Mortality in patients older than 65 years undergoing surgery for degenerative lumbar spine disease: a comparison with the general population.

Background: The increased life expectancy and prevalence of spondylarthrosis have led to a growing frequency of spinal surgery in older people. This study aims to assess whether there is an excess mortality concerning that expected in the general population associated with surgical procedures performed in patients over 65 years old for a degenerative disease of the lumbar spine.

Methods: All patients aged 65 years or older undergoing surgery at a single center between 2009 and 2019 for lumbar spine degenerative disease were included. Standardized mortality ratios (SMRs) were estimated to compare the mortality risk with the expected in the Spanish population for the same age, gender, and calendar-period. Multivariable Cox analysis was employed to determine risk factors of mortality.

Results: A total of 411 procedures were analyzed. The mean age was 72.6 years old. SMR was 0.67 (CI 95% 0.54-0.84). That benefit was significant in women after gender stratification. Patients operated on between 65-84 years old had a lower mortality rate than that expected for the general population. For patients aged 85 or older, the observed mortality was not different from that expected in the general population. Multivariable Cox analysis observed an association between higher mortality and the variables age, male, and Charlson comorbidity index score.

Conclusions: Compared with the general population, patients over 65 years old who underwent spinal surgery for degenerative disease of the lumbar spine experienced a reduction in mortality. This effect was particularly significant in women and patients aged 65-84 years. Age, male gender, and Charlson comorbidity index score were associated with higher mortality risk.