Using blood culture as ` gold standard ' , BinaxNOW pneumococcal POCT detected 57.1 % ( 95 % CI 18.4 % to 90.1 % ) of pneumococcal infections ( specificity 92.5 % ; 95 % CI 90.6 % to 94.1 % ) ; sputum culture detected 100 % ( 95 % CI 2.5 % to 100 % ; specificity 97.2 % , 95 % CI 94.3 % to 98.9 % ) .