Managing the prevention of retained surgical instruments: what is the value of counting?

Preventing retained foreign bodies is critical for patient safety. However, the value of counting surgical instruments and the reliability of the information provided have never been quantified. This study examines the diagnostic characteristics of counting and its impact on surgical costs.

We examined data from the Medical Event Reporting System-Total HealthSystem (MERS-TH), administrative hospital, and the New York State Cardiac Surgery Report databases (2000-2004). The cost per count discrepancy was examined by studying a cohort of patients undergoing coronary artery bypass graft (CABG) surgery. Linear and logistic multivariable regression models were used for statistical analysis.

Of 153,263 operations, there were 1062 count discrepancies. The rate of retained items was 1 of 7000 surgeries or 1 of 70 discrepancy cases. Final count discrepancies identified 77% and prevented 54% of retained items. The sensitivity of counting was 77.2%, specificity was 99.2%, but the positive predictive value was only 1.6%. Count discrepancies increased with surgery duration, late time procedures, and number of nursing teams. Bypass time, intravenous nitroglycerin injections, or myocardial infarction in the previous 24 hours were independent predictors of count discrepancies in CABG surgery. The incremental OR cost for CABG because of a count discrepancy was $932. Nationally, this would amount to an additional $24 million/yr in OR CABG cost.

This study, for the first time, quantifies the diagnostic accuracy of counting and defines the parameters against which alternative strategies of prevention should be measured, before being adopted in standard practice.