Evidence base of randomized controlled trials and guideline recommendations of patent Traditional Chinese Medicines for uncomplicated acute lower respiratory tract infections in adults

OBJECTIVE: To compare clinical practice guideline recommendations on the use of oral patent Traditional Chinese Medicines (PTCMs) for uncomplicated acute lower respiratory tract infections (ALRTIs) in adults with the existing evidence using results of a systematic review of randomized controlled trials (RCTs). METHODS: A systematic review on RCTs and a systematic review of current guidelines on orally taken PTCMs for uncomplicated ALRTIs were performed. PubMed, Cochrane Library, EMBASE and four Chinese databases were searched from inception to September 2016 for RCTs testing orally taken PTCMs for uncomplicated ALRTIs (excluding pneumonia). Two reviewers independently screened each study, extracted study data, and assessed risk of bias. Disagreements were resolved through discussion or by consultation with a third reviewer. Clinical practice guidelines for uncomplicated ALRTIs containing PTCM recommendations were identified and quality appraised. The quality of pooled evidence of the RCTs and the guidelines was assessed with GRADE and AGREE Ⅱ respectively. The consistency of the evidence base in RCTs and the guideline recommendations were then compared. RESULTS: For the systematic review of RCTs, 4810 papers were identified, among which 29 RCTs (5093 patients) were included in the review. PTCMs compared to placebo increased the effective treatment rate of cough (3 trials, 949 patients, risk ratio (RR) 2.50, 1.16 to 5.43; low certainty); improved assessment of global health (3 trials, 948 patients, RR 1.70, 1.44 to 2.01; low certainty); and increased the effective rate of specific symptom relief (1 trial, 478 patients, RR 4.01, 2.76 to 5.81; moderate certainty). 21 trials (3432 patients) compared effects of different PTCMs. For the guideline evaluation, 29 PTCMs were recommended for the use of uncomplicated ALRTIs, of which27 had no supportive evidence from RCTs. CONCLUSION: The evidence base of PTCMs for uncomplicated ALRTIs is weak and the guideline recommendations were based on almost no clinical trial evidence. Rigorous clinical research is urgently needed to inform the clinical use of these herbal medicines. Further training in evidence-based medicine methods for Traditional Chinese Medicine guideline developers is essential.