Smoking, comorbidities, EAMs up death risk in hospitalized ankylosing spondylitis patients

Smoking, extra-articular manifestations (EAMs), and comorbidities are all associated with a higher risk of all-cause mortality in hospitalized patients with ankylosing spondylitis (AS) than those in the comparison cohort, reports a study.

This retrospective, population-based cohort study used linked administrative data from AS patients who were hospitalized (n=1,791) and those in a matched comparison group (n=8,955). Mortality data for patients were sourced from the Western Australia Death Register. Hospital records were reviewed to identify the presence of comorbidities and EAMs.

Finally, the authors compared mortality rates between the two groups using Cox proportional hazard models overall and stratified by a history of EAMs, comorbidities, and smoking status.

AS patients had higher crude mortality rates than those in the comparison group (hazard ratio [HR], 1.85, 95 percent confidence interval [CI], 1.62‒2.12), with excess mortality in the AS group associated with cardiovascular disease (CVD; HR, 5.32, 95 percent CI, 3.84‒7.35), cancer (HR, 1.68, 95 percent CI, 1.27‒2.23), external causes (HR, 3.92, 95 percent CI, 2.28‒6.77), and infectious diseases (HR, 25.92, 95 percent CI, 7.50‒89.56).

Stratification by history of EAMs, CVD, and smoking showed increased mortality risk in patients both with and without each risk factor. Among AS patients, histories of CVD (HR, 6.33, 95 percent CI, 4.79‒8.38), diabetes (HR, 2.81, 95 percent CI, 1.99‒3.95), smoking (HR, 1.49, 95 percent CI, 1.18‒1.89), and EAMs (HR, 1.62, 95 percent CI< 1.24‒2.11) correlated with an elevated risk of mortality.

“These results support the need to prevent or reduce the occurrence of comorbidities and smoking in patients with AS,” the authors said.