“…Four studies were reported from India [1,18,19,20], three from the Middle East [21,22,23], two from Europe [24,25], and one from Brazil [8]. In six studies [1,18,21,22,23,24], the detection method of salivary cortisol level was enzyme-linked immunosorbent assay (ELISA), whereas the remaining methods were radioimmunoassay in one study [8] and the chemiluminescence immunoassay in three studies [19,20,25]. Eight studies [1,8,18,19,21,22,23,24] had case-control design and two studies [20,25] had comparative cross-sectional design.…”