Table 2

Summary of the findings of studies assessing risk-predicting scores after spine surgery.

Study	No. of Patients	Procedure	Outcome
Hartin et al, 201318	364	Thoracic or lumbar and fusion	The fusion risk score was a reliable indicator of ICU admission (P < 0.0001), blood loss (P < 0.0001), and operative time (P < 0.0001).
Deogaonkar et al, 201819	242	Lumbar and thoracic fusion surgery	The fusion risk score was an effective indicator of ICU admission (P < 0.01), blood loss (P < 0.001) and operative time (P < 0.001).
Nahtomi-Shick et al, 200115	103	Spinal decompression without or with fusion and/or instrumentation and other procedures	The ASA score was correlated with age and predictive of length of stay (P = 0.000) and ICU length of stay (P = 0.012).
Howe et al, 201120	103	Spinal fusion	The ASA grade was correlated with ICU length of stay (P = 0.011). The ASA grade was also associated with complications (P = 0.030) and discharge to skilled nursing facilities (P = 0.008). The CCI was correlated with complications (P = 0.028) and discharge to skilled nursing facilities (P = 0.039).
Kay et al, 20166	808	Laminectomy, with or without fusion	The ASA score was a predictive factor of ICU admission (P = 0.008).
Ibrahim et al, 202022	101	Multilevel spinal fusion	Lower ASA and CCI scores were consistent with greater patient-perceived improvement in health.
Khechen et al, 201923	298	Single-level minimally invasive transforaminal lumbar interbody fusion	A higher CCI was associated with greater ICU costs (P = 0.002) and higher likelihood of complication (P = 0.005).

Abbreviations: ASA, American society of Anesthesiologists; CCI, Charlson Comorbidity Index; ICU, intensive care unit.