关键词: 全科医学, 质性研究, 样本量, 信息效能

Abstract: The use of qualitative methods in general practice research has important practical significance，which can better reflect the features of patient-centered care and promote the development of primary health care services. Qualitative research in general practice has reached a relatively mature stage in foreign countries，but it is still in a preliminary stage in China，and many practical problems will be encountered when conducting relevant studies，among them，a common problem is about sample size. However，there is no a standard answer to it. In general，the depth and breadth in one study are interdependent. As qualitative research focuses on a deeper and more detailed understanding of the research phenomenon，it is generally believed that the richness of data in qualitative research is far more important than the number of samples，and the sample size needs not to be too large. However，the sample size and its related reference dimensions still need to be considered when writing a qualitative research proposal. This article introduces the estimation of the sample size of qualitative interviews based on information power，to provide a reference for qualitative researchers.

Key words: General practice, Qualitative research, Sample size, Information power