A longitudinal study of changes in respiratory status in young adults, 1993-2001

There is little information regarding the prognosis of respiratory symptoms in early adulthood or the effects of potential risk factors.

To observe changing respiratory morbidity in a group of young adults over a period of 6-8 years.

Subjects responding to three or more consecutive postal respiratory surveys carried out between 1993 and 2001 were included in the study. In addition to asthma (defined by a validated scoring system), two symptoms were examined: wheeze and being woken by cough. Five outcomes were defined: persistent, remission, new onset, never and intermittent.

Of 2693 subjects who responded to at least one survey, about one third were eligible for inclusion: 10.2% reported wheeze at each survey (persistent) and 3.6% had persistent asthma. Persistent wheeze was seen in almost half (46.7%) of those reporting the symptom at their first survey. The corresponding figure for asthma was 32%. New onset wheeze was found in 16.2% of subjects without wheeze at baseline (asthma 9.7%). Smoking was significantly associated with new onset wheeze (OR 1.97, 95% CI 1.30-3.00) and asthma (OR 2.14, 95% CI 1.26-3.50), but not with persistent symptoms.

These findings highlight the importance of policies to reduce smoking prevalence in young adults, and will help in the planning of future health care.