Friday, January 02, 2009

On the incidence of inflicted injury: appearance and reality

The article on inflicted injuries in Sweden prompted a couple of thoughts...

Looking up the birth rate, I was surprised to find the crime rate in Sweden is reported to be above average for EU counties.

With 107,400 births, applying the rates of inflicted head injury found by the Barlow/Minns (24/100,00 under age 1) and Dias (41.5/100,000) studies, the expected incidence of inflicted head injury would be somewhere between 26 and 45 cases a year.

Tracking the Barlow and Minns paper, I found several studies of incidence, with some wide variation in rates. There seem to be a number of reasons that contribute to the diversity:

- the criteria used to define SBS/AHT/NAHI cases included in the studies vary;
- sources of case information are generally secondary;
- the upper age range of cases included in the study vary - age limit of one or two years were common, but the 2001 AAP Technical Report states injury can result up to age 5 (and there is a report of injury inflicted by shaking at age 7);
- the quality of diagnosis varies cnsiderably among hospitals
- medical professionals elect not to report cases of suspected abuse; see also Sege and Flaherty, Forty years later: inconsistencies in reporting of child abuse, Arch Dis Child, 2008 93: 822-82; a 2005 study of Pennsylvania pediatricians

Other sources on incidence:

King et al. Shaken Baby Syndrome in Canada:clinical characteristics and outcomes of hospital cases
2003 Can. Med. Assoc. J., 168(2): 155-159
10.6/100,000 (under age 5)
Email: king @

Kessler, Dias et al. Demographics of Abusive Head Trauma in the Commonwealth of Pennsylvania, J. Neurosurgery in Pediatrics, May 2008 Vol 1(5)
14.7/100,000 under age 2
Email: Mdias @

Keenan et al. A Population-Based Study of Inflicted Traumatic Brain Injury in Young Children, JAMA, August 2003;290:621-626
17.0/100,000 under age 2
Email heather.keenan @

Talvik et al. Inflicted traumatic brain injury (ITBI) or shaken baby syndrome (SBS) in Estonia, Acta P├Ždiatrica, 2007 Vol 95(7), 799 - 804 (dissertation)
28.7/100,000 infants
Email: inga.talvik @

Wirtz et al, Passive surveillance of shaken baby syndrome using hospital inpatient data, Am J Prev Med., 2008 34(4 Suppl): S134-9
Using CA inpatient data (1998-2004)
5.1/100,000 "strict SBS definition
14.0/100,000 "broader" SBS definition
Email: steve.wirtz @

Minns et al., Incidence and demography of non-accidental head injury in southeast Scotland from a national database, Am J Prev Med, 2008 34(4 Suppl):S126-33
33.8/100,000 infants (NAHI)
Email: Robert.Minns @

Alexander et al., Incidence of impact trauma with cranial injuries ascribed to shaking, 1990 Am J Dis Child 144:724-726

Jayawant et al.,  Subdural haemorrhages in infants: population based study. 1998 BMJ 317:1558–61.
12.8/100,000 (SDH, 82% suggestive of abuse, under age 2)
21.0/100,000 (SDH under age 1)
kempam @

Kelly, P. Infantile subdural haematoma in Auckland, New Zealand: 1988–1998, 2004 J. NZ Med Assn Vol 117(1204)

Kelly P et al., Shaken baby syndrome in New Zealand, 2000-2002, 2007 J Paediatr Child Health, 12,
14.7/100,000 'minimum' inflicted infantile SDH
19.6 per 100,000 'maximum'
Email: patrickk @

Barlow KM, Minns RA; Annual incidence of shaken impact syndrome in young children. Lancet 356:1571-1572, 2000 [requires free Lancet registration]

Gessner et al. Incidence of infant physical abuse in Alaska, Child Abuse & Neglect, 2004 28, 9-23
66/100,000 (inflicted head injuries, contrasting incidence reported in Barlow and discussing possible reasons)
Email: Brad_Gessner @

Sun et al. , Non-accidental subdural haemorrhage in Hong Kong: incidence, clinical features, management and outcome, Child's Nervous System, 2006 Vol 22(6) 593-598
1.5/100,000 children under age 5
Email: wpoon @

Incidence of reported shaking in response to crying

Reijneveld, Infant Crying and Abuse, Lancet (2004)
5.6% parents of children 6 months reported shaking, slapping, smothering

Theodore et al. Epidemiologic Features of the Physical and Sexual Maltreatment of Children in the Carolinas, Pediatrics, Vol 115(3), March 2005, e331-e337
2.6% of US parents reported shaking of a child under age 2 in their household

Runyan, The Challenges of Assessing the Incidence of Inflicted Traumatic Brain Injury: A World Perspective, Vol 34(4) Supplement, S112-S115 (April 2008)
While 2.6% of parents of children aged under 2 years in the U.S. report shaking their child as an act of “discipline,” survey data from lesser-developed countries on four continents indicate that shaking, as a form of discipline, may be many times more common among infants in their countries and that the consequences, short of hospitalization or death, are inadequately studied.

1 comment:

Des Runyan said...

Sorting out the incidence will be important as we assess the usefulness of state laws and educational programs to reduce child abuse. Some states (e.g. Massachusetts) are substituting a shorter video for the one that was tested by Dias and colleagues in New York without any evaluation of effectiveness because it is cheaper. These efforts to characterize the incidence are important because we will need these data to determine if the laws triggering education are effective. The studies vary by who was included and by definitions. The Ellingson study only included children who survived to discharge- when compared to the Keenan study with dead children removed, the rates were identical. We looked at our North Carolina experience related to age, the oldest child we had in our hospital during a 6 year period was 19 months. It takes a very strong person to inflict life-threatening to a child who weighs more than a bowling ball. In North and South Carolina, more mothers indicated that they had shaken a child than that their partners had but when only hospitalized cases were examined, 70% of the children were shaken by males. Overall, current data indicate that this is a problem for about 30 out of every 100,000 newborns and that the rate is about 1/8th of that in the second year of life.
My other comment is that it will be tough to show an impact of education programs in the downturn of the economy. A paper in Child Maltreatment this month, looking at the Triple-P prevention program for child abuse, noted a 50% increase in child abuse cases in the counties that were controls and only about a 10% increase in cases in counties with the prevention program. The prevention program is reported as a success as it slowed the rise but all counties had an increase in cases.