Table 3.
Significant Predictors of Treatment Received within 2 Years among Patients in the Randomized Cohort.*
| Predictor | Assigned to Surgical Group | Assigned to Nonsurgical Group | ||||
|---|---|---|---|---|---|---|
| Surgery (N=89) | No Surgery (N=43) | P Value | Surgery (N=64) | No Surgery (N=82) | P Value | |
| White race — no. (%) | 80 (90) | 29 (67) | 0.003 | 58 (91) | 71 (87) | 0.62 |
| Mental Component Summary score† | 49.9±12.2 | 50.4±14.0 | 0.84 | 47.0±12.6 | 51.6±11.2 | 0.02 |
| Oswestry Disability Index‡ | 44.6±18.2 | 38.9±18.8 | 0.10 | 46.7±18 | 39.4±16.2 | 0.01 |
| Stenosis Frequency Index§ | 14.8±5.3 | 11.6±6.2 | 0.002 | 14.7±5.5 | 12.1±5.5 | 0.005 |
| Stenosis Bothersomeness Index¶ | 15.0±4.9 | 12.0±6.0 | 0.002 | 15.3±5.5 | 12.6±6.1 | 0.005 |
| Leg Pain Bothersomeness Scale∥ | 4.5±1.6 | 4.0±1.9 | 0.09 | 4.6±1.5 | 3.9±1.8 | 0.01 |
| Very dissatisfied with symptoms — no. (%) | 65 (73) | 25 (58) | 0.13 | 49 (77) | 44 (54) | 0.007 |
| Problem getting better or worse — no. (%) | 0.009 | 0.31 | ||||
| Getting better | 2 (2) | 6 (14) | 2 (3) | 8 (10) | ||
| Staying about the same | 27 (30) | 18 (42) | 22 (34) | 28 (34) | ||
| Getting worse | 57 (64) | 19 (44) | 38 (59) | 46 (56) | ||
| Treatment preference — no. (%) | 0.01 | <0.001 | ||||
| Nonsurgical | ||||||
| Definitely | 9 (10) | 8 (19) | 7 (11) | 13 (16) | ||
| Probably | 15 (17) | 15 (35) | 9 (14) | 22 (27) | ||
| Not sure | 31 (35) | 13 (30) | 15 (23) | 36 (44) | ||
| Surgical | ||||||
| Definitely | 11 (12) | 0 | 17 (27) | 5 (6) | ||
| Probably | 23 (26) | 7 (16) | 16 (25) | 5 (6) | ||
Plus—minus values are means ±SD. Numbers of patients include only those who completed at least one follow-up survey within 2 years after enrollment.
Scores on the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36) 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 Frequency Index ranges from 0 to 24, 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.