Qualitative research methods allow investigators to gain a detailed understanding of phenomena, based on the collection and analysis of rich data. An important element of some qualitative studies is key informants (KIs)—those are a specific set of participants who are able to provide particularly valuable viewpoints and insights on the issues or questions being examined.1 2

The concept of using KIs dates back to early anthropological studies, where researchers relied on local experts to help better understand cultural practices and social structures. Over time, this approach has evolved, with increasing recognition of the value that KIs bring to a wide array of fields, including public health, education, social sciences, medicine and nursing.3 This ‘Research Made Simple’ article explores what KIs are, how they can benefit nursing and healthcare research and what practical steps can be taken by researchers to optimise the...