Skip to main content
. 2012 Apr 17;184(7):755–762. doi: 10.1503/cmaj.111619

Table 4:

Sensitivity analyses for risk of receiving a diagnosis of attention-deficit/hyperactivity disorder or treatment for the condition for children aged 6–12 years who were born in different periods

Exposed cohort Unexposed cohort RD (95% CI) RR (95% CI)
Analysis 1, date of birth Dec. 17–31 Jan. 1–15
Boys, no. 14 853 15 068
 Diagnosis, no. (%) 1 085 (7.3) 856 (5.7) 1.62 (1.07 to 2.18) 1.29 (1.18 to 1.40)
 Treatment, no. (%) 884 (6.0) 666 (4.4) 1.53 (1.03 to 2.03) 1.35 (1.22 to 1.49)
Girls, no. 13 960 14 529
 Diagnosis, no. (%) 376 (2.7) 231 (1.6) 1.10 (0.77 to 1.44) 1.69 (1.44 to 1.99)
 Treatment, no. (%) 261 (1.9) 150 (1.0) 0.84 (0.56 to 1.12) 1.81 (1.48 to 2.21)
Analysis 2, date of birth Dec. 2–16 Dec. 17–31
Boys, no. 18 957 14 853
 Diagnosis, no. (%) 1 420 (7.5) 1 085 (7.3) 0.19 (−0.38 to 0.75) 1.03 (0.95 to 1.11)
 Treatment, no. (%) 1 190 (6.3) 884 (6.0) 0.33 (−0.19 to 0.84) 1.05 (0.97 to 1.15)
Girls, no. 17 924 13 960
 Diagnosis, no. (%) 469 (2.6) 376 (2.7) −0.08 (−0.43 to 0.28) 0.97 (0.85 to 1.11)
 Treatment, no. (%) 347 (1.9) 261 (1.9) 0.07 (−0.24 to 0.37) 1.04 (0.88 to 1.21)
Analysis 3, date of birth Jan. 1–15 Jan. 16–30
Boys, no. 15 068 19 154
 Diagnosis, no. (%) 856 (5.7) 1 103 (5.8) −0.08 (−0.57 to 0.42) 0.99 (0.90 to 1.08)
 Treatment, no. (%) 666 (4.4) 837 (4.4) 0.05 (−0.39 to 0.49) 1.01 (0.92 to 1.12)
Girls, no. 14 529 18 179
 Diagnosis, no. (%) 231 (1.6) 276 (1.5) 0.07 (−0.20 to 0.34) 1.05 (0.88 to 1.25)
 Treatment, no. (%) 150 (1.0) 194 (1.1) −0.03 (−0.26 to 0.19) 0.97 (0.78 to 1.20)
Analysis 4, date of birth Dec. 29–31 Jan. 1–3
Boys, no. 3 907 3 609
 Diagnosis, no. (%) 272 (6.7) 190 (5.3) 1.70 (0.62 to 2.78) 1.32 (1.10 to 1.58)
 Treatment, no. (%) 252 (6.5) 155 (4.3) 2.16 (1.14 to 3.17) 1.50 (1.24 to 1.82)
Girls, no. 3 710 3 491
 Diagnosis, no. (%) 93 (2.5) 59 (1.7) 0.82 (0.16 to 1.48) 1.48 (1.07 to 2.05)
 Treatment, no. (%) 74 (2.0) 49 (1.4) 0.59 (0.00 to 1.19) 1.42 (0.99 to 2.03)

Note: CI = confidence interval, RD = risk difference, RR = relative risk.