Table 4.

Intention-to-Treat Analysis for the Randomized Cohort and Adjusted Analyses, According to Treatment Received, for the Randomized and Observational Cohorts Combined.^*

^*Plus—minus values are means ±SE. Values in the as-treated analysis have been adjusted for age, sex, the presence or absence of stomach or joint disorders, the presence or absence of pain on straight-leg raising or femoral-nerve tension signs, smoking status, patient-assessed health trend, income, other compensation, body-mass index, baseline score for the outcome variable, and center. NA denotes not available.

^†The treatment effect is the difference in the mean change from baseline between the surgical group and the nonsurgical group.

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

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

^¶The Stenosis Bothersomeness Index ranges from 0 to 24, with lower scores indicating less severe symptoms.

^∥The Leg Pain Bothersomeness Scale ranges from 0 to 6, with lower scores indicating less severe symptoms.

^**The Low Back Pain Bothersomeness Scale ranges from 0 to 6, with lower scores indicating less severe symptoms.

^††The number of patients in the as-treated analyses reflects the number of patients contributing to the estimate in a given period with the use of the longitudinal-modeling strategy (explained in the Methods section) and may not correspond to the number shown for each visit time in Figure 1.