Increase in spinal deformity surgery in patients age 60 and older is not associated with increased complications

Background Context

Surgical treatment for adult spinal deformity improves patient quality of life; however, trends in surgical utilization in the elderly, who may be at higher risk for complications, remain unclear.

Purpose

To identify trends in the utilization of adult deformity and determine complication rates among older patients.

Study Design

This is a retrospective database analysis.

Patient Sample

The Nationwide Inpatient Sample database was queried from 2004 to 2011 to identify adult patients who underwent spinal fusion of eight or more levels using International Classification of Diseases, Ninth Revision (ICD-9) coding.

Outcome Measures

Incidence of surgery, complication rates, length of stay, and total hospital charges.

Methods

The incidence of surgery was normalized to United States census data by age group. Trends in complications, length of stay, and inflation-adjusted hospital charges were determined using linear regression and Cochran-Armitage trend testing.

Results

An estimated 29,237 patients underwent adult spinal deformity surgery with an increase from 2,137 to 5,030 cases per year from 2004 to 2011. Surgical incidence among patients 60 years and older increased from 1.9 to 6.5 cases per 100,000 people from 2004 to 2011 (p<.001), whereas utilization in patients younger than 60 increased from 0.59 to 0.93. Linear regression revealed that the largest increase in surgical utilization was for patients aged 65–69 years with an increase of 0.68 patients per 100,000 people per year (p<.001), followed by patients aged 70–74 years with a rate of 0.56 patients per 100,000 people per year (p=.001). Overall complication rates were 22.5% in 2004 and 26.7% in 2011. Although complication risk increased with age (≥60 vs. <60: relative risk 1.91 1.83, 1.99], p<.001), within-age group rates were stable over time. Mean length of stay was 9.6 days in 2004 and 9.0 days in 2011. Inflation-adjusted mean hospital charges increased from $171,517 in 2004 to $303,479 in 2011 (p<.001).

Conclusions

Operative management of adult spinal deformity increased 3.4-fold among patients ≥60 years from 2004 to 2011, with an associated 1.8-fold increase in hospital charges. Although the exact reasons for the striking increase in hospital charges remain unclear, some of the increase is likely related to decreasing reimbursement of charges by payors over the same period of time. The large majority of cases were performed in large academic centers, and growth in deformity trained spine specialists in these centers may have contributed to this trend. Despite the increased utilization of surgery for adult spinal deformity, in-hospital complications remained stable across all ages.