Systematic review of randomized controlled trials of traditional Chinese medicine treatment of non-acute bronchial asthma complicated by gastroesophageal reflux.

OBJECTIVE: To assess the effectiveness and safety of Traditional Chinese Medicine (TCM) treatment of non-acute bronchial asthma complicated by gastroesophageal reflux.

METHODS: We searched databases from MEDLINE, Cochrane Library, CNKI, VIP, CBM, Wanfang Data, and TCM Database Systems. All randomized, controlled trials (RTCs) of TCM treatment of non-acute asthma complicated by gastroesophageal reflux were included. Data were independently collected by two reviewers. The standards for assessing quality described in the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate articles. Meta-analyses were conducted using Rev- Man 5.0.17 software. Heterogeneity was assessed, and a corresponding effects model was used to merge and analyze results. Indexes used to evaluate curative effects were: clinical efficacy, symptom scores, pulmonary function values, and adverse incidents. Effectiveness was indicated using risk ratio (RR) or mean difference (MD), and 95% confidence intervals (CIs) were calculated.

RESULTS: Six RCTs were included, involving 304 patients with non-acute asthma complicated by gastroesophageal reflux. The treatment groups received Chinese drugs alone or TCM combined with standard Western medical treatment, and the control groups received standard Western medical treatment alone. Standard Western medical treatment included anti-inflammatory drugs and bronchodilators for asthma, and drugs to promote gastric peristalsis and inhibit gastric acid production for gastroesophageal reflux. Methodological quality was low in all six RCTs. Two RCTs showed that clinical efficacy was higher in the treatment group than in the control group (RR: 1.43, 95%CI: 1.10 to 1.87 vs RR: 1.51, 95% CI: 1.09 to 2.08). One RCT showed that the asthma score was lowered more effectively in the treatment group than in the control group (MD:-1.10, 95% CI:-2.04 to-0.16). Two RCTs showed that the gastroesophageal reflux score was reduced more effectively in the treatment group than in the control group (RR:-3.70, 95% CI:-4.30 to 3.10 vs RR:-5.30, 95% CI:-6.32 to -4.28). One RCT showed that some pulmonary function values were improved more effectively in the treatment group than in the control group (P < 0.05). No differences were seen in the various indexes between groups in the other RCTs. No adverse reactions, dropout rates, or follow-up rates were reported in any of the RCTs.

CONCLUSIONS: The clinical symptoms of non-acute asthma complicated by gastroesophageal reflux can be improved by some Chinese drugs. Curative effects can be increased by combining the use of TCM with Western medicine. Because of the small quantity and low quality of research reported to date, it is necessary to conduct further RCTs to confirm these results. The results of this systematic review indicate that the quality of future clinical trials should be improved by including larger patient numbers, correctly randomizing patients into study groups, using blinding methods to measure and assess outcomes, and using accepted indexes to evaluate curative effects.