The ` cohort ' and ` control ' groups accessed the material to a similar extent ( 59 % versus 57 % ) while the ` intervention ' group were more likely to access it ( 78 % ) and to read it for longer ( median 35 s ( 25th and 75th percentiles : 6 , 97 ) versus medians of 7 s ( 0 , 28 ) and 8 s ( 4 , 42 ) for the ` cohort ' and ` control ' groups , respectively ) .