clinical setting
1 = outpatient
2 = inpatient

1 = male
2 = female

1 = -54
2 = 55-64
3 = 65-74
4 = 75+

1 = middle school and above
2 = primary school and below

1 = married
2 = others

1 = urban
2 = rural
3 = urban-rural fringe

1 = moderate and above
2 = poor

1 = no
2 = yes

1 = cortical
2 = nuclear
3 = posterior subcapsular
4 = mixed

current treatment stage
1 = before surgery
2 = after surgery