Effects of Ginger for Nausea and Vomiting in Early Pregnancy
Effects of Ginger for Nausea and Vomiting in Early Pregnancy
NVEP is a commonly encountered condition in family medicine, and ginger has been used as a nonpharmacological remedy. Our meta-analysis aimed to critically examine and synthesize available data from good-quality randomized clinical trials to evaluate the efficacy of ginger in treating NVEP.
Our primary interest was the treatment of NVEP using ginger as the therapeutic intervention. To minimize heterogeneity, we limited our scope to randomized, placebo-controlled trials with a satisfactory score on the Cochrane Risk of Bias assessment tool.
A literature search of published medical reports was performed in all languages using PubMed, EMBASE, CINAHL, the Cochrane Library, and all evidence-based medicine reviews using the OVID Portal of Queen's University, Kingston, Ontario. Abstracts were initially obtained using MeSH keywords ofearly pregnancy, nausea, vomiting, and ginger. Manual searches of references and review articles supplemented the computerized search.
Two reviewers (MT and RC) went through the initial abstracts. A simple form was adopted to select trials that satisfied the eligibility criteria stated above. Selected studies were evaluated according to the Cochrane Risk of Bias tool with regard to quality of the study, randomization protocol, adequacy of concealment and blinding, and rigor of follow-up for drop-outs. Information regarding the demography of the study population, duration of the study, the number of affected subjects who improved with treatment and placebo, and finally a numeric score for the Cochrane risk of bias was extracted and tabulated in spreadsheets. Of note, we found only 6 randomized, placebo-controlled trials of ginger that displayed data required for our meta-analysis (see Table 1 ). The primary outcome was improvement of pregnancy-related nausea and vomiting.
All data from the 6 appropriate studies of ginger were synthesized in a meta-analysis, and odds ratios (ORs) were calculated with appropriate confidence intervals (CIs) based on the number of subjects reporting improvement in both the intervention and control groups. Where necessary, the value of 1 was added to any arm with zero outcome events according to the Sheele + 1 rule. To assess heterogeneity, we used the Cochrane Q-statistic with 95% confidence CIs. We assumed a P value of <.05 for the Cochran Q-statistic. Forest plots were generated with ORs for each ginger study. Statistical advice was provided by our data analyst at our Centre of Studies in Primary Care.
Methods
Study Aim
NVEP is a commonly encountered condition in family medicine, and ginger has been used as a nonpharmacological remedy. Our meta-analysis aimed to critically examine and synthesize available data from good-quality randomized clinical trials to evaluate the efficacy of ginger in treating NVEP.
Eligibility Criteria
Our primary interest was the treatment of NVEP using ginger as the therapeutic intervention. To minimize heterogeneity, we limited our scope to randomized, placebo-controlled trials with a satisfactory score on the Cochrane Risk of Bias assessment tool.
Search Strategy
A literature search of published medical reports was performed in all languages using PubMed, EMBASE, CINAHL, the Cochrane Library, and all evidence-based medicine reviews using the OVID Portal of Queen's University, Kingston, Ontario. Abstracts were initially obtained using MeSH keywords ofearly pregnancy, nausea, vomiting, and ginger. Manual searches of references and review articles supplemented the computerized search.
Study Selection, Data Extraction, and Quality Assessment
Two reviewers (MT and RC) went through the initial abstracts. A simple form was adopted to select trials that satisfied the eligibility criteria stated above. Selected studies were evaluated according to the Cochrane Risk of Bias tool with regard to quality of the study, randomization protocol, adequacy of concealment and blinding, and rigor of follow-up for drop-outs. Information regarding the demography of the study population, duration of the study, the number of affected subjects who improved with treatment and placebo, and finally a numeric score for the Cochrane risk of bias was extracted and tabulated in spreadsheets. Of note, we found only 6 randomized, placebo-controlled trials of ginger that displayed data required for our meta-analysis (see Table 1 ). The primary outcome was improvement of pregnancy-related nausea and vomiting.
Statistical Analysis
All data from the 6 appropriate studies of ginger were synthesized in a meta-analysis, and odds ratios (ORs) were calculated with appropriate confidence intervals (CIs) based on the number of subjects reporting improvement in both the intervention and control groups. Where necessary, the value of 1 was added to any arm with zero outcome events according to the Sheele + 1 rule. To assess heterogeneity, we used the Cochrane Q-statistic with 95% confidence CIs. We assumed a P value of <.05 for the Cochran Q-statistic. Forest plots were generated with ORs for each ginger study. Statistical advice was provided by our data analyst at our Centre of Studies in Primary Care.
