Key Informants in Applied Qualitative Health Research.

Identifying and recruiting key informants is a widely used sampling strategy in applied qualitative health research. Key informants were first conceptualized within ethnography, but there is little methodological guidance about how to use this technique outside of that research tradition. The objective of this article is to offer practical suggestions about how existing methods for data collection with key informants could be translated to methodologies commonly used in applied qualitative health research. This article delineates how key informants could be conceptualized and sampled and how data sufficiency can be approached. The article prompts deeper consideration of the politics of representation and epistemic power that are inherent to the use of key informants in applied qualitative health research.