249. The phenotypes of anxiety and depression: analysis of combined comorbidity and treatment in patients undergoing spinal fusion

BACKGROUND CONTEXT Anxiety and depression are associated with suboptimal outcomes, higher complications and cost of care after elective spine surgery. Extensive literature on the topic has studied the effect of anxiety and depression as independent comorbid conditions. Whether presence of combined anxiety-depression in spinal fusion patients is different than either comorbidity alone has not been studied. Additionally, there are no comparative studies on the effect of preoperative treatment of anxiety and depression. PURPOSE Our aim was to study the burden of combined anxiety-depression and its impact on health care utilization and costs in patients undergoing spinal fusion. Second, to study the prevalence and impact of treatment of their anxiety and/or depression STUDY DESIGN/SETTING Retrospective, IBM® MarketScan® Research Database (2000-2018) PATIENT SAMPLE A total of 75,087 patients with median age of 57 years who underwent spinal fusion for degenerative pathology. OUTCOME MEASURES Health care utilization and costs from 1-year preoperative to 2-years postoperatively, including index hospitalization, opioid use, readmissions, re-operations, complications, and emergency department (ED) visits. METHODS Adult (>18 years) patients who underwent spinal fusion were studied in seven different “phenotypes” of anxiety and depression based on various combinations of diagnoses and treatment. The first comparison was between patients with no diagnosis of anxiety/depression, diagnosis of anxiety only, diagnosis of depression only, and combined anxiety-depression. The second comparison was between untreated and treated patients with anxiety, depression, and combined anxiety-depression, respectively. Univariate and multivariate analysis has been reported. RESULTS Patients with combined anxiety-depression had higher 1-year preoperative health care utilization, 30-day complications and ED visits, and opioid use as compared to patients with anxiety or depression alone. They also had a higher 2-year reoperation rate and health care utilization as compared to patients with anxiety alone. Treated patients had a higher 1-year preoperative utilization of inpatient and outpatient services, with higher overall costs.  Chronic opioid use was significantly more prevalent in all treated patients as compared to untreated patients. The 2-year reoperation rate was not significantly different between treated and untreated cohorts. The post-discharge 2-year health care utilization cost was significantly higher in treated patients. CONCLUSIONS Spine surgeons should use appropriate measures/questionnaires to screen depressed patients for anxiety signs/symptoms and vice versa since the presence of both adds significant risk of higher health care utilization and costs over patients with one diagnosis, especially anxiety alone. While combined anxiety-depression shows higher risk of sub-optimal outcomes, the effect of treatment is variable. There is a higher prevalence of opioid use in anxiety and/or depression patients on antidepressant treatment. Future clinical studies on postoperative outcomes based on response to initial antidepressant treatment are needed. That is, distinguish between favorable initial responders versus those with failure/prolonged time to achieve remission and use of multiple medications. Identifying “phenotypes of anxiety and/or depression” based on treatment response, with high likelihood of poor pain outcomes and opioid use will be useful for preoperative decision making before spinal fusion. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.