Efficacy of turmeric in the treatment of digestive disorders: a systematic review and meta-analysis protocol

BACKGROUND: Digestive disorders pose significant burdens to millions of people worldwide in terms of morbidity, mortality and healthcare costs. Turmeric has been traditionally used for conditions associated with the digestive system, and its therapeutic benefits were also confirmed in clinical studies. However, rigorous systematic review on this topic is severely limited. Our study aims to systematically review the therapeutic and adverse effects of turmeric and its compounds on digestive disorders, including dyspepsia, peptic ulcer, irritable bowel disease, Crohn’s disease, ulcerative colitis, and gastroesophageal reflux disease. METHODS/DESIGN: This study will include both randomized controlled trials and non-randomized controlled trials assessing the efficacy and safety of turmeric or its compounds in comparison to a placebo or any other active interventions for digestive disorders without any restrictions on participant age or language of publication. The primary outcome is the proportion of patients that have experienced treatment success. Secondary outcomes are the prevalence of an individual symptom of digestive disorders, the proportion of patients who experienced relapse, the number of physician visits/hospitalization due to digestive disorders, health-related quality of life and the proportion of patients who experienced adverse events. Relevant studies will be identified through MEDLINE, EMBASE, AMED, Dissertations & Theses Database and the Cochrane Central Register of Control Trials from their inception to August 31, 2013. In addition, grey literature such as information published on drug regulatory agencies websites and abstracts/proceedings from conferences will also be reviewed. A calibration exercise will be conducted in a process of study screening, whereby two reviewers will independently screen titles and abstracts from the literature search. Any conflicts will be resolved through a subsequent team discussion. The same process will be adopted in data abstraction and methodological quality appraisal by the Cochrane Risk of Bias Tool and the Newcastle-Ottawa Scale. We will describe study and patient characteristics, risk of bias/methodological quality results, and outcomes of the included studies. If we have sufficient data and homogeneity, a random effects meta-analysis will be performed. DISCUSSION: Our results will help patients and healthcare practitioners to make informed decisions when considering turmeric as an alternative therapy for digestive disorders. TRIAL REGISTRATION: PROSPERO registry number: CRD42013005739.