Oral huangqi formulae for stable chronic obstructive pulmonary disease: a systematic review and meta-analysis

Abstract

Objective. To evaluate the efficacy and safety of oral Huangqi formulae for the treatment of stable COPD. Methods. The major databases were searched until September 2010 and supplemented with a manual search. Randomized controlled trials (RCTs) of oral Huangqi formulae that reported on lung function, St. George's Respiratory Questionnaire, symptom improvement and/or frequency of exacerbations were extracted by two reviewers. The Cochrane tool was used for the assessment of risk of bias in the included trials. Data were analyzed with RevMan 5.1.2 software. Results. 25 RCTs (1,661 participants) were included. Compared with conventional therapy (CT) alone, oral Huangqi formulae plus CT increased FEV1, and a similar result was found comparing Huangqi formulae with no treatment. Improvements in SGRQ total score, COPD-related symptoms and reduction of frequency of exacerbations were found in patients receiving Huangqi formulae plus CT compared to those receiving CT alone or CT plus placebo. No serious adverse events were reported. However, there were some methodological inadequacies in the included studies. Conclusions. The benefits of Huangqi formulae for stable COPD were promising, but its efficacy and safety have not been established due to methodological weakness and possible bias in the reported results. Further rigorously designed studies are warranted.

Figure 1

Flow diagram showing the trial selection process for the systematic review.

Figure 2

Summary of assessment of risk of bias for each included study.

Figure 3

Funnel plot of publication bias using symptom improvement.

Figure 4

Forest plot of Huangqi formulae plus conventional therapy versus conventional therapy, or Huangqi formulae versus no treatment in patients with stable COPD: change in FEV₁ (L).

Figure 5

Comparison of Huangqi formulae plus conventional therapy versus conventional therapy alone in patients with stable COPD: change in SGRQ total scores.

Figure 6

Comparison of Huangqi formulae plus conventional therapy versus conventional therapy alone in patients with stable COPD: overall symptom improvement (defined as “good” or above).

Figure 7

Comparison of Huangqi formulae plus conventional therapy versus placebo plus conventional therapy or conventional alone in patients with stable COPD: change in frequency of exacerbations.