Cost analysis of blood cultures

Richard HuynhMarch 2013

Introduction

• 4-7% of blood cultures are positive.• False positives -> 50% increase in cost, 64%

increase in length of stay. • Average of $70-100 per culture• Goal is to identify indications for blood

cultures• Cross sectional study of all patients currently

on medicine team D to assess if orders were appropriate vs inappropriate

Indication

• 1 Major criteria included temperature > 39.5°C, indwelling vascular catheter, or clinical suspicion of endocarditis.

• 2 Minor criteria included temperature 38.3-39.4°C, age > 65 years, chills, vomiting, systolic blood pressure < 90 mm Hg, neutrophil% > 80, white blood cell count > 18, bands > 5%, platelets < 150, and creatinine > 2.0.

Results Admitting Dx Culture Criteria

AKI Negative age>65 and Cr>2

Hypoglycemia HD 2 Negative 38.3, age>65 and Cr>2

UTI Negative WBC>18, chills

N/V, Liver abscess Negative 38.9, chills, vomiting

Weakness, HD 2 Negative 38.6, age>65

Obstructive jaundice

Negative Cr>2, vomiting

Chest pain Not ordered Cr>2

DM foot ulcer Negative None

AMS Negative age >65

Fatigue Negative WBC>18

SOB Negative WBC>18

• Of 11 patients:– 55% (6) met criteria– 36% (4) did not meet criteria– 9% (1) appropriately not ordered

Conclusions

• 4/11 did not meet criteria• Only 1/5 properly not ordered• Practice preventative medicine• Fever=culture• Confounding key factors• Physician dependent, ED vs IM• Sample size• Criteria may not be practical: wait until WBC>18?

Subjective chills and vomiting?

Resources

Coburn B, Morris AM, Tomlinson G, Detsky AS. Does this adult patient with suspected bacteremia require blood cultures? JAMA. 2012 Aug;308(5):502-11.

Shapiro NI, Wolfe RE, Wright SB, Moore R, Bates DW. Who needs a blood culture? a prospectively derived and validated prediction rule.J Emerg Med. 2008; 35(3):255-264

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