Table 1.

Characteristics of participating countries and datasets

	Netherlands	Norway	Sweden
Inhabitants (× 106)	16.9	5.2	9.8
Numer of bariatric proceduresper 100,000 inhabitants	65.1	55.6	61.4
Minimum required procedures per hospital	2015: 100/year 2016: 200/year	2015: not defined 2016: not defined	2015: not defined 2016: not defined
Registry
Registry	DATO	SOReg-N	SOReg-S
Registry active since	2015	2015	2007
Registry organization	18 hospitals 1 central database	20 hospitals 1 central database	42 hospitals 1 central database
Data availabilitya
Patient characteristics	+	+	+
Obesity-related diseases	+	+	+
Surgical technique	+	+	+
Perioperative complications	+	+	+
Reinterventions	+	+	+
IC/ICU admission	+	+	+
Hospital stay	+	+	+
Readmission	+	+	+
Mortality	+	+	+

DATO Dutch Audit for Treatment of Obesity, SOReg Scandinavian Obesity surgery Registry, IC intensive care, ICU intensive care unit

^aObligatory in all registries