Table 1 The characteristics of the 68 subjects who responded to the follow-up letter

Age, years

59 ± 11

Female sex

51 (75%)

Body mass index at initial assessment, kg/m²

27.6 ± 4.3

Atopic subjects

28 (41%)

Ex-smokers

27 (40%)

Current smokers

1 (2%)

Passive smoking

6 (9%)

Pet ownership

24 (35%)

Home damaged by dampness

8 (12%)

Duration of cough at initial assessment, years

6.0 ± 6.3

Presence of an autoimmune disease

17 (25%)

 with hypothyroidism

13

Presence of chronic rhinitis

32 (47%)

 with nasal corticosteroids

21

 with antihistamines

9

Presence of doctor’s diagnosis of asthma

34 (50%)

 with inhaled corticosteroids

27

Presence of esophageal reflux disease

17 (25%)

 with proton pump inhibitors

6

Responsiveness to histamine airway challenge at initial assessment, RDR, %/mg ^a

10 ± 5

Responsiveness to hypertonic saline cough provocation test at initial assessment, CDR, coughs/Osm/kg ^a

4.7 ± 7.1

Mean daily mean peak flow variation at initial assessment, percent

6.1 ± 4.3

FEV₁ at initial assessment, percent of predicted ^b

96 ± 14

Improvement in FEV₁ after salbutamol at initial assessment, percent

4.3 ± 4.7

Exhaled nitric oxide concentration at initial assessment, ppm

21 ± 19