Table 1.

Description of the study population: sex, type of practices, and approval for reimbursement of ultrasound diagnostic

	Sample (n = 286)	Total population (n = 4178)	95% C.I. within sample; test for differences between sample and total population
Sex
Male	118 / 286 (41.3%)	1642 / 4178 (39.3%)	[35.6%; 47.0%] p = 0.489
Female	168 / 286 (58.7%)	2536 / 4178 (60.7%)
Types of practices
Single practice	202 / 286 (70.6%)	3126 / 4169 (75.0%)	[65.3%; 75.9%] p = 0.086
Medical care center	23 / 286 (8.0%)	343 / 4169 (8.2%)	[4.9%; 11.1%] p = 0.902
Joint practice	61 / 286 (21.3%)	700 / 4169 (16.8%)	[16.6%; 26.0%] p = 0.063
Approval of ultrasound	n.a.	1609 / 4178 (38.5%)	n.a.
Users of ultrasound	139 / 286 (48.6%)	n.a.	[42.8%; 54.4%]
Ultrasound unit in practices	159 / 286 (55.6%)	n.a.	[49.8%; 61.4%]