Appropriate hand hygiene at the five evidence-based moments proposed by the World Health Organization (WHO) during the delivery of patient care by healthcare workers (HCWs) is crucial in the prevention and control of healthcare associated infections. Audits of hand hygiene are required by health and social care regulators and organisations to provide assurance of practice. Compliance with hand hygiene is frequently low and electronic monitoring systems (EMSs) offer a potential way of generating data to inform improvement to practice which avoids some of the drawbacks of auditing via direct observation. It is important that these electronic systems generate data which is reflective of the reality of frontline practice in terms of the occurrence of opportunities for hand hygiene. Therefore, this mixed methods research aimed to fill a key gap in this field by developing a denominator for hand hygiene based on the average number of opportunities on inpatient wards in England. This was achieved via observations of the provision of care by frontline HCWs on two wards. In addition, compliance data captured during observations of care was compared with data from an EMS running concurrently on the wards. Following this, the second phase of the research explored the findings from the observation phase through interviews with frontline HCWs. Interview topics included the practical application of the five moments for hand hygiene, the role of audit in driving practice, the potential role of EMSs, and the impact on hand hygiene behaviour of the COVID-19 pandemic. This data can not only be used to inform a denominator for EMSs but also provides additional knowledge of the burden of hand hygiene for HCWs. Further to this, interviews revealed some of the key challenges and common issues which arise when applying hand hygiene in the dynamic hospital environment. It was found that during the COVID-19 pandemic the use of personal protective equipment (PPE) and motivation of self-protection created barriers to effective hand hygiene practice. This thesis provides insight into the perceived value and trustworthiness of data gathered during direct audit of practice, bringing its usefulness into debate. With triggers to audit, and greater staff engagement, often seen as a reactive response to an outbreak of infection rather than an ongoing process of embedded preventative practices. Of particular interest was how EMSs may be accepted as an adjunct to, not a replacement of, existing audit practice.