Validation of a Clinical Decision Rule to Predict Abuse in Young Children Based on Bruising Characteristics

Abstract

Importance: Bruising caused by physical abuse is the most common antecedent injury to be overlooked or misdiagnosed as nonabusive before an abuse-related fatality or near-fatality in a young child. Bruising occurs from both nonabuse and abuse, but differences identified by a clinical decision rule may allow improved and earlier recognition of the abused child.

Objective: To refine and validate a previously derived bruising clinical decision rule (BCDR), the TEN-4 (bruising to torso, ear, or neck or any bruising on an infant <4.99 months of age), for identifying children at risk of having been physically abused.

Design, setting, and participants: This prospective cross-sectional study was conducted from December 1, 2011, to March 31, 2016, at emergency departments of 5 urban children's hospitals. Children younger than 4 years with bruising were identified through deliberate examination. Statistical analysis was completed in June 2020.

Exposures: Bruising characteristics in 34 discrete body regions, patterned bruising, cumulative bruise counts, and patient's age. The BCDR was refined and validated based on these variables using binary recursive partitioning analysis.

Main outcomes and measures: Injury from abusive vs nonabusive trauma was determined by the consensus judgment of a multidisciplinary expert panel.

Results: A total of 21 123 children were consecutively screened for bruising, and 2161 patients (mean [SD] age, 2.1 [1.1] years; 1296 [60%] male; 1785 [83%] White; 1484 [69%] non-Hispanic/Latino) were enrolled. The expert panel achieved consensus on 2123 patients (98%), classifying 410 (19%) as abuse and 1713 (79%) as nonabuse. A classification tree was fit to refine the rule and validated via bootstrap resampling. The resulting BCDR was 95.6% (95% CI, 93.0%-97.3%) sensitive and 87.1% (95% CI, 85.4%-88.6%) specific for distinguishing abuse from nonabusive trauma based on body region bruised (torso, ear, neck, frenulum, angle of jaw, cheeks [fleshy], eyelids, and subconjunctivae), bruising anywhere on an infant 4.99 months and younger, or patterned bruising (TEN-4-FACESp).

Conclusions and relevance: In this study, an affirmative finding for any of the 3 BCDR TEN-4-FACESp components in children younger than 4 years indicated a potential risk for abuse; these results warrant further evaluation. Clinical application of this tool has the potential to improve recognition of abuse in young children with bruising.

Figure 1.. Flow of Patient Enrollment

Screening for bruising and patient eligibility with final enrollment counts and expert panel categorization of abuse and nonabuse. ED indicates emergency department.

Figure 2.. Occurrence of Bruises in Body Regions

The χ² statistics were derived from tests of bruising in each body region against abuse status, with signs defined by direction of association (positive is defined as abuse greater than nonabuse). Body regions are sorted in order of discriminatory power for abuse, defined by the signed χ² statistic. GU indicates genitourinary.

Figure 3.. Bruising Clinical Decision Rule (BCDR)

A, Classification of patients into abuse and nonabuse groups based on dichotomous independent variables (ie, TEN-4 [bruising to the torso, ear, and/or neck or any bruising on an infant <4 months of age]), positive, patterned bruise, or FACES [frenulum, angle of jaw, cheeks (fleshy), eyelids, subconjunctivae] bruise) according to an expert panel. The BCDR results were positive for 613 patients, of whom 392 were abuse patients and 221 nonabuse patients. The BCDR results were negative in 1713 patients, of whom 1492 were nonabuse patients and 18 abuse patients. B, Classification summary. C, Diagnostic accuracy statistics. Data in parentheses are 95% CIs. LR indicates likelihood ratio; NPV, negative predictive value; PPV, positive predictive value.