Table 2

Mean differences in acute throat infection (ATI) consultations per child prior to and subsequent to the index date in 2001

 Mean number of ATI consultations and mean differences (with 95% CIs) comparing 3-year time intervals (1998–2001, 2002–2004 and 2005–2007)
n1998–2001
3 years prior
to index
2002–2004
1–3 years postindex
Mean difference
between 1998–2001
and 2002–2004†
n1998–2001
3 years prior
to index
2005–2007
4–6 years
postindex
Mean difference between 1998–2001 and 2005–2007†
3 years prior to index date and 1–3 years' follow-up3 years prior to index date and 4–6 years' follow-up
All children
 No tonsillectomy12 0530.442.25+1.81 (1.78 to 1.84) ***10 5930.440.93+0.49 (0.46 to 0.52)***
 Tonsillectomy4141.310.66−0.65 (−0.78 to −0.51)***3581.320.6−0.72 (−0.88 to −0.56)***
Girls 4–7 years
 No tonsillectomy23750.72.43+1.74 (1.66 to 1.81)***20920.71.04+0.35 (0.27 to 0.42)***
 Tonsillectomy781.320.76−0.56 (−0.94 to −0.19)**711.340.65−0.69 (−1.08 to −0.31)***
Boys 4–7 years
 No tonsillectomy22420.72.29+1.59 (1.51 to 1.67)***19890.690.76+0.06 (0.00 to 0.13)
 Tonsillectomy1101.320.83−0.49 (−0.81 to −0.18)** 921.320.55−0.76 (−1.02 to −0.50)***
Girls 8–11 years
 No tonsillectomy19440.352.23+1.87 (1.80 to 1.95)***17440.351.08+0.73 (0.65 to 0.81)***
 Tonsillectomy711.430.73−0.70 (−0.99 to −0.42)***651.430.92−0.51 (−1.00 to −0.01)*
Boys 8–11 years
 No tonsillectomy15260.312.04+1.73 (1.65 to 1.80)***13950.310.71+0.40 (0.33 to 0.47)***
 Tonsillectomy591.170.34−0.83 (−1.16 to −0.51)***491.220.39−0.84 (−1.23 to −0.45)***
Girls 12–15 years
 No tonsillectomy22060.232.45+2.22 (2.14 to 2.30)***18660.231.2+0.97 (0.89 to 1.04)***
 Tonsillectomy661.290.62−0.67 (−0.95 to −0.38)***551.220.62−0.60 (−0.96 to −0.24)**
Boys 12–15 years
 No tonsillectomy17600.21.91+1.70 (1.64 to 1.77)***15070.210.68+0.47 (0.41 to 0.53)***
 Tonsillectomy301.270.37−0.90 (−1.28 to −0.52)***261.420.23−1.19 (−1.69 to −0.69)***
  • *p<0.05.

  • **p<0.01.

  • ***p<0.001.

  • †Paired t test.