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The prevalence of adult onset wheeze: longitudinal study

BMJ 1997; 314 doi: http://dx.doi.org/10.1136/bmj.314.7083.792 (Published 15 March 1997) Cite this as: BMJ 1997;314:792
  1. Coreen Bodner, research assistanta,
  2. Sue Ross, lecturerb,
  3. Graham Douglas, consultantc,
  4. Julian Little, professor of epidemiologya,
  5. Joseph Legge, consultantc,
  6. James Friend, consultantc,
  7. David Godden, consultantc
  1. a Department of Medicine and Therapeutics University of Aberdeen Aberdeen AB9 2ZD
  2. b Department of General Practice University of Glasgow Glasgow G20 7LR
  3. c Department of Thoracic Medicine Aberdeen Royal Infirmary Aberdeen AB9 2ZB
  1. Correspondence to: Ms Bodner
  • Accepted 7 November 1996

Introduction

In contrast to wheeze in childhood, less is known about the prevalence of and factors associated with wheeze in adulthood. We studied the onset of wheezing in adults who had had no respiratory symptoms as children.

Subjects, methods and results

A 1964 random community survey in Aberdeen of 2511 children aged 10-14 years identified 121 children with asthma and 167 with wheeze with infection. The outcome at age 34-40 years of these children with wheeze, together with that of 167 children selected from those who were asymptomatic, has been described.1 In 1995 we tried to contact the 2056 individuals (now aged 39-45 years) who had had no childhood wheezing; 1799 subjects were traced. We posted questionnaires about symptoms, smoking, and employment to 1758 surviving subjects, of whom 1542 (87.7%) responded (75.0% of 2056).

Attacks of wheezing ever were reported by 239 (15.5%) respondents, of whom 177 (11.5% of 1542) reported adult onset wheeze–that is, onset at or after age 15 years. The prevalence of adult onset wheeze was similar for men and women (10.7% v 13.0%, χ2=1.95, P=0.16). Other subjects reporting wheeze included 17 with onset at age 10-14 years, 27 with onset before age 10 years, and 18 with no age specified.

Of the 177 subjects with adult onset wheeze, 133 (75.1%) wheezed during the previous year; 90 (50.8%) wheezed during the previous week; 34 (19.2%) experienced activity limitation owing to wheeze in the previous week; 28 (15.8%) were receiving regular inhaled bronchodilators or steroids, or both; and 38 (21.5%) were receiving occasional treatment. Of the 34 subjects with activity limitation, 20 were receiving treatment for wheeze.

In logistic regression analysis current smoking and manual social class were significant independent risk factors for wheeze (table 1). Odds ratios for a variable combining smoking and social class showed a greater risk of wheeze for smokers in the manual class than those in the non-manual class; both duration and amount of smoking were significantly greater in the manual class (data not shown).

Table 1

Adult onset wheeze: effect of sex, smoking habit, and social class. Values are numbers (percentages) unless stated otherwise

View this table:

We determined the overall burden of current wheezing illness in middle age, including onset in both childhood1 and adulthood, by examining our data for the complete cohort of 2511 subjects. Among the 1902 subjects for whom follow up information was available, 278 (14.6%) reported wheeze in the previous year; the time of onset was unclear for 32 of these subjects. Of the 246 subjects with known age of onset, 99 (40.2%) had child onset and 147 (59.8%) had adult onset symptoms.

Comment

The prevalence of adult onset wheeze at age 15-45 years was 11.5%. In the full cohort followed up in middle life, adult onset disease accounted for a greater proportion of current wheezing than child onset disease. This age-specific pattern of onset is similar to that found in other population studies of wheeze in adults.2 3 4 Although wheeze in adults is likely to include both asthma and chronic airways obstruction, using a narrower definition, such as “doctor diagnosed asthma,” would exclude many subjects who have not received a diagnostic label.2 3 4 Underdiagnosis resulting from underreporting and misinterpretation of symptoms may result in undertreatment.5 Over 40% of the subjects who reported limitation in their activities were not receiving treatment.

Smoking and manual social class conferred an increased risk of adult onset wheeze. A smoking effect has been shown by others2 3 and may reflect inclusion of subjects with smoking related chronic airways obstruction. The effect of social class may be partially explained by greater cumulative cigarette exposure in the manual class. Other risk factors, such as atopy and family history, require further investigation. This study shows that adult onset wheeze represents an important source of morbidity that may be currently underrecognised and undertreated.

Acknowledgments

We thank Professor Sally MacIntyre, Mr David Oldman, and Mr Eduardo Zanre for cooperation in tracing the subjects and Mrs Betty Calder for secretarial help.

Footnotes

  • Funding National Asthma Campaign.

  • Competing interests None

References

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