Characteristics (as reported at clinic interview in 1999/2000) of those providing information on HONO levels and those not providing information on HONO levels (random sample subjects only shown)
| Did not provide HONO (n = 351) | Did provide HONO (n = 203) | Test for difference* | |
|---|---|---|---|
| *χ2 test for categorical variables, unpaired t test for continuous variables. | |||
| †ISCO code 1–3: senior officials, managers, professionals and technicians; 4–6: clerks, service workers and skilled agricultural and fishery workers; 7–9: trade workers, plant and machine operators and elementary occupations. | |||
| ‡283 non-responders and 179 responders had IgE levels measured. | |||
| Female (%) | 56.9 | 61.0 | p = 0.34 |
| Mean age (years) | 42.6 | 43.5 | p = 0.10 |
| Currently living in Norwich (%) | 39.3 | 58.1 | p<0.001 |
| Wheeze in last 12 months (%) | 30.2 | 30.1 | p = 0.97 |
| Woken by attack of SOB in last 12 months (%) | 5.4 | 5.9 | p = 0.82 |
| Ever asthma (%) | 14.5 | 17.2 | p = 0.39 |
| Mostly used gas for cooking (%) | 57.7 | 53.3 | p = 0.32 |
| Employment status (%) | |||
| Employed/self employed | 83.5 | 81.8 | p = 0.10 |
| Full-time houseperson | 9.9 | 5.9 | |
| Unemployed looking for work | 1.9 | 2.0 | |
| Unemployed due to poor health | 4.4 | 6.4 | |
| Student/retired/other | 1.5 | 3.9 | |
| Occupational status† | |||
| ISCO code 1–3 | 34.8 | 43.2 | p = 0.23 |
| ISCO code 4–6 | 26.1 | 21.6 | |
| ISCO code 7–9 | 21.1 | 16.7 | |
| Other | 18.0 | 18.4 | |
| Smoking status (%) | |||
| Lifetime non-smoker | 51.4 | 53.2 | p = 0.10 |
| Ex-smoker | 27.4 | 32.5 | |
| Current smoker | 21.4 | 14.3 | |
| Pack years of smoking among smokers | 22.6 | 17.9 | p = 0.19 |
| Sensitised to either house dust mite, grass,cat or Cladosporium (>0.35 kU/l)‡ | 33.9 | 46.3 | p = 0.007 |