Characteristics included in linear regression analyses.

*Moderate or greater severity – graded according to 2009 Division of AIDS Classification.CDC, Centers for Disease Control and Prevention; HIV, human immunodeficiency virus; NRTI, nucleoside reverse transcriptase inhibitor.* 中度及以上严重程度——依据2009年艾滋病分类署（Division of AIDS）分类标准进行分级。CDC即疾病预防控制中心（Centers for Disease Control and Prevention）；HIV即人类免疫缺陷病毒（human immunodeficiency virus）；NRTI即核苷类逆转录酶抑制剂（nucleoside reverse transcriptase inhibitor）。