Identifying risks for male street gang affiliation: a systematic review and design and validation of the gang affiliation risk measure (GARM)

This study aimed to create the first measure of risk for UK gang-affiliation. A pilot stage invited gang affiliated and non-gang affiliated participants between the ages of 16–25 to retrospectively self-report on 58 items of risk exposure at the age of 11. Based on performance of these items, a 26-item measure was developed and administered to a main study sample (n=185) of gang affiliated and non-gang affiliated participants. Categorical Principal Component Analysis was applied to data, yielding a single-factor solution (historic lack of safety and current perception of threat). A 15-item gang-affiliation risk measure (GARM) was subsequently created. The GARM demonstrated good internal consistency, construct validity and discriminative ability. Items from the GARM were then transformed to read prospectively, resulting in a test measure for predictive purposes (T-GARM). However, the T-GARM requires further validation regarding its predictive utility and generalisability.