Mortality and Ankylosing Spondylitis in the US population: leading causes and associated factors

Ankylosing Spondylitis (AS) is a chronic inflammatory condition that affects the axial skeleton. Recent studies have shown that mortality risk is higher in AS patients and that it is possibly related to disease activity and duration. Our aim was to investigate the leading causes and factors associated with mortality in hospitalized AS patients in the USA.

This is a case-control study using the Cerner Health Facts® database between 2015 and 2017. The search was done using ICD codes and administrative claims. Cases were hospitalized AS patients who died during that hospitalization, while controls were patients who survived. In addition to demographics, we collected data on the inpatient use of medications such as NSAIDs, as well as different comorbidities and systemic disease manifestations. The discharge diagnoses for deceased patients were collected to infer causes of mortality. Analysis of association was performed using chi-square tests, t-tests, Wilcoxon rank-sum tests, and logistic regression methods.

The leading causes of death were cardiovascular, infectious, respiratory, and traumatic. The Elixhauser comorbidity index was the factor most associated with mortality (p-value < 0.0001), with congestive heart failure and renal disease the most contributing. Drug use disorder was associated with mortality (adjusted OR = 10.9; p = 0.001). Inpatient NSAIDs use was not associated with increased odds for mortality (p-value 0.33).

Cardiovascular and renal comorbidities are associated with mortality and need to be targeted early on to lower the odds of mortality as patients age. Strategies to prevent opioid and drug abuse should be strengthened in the AS population. Key Points • Cardiovascular and renal comorbidities are associated with mortality and need to be screened for and targeted early on to lower the odds of mortality as patients age. • Drug use disorder including opioid dependence is associated with mortality, and strategies to prevent opioid and drug abuse should be strengthened in the AS population.