<qa>  What is the purpose of the post-marketing surveillance?This study is a post-marketing surveillance to monitor safety and efficacy of adefovir dipivoxil and identify SAEs, adverse drug reactions ADRs, and unexpected AEs not described as precautions or warnings and to identify possible factors that have an effect on the AEs and to assess effectiveness of adefovir dipivoxil in real clinical practices after marketing. The subjects are patients prescribed for adefovir dipivoxil by the investigators at the sites based on prescription information in normal clinical practices. 