Table 1

Weighted period prevalence (%), absolute difference and agreement between parent-reported wheezing and GP-diagnosed asthma in 12 months preceding each cohort interview

Target age for interview
(years) n
(n girls; w%*)		Child age at interview
(years)
Median (IQR)		Period prevalence of parent-reported wheezing
% (95% CI)
(A)		Period prevalence of GP-recorded asthma diagnosis
% (95% CI)
(B)		Absolute difference between parent-reported wheezing and GP-recorded asthma diagnosis†
% (95% CI)
(A–B)		Agreement (%) between parent-reported wheezing and GP-recorded asthma diagnosis
% (95% CI)		Cohen’s kappa
(95% CI)
Three years n=1280
(607; 46.0%)		3.1
(3.0 to 3.1)		24.1
(20.6 to 28.0)		13.4
(11.3 to 15.8)		10.7
(7.7 to 13.7)		80.8
(78.6 to 83.0)		0.39
(0.33 to 0.45)
Five years n=1347
(645; 46.5%)		5.3
(5.1 to 5.5)		18.9
(16.7 to 21.3)		13.5
(11.3 to 16.0)		5.4
(2.6 to 8.1)		85.8
(84.0 to 87.7)		0.50
(0.43 to 0.55)
Seven years n=1426
(685; 46.5%)		7.3
(7.1 to 7.5)		13.1
(11.0 to 15.5)		10.4
(8.6 to 12.6)		2.7
(0.3 to 5.1)		91.0
(89.5 to 92.4)		0.57
(0.50 to 0.63)
Eleven years n=1211
(573; 45.9%)		11.2
(11.0 to 11.5)		12.9
(10.6 to 15.4)		10.9
(8.8 to 13.3)		2.0
(−0.5 to 4.5)		91.8
(90.3 to 93.4)		0.61
(0.54 to 0.68)

  • *w%, weighted percentage.

  • †CI calculated using prtesti command in STATA on weighted prevalences. Similar estimates derived using McNemar’s test on unweighted prevalences (data not shown).

  • GP, general practitioner.