Estimating the probability of abusive head trauma after abuse evaluation

Abstract

Background: Evidence-based, patient-specific estimates of abusive head trauma probability can inform physicians' decisions to evaluate, confirm, exclude, and/or report suspected child abuse.

Objective: To derive a clinical prediction rule for pediatric abusive head trauma that incorporates the (positive or negative) predictive contributions of patients' completed skeletal surveys and retinal exams.

Participants and setting: 500 acutely head-injured children under three years of age hospitalized for intensive care at one of 18 sites between 2010 and 2013.

Methods: Secondary analysis of an existing, cross-sectional, prospective dataset, including (1) multivariable logistic regression to impute the results of abuse evaluations never ordered or completed, (2) regularized logistic regression to derive a novel clinical prediction rule that incorporates the results of completed abuse evaluations, and (3) application of the new prediction rule to calculate patient-specific estimates of abusive head trauma probability for observed combinations of its predictor variables.

Results: Applying a mean probability threshold of >0.5 to classify patients as abused, the 7-variable clinical prediction rule derived in this study demonstrated sensitivity 0.73 (95% CI: 0.66-0.79) and specificity 0.87 (95% CI: 0.82-0.90). The area under the receiver operating characteristics curve was 0.88 (95% CI: 0.85-0.92). Patient-specific estimates of abusive head trauma probability for 72 observed combinations of its seven predictor variables ranged from 0.04 (95% CI: 0.02-0.08) to 0.98 (95% CI: 0.96-0.99).

Conclusions: Seven variables facilitate patient-specific estimation of abusive head trauma probability after abuse evaluation in intensive care settings.

Keywords: Abusive head trauma; Child abuse; Clinical prediction rule; Non-accidental trauma; Prediction tool.

Figure 1.. Estimates of AHT probability (with 95% CIs) for 72 observed combinations of the PediBIRN-7’ seven predictor variables, applying definitional criteria to classify AHT vs. non-AHT.

Abbreviations: AHT=abusive head trauma; CI-confidence interval; RESP=respiratory; PediBIRN=pediatric brain injury research network; PTA=prior to admission; TEN=torso, ear(s) or neck; SDH=subdural hemorrhage or fluid collection(s); fx(s)=fracture(s); HIE=hypoxic ischemic encephalopathy ¹ Defined a priori as any skull fracture(s) other than an isolated, unilateral, nondiastatic, linear, parietal skull fracture ² Defined a priori as skeletal survey that reveals rib fracture(s), classic metaphyseal lesion fracture(s), epiphyseal separation(s), fracture(s) of the scapula or sternum, fracture(s) of digit(s), vertebral body fracture(s) or dislocation(s), OR fracture(s) of spinous process(es) ³ Defined a priori as retinal exam by an ophthalmologist that reveals retinoschisis OR retinal hemorrhages described as dense, extensive, covering a large surface area, and/or extending to the ora serrate [NOTE: Clinicians should not use these probability estimates when applying the PediBIRN-4, as doing so would be to assume that skeletal survey and retinal exam are normal.]

Figure 2.. Estimates of AHT probability (with 95% CIs) for 72 observed combinations of the PediBIRN-7’s seven predictor variables, applying physicians’ final diagnoses to classify AHT vs. non-AHT.

Abbreviations: AHT=abusive head trauma; CI-confidence interval; RESP=respiratory; PediBIRN=pediatric brain injury research network; PTA=priorto admission; TEN=torso, ear(s) or neck; SDH=subdural hemorrhage or fluid collection(s); fx(s)=fracture(s); HIE=hypoxic ischemic encephalopathy ¹Defined a priori as any skull fracture(s) other than an isolated, unilateral, nondiastatic, linear, parietal skull fracture ²Defined a priori as skeletal survey that reveals rib fracture(s), classic metaphyseal lesion fracture(s), epiphyseal separation(s), fracture(s) of the scapula or sternum, fracture(s) of digit(s), vertebral body fracture(s) or dislocation(s), OR fracture(s) of spinous process(es) ³Defined a priori as retinal exam by an ophthalmologist that reveals retinoschisis OR retinal hemorrhages described as dense, extensive, covering a large surface area, and/or extending to the ora serrate [NOTE: Clinicians should not use these probability estimates when applying the PediBIRN-4, as doing so would be to assume that skeletal survey and retinal exam are normal.]