title: [Survival and mortality rate of extremely preterm and extremely low birth weight infants admitted to neonatology departments].
abstract: OBJECTIVE
  With the progress of perinatal medicine and neonatal treatment technology, more and more extremely preterm (EP) and extremely low birth weight infant (ELBWI) survived all over the world. But in our country, there is still lack of survival analysis of large sample survey in this field. This study was designed to survey the survival and mortality rate of EP and ELBWI who were admitted to neonatology departments.
  
  
  METHODS
  Clinical data of EP and ELBWI, who were discharged from January 1, 2008 to December 31, 2012, were collected retrospectively from twenty tertiary neonatology departments in Guangdong province. Comparisons of cure rate and survival rate were made respectively according to gestational age, birth weight, year of discharge and area of birth. Categorical data were analyzed using the chi-square test, and P<0.05 was considered statistically significant.
  
  
  RESULTS
  There were 888 cases of EP and ELBWI enrolled in the study totally; 284 cases (32.0%) were discharged of cure, 41 cases (4.6%) were transferred to other hospitals, 178 cases (20.0%) died during hospitalization, and 385 cases (43.4%) were discharged without permission or discharged ahead of schedule. Among these 385 cases, 116 (13.1%) survived and 269 (30.3%) died after discharge. While the period 2011-2012 compared to 2008-2010, the proportion of EP and ELBWI in all discharged infants [0.56% (514/92 298) vs. 0.45% (371/82 834), χ2=10.318, P=0.001] and in preterm infants [2.01% (514/25 629) vs. 1.63% (371/22 716), χ2=9.290, P=0.002] had gone up. The cure rate [37.1% (182/491) vs. 28.7% (102/356), χ2=6.558, P=0.010] and survival rate [50.1% (246/491) vs. 43.3% (154/356), χ2=3.878, P=0.049] had increased too. The overall cure rate and survival rate of EP were 29.7% (140/471) and 38.0% (179/471). And the overall cure rate and survival rate of ELBWI were 31.4% (203/646) and 45.8% (296/646). Along with the increased gestational age and birth weight, the cure rate and survival rate of EP and ELBWI both increased, and mortality rate decreased. The cure rate [44.0% (201/457) vs. 21.3% (83/390), χ2=48.653, P<0.001] and survival rate [51.2% (234/457) vs. 42.6% (166/390), χ2=6.302, P=0.012] between hospitals of Guangzhou and Shenzhen were higher than those of other cities.
  
  
  CONCLUSIONS
  EP and ELBWI slightly increased in neonatology departments. And the cure rate and survival rate of them increased too. They were closely related to gestational age and birth weight. The cure rate and survival rate in the hospitals of Guangzhou and Shenzhen were higher than those of the other areas of Guangdong province.
mesh_terms: D001724:Birth Weight; D002681:China / Q000453:epidemiology; D005865:Gestational Age; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D052577:Infant, Extremely Low Birth Weight; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends*