Table 1.

Children's characteristics.

Variables	Derivation studya (n = 256)	Validation studya (n = 156)
Sociodemographic
Median age, months (IQR)	21 (9 to 35)	24 (12 to 37)
Sex, male	51	54
Ethnicity, white	82	75
Mean Townsend deprivation score	2.18	2.0
Attends day care, nursery or school	44	58
Lives with a resident smoker	47	36
Clinical history
Mean number of preschool children per session	7.1	4.7
Mean number recruited per session	2.1	0.8
GP consultations in the preceding yearb
(0–1)	27	25
(2–4)	39	40
(> 4)	34	35
Cough was main reason for consultation	66	66
Median duration of cough prior to recruitment, days	5	7
First clinician contact for the cough	71	82
Personal history of atopyc	29	32
Family history of atopyd	62	60
Clinician assessing child
GP only	96	95
Clinical examination
Illness severity
Mild	77	76
Moderate	22	23
Severe	1	1
Abnormal chest signs	22	26
Formal thermometry	24	20
Fever (clinical judgment or thermometry)	11	12
Tachypnoea	9	5
Clinical diagnosis
Classification of cough: URTIe	74	77
Treatment
Antibiotics	18	24
Bronchodilators	13	9
Post consultation cough duration
Days taken for proportion to resolve
0.25	6	5
0.5	10	9
0.75	16	15
Reconsultations
Proportion with reconsultations	19	23
Complications
Proportion with complications	10	12

^aResults as % unless stated.

^bExcluding prior consultations for this cough episode.

^cAtopy refers to asthma, eczema, or hay fever.

^dFamily history in any first-degree relative.

^eUpper-respiratory tract infection.