Table A8.
Predictors for adverse events (AE), mortality, and other outcomes.
| Comorbidity | Significant predictors | Ref. | Not significant predictors | Ref. |
|---|---|---|---|---|
| Comorbidities, Comorbidity measures (CM) | Systemic disease (hypertension, diabetes or both) associated with higher postoperative wound infection rate: adjusted (adj.) odds ratio (OR) 3.99 (95% confidence interval (CI) 2.02 to 7.86) | 43 [98] | Compared to American Society of Anesthesiology (ASA, range 1-6) groups <3, ASA groups ≥3 not associated with more complicationsd during hospitalization | 10 [78] |
| Compared to 0 comorbidity, 2-3 comorbidities associated with higher in-hospital complication ratee: 2 comorbidities adj. OR 1.2 (95% CI 1.1 to 1.2), ≥3 comorbidities adj. OR 1.5 (95% CI 1.4 to 1.6) | 11 [35] | Multivariate, number of comorbidities: no association with reoperation rate 15 years after first surgery | 28.2 [36] | |
| Multivariate, compared to 0 comorbidity, 1 comorbidity not associated with higher in-hospital complication ratee | ||||
| Gagne comorbidity score£ (1-year increment): association with more 30-days complicationsc: adj. OR 1.25 (95% CI 1.02 to 1.29) | 13 [55] | |||
| Quan comorbidity score# ≥1 (ref. Quan 0) associated with more cardiopulmonary/stroke complications or mortality <30 days: Quan 1 adj. OR 1.27 (95% CI 1.09 to 1.47); Quan 2 adj. OR 1.62 (95% CI 1.33 to 1.97); Quan 3 adj. OR 1.78 (95% CI 1.34 to 2.36); Quan 4 adj. OR 2.14 (95% CI 1.46 to 3.16); Quan 4 adj. OR 3.14 (95% CI 2.17 to 4.55) | 12 [8] | |||
| Comorbidity score§ ≥1 (ref. 0) associated with any complications < 3 years after surgery: score 1: OR 1.31 (95% CI 1.06 to 1.61), 2: OR 1.48 (95% CI 1.13 to 1.94), 3: OR 1.63 (95% CI 1.22 to 2.19) | 14 [17] | |||
| ASA score 3 or 4 associated with increased length of stay: adj. beta 0.32 (95% CI 0.09 to 0.54), and with readmission <30 days after surgery: adj. beta 2.63 (95% CI 1.54 to 4.49) | 17 [80] | |||
| Compared to 0 comorbidity, adverse outcome (death) is associated with the presence of ≥2 comorbidities within hospitalization: 2 comorbidities adj. OR 2.3 (95% CI 1.5 to 3.6) and ≥3 comorbidities adj. OR 2.1 (95% CI 1.3 to 3.6) | 11 [35] | |||
| Multivariate, compared to 0 comorbidity, adverse outcome (death) not associated with the presence of 1 comorbidity within hospitalization | ||||
| Presence of comorbidities associated with overall reoperation rate up to 6 years: adj. hazard ratio (HR) 1.37 (95% CI 1.20 to 1.55), and with reoperation at specific time periods: early (<90 days): adj. HR 1.25 (95% CI 1.01 to 1.54), short-term (91-365 days): adj. HR 1.85 (95% CI 1.32 to 2.58), and midterm (1-6 years): adj. HR 1.30 (95% CI 1.09 to 1.55) | 50 [60] | |||
| Age | High age associated with higher occurrence of perioperative dural lesion: logistic (log.) regression significant (sign.) OR 1.03 (95% CI 1.01 to 1.04) | 35 [93] | 70-75 versus (vs.) >75 years: older age not associated with higher postoperative complication rateg | 48 [105] |
| Age (1-year increment) associated with more 30-days complicationsc: adj. OR 1.02 (95% CI 1.01 to 1.03) | 13 [55] | <80 vs. ≥80 years: older age not associated with more postoperative complicationsh | 45 [103] | |
| Compared to 18-44 years, ≥65 years associated with a higher in-hospital complication ratee: 65-84 years adj. OR 1.8 (95% CI 1.5 to 2.1), >85 years adj. OR 2.3 (95% CI 1.9 to 2.7) | 11 [35] | <80 vs. ≥80 years: older age not associated with more postoperative complicationsi | 2.5 [71] | |
| Multivariate, compared to 18-44 years, 45-64 years not associated with higher in-hospital complication ratee | 80-89 vs. >90 years: older age not associated with more complications during hospitalizationj | 16 [37] | ||
| Compared to 66-70 years, 71-74, 75-79 and ≥80 years associated with more cardiopulmonary/stroke complications or mortality <30 days 71-74 years adj. OR 1.13 (95% CI 0.94 to 1.37), 75-79 years adj. OR 1.36 (95% CI 1.14 to 1.62), >80 years adj. OR 1.70 (95% CI 1.43 to 2.04) | 12 [8] | Multivariate, no association with time to reoperation until a mean of 8.6 years | 51 [106] | |
| Compared to 65-69 years, 75-79 and ≥80 years associated with any postoperative complicationsf up to 3 years: 75-79 years OR 1.37 (95% CI 1.06 to 1.76), ≥80 years: OR 2.05 (95% CI 1.58 to 2.67) | 14 [17] | Multivariate, no association with reoperation rate up to 15 years | 28.2 [36] | |
| Compared to 65-69 years, age 70-74 years not associated with any postoperative complicationsf up to 3 years | Multivariate, no association with reoperation rate up to 8 years | 2.2 [70] | ||
| 60-69 vs. 70-79 vs. ≥80 years: 60-69 and 70-79 years associated with increase of length of stay after surgery: 60-69 years beta 0.29 (95% CI 0.01 to 0.57), 70-79 beta 0.50 (95% CI 0.21 to 0.78) | 17 [80] | Multivariate, no association with 90-day readmission | 6 [54] | |
| Age ≥80 years associated with readmission <30 days after surgery: OR 2.09 (95% CI 1.05 to 4.14) | Multivariate, compared to ≥80 years, younger age not associated with reoperation rate (at undefined time) | 8 [76] | ||
| Age 60-69 vs. 70-79 vs. ≥80 years: ≥80 years not associated with increase of length of stay after surgery (beta 0.92 (95% CI 0.55 to 1.29)) | 80-89 vs. >90 years: older age not associated with reoperations <12 months post-discharge | 16 [37] | ||
| Age 60-69 and 70-79 years: no association with readmission <30 days (60-69 years OR 0.85 (95% CI 0.45 to 1.58), 70-79 years OR 0.79 (95% CI 0.42 to 1.49) | ||||
| Age >70 years associated with reoperation rate at midterm (1-6 years): adj. HR 1.87 (95% CI 1.07 to 3.27) | 50 [60] | |||
| Multivariate, age >70 years: no association with overall (<6 years), early (<90 days) and short-term (90-365 days) reoperation rate | ||||
| Higher age (per year) associated with shorter time until surgery since start of membrane stabilizing agent (MSA) treatment: adj. HR 1.02 (95% CI 1.00 to 1.04) | 7 [52] | |||
| Multivariate, higher age (per year) not associated with need for surgery <1 year since start of MSA treatment | ||||
| >85 years associated with adverse outcome (death) within hospitalization: adj. OR 8.7 (95% CI 2.0 to 38.5) | 11 [35] | |||
| Multivariate, compared to 18-44 years, 45-84 years not associated with adverse outcome (death) within hospitalization | ||||
| Older age associated with higher 10-year survival rate: adj. HR 1.09 (95% CI 1.04 to 1.13) | 42 [97] | |||
| Previous spine surgery | Any previous operation associated with occurrence of perioperative dural lesion: log. regression sign. OR 0.70 (95% CI 0.50 to 0.98) | 35 [93] | Multivariate, any previous spine surgery: no association with cardiopulmonary, stroke complications, or mortality <30 days | 12 [8] |
| Symptom duration | - | - | Log. regression, duration of low back/leg pain (not specified): no association with occurrence of perioperative dural lesion | 35 [93] |
| Bivariate, pain <1 year (reference) vs. pain >1 year: no association with reoperation rates | 9 [77] | |||
| Body weight | Morbid obesity associated with surgical site infection: log. regression OR 6.99 (95% CI 2.65-22.03), (p<0.001) | 6 [54] | Multivariate, obesity: no association with 30-days complicationsc | 13 [55] |
| Body mass index (BMI) <30 vs. 30 to <35 vs. ≥35: BMI 30 to <35 associated with no postoperative complication up to 8 weeks after surgery: BMI <30: 85% vs. 30 to <35: 95% vs. ≥35: 83% (p=0.02) | 2.4 [41] | Binary logistic analysis, BMI >24.32 not associated with more perioperative complications (life-threatening/minor) | 46 [56] | |
| BMI <30 vs. 30 to <35 vs. ≥35: obesity not associated with postoperative complicationsb up to 8 weeks after surgery | ||||
| Obesity (BMI ≥30) associated with increased length of stay after surgery: adj. beta 0.58 (95% CI 0.26 to 0.90), and with readmission <30 days after surgery: adj. beta 3.38 (95% CI 1.36 to 8.36) | 17 [80] | Multivariate, no association with time to reoperation | 51 [106] | |
| Hypertension | - | - | Log. regression, hypertension: no association with in-hospital perioperative complicationsa | 44.2 [57] |
| Hypertension: no association with increased length of stay after surgery (multivariate) and readmission <30 days (bivariate) | 17 [80] | |||
| Multivariate, no association with mortality up to 8 years | 49 [61] | |||
| Univariate, no association with reoperation rate up to 8 years | 2.2 [70] | |||
| Diabetes | Diabetes vs. no-diabetes: diabetes associated with more “other” complications (not specified) <8 weeks after surgery: diabetes 13%, no-diabetes 4% (p=0.021) | 2.3 [59] | Multivariate: no association with 30-days complicationsc | 13 [55] |
| Diabetes vs. no-diabetes: no-diabetes associated with no complication <8 weeks after surgery: diabetes 74%, no-diabetes 90% (p=0.002) | Multivariate, treated diabetes: no association with time to reoperation | 51 [106] | ||
| Diabetes vs. no-diabetes: diabetes not associated with postoperative wound infections/hematoma <8 weeks after surgery | No association with increased length of stay after surgery (multivariate) and readmission <30 days (bivariate) | 17 [80] | ||
| Diabetes vs. no-diabetes: diabetes associated with more in-hospital perioperative complicationsa: diabetes 67%, no-diabetes 28% (p<0.0001) | 44.5 [39] | Univariate, no association with reoperation rate up to 8 years | 2.2 [70] | |
| Diabetes mellitus associated with in-hospital perioperative complicationsa: log. regression sign. OR 1.85 (95% CI 1.03 ± 3.33) | 44.2 [57] | |||
| Diabetes associated with short-term reoperation rate (91-365 days): adj. HR 1.32 (95% CI 1.02 to 1.70), and with midterm reoperation rate (1-6 years): adj. HR 1.21 (95% CI 1.04 to 1.41) | 50 [60] | |||
| Multivariate, no association with early reoperation rate (<90 days) | ||||
| Diabetes associated with mortality up to 8 years after surgery: adj. HR 1.12 (95% CI 1.0 to 1.25) | 49 [61] | |||
| Diabetes vs. no-diabetes: diabetes associated with increased length of stay (days): diabetes: mean 34.9 vs. no-diabetes: 30.7 (p=0.0008) | ||||
| Smoking | Smoking associated with occurrence of perioperative dural lesion: logistic regression, sign. OR 0.70 (95% CI 0.49 to 0.999) | 35 [93] | No association with increased length of stay after surgery (multivariate) and readmission <30 days (bivariate) | 17 [80] |
| Multivariate, no association with time to reoperation | 51 [106] | |||
| Univariate, no association with reoperation rate up to 8 years | 2.2 [70] | |||
| Cardiovascular disease | Congestive heart failure associated with in-hospital perioperative complicationsa: log. regression OR 2.96 (95% CI 1.55 ± 5.66) | 44.2 [57] | Univariate, heart problem: no association with reoperation up to 8 years | 2.2 [70] |
| Ischemic heart disease associated with in-hospital perioperative complicationsa: log. regression, sign. OR 2.02 (95% CI 1.22 ± 3.35) | Anemia (hematocrit <36) associated with increased length of stay after surgery: adj. beta 0.65 (95% CI 0.28 to 1.02) | 17 [80] | ||
| Log. regression, peripheral vascular disease: no association with in-hospital perioperative complicationsa | Bivariate, heart disease: no association with increased length of stay after surgery and readmission <30 days | |||
| History of coronary artery disease associated with surgical site infection: log. regression, sign. OR 2.26 (95% CI 1.31-3.84), p=0.003 | 6 [54] | Bivariate, anemia (hematocrit <36): no association with readmission <30 days | ||
| Cardiovascular disease associated with mortality up to 8 years after surgery: adj. HR 1.64 (95% CI 1.48 to 1.82) | 49 [61] | |||
| History of congestive heart failure associated with 90-day readmission OR 3.03 (95%CI 1.69-5.28), p<0.001 | 6 [54] | |||
| Lung disease | Pulmonary disease associated with in-hospital perioperative complicationsa: log. regression, sign. OR 2.63 (95% CI 1.42 ± 4.87) | 44.2 [57] | Pulmonary disease: no association with increased length of stay (bivariate) after surgery and readmission <30 days after surgery (multivariate) | 17 [80] |
| Neurologic disease | Cerebrovascular disease associated with mortality up to 8 years after surgery: adj. HR 1.23 (95% CI 1.11 to 1.37) | 49 [61] | - | - |
| Rheumatologic disease | Osteoarthritis associated with reoperation rate after a mean of 5.3 years: linear regression sign. beta 0.14 (p<0.001) | 44.3 [100] | Univariate, osteoporosis/joint problem: no association with reoperation up to 8 years | 2.2 [70] |
| Psychiatric disease | - | - | Multivariate, greater depression (higher Personal Health Questionnaire depression scale (PHQ-9, range 0-24)) not associated with shorter time until surgery or need for surgery <1 year since start of MSA treatment | 7 [52] |
| Univariate, depression: no association with reoperation rate <8 years | 2.2 [70] | |||
| Kidney disease | Chronic kidney disease associated with mortality up to 8 years after surgery: adj. HR 2.83 (95% CI 2.51 to 3.19) | 49 [61] | - | - |
£
Gagne score (-2–26);
§
Charlson comorbidity score based on coexisting conditions (range 0–3+);
#
Quan comorbidity score (adapted Charlson comorbidity score) based on comorbid conditions in any hospitalization during the previous year (range 0–3+);
a
urinary complications (retention, infection, incontinence), exacerbation of congestive heart failure/chronic obstructive pulmonary disease, atrial fibrillation, wound infection, delirium, unstable angina, depression, cerebrovascular accident, gastrointestinal bleeding, hypotension39 and in-hospital death; [57]
b
wound infections, wound hematoma and other complications;
c
renal, cardiac, neurological, pulmonary, deep vein thrombosis, pulmonary embolism, infection;
d
dural tears, confusion, pseudogout, ileus, hypotension, wound infection, urinary retention, dehiscence;
e
neurologic, pulmonary, thromboembolic, cardiac, urinary, renal, hemorrhage/hematoma complicating a procedure, fluid/electrolyte abnormalities;
f
cardiopulmonary, vascular, infectious;
g
infection, hematoma, pneumonia, urinary tract infection, delirium, cerebrovascular accident, acute renal failure, neutropenia;
h
cerebrospinal fluid leakage, delirium, epidural hematoma, infection, dysuria, insufficiency fracture, wound problem, ileus, acute cholecystitis, aortic aneurysm, deep venous thrombosis;
i
wound complications (infections, hematoma, dehiscence), nerve root injury or other complications;
j
cardiac, general neurological, pulmonary, renal, deep vein thrombosis or pulmonary embolism, infection, wound infection