This is from Seppälä and colleagues 97 "Consumption of macrolide antibiotics decreased from 2.40 defined daily doses per 1000 inhabitants per day in 1991 to 1.38 in 1992 (P = 0.007) and remained near the lower level during the study period. The change in consumption was followed by a steady decrease in the frequency of erythromycin resistance among group A streptococcal isolates from throat swabs and pus samples, from 16.5 percent in 1992 to 8.6 percent in 1996 (odds ratio for 1996 as compared with 1992, 0.5; 95 percent confidence interval, 0.4 to 0.5)."