Limitations and strengths
One limitation of this cross-sectional study is the absence of
longitudinal evaluation that would allow phenotype-specific trends in
disease progression and pulmonary functions to be monitored over time.
We also acknowledge that definitions of symptoms, medication use and
environmental exposures used in our models are based on parental
reporting using interviewer-administered questionnaires, and that this
may reduce the accuracy of the results by introducing bias in the
responses of the study parents (e.g. inaccurate recall, misreported
information and/or interaction between respondent and interviewer).
The key advantage of our study is the availability of data from a large
study population with similar characteristics, a well-defined clinical
diagnosis and objective measures such as SPT. LCA enabled us to identify
novel clinical clusters in children with AR.