The effect of surgery on clinical characteristics at 12 and 24 months subdivided by baseline severity.

*Total number of participants seen at 12 and 24 months. On occasion, a specific part of the examination was not possible for a particular participant; therefore the total for each examination characteristic is not always identical to these total figures.本数据集统计了12个月与24个月随访阶段的受访参与者总人数。部分参与者有时无法完成某一特定检查项目；因此，各项检查特征对应的统计总人数，并不始终与上述总人数一致。