The Extended Modified Maltreatment Classification System (EMMCS): A validation study

One way to measure maltreatment is to code the narratives in Child Protective Services (CPS) files on a standardized instrument. This serves to document dimensions of maltreatment-such as types/subtypes, severity, frequency and chronicity-difficult if not impossible to measure from administrative data. The instrument most commonly used for this purpose is the Modified Maltreatment Classification System (MMCS, English & Longscan, 1997). Few studies have focused on the psychometric properties of such instruments.

This study sought to present the Extended Modified Maltreatment Classification System (EMMCS) and inter-rater reliability and convergent validity data for this updated instrument.

The convenience sample was composed of the CPS files of 240 children 0 to 17 years old reported to a single CPS agency in Québec (Canada) and for which the allegations were declared substantiated by CPS practitioner.

Written narratives were coded on two instruments: the EMMCS (two coders) and the form used in the Étude d'incidence québécoise sur les situations évaluées en protection de la jeunesse - short form (FEIQ-SF, one coder). Inter-rater reliability was assessed by calculating kappas and intra-class correlations for all variables generated by the EMMCS for two coders and convergent validity by measuring the relationship between the EMMCS maltreatment variables and: a) the FEIQ-SF maltreatment variables and b) the FEIQ-SF child's functioning problems on the FEIQ.

Inter-rater agreement on nearly all EMMCS variables (97 %) proved excellent, and EMMCS maltreatment type variables showed good convergent validity with FEIQ-SF variables (narrow convergent validity) and with indicators of child's functioning problems (broad convergent validity).

Overall, the results of our study indicate that the EMMCS possesses excellent inter-rater reliability and good convergent validity. These promising results underscore the potential of the EMMCS to become a reference in the field.