The Montreal consensus recognizes chronic cough as an extra-esophageal manifestation
of gastroesophageal reflux disease. We performed a meta-analysis to assess the effects
of acid-suppressive medications in adults with non-specific chronic cough. The protocol
was registered on PROSPERO (CRD42022368769). Placebo-controlled randomized trials
evaluating the impact of acid-suppressive medications on persistent cough were included.
The systematic search was performed on the 1st of November 2022 in three databases.
A random-effects model was used for the calculations. The effect size was the standardized
mean difference (SMD) with 95% confidence interval (CI). A total number of 11 double-blinded
placebo-controlled randomized trials were included in the meta-analysis. Data showed
that compared to placebo, PPIs decreased the severity of cough (SMD 0.33; CI 0.05;
0.61). Therapeutic response was not different in patients with non-specific chronic
cough only, compared to those with laryngopharyngeal reflux. Prolonged treatment durations
did not result in greater symptomatic improvement, with SMD 0.33 (CI - 0.22; 0.88),
0.31 (CI - 1.74; 2.35), 0.32 (CI - 0.29; 0.93) and 0.34 (CI - 0.16; 0.85), following
4, 6, 8 and 12 weeks of treatment, respectively. The pooled analysis of the improvement
in quality of life with PPIs found an SMD of 0.39 (CI - 0.51; 1.29). PPIs mildly decrease
the severity of non-specific chronic cough, irrespective of treatment duration.
