North American (Panax quinquefolius) and Asian Ginseng (Panax ginseng) Preparations for Prevention of the Common Cold in Healthy Adults: A Systematic Review

Table 2

Methodological quality of included studies according to Jadad et al. [4] and Schultz et al. [5].

Reference	Described as randomized	Randomization well described and appropriate	Outcome assessment blinded	Blinding well described and appropriate	Description of withdrawals and drop-outs	Total Jadad score	Allocation concealment
McElhaney et al. [8], trial A	Yes	No	Yes	No	No	2/5	Unclear
McElhaney et al. [8], trial B	Yes	No	Yes	No	No	2/5	Unclear
McElhaney et al. [11]	Yes	Yes	Yes	Yes	Yes	5/5	Adequate
Predy et al. [10]	Yes	Yes	Yes	Yes	Yes	5/5	Adequate
Scaglione et al. [9]	Yes	No	Yes	No	No	2/5	Unclear