Stawicki SP, et al. Retained surgical items: a problem yet to be solved. J Am Coll. Surg. 2013;216(1):15-22.
This study analyzed 59 cases of retained surgical items (RSIs) as well as 118 matched controls. Incorrect counts during a procedure elevated the risk of RSI. An odds ratio of 20 for RSI risk was found for any incorrect surgical count.

Cima RR, et al. Incidence and characteristics of potential and actual retained foreign object events in surgical patients. J Am Coll Surg. 2008;207(1):80-87.
Thirty-four cases of actual retained foreign objects (RFOs) in 21 patients occurred when the count had been reported as correct.

Jackson S, Brady S.  Counting difficulties:  retained instruments, sponges, and needles.  AORN.  2008;87(2): 513-21.
This review article discusses prevention of errors and references Association of Perioperative Registered Nurses (AORN) recommended practices.

Egorova NN, et al.  Managing the prevention of retained surgical instruments: what is the value of counting?  Ann Surg. 2008 Jan;247(1):13-8.
Reviews data on count prevalence of discrepancies in 153,263 operations. There were 1062 count discrepancies, and 1 in every 70 discrepancy cases had a retained item. Final count discrepancies prevented 54% of retained items. Due to the low incidence of retained foreign bodies, the positive predictive value of a count discrepancy for an actual retained foreign body was only 1.6.

Reviewed and updated 4/15/2014 ldt