Table 2. Spirometric data, expressed as mean, standard deviation, median and confidence interval of the total sample (non-cough group and cough group), as well as a comparison between them, according to the t-test or Mann-Whitney test.
| Spirometric parameters | Total Group (n=43) M±SD (95%CI) |
NCG (n=25) M±SD (95%CI) |
CG (n=18) M±SD (95%CI) |
p-value |
|---|---|---|---|---|
| FVC (L) | 2.26±0.71 (2.05–2.48) | 2.37±0.72 (2.07–2.66) | 2.13±0.68 (1.78–2.47) | 0.280* |
| FVC (%) | 93.59±20.50 (87.28–99.90) | 96.80±19.79 (88.63–104.97) | 89.14±21.21 (78.59–99.68) | 0.231* |
| FVC (LLN) | 2.01±0.67 (1.80–2.21) | 2.02±0.71 (1.73–2.32) | 1.99±0.62 (1.68–2.30) | 0.863 † |
| FVC (Z-score) | -0.58±1.80 (-1.13–(-0.03)) | -0.26±1.76 (-0.98–0.47) | -1.03±1.80 (-1.93–(-0.13)) | 0.170* |
| %GLI FVC | 93.57± 21.16 (87.05–100.08) | 97.33±20.91 (88.70–105.96) | 88.35±20.97 (77.92–98.78) | 0.173* |
| FEV1 (L) | 1.74±0.62 (1.55–1.93) | 1.83±0.58 (1.59–2.07) | 1.63±0.66 (1.30–1.96) | 0.300* |
| FEV1 (%) | 78.51±23.28 (71.34–85.67) | 82.14±22.35 (72.91–91.37) | 73.46±24.22 (61.41–85.50) | 0.232* |
| FEV1 (LLN) | 1.76±0.57 (1.58–1.93) | 1.77±0.61 (1.52–2.02) | 1.74±0.53 (1.48–2.00) | 0.863 † |
| FEV1 (Z-score) | -1.45±1.94 (-2.05–(-0.85)) | -1.12±1.89 (-1.90–(-0.34)) | -1.90±1.98 (-2.88–(-0.92)) | 0.200* |
| %GLI FEV1 | 82.42±23.87 (75.08–89.77) | 86.51±23.09 (76.98–96.04) | 76.74±24.42 (64.60–88.88) | 0.190* |
| PEF (L) | 3.66±1.53 (3.19–4.14) | 3.95±1.54 (3.32–4.59) | 3.26±1.47 (2.53–3.99) | 0.150* |
| PEF (%) | 69.34±22.42 (62.44–76.24) | 74.70±20.83 (66.11–83.30) | 61.88±22.98 (50.45–73.31) | 0.064* |
| FEF 25–75 (L) | 1.67±0.84 (1.41–1.93) | 1.74±0.75 (1.43–2.05) | 1.58±0.96 (1.10–2.05) | 0.530* |
| FEF 25–75 (%) | 60.96±27.08 (52.63–69.30) | 63.79±25.52 (53.25–74.32) | 57.04±29.40 (42.42–71.66) | 0.430* |
| FEF 25–75% (LLN) | 1.72±0.53 (1.56–1.89) | 1.71±0.57 (1.48–1.95) | 1.74±0.50 (1.49–1.99) | 0.941 † |
| FEF 25–75% (Z-score) | -1.74±1.50 (-2.20–(-1.28) ) | -1.55±1.43 (-2.14–(-0.97)) | -2.00±1.60 (-2.79–(-1.20)) | 0.350* |
| %GLI FEF25-75% | 65.25±28.88 (56.36–74.14) | 69.04±27.71 (57.61–80.48) | 59.98±30.44 (44.84–75.12) | 0.320* |
M: mean; SD: standard deviation; n: number; 95%CI: 95% confidence interval for the mean; NCG: non-cough group; CG: cough group; p-value: comparison between NCG and CG; FVC: forced vital capacity; FEV1: forced expiratory volume in one second; PEF: peak expiratory flow; FEF25–75%: forced expiratory flow between 25 and 75% of FVC; GLI: Global Lung Function Initiative; %: percentage of predicted; L: liters; LLN: lower limit of normal; p-value: comparison between the NCG and CG by the t test and Mann-Whitney test.
*p≤0.05 according to the independent t test
†p≤0.05 according to the Mann-Whitney U test.