Q tests were also performed for differences in OR between studies using the World Health Organization’s International Statistical Classification of Diseases and Related Health Problems (ICD) (World Health Organization) or the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM) (American Psychiatric Association) system and others; between the English-language publications and Chinese-language publications; between studies originating in mainland China and others (identified by institutions and addresses of the authors); and between studies originating in the United States and others.
