Table 4

Respiratory and sensory irritation symptoms at baseline and at follow-up surveys among non-smokers* in the Republic of Ireland and Northern Ireland (n=138 and 20). Values are numbers (percentages) unless stated otherwise

No (%) with symptomsBaselineFollow upP valueDifference (95% Cl)
Republic of Ireland
Respiratory symptoms:
Median (IQR) No of symptoms1 (0-2)0 (0-2)0.0010 (–0.5 to 0)
Any symptom90 (65)67 (49)0.001–16.7 (–26.1 to –7.3)
Wheezing/whistling29 (21)27 (20)0.86–1.5 (–9.9 to 7.1)
Shortness of breath22 (16)22 (16)1.000 (–8.2 to 8.2)
Cough, morning29 (21)20 (15)0.14–6.5 (–14.8 to 1.8)
Cough, rest of day or night53 (38)34 (25)0.004–13.8 (–23.1 to –4.5)
Phlegm production59 (43)§40 (29)0.002–14.7 (–24.0 to –5.4)
Sensory symptoms:
Median (IQR) No of symptoms1 (0-2)0 (0-1)<0.001–1 (–1.27 to –0.7)
Any symptom93 (67)62 (45)<0.001–22.5 (–33.8 to –11.1)
Eyes, red or irritated57 (41)19 (14)<0.001–27.5 (–37.4 to –17.7)
Nose, runny or sneezing61 (44)48 (35)0.08–9.4 (–19.8 to 0.9)
Throat, sore or scratchy46 (33)26 (19)0.004–14.5 (–24.3 to –4.7)
Northern Ireland
Respiratory symptoms:
Median (IQR) No of symptoms0 (0-1)0 (0-1)0.530 (–0.5 to 1)
Any symptom9 (45)9 (45)1.000 (–32.7 to 32.7)
Wheezing/whistling1 (5)1 (5)1.000 (–18.9 to 18.9)
Shortness of breath5 (25)3 (15)0.69–10 (–38.6 to 18.6)
Cough, morning1 (5)3 (15)0.5010.0 (–8.1 to 28.1)
Cough, rest of day or night2 (10)3 (15)1.005.0 (–16.8 to 26.8)
Phlegm production4 (20)6 (30)0.6310.0 (–14.1 to 34.1)
Sensory symptoms:
Median (IQR) No of symptoms1 (0.3-2)1 (0-1)0.070 (–1 to 0.5)
Any symptom15 (75)11 (55)0.13–20.0 (–42.5 to 2.5)
Eyes, red or irritated9 (45)8 (40)1.00–5.0 (–31.8 to 21.8)
Nose, runny or sneezing10 (50)5 (25)0.06–25 (–49.0 to –1)
Throat, sore or scratchy4 (20)3 (15)1.00–5.0 (–35.8 to 25.8)
  • IQR=interquartile range.

  • * Non-smokers defined as participants who said they did not smoke or had given up and had salivary cotinine concentrations <113.6 nmol/l at baseline and follow-up surveys. Excludes participants who changed smoking status between surveys.

  • † P value for McNemar χ2 test for paired comparison of individual symptoms and Wilcoxon signed rank test for comparing median number of symptoms at baseline and follow-up.

  • ‡ Differences refer either to medians or percentages.

  • § Two respondents did not answer this question.