The indirect costs of ankylosing spondylitis: a systematic review and meta-analysis.

The aim of this systematic review was to collect and summarize all current data on the indirect costs related to absenteeism and presenteeism associated with ankylosing spondylitis. The search was conducted using Medline, Embase and Centre for Reviews and Dissemination databases. All collected costs were recalculated to average annual cost per patient, expressed in 2013 prices USD using the consumer price index and purchasing power parity. Identified studies were then analyzed to assess their possible inclusion in the meta-analysis. We identified 32 records. The average annual indirect cost per patient varies among all the identified results from US$660.95 to 45,953.87. The mean annual indirect per patient equals US$6454.76. This systematic review summarizes current data related to indirect costs generated by ankylosing spondylitis; it revealed the great economic burden of the disease for society. We observed a great variety of the considered components of indirect costs and their definitions.