Table 4: Mean (SD) and median (min-max) health care costs (summary of 1, 2, and 3) and health care- and social costs (summary of 1, 2, 3, and 4) for the whole observation period. Costs are in Euro (€).

Inflamm. disease hospital ( 𝑛 = 4 8 ) Inflamm. disease outpatient hospital ( 𝑛 = 1 4 ) Inflamm. disease rehab centre ( 𝑛 = 5 0 ) OA conventional rehab centre ( 𝑛 = 6 3 ) OA postsurgery rehab ( 𝑛 = 1 3 1 )

Cost group 1, 2 and 3 including rehab stay
 Mean (SD)23,605 (17,399)8,749 (7,971)11,038 (7,998)11,817 (8,978)25,136 (7,298)
 Median (min-max)15,145 (7,779–91,336)5,208 (3,033–27,687)8,575 (3,900–38,793)8,019 (5,006–46,703)24,239 (4,539–48,468)

Cost group 1, 2, 3 and 4 including rehab stay
 Mean (SD)51,492 (29,894)32,410 (24,498)45,880 (24,109)42,804 (24,288)45,952 (20,889)
 Median (min-max)59,986 (32,410–24,498)24,993 (5,714–73,993)57,801 (8,040–92,906)52,065 (9,196–89,801)40,993 (7,951–90,491)

Cost groups 1–4 refer to costs related to health consumption in the primary healthcare services (cost group 1), secondary healthcare services (cost group 2), use of medication (cost group 3), and costs related to production loss in terms of sick leave (cost group 4). All costs are presented in Euros: 1€ = 8 NOK.
OA: osteoarthritis; rehab: rehabilitation.
𝑃 -values refer to Kruskal Wallis testing for differences within period and cost group, but between diagnostic and clinical setting.