The impact of a rapid screen for streptococcal pharyngitis on clinical decision making in the emergency department

The impact of a rapid streptococcal screening test (RSS) on clinical decision making in the management of patients with acute pharyngitis was evaluated. Physicians managing 95 ambulatory patients with the complaint of sore throat were asked to estimate the probability of group A beta-hemolytic streptococcal pharyngitis (GRABS) in each patient and whether they intended to treat with antibiotics both before and after the results of the RSS were known. Simultaneous throat cultures were obtained for 80 patients at the discretion of the treating physicians. Regression analysis revealed that the RSS result was an important independent predictor for the posttest decision to treat with antibiotics and for the estimated probability of disease. The mean absolute log-likelihood ratio was used to quantify the effect of the RSS on diagnostic certainty; a greater contribution to diagnostic certainty occurred when the RSS was positive. Physicians would have prescribed an antibiotic 49 times without the benefit of the RSS and prescribed an antibiotic 48 times given the RSS result. Without the RSS, the treatment decision contradicted the throat culture result in 25 cases. With the RSS, this occurred in 26 cases. The RSS, while influencing decision making, especially when positive, did not decrease the use of antibiotics.