There is limited knowledge about determinants of chronic bronchitis (CB) among Aboriginal children and adolescents in Canada. The objective of the study was to determine the prevalence and associated risk factors of chronic bronchitis in Aboriginal children (6-11 yrs.) and adolescents (12-19 yrs.).
Canadian Aboriginal Peoples Survey (APS)-2012 data were analyzed. Logistic regression analysis with appropriate weight variable to estimate regression coefficient and the balanced repeated replication method (to account for stratification and clustering) to compute robust standard errors were used. The outcome of interest for children was self-reported response by a parent/guardian to the question: 'Has your child ever had bronchitis?' and for adolescents self-reported response to the question 'Do you have chronic bronchitis?' Individual, environmental, and contextual factors were investigated for an association with CB.
Results are presented for (weighted numbers) 1,09,030 children 6-11 years old and 1,66,730 adolescents 12-19 years old. The prevalence of CB was 4.49% for boys (0.74% for adolescent boys) and 4.16% for girls (2.38% for adolescent girls).
The significant risk factors of CB were: age [odds ratio (OR) (95% confidence interval (CI) = 0.75 (0.66-0.86) for age group 9-11 years compared to age group 6-8 years]; household income (1.82 [1.56-2.13] for $25,000-$44,999 income category compared to income group ≥ 85,000), body mass index (1.54 [1.28-1.85] for overweight compared to normal), allergies (2.24 [1.96-2.56] for allergies compared to no allergies), asthma (5.69 [5.00-6.49] for asthma compared to no asthma), and location of residence (rural vs. urban). The relationship between the prevalence of CB and (i) Body mass index, and (ii) Location of residence, was modified by sex. There was significant increase in the prevalence of CB for obese boys (5.4%) comped to (i) Neither overweight nor obese boys (3%) and girls (4%) and (ii) Obese girls (3.5%). Girls residing in rural areas had the significantly increased prevalence (5.6%) of CB compared to boys irrespective of their location residence and girls who live in urban areas.
The significant risk factors of CB were: age (4.25 [3.58-5.04] for 15-19 years compared to 12-15 years), household income (3.22 [2.42-4.29] for income category < $25,000 compared to income category ≥ $85,000), parent's education (1.60 [1.20-2.17] for 'less than or some high school' compared to 'university education'), smoking in house (1.80 [1.53-2.13] for 'smoking house' compared to 'non-smoking house'), and the location of residence. The relationship between the prevalence of CB and (i) Body mass index, and (ii) Location of residence was modified by sex. Boys (2.5%) and girls (2.2%) with BMI > 30 had significantly higher prevalence compared to boys (0.57%) and girls (1.4%) with BMI < 25 and boys with BMI category 25-30.
Also, overweight girls had significantly higher prevalence with boys with normal weight and overweight boys. Contrarily to findings of effect of gender*location of residence on prevalence of CB, adolescents girls living in urban areas had significantly higher probability of CB (1.7%) compared to boys (1.25%) and girls (1.2%) living in rural areas and boys (0.39%) living in urban areas.
The prevalence of CB was related to modifiable risk factors age, household income, parental education, and environmental smoking, and location of residence.