Acupuncture and related therapies for post-infectious cough: protocol for a systematic review and meta-analysis of randomized controlled trials (Preprint)

BACKGROUND Post-infectious cough (PIC) is a distinct subacute condition lasting 3 to 8 weeks, affecting 11% to 25% of patients following a respiratory infection. While recent reviews have addressed acupuncture for chronic cough (>8 weeks), the efficacy and safety of these therapies specifically targeting the transient inflammatory pathophysiology of subacute PIC remain unsynthesized. Current pharmacological interventions often provide limited relief or carry adverse effects. OBJECTIVE This protocol aims to evaluate the efficacy and safety of needle-based acupuncture therapies for adults with subacute PIC, compared to conventional medication, sham treatment, or no treatment. METHODS We will search MEDLINE (via PubMed), Embase, CENTRAL, CINAHL, Scopus, AMED, SCI, and five Chinese databases from inception onwards. Randomized controlled trials (RCTs) involving adults (≥18 years) with PIC will be included. To avoid pharmacological confounding, acupoint injection will be excluded. Primary outcomes are the Leicester Cough Questionnaire (LCQ) total score and validated cough severity scales (e.g., Visual Analogue Scale). Two reviewers will independently screen studies, extract data, and assess the risk of bias using the Cochrane RoB 2 tool. A random-effects model will be used for meta-analysis, with results stratified by predefined comparison strata (acupuncture vs sham/placebo, active therapy, or add-on designs). Evidence certainty will be evaluated using the GRADE framework. RESULTS This protocol was registered in PROSPERO (CRD420251268158). As of February 2026, preliminary database searches have been piloted. Formal study screening, data extraction, and evidence synthesis are scheduled to commence in April 2026. CONCLUSIONS This systematic review will provide rigorously synthesized evidence exclusively for the subacute PIC population, offering targeted clinical guidance that is currently missing from broader chronic cough assessments. CLINICALTRIAL PROSPERO CRD420251268158; https://www.crd.york.ac.uk/PROSPERO/view/CRD420251268158