the current hash is
{\\\"report_name\\\"=>\\\"Study/Control: ABIRATERONE ACETATE - 20151413355\\\", \\\"left_mue_start_date\\\"=>\\\"02-26-2015\\\",
To avoid using eval you could use JSON.parse ch.gsub('=>', ':') this way you will get a HASH from your HASH stored as STRING
eval
JSON.parse ch.gsub('=>', ':')
HASH
STRING