Table 1.
Mortality rates of neonatal intensive care unit in-hospital patients.
| Author | Country | Year(s) | Methods | Age of infants | Mortality outcome | Reasons for death |
|---|---|---|---|---|---|---|
| Feng et al. (20) | Australia | 1995–2006 | Data for 24,131 infants admitted to 10 NICUs | GA of <24 weeks (n = 145) GA of ≥37 weeks (n = 6,239) Median age at death: 4 days |
Overall mortality rate: 9.2% (2,224/24,131) Mortality rate between 1995 and 2000: 10.3% (1,152/11,185) Mortality rate between 2001 and 2006: 8.3% (1,072/12,946) |
Overall leading causes of death: congenital abnormalities (n = >445, >20%), respiratory failure (n ≈ 400, ~18%), HIE (n ≈ 222, ~10%), infection (n ≈ 222, ~10%) Most common causes of death in term infants: congenital abnormalities (40%), HIE (28%) Most common causes of death in preterm infants: respiratory failure (20%) 1995–2000: congenital problems (n = 252, 21.9%), respiratory failure (n = 217, 18.8%), infection (n = 136, 11.8%), HIE (n = 128, 11.1%), IVH (n = 80, 6.9%), cardiovascular failure (n = 56, 4.9%), NEC (n = 47, 4.1%), chronic lung disease (n = 25, 2.2%), renal failure (n = 19, 1.6%), SIDS (n = 13, 1.1%), hematological disorders (n = 8, 0.7%), neoplasm (n = 6, 0.5%), trauma (n = 4, 0.3%), maternal conditions (n = 3, 0.3%) 2001–2006: congenital problems (n = 226, 21.1%), respiratory failure (n = 188, 17.5%), HIE (n = 129, 12.0%), infection (n = 116, 10.8%), IVH (n = 112, 10.4%), extreme prematurity (n = 76, 7.1%), NEC (n = 58, 5.4%), cardiovascular failure (n = 36, 3.4%), chronic lung disease (n = 21, 2.0%), renal failure (n = 20, 1.9%), SIDS (n = 14, 1.3%), neoplasm (n = 8, 0.7%), maternal conditions (n = 6, 0.6%), trauma (n = 5, 0.5%), hematological disorders (n = 4, 0.4%) |
| Keir et al. (21) | Australia | 2005–2010 | Data for 36 extremely low birth weight infants (≤500 g), including 26 NICU patients, born at a tertiary hospital | GA of ≥22 weeks Mean GA of the 12 deceased infants: 24.4 ± 1.4 weeks Median age at death: 20 days |
46% (12/26) | NEC (n = 2, 17%), fulminating NEC (n = 2, 17%), recurrent NEC/multiple cardiorespiratory arrests (n = 1, 8%), progressive lactic acidosis – unresponsive to treatment (n = 1, 8%), severe lung disease (n = 1, 8%), respiratory failure/sepsis (n = 1, 8%), massive liver necrosis and fibrosis – etiology unclear (n = 1, 8%), severe irrecoverable chronic lung disease (n = 1, 8%), lower limb gangrene/cardiorespiratory arrest (n = 1, 8%), bilateral grade IV IVH (n = 1, 8%) |
| Sankaran et al. (22) | Canada | January 8, 1996–October 31, 1997 | Data for 19,265 infants admitted to 17 tertiary-level NICUs. | Age at death: 2 (n = 318, 40%), 3 (n = 397, 50%), 12 (n = 596, 75%) days since NICU admission; 1 month after admission (n = 79, 10%) | Overall mortality rate: 4% (795/19 265) Mortality rate for infants with birth weight ≤500 g: 51% Mortality rate for infants with birth weight ≤1,500 g: 2% |
Outborn status (n = 334, 42%), GA of <24 weeks (n = 310, 39%), chromosomal or congenital anomalies (n = 270, 34%), HIE (n = 127, 16%), infection (n = 111, 14%), GA of 24–28 weeks (n = 103, 13%), small for GA (n = 79, 10%) |
| Simpson et al. (23) | Canada | 1997, 2002, 2007 | Data for 156 in-hospital deaths (53 in 1997, 50 in 2002, 53 in 2007) at a tertiary-level NICU | 2007: GA of 23–27 (n = 104, 14.3%), 28–32 (n = 113, 15.5%), 33–35 (n = 102, 14.0%), ≥36 (n = 407, 55.9%) weeks Median age at death: 16 days (range: 1–180 days) |
Average annual mortality rate between 1988 and 2007: 7.6% | 2007: gastrointestinal (n = 15, 28.3%), neurologic (n = 14, 26.4%), cardiorespiratory disorders (n = 10, 18.9%), congenital abnormality (n = 8, 15.1%), infection (n = 4, 7.5%), extreme prematurity (n = 2, 3.8%) |
| Zhou et al. (24) | China | October 2010–September 2011 | Data for 729 very preterm infants admitted to a tertiary NICU | GA of <32 weeks Age at death: 26 (44%) of deaths occurred in the early neonatal period (0–6 days), 28 (49%) in the late neonatal period (7–28 days), 4 (7%) after the neonatal period |
Overall mortality rate: 8% (58/729) Mortality rate of extremely low birth weight infants: 27% Mortality rate of very low birth weight infants: 11% |
Not listed |
| Manktelow et al. (25) | England | 2008–2010 | Data for 2,995 white singleton infants admitted to NICUs in the East Midlands and Yorkshire regions of England | GA of 23 (n = 18)–32 weeks (n = 1,329) | 8.1% (244/2,995) | Not listed |
| Tagare et al. (26) | India | December 1, 2006–April 30, 2008 | Data for 87 extremely low birth weight infants admitted to a level III NICU | Mean GA of deceased infants: 27.2 weeks (range: 26.6–27.8) | 45.9% (40/87) | Pulmonary hemorrhage (n = 10, 25%), RDS (n = 9, 22.5%), IVH (n = 9, 22.5%), sepsis (n = 8, 20%), NEC (n = 1, 2%), BPD (n = 1, 1%), pneumothorax (n = 1, 1%) |
| Navaei et al. (27) | Iran | January 2005–March 2006 | Data for 194 preterm infants with birth weight of ≤1,500 g who were admitted to two NICUs | GA of 24–27 (n = 48), 27–28 (n = 74), 28–30 weeks (n = 72) Average age at death: 28.9 days |
64.4% (125/194) | Prematurity, low birth weight |
| Eventov-Friedman et al. (28) | Israel | 2000–2009 | Data for the in-hospital deaths at two tertiary-level NICUs | Age at death: 69 (29%) of the 239 infants died on the first day of life, 31 (13%) dying at up to 48 h of life, 55 (23%) died between days 3 and 7, 53 (22%) died between days 8 and 30, 33 (14%) died after 30 days of life | 0.2% (239/96 643) | Overall leading cause of death: prematurity and its complications (n = 182, 76%) For infants born at ≤26 weeks: respiratory system failure (due to RDS, air leaks, pulmonary hemorrhage, pulmonary hypertension, BPD) and cardiovascular collapse (57%), ICH (45%), sepsis (18%), NEC (7%) For infants born at ≥37 weeks: congenital anomalies (48%), including cardiac (23%), chromosomal (23%), central nervous system (19%), renal (14%), and lung (9%) anomalies, asphyxia (19%), sepsis (7%) For early deaths (<3 days): severe lung disease in preterm infants (n = 60, 60%) For later deaths: sepsis, multiorgan failure For deaths at >30 days of life: chronic lung disease (n = 19, 57%), complications of NEC (n = 3, 9%) |
| Corchia et al. (29) | Italy | 2005 | Data for 4,014 very preterm infants admitted to 105 tertiary-level NICUs | GA of ≤23 (n = 167, 4.2%), 24 (n = 185, 4.6%), 25 (n = 226, 5.6%), 26 (n = 285, 7.1%), 27 (n = 365, 9.1%), 28 (n = 451, 11.2%), 29 (n = 560, 14.0%), 30 (n = 725, 18.1%), 31 (n = 1,048, 26.1%) weeks | 18.8% (755/4,014) | Not listed |
| Shim et al. (30) | Korea | 2009 | Data for 2,584 very low birth weight infants admitted to NICUs in 76 hospitals | Not listed | Mortality rate for infants with birth weight of <750 g: 44.8% Mortality rate for infants with birth weight of 750–999 g: 20.4% Mortality rate for infants with birth weight of 1,000–1,499 g: 6.5% |
Not listed |
| Shrestha et al. (31) | Nepal | 2007–2009 | Data for 150 preterm infants admitted to a level III NICU | Mean GA: 30.0 ± 0.37 weeks | Total mortality rate: 20.6% (31/150) Mortality rate in extremely low birth weight infants: 80% (8 deaths) Mortality rate in very low birth weight infants: 39.5% (17 deaths) |
HMD (n = 20, 64.5%), sepsis (n = 18, 58.06%), NEC (n = 8, 25.8%), DIC (n = 5, 16.1%), pneumonia (n = 4, 12.9%), pneumothorax (n = 3, 9.6%), neonatal seizure (n = 2, 6.45%), shock (n = 2, 6.45%), IVH (n = 2, 6.45%) |
| Battin et al. (32) | New Zealand | 1959–2009 | Data for very low birth weight (≤1,500 g) infants born at a single tertiary neonatal unit | Not listed | Mortality rate of infants with birth weight of 501–1,000 g in 2009: 30% Mortality rate of infants with birth weight of 1,001–1,500 g in 2009: 5% |
2008: prematurity and early cardiorespiratory problems (predominantly RDS) (33%), infection (29%), congenital anomalies (12%), NEC (12%) |
| Ekwochi et al. (33) | Nigeria | June 2012–May 2013 | Data for 261 infants admitted to a special care baby unit | Mean age at death: 4.44 days | 14.2% (37/261) | Severe form of perinatal asphyxia (n = 3, 8%), neonatal sepsis (n = 1, 4%) |
| Costa et al. (34) | Portugal | 2004–2008 | Data for 1,938 infants admitted to a NICU | Median GA: 34 weeks Median age at death: 10.5 days (range: 0–317 days) |
5.7% (110/1,938) | Congenital malformations, including cardiac anomalies (n = 55, 50%), prematurity with its complications (n = 37, 33.6%), infection (n = 5, 4.5%), and HIE (n = 3, 2.7%) |
| Parappil et al. (35) | Qatar | 2002–2006 | Data for 597 infants admitted to a tertiary-level NICU | GA of 28–32 weeks | Total mortality rate: 6.5% (39/597) Mortality rate for 29 weeks GA: 14.5% (9 deaths) Mortality rate for 30 weeks GA: 12.9% (15 deaths) Mortality rate for 31 weeks GA: 3.9% (6 deaths) Mortality rate for 32 weeks GA: 3.4% (9 deaths) Early mortality rate (<7 days): 35.89% of total mortality (14/39) Late mortality rate (>7 days): 64.11% of total mortality (25/39) |
Lethal congenital and chromosomal anomalies (n = 12, 30.77%), sepsis (n = 11, 28.20%), severe birth asphyxia (n = 6, 15.30%), NEC (n = 4, 10.25%), pulmonary hemorrhage (n = 3, 7.69%), hydrops/congenital infection (n = 3, 7.69%) |
| Pepler et al. (36) | South Africa | 2007–2008 | Data for 1,578 infants born in 2007 and 2,376 infants born in 2008 admitted to 15 NICUs in private hospitals | Median GA in 2008: 35.9 weeks (range: 23–42.3 weeks) | 2007: 3.1% (49/1,578) 2008: 3.8% (91/2,376) |
Not listed |
| Musooko et al. (37) | Uganda | February 1–March 31, 2013 | Data for 635 infants, including 341 infants with severe perinatal morbidity, admitted to a NICU | GA of ≥28 weeks Average GA for the 341 infants: 36.0 ± 1.3 weeks Age at death: 17 (45.9%) of the 37 early neonatal deaths occurred on the first day of life, 7 (18.9%) on the second day, 4 (10.8%) on the third day, and 9 (24.3%) between the fourth and seventh days |
Overall mortality rate for all NICU patients in 2012: 26–29% Early neonatal death rate (death within 7 days of birth) of the 635 admissions: 12.4% (79/635) Early neonatal death rate of the 341 infants: 10.9% (37/341) |
Not listed |
| Alleman et al. (38) | United States of America | 2006–2009 | Data for 5,418 extremely low birth weight (401–1,000 g) infants born at 16 Neonatal Research Network centers | GA of 22–28 weeks | Median mortality of all infants in the 16 centers: 34% (~1,842/5,418) (range: 11–53%) Median mortality of infants <25 weeks GA in the 16 centers: 63% (range: 28–90%) Median mortality of infants ≥25 weeks GA in the 16 centers: 16% (range: 7–26%) |
Not listed |
| Lake et al. (39) | United States of America | 2007–2008 | Data for 72,235 very low birth weight (501–1,500 g) infants born at 558 Vermont Oxford Network hospital NICUs | Mean GA: 28.2 weeks (n = 72,235) | 12.9% (9,278/71,936) | Not listed |
BPD, bronchopulmonary dysplasia; CDH, congenital diaphragmatic hernia; DIC, disseminated intravascular coagulation; g, grams; GA, gestational age; HIE, hypoxic-ischemic encephalopathy; HMD, hyaline membrane disease; ICH, intracranial hemorrhage; IVH, intraventricular hemorrhage; n, number; NEC, necrotizing enterocolitis; NICU, neonatal intensive care unit; RDS, respiratory distress syndrome; SIDS, sudden infant death syndrome; SIP, spontaneous intestinal perforation.