Occupational noise-induced hearing loss in South African large-scale mines: exploring hearing conservation programmes as complex interventions embedded in a realist approach.

Background. Complex interventions have been conducted in the field of public health to improve health at the individual, organizational policy or population level. In occupational audiology, hearing conservation programmes (HCPs), which are interventions to minimize or eliminate occupational noise-induced hearing loss, are currently not defined as complex interventions, despite them fitting the definition and features of complex interventions. Therefore, this study aimed to explore whether HCPs are a complex intervention, fitting the predefined criteria for complex interventions. Method. A qualitative, descriptive research design was conducted using three sources of data - document analysis, interviews and systematic review - to allow for triangulation. Data were collected through purposive sampling and qualitative content analysis was used. Results. This study confirmed that HCPs are a complex intervention founded on solid and consolidated theories. Therefore, these results paved the way for realist reviews to be conducted in the mining sector in South Africa in order to understand the mechanisms influencing the success or failure of HCPs locally. Conclusion. The success of HCPs in the mining sector depends on conducting contextually evidence-based evaluations such as realist reviews which can provide policy-makers with contextual evidence for why certain programmes do or do not work in certain settings.