Evaluation of asthma control using patient based measures and peak expiratory flow rate

Asthma control has not been formally evaluated in the Caribbean. This study evaluated disease control on The Asthma Control Test (ACT), The Royal College of Physicians "Three questions" for Assessing Asthma Control (RCP), peak expiratory flow rate (PEFR) and patients' self-assessment of control.

Asthma control was examined in a cross-section of 205 asthmatics above 16 years of age using the ACT, RCP and on the PEFR % predicted. Scores below 20 and equal to or above 1 on the ACT and RCP respectively, and PEFR below 80% predicted indicated uncontrolled asthma. Patients stated whether they perceived their asthma was controlled or uncontrolled.

Overall there were more females (63.9%, p < 0.001) than males (36.1%). Males aged between 17-30 years predominated (60.8%, p < 0.001) with gender reversal beyond 30 years of age (33.2%, p < 0.002) years. Self-assessed control was higher (69.3%, p < 0.001) than control evaluated by the ACT and RCP tests, which were comparable (p > 0.05). Fewer patients (13.2%) achieved control on PEFR > 80% predicted than on the ACT (22.4%) and RCP (18%). The Kappa statistic indicated good reproducibility of the RCP and ACT and concordance between the PEFR and RCP (0.63) and the PEFR and ACT (0.56). Higher education was associated with control on the ACT (p < 0.0005) and RCP (p < 0.002) but not on PEFR or self-assessment (p > 0.05).

Approximately 80% of study asthmatics were uncontrolled, and patients tended to overestimate their disease control. The ACT and RCP instruments were comparable with the PEFR. Efforts to study their validity and formal evaluation of asthma control in Trinidad are recommended.