Economic Effects of Anti-Depressant Usage on Elective Lumbar Fusion Surgery.

Background: It has been suggested, although not proven, that presence of concomitant psychiatric disorders may increase the inpatient costs for patients undergoing elective surgery. This study was designed to test the hypothesis that elective lumbar fusion surgery is more costly in patients with under treatment for depression.

Methods: This is a retrospective case-control study of 142 patients who underwent elective lumbar fusion. Of those 142 patients, 41 patients were chronically using an antidepressant medication that considered as a "study group", and 101 patients were not taking an antidepressant medication that considered as a "control group". Data was collected for this cohort regarding antidepressant usage patient demographics, length of stay (LOS), age-adjusted Charlson comorbidity index scores and cost. Costs were compared between those with a concomitant antidepressant usage and those without antidepressant usage using multivariate analysis.

Results: Patients using antidepressants and those with no history of antidepressant usage were similar in terms of gender, age and number of operative levels. The LOS demonstrated a non-significant trend towards longer stays in those using anti-depressants. Total charges, payments, variable costs and fixed costs were all higher in the antidepressant group but none of the differences reached statistical significance. Using Total Charges as the dependent variable, gender and having psychiatric comorbidities were retained independent variables. Use of an antidepressant was independently predictive of a 36% increase in Total Charges. Antidepressant usage as an independent variable also conferred a 22% increase in cost and predictive of a 19% increase in Fixed Cost. Male gender was predictive of a 30% increase in Total Charges.

Conclusion: This study suggests use of antidepressant in patients who undergo elective spine fusion compared with control group is associated with increasing total cost and length of hospitalization, although none of the differences reached statistical significance.