I thought it might be good to post some of the articles and material I come across. Here's a recent study of SBS incidence in North Carolina that was published in the Journal of the American Medical Association earlier this month...

A Population-Based Study of Inflicted Traumatic Brain Injury in Young Children
Heather T. Keenan, MDCM, MPH; Desmond K. Runyan, MD, DrPH; Stephen W. Marshall, PhD; Mary Alice Nocera, RN, MSN; David F. Merten, MD; Sara H. Sinal, MD
JAMA. 2003;290:621-626.

Context Physical abuse is a leading cause of serious head injury and death in children aged 2 years or younger. The incidence of inflicted traumatic brain injury (TBI) in US children is unknown.

Objective To determine the incidence of serious or fatal inflicted TBI in a defined US population of approximately 230 000 children aged 2 years or younger.

Design, Setting, and Subjects All North Carolina children aged 2 years or younger who were admitted to a pediatric intensive care unit or who died with a TBI in 2000 and 2001 were identified prospectively. Injuries were considered inflicted if accompanied by a confession or a medical and social service agency determination of abuse.

Main Outcome Measure Incidence of inflicted TBI. Multivariate logistic regression models were used to compare children with inflicted injuries with those with noninflicted injuries and with the general state population aged 2 years or younger.

Results A total of 152 cases of serious or fatal TBI were identified, with 80 (53%) incurring inflicted TBI. The incidence of inflicted traumatic brain injury in the first 2 years of life was 17.0 (95% confidence interval [CI], 13.3-20.7) per 100 000 person-years. Infants had a higher incidence than children in the second year of life (29.7 [95% CI, 22.9-36.7] vs 3.8 [95% CI, 1.3-6.4] per 100 000 person-years). Boys had a higher incidence than girls (21.0 [95% CI, 15.1-26.6] vs 13.0 [95% CI, 8.4-17.7] per 100 000 person-years). Relative to the general population, children who incurred an increased risk of inflicted injury were born to young mothers (21 years), non–European American, or products of multiple births.

Conclusions In this population of North Carolina children, the incidence of inflicted TBI varied by characteristics of the injured children and their mothers. These data may be helpful for informing preventive interventions.