Centres n (%) | 95% CI of percentages | |
Countries | ||
UK | 14 (22) | 12–33 |
USA | 13 (20) | 11–32 |
France | 9 (14) | 7–25 |
The Netherlands | 7 (11) | 4–21 |
Belgium | 4 (6) | 2–15 |
Australia | 3 (5) | 1–13 |
Others with one or two respondents# | 14 (22) | 12–33 |
Number of tests performed per year | ||
<25 tests | 27 (42) | 29–54 |
>25 tests | 38 (58) | 46–70 |
Of which >100 tests | 15 (23) | 14–35 |
Qualification of professionals performing measurement | ||
Physiologists/respiratory therapists | 21 (32) | 21–45 |
Pulmonary function technicians | 9 (13) | 6–24 |
Paediatric pulmonologists | 5 (8) | 3–17 |
Nurses | 4 (6) | 2–15 |
Others or association of professionals | 26 (40) | 30–53 |
Training programme for measuring nNO | ||
Yes, standardised | 26 (40) | 30–53 |
Yes, informal | 9 (13) | 6–24 |
No | 30 (46) | 34–59 |
Population tested | ||
Children and adults | 44 (68) | 55–79 |
Only children | 17 (26) | 16–39 |
Only adults | 4 (6) | 2–15 |
Younger age of children tested in 61 centres | ||
≤2 years | 25 (41) | 29–54 |
3–4 years | 9 (15) | 7–26 |
≥5 years | 27 (44) | 31–58 |
Test postponed if recent respiratory infection | ||
Total | 64 | |
No | 20 (31) | 20–44 |
Yes | 44 (69) | 56–80 |
Delay for 2 weeks | 22/44 (50) | 35–65 |
Delay for 4 weeks | 15/44 (34) | 20–50 |
Technique used to measure NO | ||
Total | 64 | |
Electrochemical | 31 (48) | 36–61 |
Chemiluminescence | 23 (36) | 24–49 |
Both | 10 (15) | 8–27 |
Sampling flow of the device | ||
Unknown | 22 (34) | 23–47 |
0.25–0.40 L·min−1 | 30 (46) | 34–59 |
>0.40 L·min−1 | 13 (20) | 11–32 |
#: Canada, Chile, Czech Republic, Switzerland, Brazil, Denmark, Germany, Ireland, Mexico, Palestine, Portugal and Tunisia.