Kirk DS - Researchers examined if re-incarceration risk could be reduced by relocating the residence of drug-dependent former prisoners to a different geographic area. Using Hurricane Katrina as a natural experiment, they performed a non-randomized observational study. Individuals released from Louisiana prisons from September 2003 to February 2004 with a history of drug misuse (n = 796) formed the pre-Katrina cohort. Prisoners released from a Louisiana prison immediately after the hurricane, from September 2005 to February 2006 (n=677) formed the post-Katrina cohort. Outcomes revealed reduction in the likelihood of re-incarceration in correlation to residential relocation of drug-dependent former prisoners in Louisiana as a result of Hurricane Katrina. Approximately 20% of the parolees who stayed were re-incarcerated within 1 year of their release from prison vs. 10% of parolees who moved.