Results From Segmented Regression Analyses

Dependent VariableCoefficientEstimate (95% CI)a
≥1 prescription fills for codeine after tonsillectomyIntercept32.3 (31.6 to 33.0)
Monthb−0.3 (−0.3 to −0.2)
Postb−13.3 (−14.5 to −12.1)
Monthsafterb0.1 (0.1 to 0.2)
≥1 prescription fills for an alternative opioid after tonsillectomyIntercept35.1 (33.2 to 37.0)
Monthb0.2 (0.1 to 0.3)
Postb−1.2 (−3.5 to 1.0)
Monthsafterb−0.2 (−0.3 to −0.1)
  • a Coefficients from regressions were multiplied by 100 and are expressed as percentage point changes.

  • b The coefficient for month represents the absolute percentage point change per month over the study period; the coefficient for post represents the immediate level change after the investigation ended; and the coefficient for monthsafter represents the slope change after the investigation ended.