Characteristics of methods used in 22 reviewed studies

Name and year Study design Herb assayed Control group Blinding Randomisation Sample size discussed Mathijssen, 20025 Before and after No No No No No Markowitz, 200016 Before and after Yes No No No No Burstein, 200014 Before and after Yes No No No No Durr, 200020 Before and after No No No No No Piscitelli, 200021 Before and after Yes No No No No Mai, 20037 Before and after Yes No No No Yes Hebert, 200423 Before and after Yes No No No No Bauer, 20036 Before and after Yes No No No Yes Hall, 20038 Before and after Yes No No No Yes Jiang, 200422 Before and after Yes No No Yes Yes Johne, 20024 Before and after Yes No No No Yes Wang, 200110 Before and after Yes No No No Yes Wang, 20029 Before and after Yes No No No No Markowitz, 200324 Before and after No No No No Yes Dresser, 200325 Before and after No No No No No Roby, 200111 Before and after Yes No No No No Wenk, 200412 Before and after No No No No No Sugimoto, 200115 Crossover No Yes (placebo) Yes Yes No Pfrunder, 200317 Crossover Yes Yes No Yes No Wang, 200418 Crossover No Yes (placebo) Yes Yes No Morimoto, 200419 Crossover Yes No No No No Johne, 199913 Parallel Yes Yes (placebo) Yes No Yes