Hospital costs for cervical spine surgeries rose significantly between 2002 and 2009, according to a study presented at the 2012 Cervical Spine Research Society annual meeting.

The increase in costs may be due to older patients undergoing these procedures, according to Kern Singh, MD, who worked with his colleagues to analyze national trends in cervical spine procedures.

“As patients with chronic conditions receive better care that enables them to live longer, increasing numbers of older patients are now undergoing cervical spine surgeries (Fig. 1),” noted Dr. Singh.

Conducting the study
The researchers obtained data for cervical spine procedures performed between 2002 and 2009 from the National Inpatient Sample (NIS) Hospital Cost and Utilization Project, which Dr. Singh noted is the largest all-payer care database in the United States.

Using ICD-9 codes, the researchers determined a differential diagnosis for myelopathy and radiculopathy, and then identified the procedures performed, which fell into these surgical subgroups:

• Anterior cervical fusion (ACF)
• Posterior cervical fusion (PCF)
• Posterior cervical decompression (PCD) procedures without fusion, including laminoforaminotomy, laminectomy, and laminoplasty

“We used weighted counts to estimate the national incidence of these procedures,” said Dr. Singh. The investigators calculated comorbidities using the Charlson Comorbidity Index (CCI) score, and assessed the following factors in each surgical subgroup:

• Demographics (gender, age, and race)
• Costs (adjusted for inflation; reported in 2009 dollars)
• Mortality associated with complications

Finally, the researchers conducted statistical analysis using Pearson’s Correlation to identify significant trends and compare the surgical subgroups.

“We used a P value of 0.001,” said Dr. Singh, “which is very important to identify because we had more than 1 million data points.”

More surgery, higher costs
Although mortality rates have not significantly changed for any of the cervical spine procedures analyzed in this study, the overall number of cervical spine procedures being performed increased by more than 64,000 procedures between 2002 and 2009.

In addition, the mean age of patients undergoing cervical spine surgery increased from 56.4 years to 58 years. Researchers also found an increase in CCI scores from 1.1 to 1.6 between 2002 and 2009. The comorbidity increase was due to more patients with conditions such as hypertension and obesity undergoing cervical spine surgery.

Notably, mean in-hospital costs, adjusted for inflation, increased by an average of $4,531 per patient during the 8-year period analyzed. Patients who underwent PCF had the highest costs and the highest incidence of mortality. Costs also increased for patients who underwent ACF. No significant cost increase was found in the PCD group.

“In conclusion, mortality has not significantly changed, despite older patients with more comorbidities undergoing ACF, PCF, and PCD,” said Dr. Singh, but average hospital costs have increased.

“Possible explanations for the increased costs are the older patient population undergoing surgery, and the use of more expensive implants and biologics,” he added.

Dr. Singh acknowledged that one limitation of the study is that the NIS database only contains data on 20 percent of all hospital discharges throughout the country, and that the results rely on accurate hospital recording and coding of spine procedures.

“Finally,” he said, “this cross-sectional analysis does not account for readmissions.”

Dr. Singh’s coauthors of “Epidemiological Trends in Cervical Spine Surgery Between 2002 and 2009” are Miguel Pelton, BS; Matthew Oglesby, BS; Steven Fineberg, MD; and Alpesh Patel, MD.

Disclosures: Dr. Singh—Pioneer; Zimmer; DePuy, a Johnson & Johnson Company; Stryker; Globus Medical; Wolters Kluwer Health–Lippincott Williams & Wilkins. Dr. Patel—Amedica, Biomet, GE Healthcare, Stryker, Cytonics, Nocimed, Trinity Orthopedics, and Springer. Mr. Pelton, Mr. Oglesby, and Dr. Fineberg—no conflicts.

Jennie McKee is a staff writer for AAOS Now. She can be reached at mckee@aaos.org

Bottom Line

• An analysis of the NIS database suggests that the number of cervical spine procedures increased by more than 64,000 procedures between 2002 and 2009.
• The mean age of patients undergoing these surgeries increased from 56.4 years to 58 years; comorbidity rates also increased.
• Mean in-hospital costs, adjusted for inflation, increased by an average of $4,531 per patient, which may be linked to the increasingly older patient population.