Background
Methods
The Swedish National Quality Registry SweSpine®
Study participants
Drop-out analyses
Outcome variables
Statistical analysis
Results
General outcomes in patients who underwent LDH surgery
Normal weight BMI 18.5–24.9 | Overweight BMI 25.0–29.9 | Obese class I BMI 30.0–34.9 | Obese class II BMI 35.0–39.9 | Obese class III BMI ≥ 40.0 | |
---|---|---|---|---|---|
n = 4156 | n = 4063 | n = 1384 | n = 317 | n = 59 | |
Age (years) | 42 ± 11 | 44 ± 10 | 45 ± 10 | 43 ± 10 | 41 ± 11 |
Men/Women | 45%/55% | 64%/36% | 56%/44% | 44%/56% | 42%/58% |
Smokers | 16% | 14% | 16% | 19% | 19% |
Numeric Rating Scale leg pain | 6.7 ± 2.4 | 6.7 ± 2.5 | 6.7 ± 2.4 | 7.0 ± 2.5 | 6.8 ± 2.2 |
Numeric Rating Scale back pain | 4.5 ± 2.9 | 4.7 ± 2.9 | 5.0 ± 2.9 | 5.6 ± 3.0 | 5.4 ± 2.7 |
Oswestry Disability Index | 47 ± 19 | 47 ± 18 | 50 ± 17 | 53 ± 19 | 51 ± 17 |
Acute Surgery | 10% | 10% | 10% | 13% | 9% |
Level of operation | |||||
- L3-L4 | 3% | 5% | 6% | 7% | 2% |
- L4-L5 | 38% | 45% | 47% | 49% | 55% |
- L5-S1 | 57% | 49% | 44% | 42% | 41% |
- Other | 1% | 1% | 3% | 2% | 2% |
Type of surgery | |||||
- Microdiscectomy (open) | 47% | 44% | 40% | 38% | 36% |
- Microdiscectomy (microscope) | 43% | 44% | 45% | 45% | 44% |
- Decompression (open) | 3% | 4% | 5% | 7% | 12% |
- Decompression (microscope) | 2% | 2% | 2% | 4% | 0% |
- Other & not specified | 5% | 6% | 6% | 6% | 8% |
Outcomes in normal weight, overweight and obese patients
Normal weight BMI 18.5–24.9 | Overweight BMI 25.0–29.9 | Obese BMI ≥ 30.0 | Group comparison improvement | |||||||
---|---|---|---|---|---|---|---|---|---|---|
n1 = 4032 | n1 = 3896 | n1 = 1690 | ||||||||
n2 = 4029 | n2 = 3894 | n2 = 1692 | ||||||||
n3 = 4032 | n3 = 3900 | n3 = 1694 | ||||||||
Pre-operative | Post-operative | Improvement* | Pre-operative | Post-operative | Improvement* | Pre-operative | Post-operative | Improvement* | P-value | |
NRS leg pain (n = 9618)1 | 6.7 ± 2.4 | 1.9 ± 2.5 | 4.8 (4.7, 4.9) | 6.7 ± 2.5 | 2.1 ± 2.7 | 4.5 (4.5, 4.6) | 6.8 ± 2.4 | 2.5 ± 2.9 | 4.3 (4.2, 4.4) | < 0.001 |
NRS back pain (n = 9615)2 | 4.5 ± 2.9 | 2.3 ± 2.6 | 2.3 (2.3, 2.4) | 4.7 ± 2.9 | 2.5 ± 2.6 | 2.1 (2.0, 2.2) | 5.1 ± 2.9 | 2.9 ± 2.8 | 1.9 (1.8, 2.1) | < 0.001 |
ODI (n = 9617)3 | 47 ± 19 | 18 ± 17 | 30 (30, 31) | 47 ± 18 | 19 ± 17 | 29 (28, 29) | 51 ± 18 | 23 ± 19 | 26 (25, 27) | < 0.001 |
Normal weight BMI (18.5–24.9) | Overweight BMI (25.0–29.9) | Obese BMI (≥ 30.0) | Group comparison proportions improved ≥ MCID | |||
---|---|---|---|---|---|---|
n1 = 3548 | n1 = 3409 | n1 = 1503 | ||||
n2 = 2721 | n2 = 2760 | n2 = 1292 | ||||
n3 = 3826 | n3 = 3731 | n3 = 1645 | ||||
Proportions improved ≥ MCID | Proportions improved ≥ MCID | OR for gaining improvement ≥ MCID compared to the reference cohort | Proportions improved ≥ MCID | OR for gaining improvement ≥ MCID compared to the reference cohort | P-value | |
NRS leg pain (n = 8460)1 | 77% | 73% | 0.8 (0.7, 0.90) | 69% | 0.7 (0.6, 0.8) | < 0.001 |
NRS back pain (n = 6773)2 | 62% | 61% | 0.9 (0.8, 1.04) | 59% | 0.8 (0.9, 1.01) | 0.27 |
ODI (n = 9202)3 | 71% | 69% | 0.9 (0.8, 0.97) | 66% | 0.8 (0.7, 0.91) | < 0.01 |
Normal weight BMI 18.5–24.9 | Overweight BMI 25.0–29.9 | Obese BMI (≥ 30.0) | P-value | |
---|---|---|---|---|
n1 = 4146 | n1 = 4052 | n1 = 1745 | ||
n2 = 4145 | n2 = 4050 | n2 = 1745 | ||
n3 = 4156 | n3 = 4063 | n3 = 1760 | ||
Complications registered by surgeon | ||||
- Dural tear (n = 9945)1 | 1.9% | 2.6% | 3.1% | 0.02 |
- Injury of nerve root (n = 9940)2 | 0.2% | 0.1% | 0.3% | 0.15 |
- Other & not specified (n = 9979)3 | 0.9% | 1.2% | 0.7% | 0.20 |
- All complications (n = 9979)3 | 3.0% | 3.9% | 3.9% | 0.047 |
Odds Ratio | OR compared to the reference cohort | OR compared to the reference cohort | ||
- All complication (n = 9979)3 | ––– | 1.3 (1.04, 1.7) | 1.3 (0.99, 1.8) | –- |
- Dural tear (n = 9945)1 | ––– | 1.4 (1.02, 1.8) | 1.6 (1.1, 2.3) | –- |
Outcomes in relation to obesity class
Obese class I BMI 30.0–34.9 | Obese class II BMI 35.0–39.9 | Obese class III BMI ≥ 40.0 | Group comparison improvement | |||||||
---|---|---|---|---|---|---|---|---|---|---|
n1 = 1329 | n1 = 304 | n1 = 57 | ||||||||
n2 = 1328 | n2 = 307 | n2 = 57 | ||||||||
n3 = 1332 | n3 = 305 | n3 = 57 | ||||||||
Pre-operative | Post-operative | Improvement* | Pre-operative | Post-operative | Improvement* | Pre-operative | Post-operative | Improvement* | p-value | |
NRS leg pain (n = 1690)1 | 6.7 ± 2.4 | 2.3 ± 2.8 | 4.4 (4.3, 4.6) | 7.0 ± 2.5 | 3.1 ± 3.2 | 3.8 (3.5, 4.1) | 6.8 ± 2.2 | 2.1 ± 2.7 | 4.6 (3.9, 5.3) | < 0.001 |
NRS back pain (n = 1692)2 | 5.0 ± 2.9 | 2.8 ± 2.8 | 2.3 (2.1, 2.4) | 5.6 ± 3.0 | 3.2 ± 2.9 | 2.2 (1.9, 2.5) | 5.4 ± 2.7 | 2.8 ± 2.8 | 2.6 (1.9, 3.3) | 0.50 |
ODI (n = 1694)3 | 50 ± 17 | 22 ± 19 | 29 (28, 29) | 53 ± 19 | 27 ± 20 | 25 (22, 27) | 51 ± 17 | 25 ± 21 | 27 (22, 32) | < 0.01 |
Obese class I BMI 30.0–34.9 | Obese class II BMI 35.0–39.9 | Obese class III BMI ≥ 40.0 | Group comparison proportions improved ≥ MCID | |||
---|---|---|---|---|---|---|
n1 = 1177 | n1 = 273 | n1 = 53 | ||||
n2 = 999 | n2 = 245 | n2 = 48 | ||||
n3 = 1297 | n3 = 292 | n3 = 56 | ||||
Proportions improved ≥ MCID | Proportions improved ≥ MCID | OR for gaining improvement ≥ MCID compared to reference cohort | Proportions improved ≥ MCID | OR for gaining improvement ≥ MCID compared to reference cohort | P-value | |
NRS leg pain (n = 1503)1 | 70% | 60% | 0.6 (0.5, 0.8) | 74% | 1.1 (0.6, 2.1) | < 0.01 |
NRS back pain (n = 1292)2 | 58% | 63% | 1.3 (0.9, 1.7) | 60% | 1.1 (0.6, 2.0) | 0.43 |
ODI (n = 1645)3 | 67% | 62% | 0.8 (0.6, 1.03) | 70% | 1.1 (0.6, 1.9) | 0.15 |
Obese class I BMI 30.0–34.9 | Obese class II BMI 35.0–39.9 | Obese class III BMI ≥ 40.0 | P-value | |
---|---|---|---|---|
n1 = 1373 | n1 = 317 | n1 = 57 | ||
n2 = 1372 | n2 = 316 | n2 = 57 | ||
n3 = 1384 | n3 = 317 | n3 = 59 | ||
Complications registered by surgeon | ||||
- Dural tear (n = 1747)1 | 3.0% | 3.5% | 3.5% | 0.72 |
- Injury of nerve root (n = 1745)2 | 0.4% | 0.3% | - | 1.00 |
- Other & not specified (n = 1760)3 | 0.7% | 1.3% | - | 0.54 |
- All complications (n = 1760)3 | 3.8% | 4.4% | 3.5% | 0.90 |
Odds Ratio | OR compared to the reference cohort | OR compared to the reference cohort | ||
- All complications (n = 1760)3 | ––- | 1.2 (0.6, 2.1) | 0.9 (0.2, 3.7) | – |
- Dural tear (n = 1747)1 | ––– | 1.2 (0.6, 2.3) | 1.2 (0.3, 5.0) | – |