Health care-associated infections are one of the most common adverse events in health care, although a large proportion is preventable using effective infection prevention and control (IPC). Generating high-quality IPC evidence can be challenging given the complex nature of interventions. My thesis employed pragmatic methods to assess IPC interventions and contribute to evidence gaps. Paper one was a systematic review and reanalysis of quasi-experimental studies to assess the impact of IPC on carbapenem-resistant Gram-negative bacilli. Effective intervention components were identified that could be translated into global recommendations. Paper two was a global reliability and usability study which evaluated the WHO IPC assessment framework before its dissemination in health care facilities. Paper three included semi-structured interviews with IPC experts in low-resource countries and a qualitative assessment to identify IPC implementation themes in these settings. A range of themes were categorised according to the WHO IPC core components to inform practical guidance.