GSTM1 and obstructive sleep apnea syndrome: They found that Hb levels of ≥16g/dLfor men, and ≥15 g/dL for women, whenadded to a STOP-BANG questionnairescore of ≥3 points, improved the specificityfrom 35% to 94% for all sleep apnoea, andfrom 24% to 80% for severe OSA.