Table 1

Study design and proportion of the 47 children in the RSV cohort and the 93 in the control cohort seen at follow-up during the study period

	Age (years)
	1	1.5, 2 and 2.5	3	7	13	18
Total number (RSV, controls)	47, 93	47, 93	47, 93	47, 93	46, 92	46, 92
% of cohort (RSV and controls)	100	100	100	100	98.5	98.5
Questionnaire	×	×	×	×	×	×
Examination	×		×	× (46, 89)	× (45, 89)	× (42, 87)
Skin prick tests (RSV, controls)	× (47, 92)		× (45, 92)	× (44, 89)	× (42, 87)	× (41, 85)
Egg white	×		×	×
Cat			×	×	×	×
Dog				×	×	×
Horse				×	×	×
Birch			×	×	×	×
Timothy				×	×	×
Mugworth					×	×
HDM (D pteronyssinus)			×	×	×	×
HDM (D farinae)					×	×
Mould (Cladosporium herbarum)				×	×	×
Mould (Alternaria alternata)					×	×
Blood samples			×	× (44, 87)	× (44, 86)	× (41, 85)
IgE to food allergens (Fx5)			×	×
IgE to inhaled allergens (Phadiatop)			×	×	×	× (41, 85)
Blood eosinophil counts						× (40, 86)
Lung function tests				× (44, 86)	× (44, 86)	× (42, 86)
Spirometry				×	×	×
Multiple breath washout (LCI)						× (41, 86)
FeNO						× (42, 86)
DACh					× (43, 86)	× (41, 86)

Numbers in parentheses (RSV, controls) if differed from numbers followed up at that time point.
A skin prick test weal with a mean diameter ≥3 mm was regarded positive. Phadiatop (Pharmacia Upjohn Diagnostics AB, Uppsala, Sweden) is a screening test for antibodies to inhaled allergens. Fx5 (Pharmacia Upjohn Diagnostics AB, Uppsala, Sweden) is a screening test for food allergens.
HDM, house dust mite; DACh, dry air hyperventilation challenge; LCI, lung clearance index; FeNO, fractional exhaled nitric oxide; RSV, respiratory syncytial virus.