Table 4 6-min-walk test results and reproducibility relative to age and sex differences of the participants.

From: Repeatability of the 6-min walk test in non-cystic fibrosis bronchiectasis

Variables Subclassification by age Subclassification by sex
 > 18 to < 60 years old  > 60 years old Female Male
n (%) 29 (44%) 37 (56%) 45 (68%) 21 (32%)
Age, years 39 ± 15 67 ± 5 55 ± 18 53 ± 16
Sex, men/women 10/19 11/26
Body Mass Index, kg/m2 25.4 ± 5.7 26.1 ± 5.0 26.0 ± 5.6 25.2 ± 4.5
FEV1, L 1.21 (0.88–2.00) 1.14 (0.89–1.45) 1.04 (0.81–1.24) 1.56 (1.30–2.07)*
FEV1, % predicted 43.3 ± 14.4 48.2 ± 13.3 47.0 ± 14.3 44.1 ± 13.0
FVC, L 2.30 ± 1.05 1.92 ± 0.66 1.82 ± 0.69 2.66 ± 0.95*
FVC, % predict 58.6 ± 15.3 62.0 ± 14.6 61.8 ± 15.8 57.7 ± 12.5
FEV1 post-bronchodilator, liters 1.33 (0.97–1.81) 1.22(0.93–1.47) 1.14 (0.86–1.34) 1.55 (1.31–1.79)*
FVC post-bronchodilator, liters 2.24 ± 0.82 1.91 ± 0.56 1.80 ± 0.53 2.60 ± 0.71*
BSI low/moderate/high score, n 11/5/13 7/14/16 11/10/24 7/9/5
6MWT distance, m
First 6MWT 461 ± 74 413 ± 74* 415 ± 73 474 ± 71*
Second 6MWT 444 ± 90 396 ± 80* 395 ± 80 463 ± 86*
CV (95%CI), % 10.1 (5.2 to 13.5) 8.7 (6.6 to 10.5) 9.2 (6.4–11.2) 9.8 (4.2–13.2)
Paired p-value 0.139 0.038 0.011 0.416
Post-6MWT HR, beats/min
First 6MWT 108 ± 15 115 ± 20* 113 ± 16 109 ± 23
Second 6MWT 105 ± 19 118 ± 18* 113 ± 17 111 ± 23
CV (95%CI), % 12.6 (7.1–18.0) 7.8 (3.7–11.8) 9.9 (5.5–14.3) 10.7 (5.4–16.0)
Paired p-value 0.678 0.120 0.867 0.544
Post-6MWT RR, breaths/min
First 6MWT 23 ± 4 26 ± 5* 25 ± 5 24 ± 5
Second 6MWT 23 ± 4 28 ± 5* 26 ± 5 25 ± 6
CV (95%CI), % 5.4 (2.4–7.2) 9.8 (7.1–12.0) 7.7 (5.0–9.6) 9.2 (5.2–11.9)
Paired p-value 0.699 0.043 0.145 0.410
Oxygen desaturation, %a
First 6MWT 0 (− 2 to 1) − 1 (− 4 to -1) − 1 (− 3 to 0) − 1 (− 3 to 0)
Second 6MWT 0 (− 1 to 1) − 1 (− 5 to 0)* 0 (− 2 to 0) − 1 (− 5 to 0)
  1. Data presents as mean ± SD, median (25–75) or stated otherwise.
  2. Statistical analyses: Paired t-Test for intra-group comparison between first and second 6MWT. *Statistical difference (p < 0.05) between subclassifications: > 18 to < 60 versus > 60 years-old and female versus male; non-paired t-Test for parametric data and Mann–Whitney U test for non-parametric data.
  3. CV: coefficient of variation; 95%CI: confidential interval; RR: respiratory rate; HR: heart rate; 6MWT: 6-min walk test; FEV1: forced expiratory volume; FVC: forced vital capacity; BSI: Bronchiectasis Severity Index.
  4. aSpO2 difference between before and after the 6MWT.