A statical review and analysis of the effects of Coca and Tea Intake Essay

A statical review and analysis of the effects of Coca and Tea Intake on Blood Pressure - Essay Example major steps: (1) Selection of studies; (2) The statistical procedures carried out to ensure that there was no publication bias and data heterogeneity was actually; (3) The actual data comparison on the effect of coffee and tea intervention on blood pressure. Selection of studies. Prospective articles for the meta-analysis were selected from the results of searches performed on major electronic medical databases (SCOPUS, EMBASE, and MEDLINE), the Science Citation Index, and the Cochrane Controlled Trials Registry. Matches were found using the search items â€Å"chocolate,† â€Å"cocoa,† â€Å"tea,† â€Å"blood pressure,† â€Å"cardiovascular,† â€Å"endothelium† and â€Å"hypertension.† From the search, 3106 articles were screened for relevance, but only 454 were retrieved for assessment. From these, 409 studies were screened out because neither tea nor coffee was reported to have an effect on blood pressure. More studies were excluded because they were only observational, have incomplete randomization or outcome, treatment was shorter than 7 days, and used only supplements. Finally, only ten papers were included: five studied the effects of coffee and the other five studied effects of tea on blood pressure. All were randomized controlled trials on at least 10 adults. Data was extracted from the papers independently by two investigators, and then an eleven point Jadad scale was used to evaluate the trials. Jadads scale is a five questions scale, originally used to assess the quality of clinical trials. It asks about randomization, double –blinding, description of withdrawals from the study, description of the blinding and randomization (Clark, Castro and Filho). The interrater coefficients of agreement (kappa-ÃŽ º) were 0.94 for data extraction, and 0.89 for the quality of the trials. Participants were determined to be unblinded to the interventions. The changes in the systolic and diastolic blood pressures in cocoa, tea or control groups were presented as