Table 1 Case definitions for primary outcomes

Reiter's Disease

099.3, 711.1

Minimum of two medical encounters with Reiter's disease coded within 12 months

-OR-

One medical encounter with Reiter's disease coded, preceded by at least one encounter with a nonspecific arthropathy coded within 12 months

Postdysenteric arthritis

711.3

Minimum of two medical encounters with postdysenteric arthritis coded within 12 months

-OR-

One medical encounter with postdysenteric arthritis coded, preceded by at least one encounter with a nonspecific arthropathy coded within 12 months

Specific ReA diagnosis

099.3, 711.1, 711.3

Meets criteria for Reiter's Disease OR postdysenteric arthritis

Nonspecific arthropathy/arthalgia^a

716.4, 716.5,

716.6, 716.9,

719.4

Minimum of two medical encounters with a nonspecific arthropathy coded within 12 months. Subjects meeting the Reiter's disease or postdysenteric arthritis definitions were excluded.