Early farm residency and prevalence of asthma and hay fever in adults

Abstract

Background: Asthma and hay fever have been found to be both positively and negatively associated with farming lifestyles in adulthood. Lack of congruency may depend upon early life exposure. Objective: To assess the importance of different periods of farm residency for asthma and hay fever in an adult Canadian population. Methods: We conducted a questionnaire survey in rural Saskatchewan, Canada. We assessed a history of asthma and hay fever with five categories of farm residency that were mutually exclusive: first year of life only, currently living on a farm, both first year of life and currently living on a farm, other farm living, and no farm living. Generalized estimating equations were used to adjust for clustering effects of adults within households. Results: Of the 7148 responding, 30.6% had an early farm living experience only, 34.4% had both early and current farm living experiences, while 17.4% had never lived on a farm. The overall prevalence of ever asthma and hay fever was 8.6% and 12.3%, respectively, and was higher in women. Sex modified the associations between ever asthma and hay fever with farm residency variables whereby women had a decreased risk for both asthma [adjusted odds ratio (OR_adj): 0.67, 95% confidence interval (CI):0.47–0.96] and hay fever (OR_adj: 0.60, 95% CI: 0.44–0.83) with an early farm exposure only. Men currently living on a farm without an early farm exposure had an increased risk for ever asthma (OR_adj: 1.82, 95% CI: 1.02–3.24). Conclusion: Farm residency in the first year of life shows a protective effect for adult asthma and hay fever that appears to differ by sex.

• Chronic asthma
• farming
• rhinitis
• rural
• sex
• wheeze

Acknowledgements

The Saskatchewan Rural Health Study Team consists of: James Dosman, MD (Designated Principal Investigator, University of Saskatchewan, Saskatoon, SK Canada); Dr. Punam Pahwa, PhD (Co-principal Investigator, University of Saskatchewan, Saskatoon SK Canada); Dr. John Gordon, PhD (Co-principal Investigator, University of Saskatchewan, Saskatoon SK Canada); Yue Chen, PhD (University of Ottawa, Ottawa Canada); Roland Dyck, MD (University of Saskatchewan, Saskatoon SK Canada); Louise Hagel (Project Manager, University of Saskatchewan Saskatoon SK Canada); Bonnie Janzen, PhD (University of Saskatchewan, Saskatoon SK Canada); Chandima Karunanayake, PhD (University of Saskatchewan, Saskatoon SK Canada); Shelley Kirychuk, PhD (University of Saskatchewan, Saskatoon SK Canada); Niels Koehncke, MD (University of Saskatchewan, Saskatoon SK Canada); Joshua Lawson, PhD, (University of Saskatchewan, Saskatoon SK Canada); William Pickett, PhD (Queen's University, Kingston ON Canada); Roger Pitbaldo, PhD (Professor Emeritus, Laurentian University, Sudbury ON Canada); Donna Rennie, RN, PhD, (University of Saskatchewan, Saskatoon SK Canada); Ambikaipakan Senthilselvan, PhD (University of Alberta, Edmonton, AB, Canada). We are grateful for the contributions of the rural municipality administrators and the community leaders of the towns included in the study that facilitated access to the study populations and to all of participants who donated their time to complete and return the survey.

Declaration of interest

The authors have no conflict of interests related to this study. This study was funded by a grant from the Canadian Institutes of Health Research “Saskatchewan Rural Health Study”, Canadian Institutes of Health Research MOP-187209-POP-CCAA-11829.