Over prescription of antibiotics for adult pharyngitis is prevalent in developing countries but can be reduced using McIsaac modification of Centor scores: a cross-sectional study

Adult patients were recruited from three local hospital outpatient dispensaries (OPDs). All patients aged 14–65 years who were suspected of having bacterial pharyngitis had throat swabs taken. Laboratory results for GABHS pharyngitis were then compared with their prescriptions. Appropriateness (using the World Health Organization’s definition) and type of antibiotic prescribed were assessed.Of 137 patients, 30 patients each were studied for scores of 0, 1, 2 and 3; 17 patients were studied for score 4. Although 6 (4.4%) patients were GABHS+, for a prevalence of 43.8 per 1000 population, antibiotics were prescribed to 135 patients (98.5%). Of these, only 11.1% received appropriate antibiotics while 88.9% received inappropriate antibiotics. Penicillins were prescribed most (34.1%), especially amoxicillin/clavulanate; followed by macrolides (31.1%), especially the second-generation agents, and fluoroquinolones (14.8%). McIsaac scores were found to be 100% sensitive and 68.7% specific, giving a positive predictive value (PPV) of 12.7% and a negative predictive value (NPV) of 100%.Antibiotics were prescribed irrationally to adult pharyngitis patients, as most cultures were negative for bacterial infection. McIsaac modification of Centor scores related directly to culture results. We would therefore highly recommend its use to help family physicians make treatment decisions for adult pharyngitis patients.Group A beta hemolytic Streptococcus (GABHS) is commonly implicated in bacterial pharyngitis [1]. Starting treatment with antibiotics for GABHS infection, within the first 24–48 hours of illness, when a bacterial cause is highly suspected, has been found to decrease duration of symptoms, such as sore throat, fever and adenopathy by approximately one day [2], and prevent complications of GABHS pharyngitis, particularly rheumatic fever and rheumatic heart disease [3]. However, the majority of pharyngitis cases in adults are of viral etiology [4]; only 5–15% of cases suffer