preferred_name: Back pain measured by the visual analog scale (vas) or numeric pain scale at one year (9 to 15 months) postoperatively was greater than 3.0 and back pain measured by the visual analog scale (vas) or numeric pain scale within three months preoperatively and at one year (9 to 15 months) postoperatively demonstrated improvement of less than 5.0 points
preferred_name_lc: back pain measured by the visual analog scale (vas) or numeric pain scale at one year (9 to 15 months) postoperatively was greater than 3.0 and back pain measured by the visual analog scale (vas) or numeric pain scale within three months preoperatively and at one year (9 to 15 months) postoperatively demonstrated improvement of less than 5.0 points
label: Bk pain vas 9-15mo > 3
label_lc: bk pain vas 9-15mo > 3