“…Most studies reported that the majority of patients were male, with males being a minority in only three studies 48,49,61 For studies that included a control group, 13,14,47,48,51,[53][54][55]59,68,70 the proportion of males was well balanced in both arms in only two. 13,68 The majority of studies had a greater proportion of males in the control group 48,51,[53][54][55]59,70 than the allopurinol group. 14,47 Thirteen studies [50][51][52][53][54][55][56]58,61,63,[68][69][70] explicitly reported the ethnicity of their subjects, although the ethnicity is implied (to be European) in another.…”