Relationships between measures of dysfunctional breathing in a population with concerns about their breathing

Background: Dysfunctional breathing (DB) is implicated in physical and psychological health, however evaluation is hampered by lack of rigorous definition and clearly defined measures. Screening tools for DB include biochemical measures such as end-tidal CO2, biomechanical measures such assessments of breathing pattern, breathing symptom questionnaires and tests of breathing function such as breath holding time. Aim: This study investigates whether screening tools for dysfunctional breathing measure distinct or associated aspects of breathing functionality. Method: 84 self-referred or practitioner-referred individuals with concerns about their breathing were assessed using screening tools proposed to identify DB. Correlations between these measures were determined. Results: Significant correlations where found within categories of measures however ccorrelations between variables in different categories were generally not significant. No measures were found to correlate with carbon dioxide levels. Conclusion: DB cannot be simply defined. For practical purposes DB is probably best characterised as a multi-dimensional construct with at least 3 dimensions, biochemical, biomechanical and breathing related symptoms. Comprehensive evaluation of breathing dysfunction should include measures of breathing symptoms, breathing pattern, resting CO2 and also include functional measures such a breath holding time and response of breathing to physical and psychological challenges including stress testing with CO2 monitoring.