RESUMEN
BACKGROUND: Joint health and safety committees (JHSCs) are widely acknowledged as important to a healthy and safe work environment. However, it is also generally believed that having a JHSC is necessary but not sufficient; the JHSC must be effective. METHODS: A systematic review was undertaken to find empirical studies regarding the effectiveness of JHSCs; realist review methodology was applied to determine context-mechanism-outcome patterns. Experts from across Canada and from various sectors and perspectives including government, employers, and unions, were brought together to inform the synthesis. RESULTS: Thirty-one studies met inclusion criteria. Mechanisms identified as important determinants of JHSC effectiveness across various jurisdictions include adequate information, education and training; appropriate committee composition; senior management commitment to JHSCs; and especially a clear mandate with a broad scope and corresponding empowerment (through legislation and/or union presence). CONCLUSIONS: Consistent empowerment mechanisms emerge as determinants of successful JHSCs across contexts despite few evidence-based details for best practice implementation. Intervention research is warranted.