Economic considerations of the treatment of ankylosing spondylitis.

Ankylosing spondylitis (AS) is associated with both significant direct and indirect costs, which vary by country, and have generally increased dramatically since the introduction of anti-tumor necrosis factor therapy. The cost-effectiveness of biologic agents is controversial, although cost-effectiveness studies need to consider the potential impact of anti-tumor necrosis factor treatments on work ability. Alternatives to reduce costs associated with biologics have been examined, including on-demand dosing and lower dose alternatives. Other treatment measures, such as total hip arthroplasty and physical therapy, are also effective in reducing pain and improving function in patients with AS, although the optimal type or combination of physical therapy treatment modalities, the optimal frequency and duration of treatment and whether therapy is equally effective in stable disease and uncontrolled AS need to be determined. No studies have examined differences in patient outcomes based on subspecialty care. Establishing an evidence base for these questions would help inform policy decisions to design the most cost-effective measures to treat AS.