A retrospective cohort study.
To compare 30-day readmission, reoperation, and morbidity for patients undergoing posterior cervical decompression and fusion (PCDF) in inpatient vs. outpatient settings.
PCDF has recently been increasingly performed in outpatient settings, often utilizing minimally invasive techniques. However, literature evaluating short-term outcomes for PCDF is scarce. Moreover, no currently large-scale database studies have compared short-term outcomes between PCDF performed in the inpatient and outpatient settings.
Patients who underwent PCDF from 2005 to 2018 were identified using the National Surgical Quality Improvement Program database. Regression analysis was utilized to compare primary outcomes between surgical settings and evaluate for predictors thereof.
We identified 8,912 patients. Unadjusted analysis revealed that outpatients had lower readmission (4.7% vs. 8.8%,
The 30-day outcomes were statistically similar between surgical settings, indicating that PCDF can be safely performed as an outpatient procedure. Surrogates for poor health predicted negative outcomes. These results are particularly important as we continue to shift spinal surgery to outpatient centers. This importance has been highlighted by the need to unburden inpatient sites, particularly during public health emergencies, such as the coronavirus disease 2019 pandemic.
Posterior cervical decompression and fusion (PCDF) is an effective surgical technique used to treat various cervical spine abnormalities. The addition of posterior cervical fusion to laminectomy has become increasingly utilized in treating myelopathy and radiculopathy [
Spinal surgery, in general, has been increasingly performed in the outpatient setting. PCDF has followed this pattern, with recently increased procedures performed in the outpatient settings, often utilizing minimally invasive techniques [
Outcomes for PCDF have shown clinically significant improvement along with high fusion rates and low revision rates and adverse events [
This retrospective analysis included patient data from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2005 to 2018. This project is exempt from the Institutional Review Board as this database is de-identified, without direct patient involvement.
Patients aged ≥18 years, who underwent elective single-level PCDF, were identified and included based on the Current Procedural Terminology (CPT) code 22600, in conjunction with a cervical decompression code (63045, 63001, 63015, or 22210). We evaluated multilevel fusion using CPT 22614. Patients were excluded if they had CPT codes for anterior, thoracic, and/or lumbar procedures; deformity, revision, nonelective, or spinal tumor surgery; if they were admitted from non-home settings; discharged anywhere other than home or rehabilitation; or had emergency surgery, preoperative systemic inflammatory response syndrome or sepsis, disseminated cancer, or decompression without posterior cervical fusion.
The NSQIP database provides data on patients treated as inpatient or outpatient as defined by the NSQIP Participant Use Data File [
Primary outcomes were 30-day readmission, reoperation, and morbidity. Readmission includes any inpatient stay at the same or another hospital related to the surgical procedure [
Predictors of primary outcomes were analyzed amongst the entire cohort. Variables evaluated as potential predictors included patient demographic, comorbidity, preoperative lab values, and procedural factors (
Analyses were completed using the IBM SPSS ver. 28.0 (IBM Corp., Armonk, NY, USA). Demographic, comorbidity, laboratory, and procedural factors were individually analyzed for baseline differences between inpatients and outpatients using the Student
We identified 8,912 patients (8,559 inpatient) who underwent PCDF. Baseline group differences and unadjusted primary outcomes are provided in
Unadjusted analysis revealed that outpatients had significantly lower rates of readmission (4.7% versus 8.8%,
After adjusting for significant baseline differences and primary outcome predictors, the multivariate analysis revealed that readmission (
Readmissions occurred in 620 patients (8.6%). The multivariate analysis revealed age (
Reoperations occurred in 335 patients (3.8%). ASA-class of ≥3 (
Morbidity occurred in 972 patients (10.9%). Discharge to rehabilitation (
An increasing trend toward performing spine surgery was found in the outpatient setting, but literature evaluating outpatient PCDF is limited. In the present study, 30-day outcomes were statistically similar between inpatients and outpatients, indicating that PCDF can safely be performed in the outpatient setting.
The outcomes observed in the present study are consistent with current literature on outpatient spinal procedures [
Moreover, the outcomes presented in this study are consistent with current literature that evaluates PCDF. Long-term PCDF studies have demonstrated reoperation rates ranging from 4% to 27% [
Few studies have reported on predictors of poor early outcomes in PCDF. Snyder et al. [
Baseline health status is often considered in deciding on inpatient or outpatient surgery for patients. Analysis revealed that this was evident in our present study, as patients in the inpatient cohort were more likely older and have medical comorbidities. Notably, outpatients had significantly greater rates of obesity and smoking, further suggesting that they were overall healthier by being selected for outpatient surgery, despite having these negative health attributes. These discrepancies were addressed by comparing readmission, reoperation, and morbidity before and after baseline difference adjustments. Before adjustment, the outpatient cohort had significantly lower readmission, reoperation, and morbidity rates. After adjustment, no statistically significant difference was found between the surgical settings in any of the measured variables.
Operative time was longer in the inpatient group. Similar findings were observed in the comparison of inpatient to outpatient cervical disc replacement [
The NSQIP database provides access to a large number of nationally represented patients from multiple institutions and highly relevant variables, allowing for generalizability and the development of meaningful predictive models [
Limitations exist with the NSQIP database, which uses hospital billing data to capture inpatient and outpatient status, and thus may not accurately reflect the length of stay [
This study compared 30-day outcomes between inpatient and outpatient PCDF. Rates of readmission, reoperation, and morbidity remained statistically similar between inpatient and outpatients after accounting for potential patient confounders through multivariate logistic regression. These findings suggest that PCDF can be safely performed in the outpatient setting.
David Essig receives consulting fees for Stryker and DePuy. Jeff Silber receives teaching fees for Stryker. For all remaining authors, no potential conflict of interest relevant to this article was reported.
Study conception: Junho Song, Austin David Katz, David Essig; data analysis: Junho Song, Austin David Katz, Alan Job; manuscript writing: Junho Song, Austin David Katz, Dean Perfetti, Matthew Morris; manuscript revisions: all authors; supervision: Sohrab Virk, Jeff Silber, David Essig; administrative support: Sohrab Virk, Jeff Silber; and final approval of the manuscript: all authors.
Reasons for reoperation among inpatient vs. outpatient posterior cervical decompression and fusion.
Baseline differences in patient demographic, comorbidity, laboratory, and procedural factors, and primary outcomes, compared by surgical setting
Characteristic | Outpatient | Inpatient | Cases available | |
---|---|---|---|---|
Total | 353 | 8,559 | 8,912 | |
Demographics | ||||
Age (yr) | 55.1±10.8 | 61.5±11.9 | 8,912 | |
African American race | 40 (11.9) | 1,223 (15.8) | 0.057 | 8,080 |
Hispanic ethnicity | 16 (5.6) | 436 (5.5) | 0.960 | 8,147 |
Male gender | 197 (55.8) | 4,840 (56.5) | 0.783 | 8,912 |
Rehabilitation discharge | 26 (7.4) | 2,161 (25.2) | 8,912 | |
Comorbidities | ||||
Functionally dependent | 4 (1.1) | 384 (4.5) | 8,864 | |
Obese | 184 (52.1) | 3,899 (45.7) | 8,876 | |
Smoker | 116 (32.9) | 2,116 (24.7) | 8,912 | |
Dyspnea | 16 (4.5) | 559 (6.5) | 0.134 | 8,912 |
Diabetes mellitus | 60 (17.0) | 1,710 (20.0) | 0.169 | 8,912 |
Chronic obstructive pulmonary disease | 20 (5.7) | 570 (6.7) | 0.462 | 8,912 |
Heart failure | 0 | 34 (0.4) | 0.235 | 8,912 |
Hypertension | 168 (47.6) | 5,038 (58.9) | <0.001 | 8,912 |
Open wound infection | 1 (0.3) | 56 (0.7) | 0.392 | 8,912 |
Chronic steroid use | 11 (3.1) | 445 (5.2) | 0.082 | 8,912 |
Unexpected weight loss | 1 (0.3) | 39 (0.5) | 0.635 | 8,912 |
Bleeding disorder | 4 (1.1) | 170 (2.0) | 0.256 | 8,912 |
American Society of Anesthesiologists-class ≥3 | 169 (47.9) | 5,459 (63.8) | 8,904 | |
Lab values | ||||
Elevated creatinine | 13 (4.5) | 316 (4.1) | 0.751 | 8,043 |
Elevated white cell count | 22 (6.9) | 523 (6.6) | 0.861 | 8,186 |
Decreased hematocrit | 32 (9.9) | 1,471 (18.5) | <0.001 | 8,282 |
Abnormal platelet count | 16 (5.0) | 567 (7.2) | 0.144 | 8,196 |
Procedural factors | ||||
Operative time (min) | 126±72 | 179±88 | 8,908 | |
Wound class ≥2 | 2 (0.6) | 59 (0.7) | 0.784 | 8,912 |
Levels fused | 1.8±0.9 | 2.2±1.1 | 8,912 | |
Single-level fusion | 155 (43.9) | 2,128 (24.9) | 8,912 | |
Two-level fusion | 155 (43.9) | 4,736 (55.3) | 8,912 | |
≥Three-level fusion | 43 (12.2) | 1,695 (19.8) | 8,912 | |
Primary outcomes | ||||
Readmission | 13 (4.7) | 607 (8.8) | 7,186 | |
Reoperation | 6 (1.7) | 329 (3.8) | 8,912 | |
Morbidity | 16 (4.5) | 956 (11.2) | 8,912 |
Values are presented as number, mean±standard deviation, or number (%). Bold values indicate significance (
Univariate and multivariate analysis of specific complications by surgical setting
Specific complications | Outpatient | Inpatient | Univariate |
OR (95% CI) | Multivariate |
---|---|---|---|---|---|
Site-related complication | |||||
Superficial site infections | 7 (2.0) | 100 (1.2) | 0.202 |
||
Deep wound infections | 3 (0.8) | 69 (0.8) | 0.763 |
||
Organ space infections | 0 | 41 (0.5) | 0.411 |
||
Dehiscence | 3 (0.8) | 63 (0.7) | 0.746 |
||
Pulmonary complication | |||||
Pneumonia | 2 (0.6) | 100 (1.2) | 0.442 |
||
Reintubations | 1 (0.3) | 58 (0.7) | 0.731 |
||
Pulmonary embolism | 0 | 44 (0.5) | 0.421 |
||
Prolonged ventilation | 0 | 34 (0.4) | 0.645 |
||
Renal/urinary complication | |||||
Progressive renal insufficiency | 0 | 6 (0.1) | 1.000 |
||
Acute renal failure | 0 | 13 (0.2) | 1.000 |
||
Urinary tract infection | 0 | 134 (1.6) | 2.599 (0.356–18.943) | 0.346 | |
Stroke/cerebrovascular accident | 0 | 18 (0.2) | 1.000 |
||
Cardiovascular complication | |||||
Cardiac arrest requiring CPR | 0 | 14 (0.2) | 1.000 |
||
Myocardial infarction | 0 | 31 (0.4) | 0.634 |
||
Transfusion | 1 (0.3) | 377 (4.4) | 5.066 (0.698–36.765) | 0.109 | |
DVT/thrombophlebitis | 1 (0.3) | 66 (0.8) | 0.524 | ||
Sepsis-related complications | 1 (0.3) | 73 (0.9) | 0.371 |
Values are presented as number (%) or 95% (CI), unless otherwise stated. No complications were observed for the following variables: on ventilator >48 hours, progressive renal insufficiency, acute kidney injury, stroke/cerebrovascular accident, myocardial infarction, or sepsis. Bold values indicate significance (
OR, odds ratio; CI, confidence interval; CPR, cardiopulmonary resuscitation. DVT, deep venous thrombosis.
By Fischer’s exact test.
Univariate and multivariate analysis of predictors of readmission
Variable | Univariate | Multivariate | |||
---|---|---|---|---|---|
|
| ||||
Not readmitted (N=6,566) | Readmitted (N=620) | OR (95% CI) | |||
Demographics | |||||
| |||||
Age (yr) | 60.8±11.9 | 63.6±11.7 | 1.012 (1.003–1.021) | ||
| |||||
African American race | 935 (15.6) | 99 (17.1) | 0.348 | ||
| |||||
Hispanic ethnicity | 331 (5.5) | 24 (4.1) | 0.160 | ||
| |||||
Male gender | 3,674 (56.0) | 375 (60.5) | 1.127 (0.940–1.351) | 0.197 | |
| |||||
Rehabilitation discharge | 1,569 (23.9) | 183 (29.5) | 1.026 (0.828–1.271) | 0.817 | |
| |||||
Comorbidities | |||||
| |||||
Functionally dependent | 272 (4.2) | 43 (7.0) | 1.435 (0.996–2.069) | 0.053 | |
| |||||
Obese | 2,985 (45.6) | 301 (48.6) | 0.154 | 1.085 (0.902–1.306) | 0.386 |
| |||||
Smoker | 1,688 (25.7) | 146 (23.5) | 0.238 | 1.047 (0.843–1.301) | 0.678 |
| |||||
Dyspnea | 419 (6.4) | 51 (8.2) | 0.076 | ||
| |||||
Diabetes mellitus | 1,263 (19.2) | 154 (24.8) | 1.123 (0.905–1.393) | 0.292 | |
| |||||
Chronic obstructive pulmonary disease | 417 (6.4) | 51 (8.2) | 0.071 | ||
| |||||
Heart failure | 23 (0.4) | 4 (0.6) | 0.287 |
||
| |||||
Hypertension | 3,789 (57.7) | 411 (66.3) | <0.001 | 1.092 (0.891–1.339) | 0.396 |
| |||||
Open wound infection | 42 (0.6) | 4 (0.6) | 1.000 |
||
| |||||
Chronic steroid use | 325 (4.9) | 47 (7.6) | 1.476 (1.059–2.058) | 0.022 | |
| |||||
Unexpected weight loss | 27 (0.4) | 7 (1.1) | 2.444 (1.018–5.866) | ||
| |||||
Bleeding disorder | 125 (1.9) | 19 (3.1) | 1.181 (0.700–1.992) | 0.534 | |
| |||||
American Society of Anesthesiologists-class ≥3 | 4,076 (62.1) | 451 (73.0) | 1.270 (1.026–1.572) | 0.028 | |
| |||||
Lab values | |||||
| |||||
Elevated creatinine | 225 (3.8) | 55 (9.6) | <0.001 | 2.233 (1.607–3.102) | |
| |||||
Elevated white cell count | 416 (6.9) | 33 (5.7) | 0.297 | ||
| |||||
Decreased hematocrit | 1,111 (18.2) | 134 (23.1) | 1.024 (0.819–1.279) | 0.838 | |
| |||||
Abnormal platelet count | 423 (7.0) | 52 (9.1) | 0.068 | ||
| |||||
Procedural factors | |||||
| |||||
Operative time (min) | 177±89 | 188±95 | 1.001 (1.000–1.002) | 0.086 | |
| |||||
Wound class ≥2 | 45 (0.7) | 5 (0.8) | 0.617 |
||
| |||||
Levels fused | 2.1±1.1 | 2.2±1.1 | 1.061 (0.987–1.140) | 0.111 | |
| |||||
Single-level fusion | 1,724 (26.3) | 129 (20.8) | |||
| |||||
Two-level fusion | 3,586 (54.6) | 358 (57.7) | 0.135 | ||
| |||||
≥Three-level fusion | 1,256 (19.1) | 133 (21.5) | 0.161 | ||
| |||||
Surgical setting |
1.436 (0.789–2.613) | 0.236 | |||
| |||||
Inpatient | 6,305 (91.2) | 607 (8.8) | |||
| |||||
Outpatient | 261 (95.3) | 13 (4.7) |
Values are presented as number (%), mean±standard deviation, or 95% (CI), unless otherwise stated. Bold values indicate significance (
OR, odds ratio; CI, confidence interval.
By Fischer’s exact test.
Percent readmitted within inpatient and outpatient surgical settings.
Univariate and multivariate analysis of predictors of reoperation
Variable | Univariate | Multivariate | |||
---|---|---|---|---|---|
|
| ||||
No reoperation (N=8,577) | Reoperation (N=335) | OR (95% CI) | |||
Demographics | |||||
| |||||
Age (yr) | 61.2±11.9 | 62.0±11.1 | 0.250 | 0.989 (0.977–1.000) | 0.056 |
| |||||
African American race | 1,210 (15.6) | 53 (17.0) | 0.485 | ||
| |||||
Hispanic ethnicity | 438 (5.6) | 14 (4.5) | 0.397 | ||
| |||||
Male gender | 4,832 (56.3) | 205 (61.2) | 0.079 | ||
| |||||
Rehabilitation discharge | 2,063 (24.1) | 124 (37.0) | 1.092 (0.823–1.447) | 0.543 | |
| |||||
Comorbidities | |||||
| |||||
Functionally dependent | 364 (4.3) | 24 (7.2) | 1.026 (0.623–1.689) | 0.920 | |
| |||||
Obese | 3,925 (45.9) | 158 (47.3) | 0.626 | 0.991 (0.769–1.277) | 0.946 |
| |||||
Smoker | 2,150 (25.1) | 82 (24.5) | 0.807 | 0.858 (0.633–1.162) | 0.323 |
| |||||
Dyspnea | 545 (6.4) | 30 (9.0) | 0.057 | ||
| |||||
Diabetes mellitus | 1,682 (19.6) | 88 (26.3) | 1.187 (0.889–1.587) | 0.245 | |
| |||||
Chronic obstructive pulmonary disease | 559 (6.5) | 31 (9.3) | 1.172 (0.751–1.829) | 0.483 | |
| |||||
Heart failure | 34 (0.4) | 0 | |||
| |||||
Hypertension | 4,992 (58.2) | 214 (63.9) | 1.153 (0.870–1.527) | 0.322 | |
| |||||
Open wound infection | 50 (0.6) | 7 (2.1) | 2.557 (1.042–6.278) | ||
| |||||
Chronic steroid use | 431 (5.0) | 25 (7.5) | 1.419 (0.913–2.206) | 0.119 | |
| |||||
Unexpected weight loss | 39 (0.5) | 1 (0.3) | 1.000 |
||
| |||||
Bleeding disorder | 166 (1.9) | 8 (2.4) | 0.557 | ||
| |||||
American Society of Anesthesiologists-class ≥3 | 5,377 (62.7) | 251 (75.1) | 1.406 (1.038–1.905) | ||
| |||||
Lab values | |||||
| |||||
Elevated creatinine | 310 (4.0) | 19 (6.4) | 1.378 (0.825–2.303) | 0.220 | |
| |||||
Elevated white cell count | 520 (6.6) | 25 (8.2) | 0.279 | ||
| |||||
Decreased hematocrit | 1,439 (18.1) | 62 (20.6) | 0.257 | 0.869 (0.635–1.191) | 0.383 |
| |||||
Abnormal platelet count | 556 (7.0) | 27 (8.9) | 0.222 | ||
| |||||
Procedural factors | |||||
| |||||
Operative time (min) | 176±87 | 195±106 | <0.001 | 1.000 (0.999–1.002) | 0.471 |
| |||||
Wound class ≥2 | 58 (0.7) | 3 (0.9) | 0.500 |
||
| |||||
Levels fused | 2.1±1.1 | 2.2±1.2 | 0.269 | 1.027 (0.931–1.132) | 0.601 |
| |||||
Single-level fusion | 2,205 (25.7) | 78 (23.3) | 0.319 | ||
| |||||
Two-level fusion | 4,703 (54.8) | 188 (56.1) | 0.642 | ||
| |||||
≥Three-level fusion | 1,669 (19.5) | 69 (20.6) | 0.606 | ||
| |||||
Surgical setting |
1.317 (0.565–3.066) | 0.524 | |||
| |||||
Inpatient | 8,230 (96.2) | 329 (3.8) | |||
| |||||
Outpatient | 347 (98.3) | 6 (1.7) |
Values are presented as mean±standard deviation, number (%), or 95% (CI), unless otherwise stated. Bold values indicate significance (
OR, odds ratio; CI, confidence interval.
By Fischer’s exact test.
Percent readmitted within inpatient and outpatient surgical settings.
Univariate and multivariate analysis of predictors of morbidity
Variable | Univariate | Multivariate | |||
---|---|---|---|---|---|
|
| ||||
No morbidity (N=7,940) | Morbidity (N=972) | OR (95% CI) | |||
Demographics | |||||
Age (yr) | 64.0±11.5 | 60.9±11.9 | 1.007 (0.999–1.014) | 0.077 | |
African American race | 1,112 (15.4) | 151 (17.3) | 0.147 | ||
Hispanic ethnicity | 398 (5.5) | 54 (6.1) | 0.451 | ||
Male gender | 4,485 (56.5) | 552 (56.8) | 0.857 | ||
Rehabilitation discharge | 1,764 (22.2) | 423 (43.5) | 1.412 (1.192–1.675) | ||
Comorbidities | |||||
Functionally dependent | 308 (3.9) | 80 (8.3) | 1.295 (0.965–1.739) | 0.085 | |
Obese | 3,620 (45.8) | 463 (47.9) | 0.214 | 1.096 (0.934–1.285) | 0.261 |
Smoker | 2,008 (25.3) | 224 (23.0) | 0.127 | 1.065 (0.880–1.288) | 0.518 |
Dyspnea | 481 (6.1) | 94 (9.7) | 1.282 (0.975–1.686) | 0.075 | |
Diabetes mellitus | 1,519 (19.1) | 251 (25.8) | 1.054 (0.876–1.268) | 0.577 | |
Chronic obstructive pulmonary disease | 495 (6.2) | 95 (9.8) | 1.192 (0.901–1.578) | 0.219 | |
Heart failure | 28 (0.4) | 6 (0.6) | 0.261 |
||
Hypertension | 4,558 (57.4) | 648 (66.7) | 1.051 (0.881–1.252) | 0.582 | |
Open wound infection | 46 (0.6) | 11 (1.1) | 0.816 (0.372–1.791) | 0.613 | |
Chronic steroid use | 387 (4.9) | 69 (7.1) | 1.124 (0.832–1.517) | 0.446 | |
Unexpected weight loss | 35 (0.4) | 5 (0.5) | 0.746 | ||
Bleeding disorder | 143 (1.8) | 31 (3.2) | 1.164 (0.739–1.834) | 0.512 | |
American Society of Anesthesiologists-class ≥3 | 4,878 (61.5) | 750 (77.2) | 1.296 (1.072–1.568) | ||
Lab values | |||||
Elevated creatinine | 255 (3.6) | 74 (8.3) | 1.625 (1.202–2.198) | 0.002 | |
Elevated white cell count | 491 (6.7) | 54 (6.0) | 0.391 | ||
Decreased hematocrit | 1,219 (16.5) | 284 (31.3) | 1.700 (1.425–2.029) | ||
Abnormal platelet count | 490 (6.7) | 93 (10.3) | 1.205 (0.926–1.566) | 0.165 | |
Procedural factors | |||||
Operative time (min) | 170±82 | 228±117 | 1.005 (1.004–1.006) | ||
Wound class ≥2 | 51 (0.6) | 10 (1.0) | 0.168 | ||
Levels fused | 2.1±1.1 | 2.3±1.4 | 1.028 (0.967–1.092) | 0.379 | |
Single-level fusion | 2,073 (26.1) | 210 (21.6) | |||
Two-level fusion | 4,329 (54.5) | 562 (57.8) | 0.051 | ||
≥Three-level fusion | 1,538 (19.4) | 200 (20.6) | 0.370 | ||
Surgical setting |
1.108 (0.639–1.921) | 0.716 | |||
Inpatient | 7,603 (88.8) | 956 (11.2) | |||
Outpatient | 337 (95.5) | 16 (4.5) |
Values are presented as mean±standard deviation, number (%), or 95% (CI), unless otherwise stated. Bold values indicate significance (
OR, odds ratio; CI, confidence interval.
By Fischer’s exact test.
Percent readmitted within inpatient and outpatient surgical settings.