How many key informants are enough? Analysing the validity of the community readiness assessment

Abstract

Abstract Objective Communities are important settings for health promotion and prevention. The community readiness assessment offers a structured approach to assess resources and opportunities to tackle a health problem within a community. The assessment relies on semi-structured interviews with key informants from the communities. A number of 4–6 key informant interviews are recommended in the literature. However, it is unclear whether this is sufficient to obtain a valid representation of the respective community. This study analysed whether increasing the number of key informants from 4–6 to 12–15 alters the results of the community readiness assessment. Results A total of 55 community readiness interviews were carried out in 4 communities. Overall, the community readiness scores showed little variation after having interviewed 10 key informants in a community. However, even after completing 10 interviews in a community, key informants were still able to identify up to 6 new information items regarding community efforts for physical activity promotion among the elderly, contact and communication channel for informing or approaching the target group, or barriers to participation.