[1] Tianjin Med Univ, Dept Nursing, Tianjin, Peoples R China
[2] Tianjin First Cent Hosp, Tianjin, Peoples R China
[3] Tianjin Med Coll, Tianjin, Peoples R China
[4] Chinese people Armed Police Force, Tianjin, Peoples R China
[5] Chinese Acad Med Sci, Hematol Hosp, Tianjin, Peoples R China
[6] Tianjin Cent Obstet & Gynecol Hosp, Tianjin, Peoples R China
[7] Tianjin Med Univ, Dept Nursing, 22 Qixiangtai Rd, Tianjin 300070, Peoples R China