ASSESSING THE FEASIBILITY OF ANTIBIOTIC MANAGEMENT SERVICES THROUGH PROSPECTIVE EVALUATION

Kevin D. Mills, Pharm D

1

; Corstiaan Brass, MD

2

; Marisa Rahn, Pharm D, BCPS

3

; James Fenner, B. Sc., Pharm D, BCPS

4

; Salvi Parpia, B. Sc., Pharm D, MRCF

5 1

Clinical Pharmacy Coordinator, Kaleida Health/DeGraff Memorial Hospital;

2

Clinical Associate Professor, SUNY at Buffalo School of Medicine;

3

Assistant Professor of Pharmacy Practice, Albany College of Pharmacy;

4

Clinical Pharmacy Coordinator, Kaleida Health/Millard Fillmore Suburban Hospital;

5

Clinical Assistant Professor, Faculty of Pharmaceutical Sciences, University of British Columbia

ABSTRACT

PURPOSE:

The inappropriate and unnecessary use of antibiotics is an important problem in the hospital setting. The goal of this assessment was to prospectively evaluate the extent of antibiotic misuse at a community hospital, and to realistically quantify the potential reduction of direct and indirect hospital costs if an antibiotic management service were employed.

METHODS:

A 3-week prospective evaluation was performed at a 100 bed private hospital facility. During the evaluation period, all antibiotic use at the facility was captured by a residency-trained antibiotic streamlining pharmacist. Appropriateness of antibiotic therapy was assessed based on infection diagnosis and supporting evidence for the presence of active infection. The extent of inappropriate antibiotic use, as well as the potential direct and indirect hospital cost of non focused antibiotic utilization, was estimated using a customized database.

RESULTS:

Of a total of 149 patients who received antibiotic therapy during the evaluation period, 116 were evaluated and actively followed by the streamliner. A total of 137 potential interventions were identified. Seventy-four of the potential interventions involved antibiotic change or discontinuation, while 44 involved change from IV to oral therapy. An estimated $8,354 in potential drug cost savings was identified ($144,807 annually). If an antibiotic management program were employed, the initial acceptance rate of recommendations would likely be around 85 percent. Thus, a realistically achievable estimate of drug cost savings from antibiotic management is $7,100 over three weeks, or $123,000 annually. A minimum cumulative reduction of 23 patient days could have been achieved by earlier conversion to oral therapy, accounting for an additional $5,750 in potential cost savings to the facility ($99,750 annually).

DISCUSSION:

The annual cost savings for the facility that could be achieved through focusing of antibiotic therapy is approximately $223,000. Based on the results of this observational evaluation, there is sufficient inappropriate and non-focused antibiotic use to justify the presence of an antibiotic management service at MSM. We intend to initiate an antibiotic management program at this facility beginning in 2005. Once this program has been established, we will be able to evaluate the accuracy of our methods for determining the potential cost savings of antibiotic management services.

INTRODUCTION



Antimicrobial stewardship initiatives have consistently been associated with significant reductions in antibiotic use, improved bacterial susceptibility patterns, and reduced inpatient LOS of infected patients



Many facilities continue to operate without such programs

- One likely reason is the perceived lack of financial resources needed for the development and implementation of these programs 

The relationship between sub-optimal antibiotic use and potential cost savings to a facility has not been clearly established



A valid means of prospectively evaluating the potential impact of antibiotic management initiatives would be useful



The goal of this assessment was to prospectively evaluate the extent of antibiotic misuse at this facility, and to realistically quantify the potential for reduction of direct and indirect hospital costs if an antibiotic management service were employed METHODS The Facility

 Mount St Mary’s Hospital (MSM) is a 100 bed secondary care facility • A member of the Ascension Catholic hospital network • 11 bed intensive care unit • Non-teaching facility • At the time of this evaluation, no significant measures to improve cost-effectiveness of antibiotic therapy were employed

Data collection and Analysis

 A prospective, observational evaluation was conducted at MSM over a three week period • All antibiotic use at the facility was captured along with patient demographic data, details of infection and concomitant diagnosis, and relevant laboratory and culture data • Data collection and antibiotic regimen assessment were performed by a residency trained clinical pharmacist (KM)  Antibiotic selection, dosing, and duration of therapy were evaluated based on evidence-based practice standards and guidelines  The definitions used when determining the appropriateness, redundancy, and focus of prescribed antibiotic regimens are stated below  A physician specialist in infectious diseases (CB) was consulted for further insight into the appropriateness and/or focus of a given regimen when necessary  Each IV antibiotic regimen was assessed daily for potential conversion to oral therapy based on the stated criteria

Term

Inappropriate Redundant Focused Appropriate for IV to oral conversion

Definition

No objective evidence of active infection Cultured organism(s) not susceptible to prescribed antibiotic Excessive duration of therapy based on evidence-based guidelines Use of broad spectrum antibiotic with coverage of nosocomial organisms in patients with no prior hospital exposure Two antimicrobial agents with overlapping spectra of activity used simultaneously (ex. ampicillin/sulbactam plus metronidazole: redundant coverage of anaerobic organisms) Most cost-effective and narrow-spectrum antibiotic therapy - No underlying gastrointestinal pathology existed that would preclude reliable enteral ingestion/absorption - Patient tolerating at least one other enteral medication - Patient received at least 48 hours of IV antibiotic therapy - White blood cell count < 15 x 10 9 /L - Afebrile (Temp < 100.0

o F) > 24 hours - Equivalent oral antibiotic available - Antibiotic NOT used for one of the following indications: meningitis, endocarditis, febrile neutropenia, prosthetic device infection, staph. aureus bacteremia 

Estimating potential impact on antibiotic cost

• When an antibiotic regimen was deemed inappropriate or non focused, a potential intervention was recorded and a focused regimen was formulated • Patient’s actual antibiotic regimen and the focused regimen were tracked until patient discharge or discontinuation of therapy • Estimated drug cost savings = Cost of prescribed regimen(s) - Cost of focused regimen(s) 

Estimating impact on inpatient length of stay (LOS)

• If a patient (as a result of IV to oral conversion) would subsequently be off all IV medications and had no other unresolved medical issues, a potential LOS decrease of 1 (one) day was recorded.

• Mean cost per day of inpatient stay was obtained from the facility  All data were collected and analyzed using a customized Access® database.  Cost of antibiotic therapy was determined using purchasing data obtained from the facility’s Department of Pharmacy

RESULTS Evaluation dates

: May 3 rd through May 24 th , 2004  Total No. of patients who received antibiotic therapy during study period:

149

Patient Demographics Characteristic

Age (mean +/- SD) Male sex (No, %) Inpatient LOS (patients discharged during study period only)(mean +/- SD)

Infection syndrome

Intra-abdominal Pulmonary Upper respiratory tract Skin or soft tissue Urinary Bacteremia Prophylaxis No reason Fever Leucocytosis Meningitis or CNS Bone/ joint (Patient not seen and evaluated) 68.6 +/- 17.6 years 68, 45.6% 7.7 +/- 4.8 days 29 21 18 10 9 7 7 5 4 3 2 1 33

Potential Therapy Interventions

Result

No. of patients evaluated and followed during study period No. of antibiotic regimens evaluated during study period No. of instances of

inappropriate

antibiotic therapy No. of instances of

redundant

antibiotic therapy

Potential Antibiotic Streamlining Interventions No.

116 240 51 23

137

44

(32.1%)

60

(43.8%)

D/C Antibiotic Change Antibiotic Dose Change IV to PO Change

19

(13.9%)

14

(10.2%)

Potential Therapy Interventions (Cont.) Rationale for antibiotic therapy change or discontinuation

Use of antibiotic therapy in patients with insufficient evidence of active infection

n

23

Use of multiple antibiotics with similar/ overlapping antimicrobial spectra

18

Adjustment of antibiotic therapy based on culture data or other diagnostic test result

8

Excessive duration of antibiotic therapy for active infection Use of broad spectrum antibiotic with coverage of nosocomial organisms in patients with no prior hospital exposure Excessive duration of prophylactic antibiotic

7 5 5

Inappropriate antibiotic selection based on evidence-based medicine and standard of care Use of multiple antibiotics when single agent would provide adequate antimicrobial coverage

5 3 RESULTS Antibiotic Regimen Details Over 3-week Study Period (prescribed vs. focused) Result

Total antibiotic days IV antibiotic days Oral antibiotic days Ratio IV:oral antibiotic days

Prescribed regimens

1538 1130 408 2.77

Focused regimens

1288 792 496 1.60

Mean days to oral therapy (or therapy discontinuation) 4.5

3.33

a. Total antibiotic days for prescribed regimens - focused regimens

Excess antibiotic days

a

250 338

Potential Impact of an Antibiotic Management Program on Antibiotic Spending Result

Total cost of actual (prescribed) antibiotic therapy Total cost of optimized antibiotic therapy

Study period (3 weeks)

$26,183.51

$17,829.22

Estimated potential drug cost savings $8,354.29

Annualized

$453,847.51

$309,039.81

$144,807.69

 If an antibiotic management program were employed, the initial acceptance rate of recommendations would likely be around

85%

- Thus, a realistically achievable estimate of drug cost savings from antibiotic management is

$7,100

over three weeks, or

$123,000

annually

Estimated (minimum) LOS Impact of IV to Oral Conversions Result Study period (3 weeks) Annualized

Estimated days saved through IV to oral conversions

(see criteria in methods section)

Expected cost savings to the facility per day of reduced LOS Estimated cost savings due to decrease in LOS 23 days $250.00

$5,750.00

399 days $250.00

$99,750.00

DISCUSSION

 The

minimum

expected annual cost savings for the facility from drug cost savings and decreased inpatient LOS is approx.

$223,000

 The potential decrease in LOS of 23 days over 3 weeks was meant to be a conservative estimate - In the literature, the impact of early IV to PO conversion on inpatient LOS has been suggested to be much greater (from 1 to 2.5 days per conversion)

Limitations

• Short observation period • Method for evaluating the prescribed antibiotic regimens was superficial (info. obtained from patient records, no direct patient assessment)

Conclusion

 There is sufficient inappropriate and non-focused antibiotic use to justify the presence of an antibiotic management service at MSM  Our intent is to establish an antibiotic management program at this facility beginning in 2005  Once this program has been established, we will be able to draw conclusions as to the accuracy of our methods for determining the potential cost savings of antibiotic management services