SOURCE AND COUNTRY OF TRIAL BIAS:
When the quality of a study is determined based on the country where it was conducted, instead of its scientific qualities. Specifically, when a study is judged to be of low quality because it was not conducted in that persons home country1, or a country which that person believes to be superior.
Source and Country of Trial Bias is a specific type of Interpretive Bias, and is similar to Language Bias. Source and Country of Trial Bias may introduce Publication Bias in systematic or other review studies, if research papers are excluded based on geographic region alone. Arguably, Source and Country of Trial Bias would not be an issue if was scientifically reasonable (e.g. for generalizability reasons etc.) to exclude studies from certain regions; but this would depend on the context of the study. Also see: Interpretive Bias, Language Bias, and Publication Bias.
Reference:
1. Earl-Slater A. The Handbook of Clinical Trials and Other Research. Abingdon: Radcliffe Medical Press Ltd. 2002. (Link to Reference)