Discussion
sore throat, pharyngitis
SORE THROAT, PHARYNGITIS, REGRESSION, RECRUITMENT
In unadjusted analyses, neither the active implementation of a guideline recommending the Centor or McIsaac score nor the addition of a targeted rapid antigen test reduced antibiotic prescriptions at a first consultation for sore throat in patients being at least moderately impaired by their illness. The prescription rate of 46% overall was about 3 times higher than the GAS rate of 15%. Only 24% of the patients receiving an antibiotic prescription had a positive culture for GASThe prescription rates concur with ranges reported in other studies [Regarding the GL-group and the UC-group, our findings confirm the results of former studies [Following the clinical assessment, GPs suspected a GAS-pharyngitis even more often in the intervention groups than in the UC-group (GL-group 44% and GL-RADT-group 51% versus 35% in the UC-group), despite a similar GAS-rate of about 15% in all groups. The diagnostic properties of the Centor and McIsaac scores ≤ 2 and ≥ 3 in our sample with a positive predictive value of 23% are in the range of the results found by a systematic review for the Centor score in general practice, confirming that the lower the pretest probability of GAS pharyngitis, the higher the overestimate via scores [There was, however, a significant imbalance in our sample with scores ≥ 3 being more frequent in the GL-RADT-group than in the GL-group. This may be due to some selective recruitment of patients. The regression analysis comparing the intervention groups only, showed that scores ≥ 3 were the strongest predictor for an antibiotic prescription (OR 13.03, p < 0.001) and adjustment led to fewer antibiotic prescriptions in the GL-RADT-group (OR 0.23; p 0.010). This suggests an influence of the RADT.The British RCT PRISM was run overlapping with our trial and compared their new FeverPAIN score to predict the presence of A, C and G streptococci (score group) with a combination of their score and targeted use of RADTs (RADT group) versus a strategy of “Delayed prescription” for all as control [The Spanish cRCT conducted in primary care was published during our trial. It included adults with at least one criterion of the Centor score, and compared the effect of rapid testing in all patients to usual care without RADT [In our trial all patients with a positive rapid test were prescribed an antibiotic, but also 39% of the patients with a negative test. Many GPs did not trust a negative rapid test, but were led by the patient’s signs and symptoms in their therapeutic decisions. Thus, 50% of patients with a score ≥ 3 and a negative RADT got an antibiotic.The Spanish trial [However, in daily practice, sensitivity (65%) and specificity (85%) of the RADT we used, resulting in a positive predictive value of 46%, were quite disappointing, compared to the manufacturer’s information of a sensitivity of 97.6% and a specificity of 98.4%. A Cochrane review on RADTs in children found a substantial heterogeneity in sensitivity of RADTs across studies with a summary sensitivity of 86% (range 39 – 100%) and a summary specificity of 95% (range 54–100%)[We observed a remarkable heterogeneity of the prescribing behavior across practices with a range of antibiotic prescriptions from 0 to 100% in all three groups. Ultimately, the decision on therapy remained in the GP practice. An observational study reports a similar heterogeneity in antibiotic prescriptions for sore throat [The intervention showed clear effects in terms of type of antibiotics prescribed and duration of therapy as well as recommendations of analgesics: GPs in the intervention groups chose penicillin V for 7 days and recommended analgesics more often than the GPs in the control group. These clear, concise parts of the intervention appear to be easier to adhere to.Overall, we used quite a complex intervention. Only about 1 of 3 patients wanted an antibiotic. But this was strongly associated with an antibiotic prescription (OR 10 in model 1 and OR 12 in model 2). It may have raised antibiotic prescriptions in all groups, indicating little effect of the guideline recommendation to inform the patient about the spontaneous course of a sore throat, and the modest effect of antibiotics [The course of the illness did not differ relevantly between groups confirming the favourable course reported in other studies [