TABLE 3. Subgroup Results from Adjusted* As-Treated Outcome Analysis by Diabetes for the Randomized and Observational Cohorts Combined Patients with Lumbar Intervertebral Disk Herniation.
| Outcome | 1-Yr | 2-Yr | 3-Yr | 4-Yr | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IDH (RCT & OBS) | Diabetes | Surgical | Nonoperative | Treatment Effect,† OR (95% CI) |
Surgical | Nonoperative | Treatment Effect,† OR (95% CI) |
Surgical | Nonoperative | Treatment Effect,† OR (95% CI) |
Surgical | Nonoperative | Treatment Effect,† OR (95% CI) |
| Primary outcomes | |||||||||||||
| SF-36 bodily pain (0–100), mean (SE) |
Not diabetic | 45.9 (0.9) | 33.1 (1.2) | 12.7 (9.9 to 15.5) | 45.2 (0.9) | 35.1 (1.2) | 10.1 (7.2 to 13) | 45.9 (1) | 35 (1.3) | 10.9 (7.8 to 13.9) | 47.2 (1) | 33.9 (1.4) | 13.3 (10.2 to 16.5) |
| Diabetic‡ | 41.4 (5.1) | 34.5 (5.9) | 6.8 (−7.7 to 21.3) | 34.3 (5.1) | 34.2 (6.2) | 0.1 (−14.6 to 14.8) | 33 (5.9) | 25.9 (6.4) | 7.1 (−9.2 to 23.4) | 46.8 (5.6) | 37.7 (6.9) | 9.1 (−7.6 to 25.7 | |
| P § | 0.39 | 0.82 | 0.43 | 0.035 | 0.89 | 0.19 | 0.031 | 0.16 | 0.66 | 0.95 | 0.58 | 0.62 | |
| SF-36 physical function (0–100), mean (SE) |
Not diabetic | 44 (0.8) | 28.5 (1.1) | 15.5 (13 to 18.1) | 43.5 (0.8) | 30.5 (1.1) | 13 (10.4 to 15.6) | 43.5 (0.9) | 30.8 (1.2) | 12.8 (10.1 to 15.5) | 44.4 (0.9) | 30.3 (1.2) | 14.1 (11.3 to 17) |
| Diabetic | 31 (4.7) | 29.7 (5.4) | 1.2 (−11.9 to 14.4) | 26.6 (4.7) | 29.2 (5.6) | −2.7 (−16 to 10.7) | 35.2 (5.4) | 27.1 (5.9) | 8.1 (−6.6 to 22.8) | 28.3 (5.2) | 20.8 (6.2) | 7.4 (−7.6 to 22.5) | |
| P | 0.007 | 0.83 | 0.036 | <0.001 | 0.83 | 0.024 | 0.13 | 0.54 | 0.54 | 0.002 | 0.13 | 0.39 | |
| Mental component summary (0–100), mean SE) |
Not diabetic | 7.6 (0.4) | 4.4 (0.5) | 3.2 (2.1 to 4.3) | 6.4 (0.4) | 4.4 (0.5) | 1.9 (0.8 to 3.1) | 6.3 (0.4) | 4.1 (0.5) | 2.2 (1 to 3.4) | 6 (0.4) | 4.5 (0.5) | 1.5 (0.2 to 2.8) |
| Diabetic | 6.8 (2.1) | 2 (2.4) | 4.8 (−1 to 10.6) | 6.1 (2.1) | 6.4 (2.5) | −0.3 (−6.2 to 5.7) | 3.9 (2.4) | 5.1 (2.6) | −1.3 (−7.8 to 5.3) | 6.2 (2.3) | 2.2 (2.9) | 4 (−3 to 10.9) | |
| P | 0.70 | 0.32 | 0.60 | 0.89 | 0.45 | 0.47 | 0.31 | 0.70 | 0.31 | 0.94 | 0.42 | 0.49 | |
| Oswestry Disability Index (0–100), mean (SE) |
Not diabetic | −37 (0.7) | −23 (0.9) | −14 (−16.1 to −11.9) | −36.7 (0.7) | −24.8 (0.9) | −11.9 (−14 to −9.7) | −36.8 (0.7) | −25.3 (1) | −11.5 (−13.8 to −9.3) | −37.4 (0.8) | −25.1 (1) | −12.3 (−14.7 to −10) |
| Diabetic | −32.3 (4) | −29 (4.5) | −3.3 (−14 to 7.5) | −27 (3.9) | −29.1 (4.7) | 2.1 (−8.8 to 13) | −32.8 (4.5) | −22.1 (4.9) | −10.6 (−22.6 to 1.3) | −34.3 (4.3) | −29.9 (5.1) | −4.4 (−16.6 to 7.8) | |
| P | 0.25 | 0.19 | 0.054 | 0.015 | 0.37 | 0.013 | 0.37 | 0.52 | 0.89 | 0.48 | 0.36 | 0.21 | |
| Very/somewhat satisfied with symptoms (%) |
Not diabetic | 71.5 | 46.3 | 25.3 (19.2 to 31.3) | 72.4 | 52.7 | 19.7 (13.5 to 25.8) | 71.6 | 52.8 | 18.8 (12.3 to 25.4) | 73.5 | 50 | 23.4 (16.6 to 30.3) |
| Diabetic | 70.2 | 59.8 | 10.4 (−19.7 to 40.5) | 65.8 | 30.8 | 35 (5,65) | 64.1 | 50.7 | 13.4 (−22.5 to 49.3) | 85.1 | 61.6 | 23.5 (−8.5 to 55.5) | |
| P | 0.89 | 0.28 | 0.37 | 0.53 | 0.18 | 0.48 | 0.57 | 0.89 | 0.76 | 0.32 | 0.41 | 0.79 | |
| Very/somewhat satisfied with care (%) |
Not diabetic | 92.4 | 83.7 | 8.8 (4.4 to 13.1) | 90.7 | 80.1 | 10.6 (5.8 to 15.4) | 88.6 | 75.1 | 13.5 (8 to 19) | 90.5 | 77.9 | 12.6 (7 to 18.3) |
| Diabetic | 80.5 | 76 | 4.5 (−21.5 to 30.5) | 85.3 | 66 | 19.3 (−8.8 to 47.4) | 93.7 | 81.6 | 12.1 (−11.9 to 36.1) | 80.4 | 82.8 | −2.3 (−30.6 to 26) | |
| P | 0.048 | 0.33 | 0.39 | 0.39 | 0.20 | 0.80 | 0.50 | 0.58 | 0.82 | 0.22 | 0.71 | 0.29 | |
| Self-rated progress, major improvement (%) |
Not diabetic | 80.2 | 56.3 | 23.9 (18.1 to 29.8) | 75.7 | 60.8 | 14.8 (8.8 to 20.9) | 73.5 | 57 | 16.4 (9.9 to 22.9) | 76.6 | 54.5 | 22 (15.2 to 28.8) |
| Diabetic | 77.4 | 70.4 | 7 (−20.6 to 34.6) | 63.2 | 65.8 | −2.6 (−33.5 to 28.3) | 62.7 | 64.3 | −1.6 (−36.2 to 33.1) | 67.6 | 65.8 | 1.9 (−32.9 to 36.6) | |
| P | 0.76 | 0.26 | 0.30 | 0.21 | 0.72 | 0.29 | 0.36 | 0.60 | 0.31 | 0.45 | 0.44 | 0.29 | |
| Work status, working (%) | Not diabetic | 79.3 | 77.4 | 1.9 (−2.9 to 6.6) | 78.7 | 78.9 | −0.2 (−5 to 4.5) | 76.4 | 74.4 | 2.1 (−3.3 to 7.4) | 77.5 | 73.2 | 4.3 (−1.4 to 9.9) |
| Diabetic | 62.1 | 69.2 | −7.1 (−34.6 to 20.3) | 57.4 | 54.3 | 3 (−27.3 to 33.4) | 72.3 | 63.8 | 8.5 (−21.4 to 38.4) | 57.8 | 70.2 | −12.5 (−44.2 to 19.3) | |
| P | 0.044 | 0.30 | 0.38 | 0.016 | 0.015 | 0.81 | 0.64 | 0.30 | 0.64 | 0.019 | 0.72 | 0.094 | |
*
Adjusted for age, sex, body mass index, baseline score (for SF-36, ODI), and center.
†
Treatment effect is the difference between the surgical and nonoperative mean change from baseline. Analysis is done by using a mixed model with a random subject intercept term. Treatment is a time-varying covariate where a patients’ experience before surgery is attributed to the nonoperative arm, and time is measured from enrollment; his/her postsurgery outcomes are attributed to the surgical arm, and time is measured from the time of surgery.
‡
Patients who report being told by their doctors that they have diabetes and also report that they are currently receiving treatment for diabetes.
§
P values at each time-point are from multiple degree-of-freedom Wald tests.