SPS – Patient Baseline Demographic Characteristics, Comorbid Conditions, Clinical Findings, and Health Status Measures.
| Characteristics SPS |
(BMI<30) (n=373) |
(30≤BMI<35) (n=167) |
(BMI≥35) (n=94) |
p-value |
|---|---|---|---|---|
| Mean Age (SD) | 66.2 (12.2) | 62.8 (11) | 61.4 (9.4) | <0.001 |
| Female - no. (%) | 139 (37%) | 61 (37%) | 49 (52%) | 0.022 |
| Ethnicity: Not Hispanic | 356 (95%) | 159 (95%) | 90 (96%) | 0.98 |
| Race - White | 319 (86%) | 136 (81%) | 78 (83%) | 0.46 |
| Education - At least some college | 249 (67%) | 95 (57%) | 57 (61%) | 0.076 |
| Income - Under $50,000 | 58 (16%) | 46 (28%) | 18 (19%) | 0.005 |
| Marital Status - Married | 261 (70%) | 114 (68%) | 71 (76%) | 0.45 |
| Work Status - no. (%) | <0.001 | |||
| Full or part time | 109 (29%) | 54 (32%) | 35 (37%) | |
| Disabled | 24 (6%) | 18 (11%) | 18 (19%) | |
| Other | 240 (64%) | 95 (57%) | 41 (44%) | |
| Compensation - no. (%)‡ | 14 (4%) | 19 (11%) | 15 (16%) | <0.001 |
| Mean Body Mass Index (BMI), (SD)§ | 25.9 (2.9) | 32 (1.4) | 39.4 (4.1) | <0.001 |
| Smoker - no. (%) | 41 (11%) | 15 (9%) | 6 (6%) | 0.37 |
| Comorbidities - no.(%) | ||||
| Hypertension | 151 (40%) | 76 (46%) | 61 (65%) | <0.001 |
| Diabetes | 32 (9%) | 30 (18%) | 34 (36%) | <0.001 |
| Depression | 29 (8%) | 26 (16%) | 15 (16%) | 0.007 |
| Heart Problem | 110 (29%) | 33 (20%) | 22 (23%) | 0.048 |
| Lung Problem | 28 (8%) | 13 (8%) | 7 (7%) | 0.99 |
| Stomach Problem | 76 (20%) | 39 (23%) | 24 (26%) | 0.49 |
| Bowel or Intestinal Problem | 39 (10%) | 35 (21%) | 12 (13%) | 0.004 |
| Liver Problem | 6 (2%) | 2 (1%) | 2 (2%) | 0.84 |
| Kidney Problem | 16 (4%) | 8 (5%) | 5 (5%) | 0.90 |
| Blood Vessel Problem | 19 (5%) | 12 (7%) | 7 (7%) | 0.52 |
| Nervous System Problem | 5 (1%) | 5 (3%) | 3 (3%) | 0.32 |
| Joint Problem | 197 (53%) | 88 (53%) | 61 (65%) | 0.093 |
| Other¶ | 289 (77%) | 128 (77%) | 81 (86%) | 0.15 |
| SF-36 scores, mean (SD)†† | ||||
| Bodily Pain (BP) | 34.5 (20.2) | 33.5 (19.2) | 29.4 (18.1) | 0.079 |
| Physical Functioning (PF) | 36.7 (23.9) | 34.3 (22.6) | 28.2 (21) | 0.006 |
| Vitality (VT) | 45.3 (22.1) | 40 (21.3) | 35.8 (19.2) | <0.001 |
| Physical Component Summary (PCS) | 30.4 (8.8) | 29.4 (8.3) | 27.5 (8.2) | 0.012 |
| Mental Component Summary (MCS) | 49.8 (12.2) | 49 (11.5) | 48 (11.3) | 0.37 |
| Oswestry Disability Index (ODI) (SD)‡‡ | 41.3 (19.2) | 42.8 (18.3) | 46.1 (15.6) | 0.073 |
| Stenosis Frequency Index (0–24) (SD)§§ | 13.9 (5.6) | 13.5 (5.8) | 14.4 (6.5) | 0.43 |
| Stenosis Bothersome Index (0–24) (SD)§§ | 14.4 (5.4) | 14 (6) | 14.8 (6.4) | 0.60 |
| Back Pain Bothersomeness (0–6) (SD)¶¶ | 4 (1.8) | 4.2 (1.8) | 4.1 (2) | 0.55 |
| Satisfaction with symptoms - very dissatisfied | 259 (69%) | 111 (66%) | 63 (67%) | 0.76 |
| Patient self-assessed health trend - no. (%) | 0.84 | |||
| Getting better | 26 (7%) | 14 (8%) | 6 (6%) | |
| Staying about the same | 123 (33%) | 54 (32%) | 26 (28%) | |
| Getting worse | 219 (59%) | 99 (59%) | 60 (64%) | |
| Treatment preference at baseline - no. (%) | 0.87 | |||
| Preference for non-surg | 140 (38%) | 59 (35%) | 30 (32%) | |
| Not sure | 70 (19%) | 33 (20%) | 18 (19%) | |
| Preference for surgery | 162 (43%) | 75 (45%) | 46 (49%) | |
| Pseudoclaudication - Any | 303 (81%) | 133 (80%) | 72 (77%) | 0.59 |
| SLR or Femoral Tension | 71 (19%) | 38 (23%) | 23 (24%) | 0.39 |
| Pain radiation - any | 299 (80%) | 123 (74%) | 77 (82%) | 0.17 |
| Any Neurological Deficit - no. (%) | 204 (55%) | 89 (53%) | 56 (60%) | 0.60 |
| Reflexes - Asymmetric Depressed | 101 (27%) | 39 (23%) | 28 (30%) | 0.49 |
| Sensory - Asymmetric Decrease | 95 (25%) | 46 (28%) | 41 (44%) | 0.002 |
| Motor - Asymmetric Weakness | 113 (30%) | 43 (26%) | 21 (22%) | 0.24 |
| Stenosis Levels - no. (%) | ||||
| L2–L3 | 101 (27%) | 49 (29%) | 29 (31%) | 0.72 |
| L3–L4 | 250 (67%) | 108 (65%) | 62 (66%) | 0.87 |
| L4–L5 | 340 (91%) | 151 (90%) | 88 (94%) | 0.67 |
| L5-S1 | 101 (27%) | 45 (27%) | 27 (29%) | 0.94 |
| Number of Moderate/Severe Stenotic Levels | 0.19 | |||
| None | 8 (2%) | 6 (4%) | 1 (1%) | |
| One | 141 (38%) | 65 (39%) | 28 (30%) | |
| Two | 148 (40%) | 52 (31%) | 41 (44%) | |
| Three+ | 76 (20%) | 44 (26%) | 24 (26%) | |
| Stenosis Locations - no. (%) | ||||
| Central | 316 (85%) | 139 (83%) | 88 (94%) | 0.052 |
| Lateral Recess | 293 (79%) | 136 (81%) | 74 (79%) | 0.74 |
| Neuroforamen | 120 (32%) | 54 (32%) | 33 (35%) | 0.86 |
| Stenosis Severity - no. (%) | 0.12 | |||
| Mild | 8 (2%) | 6 (4%) | 1 (1%) | |
| Moderate | 161 (43%) | 85 (51%) | 36 (38%) | |
| Severe | 204 (55%) | 76 (46%) | 57 (61%) | |
| Received surgery - no. (%)* | 250 (67%) | 104 (62%) | 59 (63%) | 0.49 |
Race or ethnic group was self-assessed. 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 compensation, or other compensation.
The body-mass index is the weight in kilograms divided by the square of the height in meters.
Other indicates problems related to stroke, cancer, lung, fibromyalgia, chronic fatigue syndrome, post traumatic stress disorder, alcohol, drug dependency, liver, kidney, blood vessel, nervous system, migraine,
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 Frequency/Bothersomeness index range from 0 to 24, with lower scores indicating less severe symptoms.
The Low Back Pain Bothersomness Scale ranges from 0 to 6, with lower scores indicating less severe symptoms
Patients received surgery were classified according to whether they received surgical treatment during the first 4 years of enrollment.