Table 1.

SDE information of different levels of medical institutions.

Medical Institution Level	Short Axis/m	Long Axis/m	Rotation Angle/°	Flat Rate
Unclassified	15,148.67	22,049.88	8.50	1.46
Primary	34,518.96	17,302.04	159.20	0.50
Secondary	25,466.40	19,880.21	166.74	0.78
Tertiary	17,918.97	17,307.33	177.64	0.97
Overall	21,070.55	18,135.32	166.70	0.86