Table 3.

Change scores and their differences (“Had revision surgery” minus “No revision surgery”) of average over 8 years area under curve for long-term SF-36 scores, Oswestry Disability Index scores, Sciatica Bothersomeness Index scores, and Very/somewhat Satisfied with Symptoms, according to status of revision surgery.^*

SPS	Mean Change in Score Compared with Baseline (Standard Error) or Percent		Difference† (95% Confidence interval)	p-value
	Had revision surgery (n=77)	No revision surgery (n=345)
SF-36 Bodily Pain (BP) (SE)††	19.1 (2.2)	27.3 (1.1)	−8.1 (−13, −3.2)	0.001
SF-36 Physical Function (PF) (SE)††	13.2 (2.4)	22.4 (1.1)	−9.2 (−14.4, −4)	<0.001
Oswestry Disability Index (ODI) (SE) ‡	−11.4 (1.8)	−20.4 (0.9)	9.1 (5.2, 13)	<0.001
Stenosis Bothersomeness Index (SE)§	−5.1 (0.6)	−7.9 (0.3)	2.8 (1.5, 4.1)	<0.001
Very/somewhat satisfied with symptoms (%)	48.9	59.6	−10.6 (−19.7, −1.5)	0.022

^*Scores are adjusted for age, gender, compensation, baseline score of stenosis bothersomeness index, income, smoking status, duration of most recent episode, treatment preference, diabetes, joint problem, stomach comorbidity, baseline score (for SF-36 and ODI), and center.

^†Difference is the difference between the revision surgery and no revision surgery mean change from baseline (“Had revision surgery” minus “No revision surgery”).

^††The SF-36 scores range from 0 to 100, with higher score indicating less severe symptoms.

^‡The Oswestry Disability Index ranges from 0 to 100, with lower scores indicating less severe symptoms.

^§The Stenosis Bothersomeness index range from 0 to 24, with lower scores indicating less severe symptoms.