**Background:** Vulnerable children exposed to Adverse Childhood Experiences (ACEs) are often invisible in healthcare and social welfare systems, particularly in low- and middle-income countries (LMICs) where integration of biopsychosocial care into traditional medical models is delayed. Poverty, political instability, ethnic conflict, and natural disasters exacerbate ACEs in these settings. Early identification of ACEs could reduce morbidity and mortality, yet little is known about available screening instruments suitable for frontline primary care in resource-limited settings. This systematic review aimed to identify, evaluate, and summarise existing screening instruments used to measure risk factors related to ACEs in vulnerable children aged 5–18 years in primary healthcare settings in LMICs.
**Methods:** The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. A search of MEDLINE, PubMed, CINAHL, PsycINFO, Web of Science, Scopus, and ProQuest databases was conducted from database inception to April 2022. Eligible studies included those involving vulnerable children aged 5–18 years and reporting on risk assessment instruments for ACEs associated with poverty. A mixed-methods narrative synthesis was performed following the European Social Research Council Guidance. Quality assessment used the Joanna Briggs Institute Critical Appraisal tools and the Mixed Methods Appraisal Tool (MMAT) version 2018. Identified instruments were assessed for measurement properties using the COSMIN (COnsensus-based Standards for selecting health status Measurement Instruments) checklist, evaluating reliability, internal consistency, content validity, structural validity, and other properties.
**Key Results:** The search yielded 2,525 articles; after removing 1,441 duplicates, 1,084 articles were screened, 954 were excluded as irrelevant, and 130 full-text articles were assessed for eligibility. Twelve studies met inclusion criteria, from which 74 risk assessment instruments were initially retrieved. After excluding duplicates and instruments unrelated to childhood adversity associated with poverty, nine instruments were included for final review: (i) African Youth Psychosocial Assessment Instrument (AYPA), (ii) Child Psychosocial Distress Screener (CPDS), (iii) Malawi Developmental Assessment Tool (MDAT), (iv) Child Status Index (CSI), (v) IPAC (Instrument for Psychosocial Assessment for Child Workers), (vi) Developmental Trauma Inventory (DTI), (vii) WHOQOL-BREF, (viii) HIV Adolescence Stigma Scale, and (ix) Strengths and Difficulties Questionnaire (SDQ). Sample sizes in included studies ranged from 300 to 2,240. Geographically, studies were conducted in China, Malawi, South Africa, Uganda, Ethiopia, Kenya, and Burundi. Cronbach's alpha scores for all scales were above 0.8. COSMIN ratings ranged from 'Fair' (Child Status Index) to 'Good' (all other instruments). None of the nine instruments was found suitable for rapidly identifying the effects of ACEs in frontline clinical settings. Four key issues were identified: (1) retrospective nature of instruments—they captured past adversity rather than enabling rapid, prospective risk assessment; (2) decisional capacity of the rater—most instruments relied on self-report or caregiver report, problematic for homeless or drug-affected children without caregivers; (3) institutional capacity—instruments had too many items (e.g., MDAT had 136 items, AYPA had 60 items) for busy LMIC primary care settings with a physician-to-patient ratio of 0.7 per 1,000 population; (4) poor capacity to assess individual risk factors across biopsychosocial dimensions—most instruments used a single cause-effect model rather than addressing biological, psychological, and social dimensions holistically.
**Clinical Implications:** The absence of a suitable rapid screening instrument represents a critical gap in identifying vulnerable children exposed to ACEs in LMIC primary care settings. Without such tools, early signs of deterioration are missed, and opportunities for preventive care, treatment, and social support are lost. The review proposes a set of indicators (appearing in >80% of instruments) that could form the basis for a rapid assessment tool: thinking/learning/concentration difficulties, sadness, withdrawal, anxiety, homelessness, income insufficiency, limited access to healthcare, and fatigue. Healthcare systems in LMICs need to commit to infrastructure and resources to integrate biopsychosocial monitoring into routine care, establish functional multidisciplinary referral pathways, and train healthcare professionals to identify and advocate for vulnerable children. The findings underscore that instruments developed in high-income countries cannot simply be transplanted to LMIC settings due to differences in socioeconomic factors, cultural values, and health system structures.