First author [Ref.] | Subjects | Inclusion criteria | Exclusion criteria | Age yrs | Smoking history | Male/ female | Flow rate mL·s−1 | Analyser | NO ppb |
Olin 44 | 2200 | Unselected Random general population | NA | (25–75) | NS | 1089/1111 | 50 | Niox (Aerocrine, Solna, Sweden) | (2.4–199) 16.0 |
Haight 45 | 48 | PFT | SmokingRS, SC, SAI, RD | (18–79)Young group (n = 23): 23.4±0.6Old group (n = 25): 71.3±1.1 | NS | 23/25 | 50 | NOA 208 (Sievers, Seevetal-Hittfeld, Switzerland) | Young group: 25.2±4.8Old group: 47.8±8.3 |
Olivieri 46 | 204 | PFT | SmokingRS, RD, A,allergies | 36±9 | NS | 102/102 | 50 | CLD 88 (EcoMedics, Duernten, Switzerland) | (0.7–28.8) 10.8±4.7 |
Data are presented as n, (range), (range) median, mean±sd or (range) mean±sd. NO: nitric oxide; ppb: parts per billion; NA: not available; NS: never-smoker; PFT: pulmonary function tests; RS: respiratory symptoms; SC: symptoms of a cold in the past month; SAI: symptoms of airway infections in the 3 months prior to the study; RD: respiratory diseases; A: asthma.