules — DNA “mimics” in which the negatively
charged sugar-phosphate backbone of DNA is replaced with a non-charged
polyamide or “peptide” backbone. The synthetic backbone provides PNA
probes with unique hybridization. Because of the non-charged backbone,
PNA probes — unlike DNA probes — do not encounter electrostatic
repulsion, allowing them to hybridize rapidly and tightly to
nucleic-acid targets.

Growing bacteria and yeast cells produce an abundance
of ribosomal RNAs (rRNA) that contain regions of highly conserved,
species-specific sequences and are, therefore, ideal targets for
identification assays such as fluorescence in situ hybridization
(FISH). The target sequences, however, are frequently located in highly
structured regions of the rRNA, which are virtually inaccessible to DNA
probes. The unique properties of PNA probes allow access to these
regions under conditions optimal for FISH, resulting in a simple yet
highly sensitive and specific hybridization assay, or PNA FISH, suited
for rapid and accurate identification of bacteria and yeast.

Molecular systems that provide rapid identification
of positive cultures can reduce:

  1. mortality and costs associated with S aureus bacteremia3;
  2. length of stay and unnecessary vancomycin use due
    to coagulase-negative Staphylococcus-contaminated blood
  3. time to correct therapy and mortality for
    Enterococcus faecium
    bacteremia5; and
  4. antifungal-drug costs associated with Candida

Together, the bundling of a blood-culture collection
system with a rapid molecular-identification system can help hospitals
and labs avoid the road to reimbursement denial. The key is to find
complementary systems that meet specific needs and are fast, reliable,
and accurate.


  1. Wenzel RP, Edmond MB. 2001. The Impact of
    Hospital-Acquired Bloodstream Infections. Emerging Infectious
    . 2001;7(2);
  2. Elixhauser A. Steiner C. July 2007. Infections
    with Methicillin-Resistant Staphylococcus Aureus (MRSA) in U.S.
    Hospitals, 1993-2005. Healthcare Cost and Utilization Project,
    Statistical Brief #35.
  3. Ly T, Gulia J, Pyrgos V, Waga M, Shoham S. 2008.
    Impact upon clinical outcomes of translation of PNA FISH-generated
    laboratory data from the clinical microbiology bench to bedside in
    real time. Therapeutics and Clinical Risk Management, in press,
  4. Forrest GN, Mehta S, Weekes E, Lincalis DP, et
    al. Impact of rapid in situ hybridization testing on coagulase-negative
    staphylocci positive blood cultures. J Antimicrob Chemother.
  5. Forrest GN. PNA FISH: present and future impact
    on patient management. Expert Rev Mol Diagn.
  6. Forrest GN, Mankes K, Jabra-Rizk MA, Weekes E, et al. Peptide Nucleic
    Acid Fluorescence In Situ Hybridization- Based Identification of Candida
    albicans and Its Impact on Mortality and Antifungal Therapy Costs. J Clin Microbiol. 2006;44:3381-3383.

Douglas Matthews, CLS, MT(ASCP), MBA, is a marketing manager at bioM'erieux in Durham, NC.