Table 1.
Demographic Characteristics, Coexisting Illnesses, and Measures of Health Status of the Patients.*
| Variable | SPORT Study Cohort | Combined Randomized and Observational Cohorts | ||||
|---|---|---|---|---|---|---|
| Randomized Group (N=278) | Observational Group (N=356) | P Value | Surgical Group (N=394) | Nonsurgical Group (N=240) | P Value | |
| Age — yr | 65.5±10.5 | 63.9±12.5 | 0.10 | 63.6±12.2 | 66.3±10.5 | 0.004 |
| Female sex — no. (%) | 106 (38) | 143 (40) | 0.66 | 152 (39) | 97 (40) | 0.71 |
| Race or ethnic background — no. (%)† | ||||||
| Non-Hispanic | 259 (93) | 346 (97) | 0.03 | 378 (96) | 227 (95) | 0.55 |
| White | 238 (86) | 295 (83) | 0.41 | 332 (84) | 201 (84) | 0.95 |
| Attended college — no. (%) | 176 (63) | 225 (63) | 0.96 | 245 (62) | 156 (65) | 0.53 |
| Married — no. (%) | 197 (71) | 249 (70) | 0.87 | 288 (73) | 158 (66) | 0.06 |
| Employment status — no. (%) | 0.12 | 0.05 | ||||
| Full-time or part-time | 88 (32) | 128 (36) | 144 (37) | 72 (30) | ||
| Disabled | 24 (9) | 36 (10) | 40 (10) | 20 (8) | ||
| Retired | 144 (52) | 152 (43) | 167 (42) | 129 (54) | ||
| Other | 22 (8) | 40 (11) | 43 (11) | 19 (8) | ||
| Disability compensation — no. (%)‡ | 21 (8) | 27 (8) | 0.89 | 30 (8) | 18 (8) | 0.92 |
| Body-mass index§ | 29.8±5.6 | 29.3±5.6 | 0.31 | 29.3±5.3 | 29.9±6.1 | 0.25 |
| Current smoker — no. (%) | 34 (12) | 28 (8) | 0.09 | 36 (9) | 26 (11) | 0.58 |
| Coexisting condition — no. (%) | ||||||
| Hypertension | 134 (48) | 154 (43) | 0.25 | 168 (43) | 120 (50) | 0.09 |
| Diabetes | 50 (18) | 46 (13) | 0.10 | 53 (13) | 43 (18) | 0.16 |
| Osteoporosis | 22 (8) | 38 (11) | 0.30 | 30 (8) | 30 (12) | 0.06 |
| Heart disorder | 80 (29) | 85 (24) | 0.19 | 95 (24) | 70 (29) | 0.19 |
| Stomach disorder | 60 (22) | 79 (22) | 0.93 | 82 (21) | 57 (24) | 0.44 |
| Bowel or intestinal disorder | 36 (13) | 50 (14) | 0.78 | 49 (12) | 37 (15) | 0.35 |
| Depression | 36 (13) | 34 (10) | 0.22 | 41 (10) | 29 (12) | 0.60 |
| Joint disorder | 158 (57) | 188 (53) | 0.35 | 210 (53) | 136 (57) | 0.46 |
| Other disorder¶ | 95 (34) | 125 (35) | 0.87 | 136 (35) | 84 (35) | 0.97 |
| Symptom duration >6 mo — no. (%) | 158 (57) | 210 (59) | 0.64 | 236 (60) | 132 (55) | 0.26 |
| SF-36 score∥ | ||||||
| Bodily pain | 31.9±17.5 | 31.4±17.4 | 0.73 | 28.6±16.2 | 36.6±18.4 | <0.001 |
| Physical function | 35.4±22.6 | 34.3±23.8 | 0.55 | 31.7±21.9 | 39.9±24.5 | <0.001 |
| Mental component summary | 49.8±12.4 | 49.1±11.6 | 0.47 | 48.5±12.0 | 50.9±11.7 | 0.02 |
| Oswestry Disability Index** | 42.7±17.9 | 42.1±19.0 | 0.70 | 46.0±17.9 | 36.4±17.9 | <0.001 |
| Stenosis Frequency Index†† | 13.5±5.7 | 14.2±5.8 | 0.13 | 15.2±5.6 | 11.8±5.6 | <0.001 |
| Stenosis Bothersomeness Index‡‡ | 13.9±5.7 | 14.7±5.8 | 0.08 | 15.6±5.4 | 12.3±5.7 | <0.001 |
| Low Back Pain Bothersomeness Scale§§ | 4.0±1.9 | 4.2±1.8 | 0.19 | 4.3±1.8 | 3.8±1.8 | 0.002 |
| Leg Pain Bothersomeness Scale¶¶ | 4.3±1.7 | 4.4±1.7 | 0.44 | 4.6±1.6 | 3.9±1.8 | <0.001 |
| Patient very dissatisfied with symptoms — no. (%) | 183 (66) | 250 (70) | 0.27 | 309 (78) | 124 (52) | <0.001 |
| Patient's self-assessed health trend — no. (%) | 0.48 | <0.001 | ||||
| Problem getting better | 18 (6) | 28 (8) | 14 (4) | 32 (13) | ||
| Problem staying about the same | 95 (34) | 108 (30) | 108 (27) | 95 (40) | ||
| Problem getting worse | 160 (58) | 218 (61) | 265 (67) | 113 (47) | ||
| Treatment preference — no. (%) | <0.001 | <0.001 | ||||
| Nonsurgical | ||||||
| Definitely | 37 (13) | 86 (24) | 36 (9) | 87 (36) | ||
| Probably | 61 (22) | 45 (13) | 36 (9) | 70 (29) | ||
| Not sure | 95 (34) | 26 (7) | 61 (15) | 60 (25) | ||
| Surgical | ||||||
| Definitely | 33 (12) | 163 (46) | 188 (48) | 8 (3) | ||
| Probably | 51 (18) | 36 (10) | 73 (19) | 14 (6) | ||
| Signs and symptoms — no. (%) | ||||||
| Neurogenic claudication | 219 (79) | 289 (81) | 0.51 | 317 (80) | 191 (80) | 0.87 |
| Pain on straight-leg raising or femoral-nerve tension sign | 41 (15) | 91 (26) | 0.001 | 85 (22) | 47 (20) | 0.62 |
| Dermatomal pain radiation | 215 (77) | 284 (80) | 0.52 | 310 (79) | 189 (79) | 0.94 |
| Any neurologic deficit | 146 (53) | 203 (57) | 0.29 | 210 (53) | 139 (58) | 0.29 |
| Asymmetric depressed reflexes | 76 (27) | 92 (26) | 0.74 | 102 (26) | 66 (28) | 0.72 |
| Asymmetric decrease in sensory reflexes | 68 (24) | 114 (32) | 0.05 | 116 (29) | 66 (28) | 0.66 |
| Asymmetric motor weakness | 71 (26) | 106 (30) | 0.28 | 104 (26) | 73 (30) | 0.32 |
| Stenosis level — no. (%) | ||||||
| L2—L3 | 77 (28) | 102 (29) | 0.86 | 121 (31) | 58 (24) | 0.09 |
| L3—L4 | 183 (66) | 237 (67) | 0.91 | 266 (68) | 154 (64) | 0.44 |
| L4—L5 | 255 (92) | 324 (91) | 0.86 | 362 (92) | 217 (90) | 0.63 |
| L5—S1 | 72 (26) | 101 (28) | 0.55 | 100 (25) | 73 (30) | 0.20 |
| Moderate or severe stenotic levels — no. (%) | 0.45 | 0.19 | ||||
| 0 | 4 (1) | 11 (3) | 6 (2) | 9 (4) | ||
| 1 | 106 (38) | 128 (36) | 140 (36) | 94 (39) | ||
| 2 | 109 (39) | 132 (37) | 153 (39) | 88 (37) | ||
| ≥3 | 59 (21) | 85 (24) | 95 (24) | 49 (20) | ||
| Location of stenosis — no. (%) | ||||||
| Central | 241 (87) | 302 (85) | 0.58 | 338 (86) | 205 (85) | 0.99 |
| Lateral recess | 236 (85) | 267 (75) | 0.003 | 321 (81) | 182 (76) | 0.11 |
| Neuroforamen | 88 (32) | 119 (33) | 0.70 | 119 (30) | 88 (37) | 0.11 |
| Severity of stenosis — no. (%) | 0.24 | 0.006 | ||||
| Mild | 4 (1) | 11 (3) | 6 (2) | 9 (4) | ||
| Moderate | 131 (47) | 151 (42) | 161 (41) | 121 (50) | ||
| Severe | 143 (51) | 194 (54) | 227 (58) | 110 (46) | ||
| Spinal instability | 0 | 0 | 0 | 0 | ||
Plus–minus values are means ±SD. Patients in the combined two cohorts were classified according to whether they received surgical treatment or nonsurgical treatment during the first 2 years of enrollment. Numbers of patients include only those who completed at least one follow-up survey within 2 years after enrollment.
Race or ethnic group was self-reported. Whites and blacks could be either Hispanic or non-Hispanic.
This category includes patients who were receiving or had applications pending for workers' compensation, Social Security benefits, or other compensation.
The body-mass index is the weight in kilograms divided by the square of the height in meters.
Other disorders included problems related to stroke, cancer, lung disorders, fibromyalgia, chronic fatigue syndrome, post-traumatic stress disorder, alcohol or drug dependency, migraine, anxiety, or disorders of the liver, kidney, blood vessels, or nervous system.
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 Low Back Pain Bothersomeness Scale ranges from 0 to 6, with lower scores indicating less severe symptoms.
The Leg Pain Bothersomeness Scale ranges from 0 to 6, with lower scores indicating less severe symptoms.