Table 2.

Estimation of Rates of Adverse Events 24 Months Before and 12 Months After Generic Losartan Commercialization

All UsersGenericsBrand NameDifference in Proportions95% CI
Trend before generics commercialization (%, 1st to 23rd month)−0.3*NA−0.3NANA
Level change the month of generics commercialization (%, 24th month)2.88.00.57.5−0.9 to 15.9
One-year trend change after generics commercialization (%, 24th to 36th month)0.60.0−2.02.0*0.7 to 3.4
  • For interrupted time series analyzed by negative binomial segmented regression (% = ecoefficient-1×100). All users include generic and brand-name users; generics include 8 different versions of generic losartan. 95% CI indicates 95% confidence interval around the difference in proportions; and NA, not applicable; difference in proportions of change in adverse events between generic and brand-name users.

  • * P<0.01.

  • P<0.05.

  • P<0.001.