Efficacy of sequential three-step empirical therapy for chroniccough

Background: Empirical three-step therapy has been proved in just one hospital. This study aimed todemonstrate applicability of the sequential empirical three-step therapy for chroniccough in different clinical settings. Methods: Sequential empirical three-step therapy was given to patients with chronic cough in onetertiary and three secondary care respiratory clinics. Recruiters were initially treatedwith methoxyphenamine compound as the first-step therapy, followed by corticosteroids asthe second-step therapy and the combination of a proton-pump inhibitor and a prokineticagent as the third-step therapy. The efficacy of the therapy was verified according tothe changes in cough symptom score between pre- and post-treatment, and compared amongthe different clinics. Results: In total 155 patients in one tertiary clinic and 193 patients in secondary care clinicswere recruited. The total dropout ratio is significantly higher in the secondary careclinics than that in the tertiary clinic (9.3% versus 3.2%,p = 0.023). The therapeutic success rate for cough was 38.7% atfirst-step therapy, 32.3% at second-step therapy and 20.0% at third-step therapy in thetertiary clinic, and comparable to corresponding 49.7%, 31.1% and 4.1% in secondary careclinics. Furthermore, the overall cough resolution rate was not significantly different(91.0% versus 85.0%, p = 0.091). However, the efficacyof the third-step therapy is much higher (20.0% versus 4.1%,p = 0.001) in the tertiary clinic than in the secondary careclinics. Conclusions: Sequential empirical three-step therapy is universally efficacious and useful formanagement of chronic cough in different clinical settings.