passages.id: split_6_test_1910_passage
passages.type: progene_text
passages.text: Of 894 patients aged between 18 and 70 years , 636 ( 71 % ) [ females 80 % , mean ( SD ) age 53.6 ( 12.2 ) years and mean ( SD ) disease duration 12.2 ( 9.3 ) years ] had a clinical and radiographic examination .