From: A study on depression of the elderly with different sleep quality in pension institutions in Northeastern China
City
Shenyang(1)
Shenyang(2)
Anshan(1)
Anshan(2)
Tieling
Benxi
Total
Number of beds
696
624
576
564
552
516
3528
Number of people selected
116
104
96
94
92
86
588