Rheumatoid Arthritis Independently Increases In-Hospital Morbidity and Discharge Complexity After Cervical Spine Surgery: A Propensity Score-Weighted Analysis.

BACKGROUND

Rheumatoid arthritis (RA) is a systemic inflammatory disease that frequently involves the cervical spine and often necessitates surgical intervention. Although the peripheral joint burden of RA has declined in the biological era, many patients still require cervical spine surgery, and whether RA status independently influences in-hospital outcomes remains poorly defined in contemporary, nationally representative data.

METHODS

We queried the National Inpatient Sample for all adult cervical spine surgery admissions from 2016 to 2021, identifying 164,837 unweighted cases (approximately 840,820 weighted). Patients with RA (ICD-10-CM M05-M06; n = 5082, 3.1%) were compared with non-RA controls (n = 159,755, 96.9%). Inverse probability of treatment weighting was applied to balance 27 preoperative covariates across 28 propensity model terms. Primary outcomes were in-hospital mortality, nonroutine discharge, length of stay, and total charges. Secondary outcomes included blood transfusion, blood loss anemia, pulmonary complications, sepsis/surgical site infection, venous thromboembolism, acute kidney injury, myocardial infarction/stroke, and additional cervical procedures during admission (proxy for unplanned intra-admission intervention).

RESULTS

After inverse probability of treatment weighting adjustment (propensity model area under the curve = 0.702; maximum standardized mean difference = 0.085; all 40 balance metrics standardized mean difference < 0.10), the most striking finding was among RA patients undergoing occipitocervical or cervicothoracic fusion, who faced 7-fold higher odds of blood transfusion (OR 7.41; 95% CI 3.88-14.2) and nearly 4-fold higher odds of nonroutine discharge (OR 3.84; 95% CI 3.17-4.64) compared with single-level fusion. Across the full cohort, RA was independently associated with higher odds of nonroutine discharge (OR 1.339; 95% CI 1.261-1.421; P < 0.001), longer length of stay (+0.28 days; 95% CI 0.11-0.45; P = 0.001), greater total charges (+9.1 %; P < 0.001), blood transfusion (OR 1.526; 95% CI 1.263-1.844; P < 0.001), blood loss anemia (OR 1.479; 95% CI 1.318-1.660; P < 0.001), pulmonary complications (OR 1.183; 95% CI 1.018-1.375; P = 0.028), and additional cervical procedures during the same admission (OR 1.331; 95% CI 1.073-1.651; P = 0.009). In-hospital mortality did not differ significantly (OR 0.856; 95% CI 0.500-1.464; P = 0.569).

CONCLUSIONS

RA is independently associated with increased in-hospital morbidity and resource utilization following cervical spine surgery. These risks are graded by procedural complexity and are most pronounced among RA patients undergoing occipitocervical or cervicothoracic fusion, who demonstrate markedly increased transfusion requirements. The magnitude and procedure-specific gradient of these risks-quantified here in contemporary, biological-era data-provide an actionable basis for preoperative risk stratification, transfusion planning, and anticipatory discharge coordination in this population.

CLINICAL RELEVANCE: RA patients undergoing cervical spine surgery-particularly those requiring occipitocervical or cervicothoracic fusion-warrant proactive transfusion preparedness (type-and-screen and blood-product availability), preoperative anemia optimization, and discharge planning initiated at the time of surgical scheduling. These procedure-specific risk estimates allow surgeons to counsel patients and plan perioperative care in concrete rather than generic terms.