Evaluation of systematic assessment of asthma-like symptoms and tobacco smoke exposure in early childhood by well-child professionals: a randomised trial

Abstract

Objectives: This study aimed to evaluate the effectiveness of systematic assessment of asthma-like symptoms and environmental tobacco smoke (ETS) exposure during regular preventive well-child visits between age 1 and 4 years by well-child professionals.

Methods: Sixteen well-child centres in Rotterdam, the Netherlands, were randomised into 8 centres where the brief assessment form regarding asthma-like symptoms and ETS exposure was used and 8 centres that applied usual care. 3596 and 4179 children (born between April 2002 and January 2006) and their parents visited the intervention and control centres, respectively. At child's age 6 years, physician-diagnosed asthma ever, wheezing, fractional exhaled nitric oxide (FeNO), airway resistance (Rint), health-related quality of life (HRQOL) and ETS exposure at home ever were measured. Linear mixed models were applied.

Results: No differences in asthma, wheezing, FeNO, Rint or HRQOL measurements between intervention and control group were found using multilevel regression in an intention-to-treat analysis (p>0.05). Children of whom the parents were interviewed by using the brief assessment form at the intervention well-child centres had a decreased risk on ETS exposure at home ever, compared to children who visited the control well-child centres, in an explorative per-protocol analysis (aOR = 0.71, 95% CI:0.59-0.87).

Conclusions: Systematic assessment and counselling of asthma-like symptoms and ETS exposure in early childhood by well-child care professionals using a brief assessment form was not effective in reducing the prevalence of physician-diagnosed asthma ever and wheezing, and did not improve FeNO, Rint or HRQOL at age 6 years. Our results hold some promise for interviewing parents and using information leaflets at well-child centres to reduce ETS exposure at home in preschool children.

Trial registration: Controlled-Trials.com ISRCTN15790308.

Figure 1. Flow of participants through the study.

FeNO = fractional exhaled nitric oxide, HRQOL = health related quality of life, Rint = airway resistance, ETS = environmental tobacco smoke.

Figure 2. Prevalence of ETS exposure at home of intervention and control (usual care) group by child’s age (Intention-to-treat analysis).

ETS exposure at home was defined based on the question ‘Do people smoke occasionally at home?’. Values are percentages and were tested for differences in characteristics in intervention and control group using logistic regression analyses. Population for analysis (N) and P values: Prenatal (N = 5598): p>0.05, 6 months (N = 4233): p>0.05, age 2 years (N = 5290): p = 0.02, age 3 years (N = 4894): p = 0.004, age 6 years (N = 4604): p>0.05.