Table 8.
Subgroup results from adjusted* as-treated outcome analysis by three groups duration of symptoms for the randomized and observational cohorts combined patients with lumbar degenerative spondylolisthesis.
| Outcome |
Duration of Symptoms |
1-Year |
2-Year |
3-Year |
4-Year |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| DS | Surgical | Non- operative |
Treatment Effect† (95% CI) |
Surgical | Non- operative |
Treatment Effect† (95% CI) |
Surgical | Non- operative |
Treatment Effect† (95% CI) |
Surgical | Non- operative |
Treatment Effect† (95% CI) |
|
|
Primary Outcomes |
|||||||||||||
| SF-36 Bodily Pain (BP) (0–100) (SE) |
6 months or less |
36.5 (3.3) | 17.1 (2.1) | 19.4 (11.6, 27.2) |
30.7 (3.3) | 16 (2.4) | 14.7 (6.6, 22.8) |
31.4 (3.6) | 18 (2.6) | 13.5 (4.8, 22.1) |
28.4 (3.6) | 16.8 (2.8) | 11.6 (2.6, 20.5) |
| 7 to 12 months |
34.1 (2.1) | 9 (2.7) | 25.2 (18.5, 31.8) |
33.2 (2.1) | 10.7 (2.9) | 22.5 (15.5, 29.5) |
35.5 (2.1) | 13.2 (3.2) | 22.4 (14.9, 29.9) |
34.1 (2.3) | 15.3 (3.5) | 18.8 (10.6, 27) |
|
| More than 1 year |
30.3 (1.7) | 13.3 (2.5) | 17 (11.4, 22.7) |
31.2 (1.6) | 11.2 (2.6) | 19.9 (14.1, 25.7) |
30.7 (1.6) | 13.2 (2.9) | 17.4 (11.1, 23.8) |
29.9 (1.8) | 14.9 (3) | 15 (8.3, 21.6) |
|
| pvalue | 0.16 | 0.052 | 0.18 | 0.66 | 0.26 | 0.34 | 0.16 | 0.36 | 0.29 | 0.22 | 0.88 | 0.49 | |
| SF-36 Physical Function PF) (0–100) (SE) |
6 months or less |
32 (3.3) | 13.9 (2) | 18.1 (10.5, 25.7) |
27.1 (3.3) | 10.1 (2.3) | 17 (9.1, 24.9) |
30.4 (3.4) | 11.3 (2.5) | 19 (10.7, 27.4) |
27.4 (3.5) | 6.4 (2.7) | 21 (12.3, 29.6) |
| 7 to 12 months |
28.8 (2) | 7.3 (2.6) | 21.5 (15.1, 27.8) |
25.8 (2) | 9.4 (2.8) | 16.4 (9.7, 23.1) |
23.5 (2) | 7.1 (3.1) | 16.4 (9.2, 23.6) |
27 (2.2) | 12.7 (3.4) | 14.3 (6.4, 22.2) |
|
| More than 1 year |
27 (1.7) | 8.8 (2.4) | 18.2 (12.8, 23.6) |
25.7 (1.6) | 8.4 (2.5) | 17.2 (11.7, 22.8) |
24.7 (1.6) | 7.2 (2.8) | 17.6 (11.5, 23.6) |
25.5 (1.7) | 6.8 (2.9) | 18.8 (12.5, 25.1) |
|
| pvalue | 0.38 | 0.083 | 0.70 | 0.93 | 0.89 | 0.98 | 0.22 | 0.42 | 0.89 | 0.81 | 0.29 | 0.50 | |
| Mental Component Summary (MCS) (0–100) (SE) |
6 months or less |
3.6 (1.3) | 2.3 (0.9) | 1.3 (−1.9, 4.5) |
3.5 (1.4) | 1.4 (1) | 2.1 (−1.2, 5.5) |
2.1 (1.5) | 1.8 (1.1) | 0.3 (−3.3, 3.9) |
2.4 (1.5) | 2.3 (1.2) | 0.1 (−3.7, 3.8) |
| 7 to 12 months |
3.5 (0.9) | 0.6 (1.1) | 2.8 (0.1, 5.6) |
2.5 (0.9) | 1.1 (1.2) | 1.5 (−1.5, 4.4) |
2.1 (0.9) | −2 (1.4) | 4.2 (1, 7.4) | 2.6 (1) | −1.2 (1.5) | 3.8 (0.3, 7.3) |
|
| More than 1 year |
2.5 (0.7) | 1 (1) | 1.5 (−0.9, 3.9) |
2.4 (0.7) | 0 (1.1) | 2.4 (−0.1, 4.8) |
2.9 (0.7) | −0.2 (1.2) | 3.1 (0.4, 5.7) |
2.1 (0.8) | −1.6 (1.3) | 3.7 (0.7, 6.6) |
|
| pvalue | 0.61 | 0.43 | 0.69 | 0.75 | 0.65 | 0.90 | 0.74 | 0.074 | 0.25 | 0.91 | 0.054 | 0.25 | |
| Oswestry Disability Index (ODI) (0–100) (SE) |
6 months or less |
−25.6 (2.6) | −10.1 (1.6) | −15.5 (−21.4, −9.5) |
−21.2 (2.6) | −10.9 (1.8) | −10.3 (−16.4, −4.1) |
−21.6 (2.7) | −12.9 (1.9) | −8.7 (−15.2, −2.2) |
−20.2 (2.7) | −10.7 (2) | −9.6 (−16.3, −2.9) |
| 7 to 12 months |
−27.5 (1.6) | −5.3 (2) | −22.2 (−27.1, −17.3) |
−26.1 (1.5) | −5.2 (2.2) | −20.8 (−26.1, −15.6) |
−23.9 (1.6) | −7 (2.4) | −16.9 (−22.5, −11.4) |
−25.2 (1.7) | −8.8 (2.6) | −16.4 (−22.5, −10.3) |
|
| More than 1 year |
−23.2 (1.3) | −6.5 (1.9) | −16.7 (−20.9, −12.6) |
−23.4 (1.2) | −6 (2) | −17.4 (−21.7, −13.1) |
−20.7 (1.2) | −5.5 (2.2) | −15.2 (−19.9, −10.5) |
−22 (1.3) | −5.9 (2.2) | −16.1 (−21, −11.2) |
|
| pvalue | 0.11 | 0.11 | 0.14 | 0.17 | 0.063 | 0.031 | 0.24 | 0.022 | 0.14 | 0.17 | 0.29 | 0.23 | |
|
Secondary Outcomes |
|||||||||||||
| Stenosis Bothersomeness Index (0–24) (SE) |
6 months or less |
−10.3 (0.9) | −4.1 (0.6) | −6.2 (−8.4, −4) |
−9 (0.9) | −4.5 (0.7) | −4.5 (−6.8, −2.3) |
−9.3 (1) | −5.3 (0.7) | −4 (−6.4, −1.6) |
−9.1 (1) | −4.4 (0.8) | −4.7 (−7.2, −2.2) |
| 7 to 12 months |
−9.1 (0.6) | −3.4 (0.7) | −5.7 (−7.6, −3.8) |
−9 (0.6) | −3.8 (0.8) | −5.2 (−7.2, −3.2) |
−9.5 (0.6) | −3.4 (0.9) | −6.1 (−8.2, −4) |
−9 (0.6) | −3.9 (1) | −5.2 (−7.5, −2.9) |
|
| More than 1 year |
−9.5 (0.5) | −4 (0.7) | −5.5 (−7, −4) | −9.1 (0.4) | −3.3 (0.7) | −5.8 (−7.4, −4.2) |
−8.8 (0.5) | −3.7 (0.8) | −5.1 (−6.8, −3.4) |
−9.2 (0.5) | −2.7 (0.8) | −6.4 (−8.3, −4.6) |
|
| pvalue | 0.52 | 0.71 | 0.88 | 0.99 | 0.49 | 0.65 | 0.66 | 0.18 | 0.42 | 0.99 | 0.32 | 0.49 | |
| Low Back Pain Bothersomeness (0–6) (SE) |
6 months or less |
−2.4 (0.2) | −1.1 (0.2) | −1.3 (−1.9, −0.7) |
−2.2 (0.3) | −1.5 (0.2) | −0.6 (−1.2, 0) |
−2 (0.3) | −1.6 (0.2) | −0.5 (−1.2, 0.2) |
−2.1 (0.3) | −1.2 (0.2) | −0.9 (−1.6, −0.2) |
| 7 to 12 months |
−2.3 (0.2) | −1.1 (0.2) | −1.2 (−1.7, −0.7) |
−2.1 (0.2) | −1.1 (0.2) | −1 (−1.6, −0.4) |
−2.2 (0.2) | −1.3 (0.3) | −0.9 (−1.5, −0.3) |
−2.2 (0.2) | −1.3 (0.3) | −0.9 (−1.6, −0.2) |
|
| More than 1 year |
−2.4 (0.1) | −1.1 (0.2) | −1.3 (−1.7, −0.9) |
−2.1 (0.1) | −0.9 (0.2) | −1.3 (−1.8, −0.8) |
−2 (0.1) | −1.1 (0.2) | −0.9 (−1.4, −0.4) |
−2.1 (0.1) | −1 (0.2) | −1.1 (−1.6, −0.6) |
|
| pvalue | 0.86 | 0.99 | 0.91 | 1 | 0.043 | 0.25 | 0.48 | 0.25 | 0.53 | 0.86 | 0.68 | 0.87 | |
| Leg pain (0–6) (SE) |
6 months or less |
−3.2 (0.3) | −1.8 (0.2) | −1.4 (−2.1, −0.7) |
−2.8 (0.3) | −1.9 (0.2) | −0.9 (−1.6, −0.2) |
−3 (0.3) | −2 (0.2) | −1 (−1.7, −0.3) |
−3.3 (0.3) | −1.8 (0.2) | −1.5 (−2.3, −0.7) |
| 7 to 12 months |
−3 (0.2) | −1 (0.2) | −1.9 (−2.5, −1.3) |
−2.9 (0.2) | −1.1 (0.3) | −1.8 (−2.4, −1.2) |
−3 (0.2) | −1.2 (0.3) | −1.8 (−2.5, −1.1) |
−3 (0.2) | −1.5 (0.3) | −1.5 (−2.2, −0.8) |
|
| More than 1 year |
−3.1 (0.1) | −1.4 (0.2) | −1.6 (−2.1, −1.1) |
−3 (0.1) | −1.1 (0.2) | −1.8 (−2.3, −1.3) |
−2.9 (0.1) | −1.5 (0.2) | −1.4 (−2, −0.8) |
−3 (0.2) | −1.2 (0.3) | −1.8 (−2.4, −1.2) |
|
| pvalue | 0.74 | 0.096 | 0.55 | 0.74 | 0.018 | 0.056 | 0.86 | 0.099 | 0.26 | 0.46 | 0.23 | 0.79 | |
| Very/somewhat satisfied with symptoms (%) |
6 months or less |
81.2 | 35 | 46.3 (31.3, 61.2) |
76 | 41.8 | 34.3 (17.1, 51.4) |
78.7 | 45.2 | 33.5 (15.5, 51.5) |
69.3 | 27.3 | 42 (23.1, 60.9) |
| 7 to 12 months |
74.6 | 26.4 | 48.2 (34.7, 61.8) |
72.5 | 27 | 45.4 (30.9, 60) |
66.2 | 30.6 | 35.6 (19.2, 52) |
65.8 | 32.6 | 33.2 (14.9, 51.5) |
|
| More than 1 year |
69.4 | 16.5 | 52.9 (42.1, 63.7) |
65.7 | 24.5 | 41.2 (28.7, 53.7) |
62.9 | 28.4 | 34.5 (20.4, 48.6) |
60.4 | 28.4 | 32 (16.7, 47.3) |
|
| pvalue | 0.31 | 0.038 | 0.78 | 0.31 | 0.083 | 0.72 | 0.18 | 0.12 | 1 | 0.53 | 0.88 | 0.75 | |
| Self-rated progress major improvement (%) |
6 months or less |
72.4 | 32 | 40.4 (23.6, 57.2) |
73.2 | 28.9 | 44.3 (27.1, 61.4) |
70.9 | 37.7 | 33.2 (13.9, 52.4) |
60.1 | 30.6 | 29.6 (8.9, 50.2) |
| 7 to 12 months |
80.5 | 22.7 | 57.8 (45.2, 70.3) |
71.7 | 23.5 | 48.3 (34, 62.5) |
75.2 | 15.9 | 59.3 (46.1, 72.5) |
71.8 | 23.6 | 48.2 (31.6, 64.8) |
|
| More than 1 year |
72.4 | 19.6 | 52.8 (41.5, 64.1) |
73.5 | 17.6 | 55.9 (44.7, 67.1) |
67.3 | 18.2 | 49.1 (36.6, 61.7) |
63.6 | 8.9 | 54.7 (43.4, 65.9) |
|
| pvalue | 0.32 | 0.22 | 0.25 | 0.95 | 0.36 | 0.50 | 0.41 | 0.029 | 0.10 | 0.32 | 0.12 | 0.12 | |
*
Adjusted for age, gender, BMI, race, smoking status, compensation, joint, stomach, bowel, osteoporosis, number of moderate/severe stenotic levels, self-assessed health trend at baseline, treatment preference, baseline stenosis bothersomeness, other *
**
Other comorbidities include: stroke, cancer, fibromyalgia, cfs, PTSD, alcohol, drug dependency, lung, liver, kidney, blood vessel, nervous system, migraine, anxiety
†
Treatment effect is the difference between the surgical and non-operative mean change from baseline. Analysis is done using a mixed model with a random subject intercept term. Treatment is a time-varying covariate where a patients' experience prior to surgery is attributed to the non-operative arm and time is measured from enrollment and his/her post-surgery outcomes are attributed to the surgical arm and time is measured from time of surgery.