BACKGROUND: Iatrogenic events are increasingly recognised as an important 
problem in all people admitted to hospital. However, few epidemiological data 
are available for iatrogenic events in neonatal high-risk units. We aimed to 
assess the incidence, nature, preventability, and severity of iatrogenic events 
in a neonatal centre and to establish the association of patient characteristics 
with the occurrence of iatrogenic events in neonates.
METHODS: We undertook an observational, prospective study from Jan 1, 2005, to 
Sept 1, 2005, including all neonates admitted in the Division of Neonatology of 
an academic, tertiary neonatal centre in southern France. Iatrogenic events were 
defined as any event that compromised the safety margin for the patient, in the 
presence or absence of harm. The report of an iatrogenic event was voluntary, 
anonymous, and non-punitive. The primary outcome was the rate of iatrogenic 
events per 1000 patient days.
FINDINGS: A total of 388 patients were studied during 10 436 patient days. We 
recorded 267 iatrogenic events in 116 patients. The incidence of iatrogenic 
events was 25.6 per 1000 patient days. 92 (34%) were preventable and 78 (29%) 
were severe. Two iatrogenic events (1%) were fatal, but neither was preventable. 
The most severe iatrogenic events were nosocomial infections (49/62 [79%]) and 
respiratory events (nine of 26 [35%]). Cutaneous injuries were frequent (n=94) 
but generally minor (89 [95%]), as were medication errors (15/19 [76%]). Most 
medication errors occurred during administration stage (12/19 [63%]) and were 
ten-fold errors (nine of 19 [47%]). The major risk factors were low birthweight 
and gestational age (both p<0.0001), length of stay (p<0.0001), a central venous 
line (p<0.0001), mechanical ventilation (p=0.0021), and support with continuous 
positive airwary pressure (p=0.0076).
INTERPRETATION: Iatrogenic events occur frequently and are often serious in 
neonates, especially in infants of low birthweight. Improved knowledge of the 
incidence and characteristics of iatrogenic events, and continuous monitoring 
could help to improve quality of health care for this vulnerable population.