Table 2.

Descriptive statistics of variables.

Variables	N	Minimum	Maximum	Mean value	Standard deviation	Skewness
selection	10,446	0	36,900	1363.41	2666.342	5.166
open_time	10,446	0	158	90.47	42.875	−0.167
hospital	10,446	0	1	0.98	0.149	−6.412
last_online	10,446	0	4	2.57	1.841	−0.607
service	10,446	0	4	1.42	1.109	0.339
title	10,446	0.5	4.0	2.983	1.0867	−0.592
article	10,446	0	5,003	29.08	174.434	18.332
avatar	10,446	0	1	0.69	0.464	−0.801
professional	10,446	1	4	2.49	1.123	0.010
introduction	10,446	1	4	2.50	1.120	0.003
report	10,446	0	22,911	488.15	1228.069	8.369
vote	10,446	0	2,020	123.74	207.883	4.104
letter	10,446	0	1,109	59.70	108.419	4.355
gift	10,446	0	3,208	119.04	298.196	5.674
heat	10,446	2.9	5.0	3.817	0.4178	1.245