Trafficking in Persons Report Improvement Act of 2011 - Amends the Trafficking Victims Protection Act of 2000 to revise the annual trafficking in persons report, including by requiring that the report: (1) describes U.S. and foreign government anti-trafficking efforts according to the certain standards and criteria set forth in such Act, (2) describes the nature and scope of trafficking in persons in each country, and (3) analyzes the trend lines for individual governmental efforts.