Table 3.
Patient baseline demographic characteristics, comorbidities, and health status measures according to patient follow-up status as of 09/03/2013 when the SPS 8yr data were pulled
| SPS | Patients currently in study (n=306) | Patients lost to follow-up (n=328) | p-value |
|---|---|---|---|
| Mean Age (SD) | 61.1 (10.4) | 67.9 (11.8) | <0.001 |
| Female - no. (%) | 113 (37%) | 136 (41%) | 0.28 |
| Ethnicity: Not Hispanic - no. (%)† | 294 (96%) | 311 (95%) | 0.57 |
| Race - White - no. (%) | 262 (86%) | 271 (83%) | 0.36 |
| Education - At least some college - no. (%) | 217 (71%) | 184 (56%) | <0.001 |
| Marital Status - Married - no. (%) | 235 (77%) | 211 (64%) | <0.001 |
| Work Status - no. (%) | <0.001 | ||
| Full or part time | 142 (46%) | 74 (23%) | |
| Disabled | 28 (9%) | 32 (10%) | |
| Retired | 113 (37%) | 183 (56%) | |
| Other | 23 (8%) | 39 (12%) | |
| Compensation - Any - no. (%)‡ | 25 (8%) | 23 (7%) | 0.69 |
| Mean Body Mass Index (BMI), (SD)§ | 29.7 (5.7) | 29.3 (5.5) | 0.33 |
| Smoker - no. (%) | 23 (8%) | 39 (12%) | 0.086 |
| Comorbidities - no. (%) | |||
| Hypertension | 137 (45%) | 151 (46%) | 0.81 |
| Diabetes | 38 (12%) | 58 (18%) | 0.082 |
| Osteoporosis | 19 (6%) | 41 (12%) | 0.01 |
| Heart Problem | 60 (20%) | 105 (32%) | <0.001 |
| Stomach Problem | 63 (21%) | 76 (23%) | 0.49 |
| Bowel or Intestinal Problem | 34 (11%) | 52 (16%) | 0.10 |
| Depression | 43 (14%) | 27 (8%) | 0.027 |
| Joint Problem | 156 (51%) | 190 (58%) | 0.094 |
| Other¶ | 91 (30%) | 129 (39%) | 0.014 |
| Time since most recent episode > 6 months | 162 (53%) | 206 (63%) | 0.015 |
| Bodily Pain (BP) Score (SD)|| | 35.3 (19.8) | 31.8 (19.5) | 0.025 |
| Physical Functioning (PF) Score (SD) | 38.6 (23.4) | 31.3 (22.6) | <0.001 |
| Mental Component Summary (MCS) Score (SD) | 49.5 (11.9) | 49.2 (11.9) | 0.78 |
| Oswestry (ODI) (SD)** | 40.4 (17.5) | 44.2 (19.3) | 0.01 |
| Stenosis Frequency Index (0–24) (SD)†† | 13.9 (5.6) | 13.9 (5.9) | 0.95 |
| Stenosis Bothersome Index (0–24) (SD)‡‡ | 14.5 (5.4) | 14.2 (6) | 0.63 |
| Back Pain Bothersomeness (SD)§§ | 4.1 (1.8) | 4.1 (1.8) | 0.90 |
| Leg Pain Bothersomeness (SD)¶¶ | 4.4 (1.6) | 4.2 (1.8) | 0.23 |
| Satisfaction with symptoms - very dissatisfied | 204 (67%) | 229 (70%) | 0.44 |
| Problem getting better or worse | 0.95 | ||
| Getting better | 22 (7%) | 24 (7%) | |
| Staying about the same | 100 (33%) | 103 (31%) | |
| Getting worse | 181 (59%) | 197 (60%) | |
| Treatment preference | 0.21 | ||
| Definitely prefer non-surg | 64 (21%) | 59 (18%) | |
| Probably prefer non-surg | 45 (15%) | 61 (19%) | |
| Not sure | 67 (22%) | 54 (16%) | |
| Probably prefer surgery | 43 (14%) | 44 (13%) | |
| Definitely prefer surgery | 87 (28%) | 109 (33%) | |
| Pseudoclaudication - Any - no. (%) | 244 (80%) | 264 (80%) | 0.89 |
| SLR or Femoral Tension | 68 (22%) | 64 (20%) | 0.46 |
| Pain radiation - any | 245 (80%) | 254 (77%) | 0.48 |
| Any Neurological Deficit | 167 (55%) | 182 (55%) | 0.88 |
| Reflexes - Asymmetric Depressed | 69 (23%) | 99 (30%) | 0.037 |
| Sensory - Asymmetric Decrease | 101 (33%) | 81 (25%) | 0.026 |
| Motor - Asymmetric Weakness | 90 (29%) | 87 (27%) | 0.47 |
| Stenosis Levels | |||
| L2-L3 | 71 (23%) | 108 (33%) | 0.009 |
| L3-L4 | 183 (60%) | 237 (72%) | 0.001 |
| L4-L5 | 282 (92%) | 297 (91%) | 0.56 |
| L5-S1 | 86 (28%) | 87 (27%) | 0.72 |
| Stenotic Levels (Mod/Severe) | 0.10 | ||
| None | 5 (2%) | 10 (3%) | |
| One | 127 (42%) | 107 (33%) | |
| Two | 109 (36%) | 132 (40%) | |
| Three+ | 65 (21%) | 79 (24%) | |
| Stenosis Locations | |||
| Central | 251 (82%) | 292 (89%) | 0.016 |
| Lateral Recess | 243 (79%) | 260 (79%) | 0.96 |
| Neuroforamen | 110 (36%) | 97 (30%) | 0.10 |
| Stenosis Severity | 0.003 | ||
| Mild | 5 (2%) | 10 (3%) | |
| Moderate | 157 (51%) | 125 (38%) | |
| Severe | 144 (47%) | 193 (59%) |
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 = problems related to stroke, cancer, fibromyalgia, chronic fatigue syndrome, Post-traumatic Stress Disorder, alcohol, drug dependency, lung, liver, kidney, blood vessel, nervous system, migraine or anxiety.
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 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.