Exhaled nitric oxide levels stratified by current asthma symptoms and atopy in Lima and Tumbes; Peru, 2009–2010
| Mean | SD | N | |
| Overall (n=1199) | 19.5 | 22.2 | 1199 |
| Asthma, atopy | 52.6 | 52.3 | 64 |
| Asthma, no atopy | 25.5 | 29.9 | 25 |
| No asthma, atopy | 22.6 | 21.9 | 492 |
| No asthma, no atopy | 13.8 | 12.0 | 618 |
| Tumbes (n=625) | 17.6 | 19.0 | 625 |
| Asthma, atopy | 33.0 | 19.9 | 11 |
| Asthma, no atopy | 48.3 | 40.5 | 9 |
| No asthma, atopy | 22.9 | 23.7 | 229 |
| No asthma, no atopy | 13.1 | 13.1 | 376 |
| Lima (n=574) | 21.7 | 25.2 | 574 |
| Asthma, atopy | 56.7 | 56.0 | 53 |
| Asthma, no atopy | 12.7 | 8.1 | 16 |
| No asthma, atopy | 22.3 | 20.2 | 263 |
| No asthma, no atopy | 14.4 | 10.2 | 242 |