Completeness and selection bias of a Belgian multidisciplinary, registration-based study on the EFFectiveness and quality of Endometrial Cancer Treatment (EFFECT)

Table 1 Center characteristics

	All centers (n = 101)		Participating (n = 55)		Non-participating (n = 46)		Participation rate
Characteristics	N	%	N	%	N	%	%
Volume
Low (< 10/year)	50	49.5%	17	30.9%	33	71.7%	34.0%
Medium (10–19/year)	31	30.7%	22	40.0%	9	19.6%	71.0%
High (≥ 20/year)	20	19.8%	16	29.1%	4	8.7%	80.0%
Region
Flemish	55	54.5%	35	63.6%	20	43.5%	63.6%
Brussels Capital	10	9.9%	8	14.5%	2	4.3%	80.0%
Walloon	36	35.6%	12	21.8%	24	52.2%	33.3%
University status
General without university character	77	76.2%	39	70.9%	38	82.6%	50.6%
General with university character	17	16.8%	10	18.2%	7	15.2%	58.8%
University hospital	7	6.9%	6	10.9%	1	2.2%	85.7%
Ownership status
Private	73	72.3%	41	74.5%	32	69.6%	56.2%
Public	28	27.7%	14	25.5%	14	30.4%	50.0%

Distribution of volume, region, university status and ownership status for (a) all centers eligible for EFFECT participation (n = 101), (b) the participating centers (n = 55), and (c) the non-participating centers (n = 46). For each subgroup of hospitals with a certain characteristic, participation rate was calculated as the percentage of centers that participated in EFFECT out of all centers

ISSN: 1471-2407