SPINE Volume 34, Number 7, pp 740 –747 ©2009, Lippincott Williams & Wilkins Mortality After Lumbar Fusion Surgery Sham Maghout Juratli, MD, MPH,*† Sohail K. Mirza, MD, MPH,¶ Deborah Fulton-Kehoe, PhD, MPH, Thomas M. Wickizer, PhD,** and Gary M. Franklin, MD, MPH‡§ Study Design. Retrospective population-based cohort study. Objective. To describe mortality after lumbar fusion surgery in Washington State workers’ compensation claimants in the perioperative period and beyond. Summary of Background Data. Although lumbar fu- sion surgery can be associated with serious complica- tions, perioperative mortality is generally considered rare. Population-based mortality estimates have been limited to surgery in older adults. Methods. We identified all Washington State workers’ compensation claimants who underwent fusion between January 1994 and December 2001 (n = 2378) and as- sessed the frequency, timing, and causes of death. Mor- tality follow-up was concluded in 2004. Death was ascer- tained from Washington State vital statistics records and from the workers’ compensation claims database. Poisson regression was used to obtain age- and gen- der-adjusted mortality rates. Years of potential life lost, percent of potential life lost, and mean potential life lost were calculated for the leading 5 causes of death and we calculated the risk of death associated with selected predictors. Results. Among the 2378 lumbar fusion subjects in the study cohort, 103 were deceased by 2004. The 3-year cumulative mortality rate was 1.93% (95% confidence in- terval, 1.41%–2.57%). The 90-day perioperative mortality rate was 0.29% (95% confidence interval, 0.11%– 0.60%). The risk of perioperative mortality was positively associ- ated with repeat fusions. The age- and gender-adjusted all-cause mortality rate was 3.1 deaths per 1000 worker- years (95% confidence interval, 0.9 –9.8). Analgesic-re- lated deaths were responsible for 21% of all deaths and 31.4% of all potential life lost. The risk of analgesic-related death was higher among workers who received instru- mentation or intervertebral cage devices compared with recipients of bone-only fusions (1.1% vs. 0.0%; P = 0.03) and among workers with degenerative disc disease (age- and gender-adjusted mortality rate ratio, 2.71) (95% con- fidence interval, 1.17– 6.28). The burden was especially high among subjects between 45 and 54 years old with degenerative disc disease (rate ratio, 7.45). Conclusion. Analgesic-related deaths are responsible for more deaths and more potential life lost among work- ers who underwent lumbar fusion than any other cause. Risk of analgesic-related death was especially high among young and middle-aged workers with degenera- tive disc disease. Key words: mortality, outcome, lumbar fusion, work- ers’ compensation. Spine 2009;34:740 –747 Information on surgical safety and efficacy is essential for informed choices. Risk of serious complications associ- ated with a treatment option may influence a patient’s choice independent of data on potential benefits. 1 Mor- tality is the ultimate adverse outcome. Knowledge about the risk of treatment-associated death is crucial when comparing treatment options for a disease that itself is non-life threatening, as is usually the case for chronic back pain associated with lumbar degenerative disease. Although death is rare following lumbar surgery, in- formation about risk factors associated with death would better inform treatment choices in high-risk pa- tients. Utilization rate of lumbar fusion surgery for lum- bar degenerative disease has been steadily rising 2–4 de- spite the lack of professional consensus on indications for surgery. 5–8 This rise is concerning because lumbar fusion, compared to less extensive spinal surgeries, can be associated with higher rates of complications 9 –11 and mortality. 11,12 Risks of serious complications and death are especially relevant to lumbar fusion in injured work- ers since pain, function, and return to work outcomes are generally poor in these subjects. 13,14 Population-based data on mortality following lumbar fusion are limited, mostly based on studies of spinal stenosis in older patient populations, such as Medicare beneficiaries. 11,12,15 These data are also limited to death within the early postoperative period; little is known about mortality be- yond this period. We designed this population-based study to describe mortality following lumbar fusion surgery among Wash- ington State workers’ compensation claimants. Because of the persistent disability following fusion in injured workers, 13,14 the recent upward trend in the use of opi- From *Division of Occupational and Environmental Medicine, Wayne State University School of Medicine, Detroit, MI; †Occupational Epi- demiology and Health Outcomes Program, University of Washington, Seattle, WA; ‡Department of Environmental and Occupational Health Sciences, School of Public Health and Community Medicine, Univer- sity of Washington, Seattle, WA; §Washington State Department of Labor and Industries, Olympia, WA; ¶Department of Orthopaedics, Dartmouth-Hitchcock Medical Center, Lebanon; Department of En- vironmental and Occupational Health Sciences, University of Wash- ington, Seattle, WA; and **Department of Health Services, School of Public Health and Community Medicine, University of Washington, Seattle, WA. Acknowledgment date: September 2, 2008. Revision date: October 20, 2008. Acceptance date: October 21, 2008. The manuscript submitted does not contain information about medical device(s)/drug(s). Federal funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript. Supported by the Accident and Medical Aid Funds of the State of Washington, Department of Labor and Industries. These research monies are targeted toward reducing the incidence and disability re- lated to occupational injuries and illnesses. Address correspondence and reprint requests to Sham Maghout Juratli, MD, MPH, 30480 Stonegate Drive, Franklin, MI 48025; E-mail: shamj@u.washington.edu, smjuratli@med.wayne.edu 740