The top three antibiotic regimens for resident-years treated by clinicians who primarily practiced in NHs in the pneumonia group were fluoroquinolones, penicillin + beta lactamase inhibitors, and third-generation cephalosporins, while the top antibiotic regimens for resident-years treated by clinicians who did not primarily practice in NHs were fluoroquinolones, other antibiotics, and macrolides (Table 3). This evidence concerns the gene LACTB and susceptibility to pneumonia measurement.