“…Common confounding variables in medicine are the attributes of subjects, and most studies related to diseases consider confounders based on sociodemographic and socioeconomic characteristics. Age, BMI, exercise, and occupation have been used in previous studies [ 2 , 11 , 13 , 23 , 24 , 27 , 38 ] and were selected as adjustment variables because these factors may influence results related to HGS or arthritis. Additionally, we adjusted for the potential confounders of education level, alcohol consumption, smoking status, and household income associated with HGS or arthritis based on previous studies [ 2 , 13 , 38 ].…”