| Number (%)with symptoms | Change in symptoms* | |||||
| Baseline | Follow-up | Number reduced | Number increased | Number no change | p Value† | |
| (A) All (n = 191) | ||||||
| Respiratory symptoms | ||||||
| Median number of symptoms (IQR) | 2 (0–3) | 1 (0–2) | 72§ | 42§ | 72 | 0.009‡ |
| Any symptom | 131 (69) | 109 (57) | 36 | 14 | 141 | 0.02 |
| Wheezing/whistling | 63 (33) | 49 (26) | 35 | 20 | 134 | 0.029 |
| Shortness of breath | 61 (32) | 45 (24) | 35 | 19 | 133 | 0.02 |
| Cough, morning | 57 (30) | 42 (22) | 33 | 17 | 138 | 0.016 |
| Cough, rest of day or night | 87 (46) | 72 (38) | 40 | 24 | 125 | 0.03 |
| Phlegm production | 73 (39) | 58 (30) | 30 | 14 | 145 | 0.011 |
| Sensory symptoms | ||||||
| Median number of symptoms | 1 (1–2) | 1 (0–2) | 65§ | 37§ | 86 | 0.037‡ |
| Any symptom | 143 (75) | 122 (64) | 36 | 15 | 140 | 0.02 |
| Eyes, red or irritated | 69 (37) | 40 (21) | 40 | 11 | 138 | <0.001 |
| Nose, runny or sneezing | 108 (57) | 106 (56) | 34 | 31 | 124 | 0.402 |
| Throat, sore or scratchy | 85 (45) | 76 (40) | 42 | 31 | 115 | 0.121 |
| (B) Those who did not report a cold at either baseline or follow-up (n = 129) | ||||||
| Respiratory symptoms | ||||||
| Median number of symptoms | 2 (0–3) | 1 (0–2) | 49§ | 54§ | 24 | 0.015‡ |
| Any symptom | 86 (67) | 70 (54) | 23 | 7 | 99 | 0.042 |
| Wheezing/whistling | 42 (33) | 29 (23) | 21 | 8 | 100 | 0.012 |
| Shortness of breath | 43 (33) | 28 (22) | 27 | 12 | 88 | 0.012 |
| Cough, morning | 39 (30) | 28 (22) | 21 | 10 | 98 | 0.035 |
| Cough, rest of day or night | 54 (42) | 43 (33) | 27 | 16 | 86 | 0.063 |
| Phlegm production | 50 (39) | 36 (28) | 20 | 6 | 103 | 0.005 |
| Sensory symptoms | ||||||
| Median number of symptoms | 1 (0–2) | 1 (0–2) | 46§ | 26§ | 57 | 0.033‡ |
| Any symptom | 89 (69) | 69 (54) | 31 | 11 | 87 | 0.011 |
| Eyes, red or irritated | 43 (33) | 24 (19) | 25 | 6 | 98 | <0.001 |
| Nose, runny or sneezing | 60 (47) | 61 (47) | 23 | 24 | 82 | 0.5 |
| Throat, sore or scratchy | 54 (42) | 39 (30) | 31 | 16 | 82 | 0.02 |
*Reduction: symptoms at baseline, none at follow-up; increase: no symptoms at baseline, symptoms at follow-up; †the p value relates to the McNemar test for matched pairs, with exact probabilities based on a binomial assumption with the exception of ‡which relates to the Wilcoxon–Mann–Whitney test; §reduction: fewer symptoms at follow-up; increase: more symptoms at follow-up. IQR, interquartile range.