In repeated-measures analysis pooling all data , mean posttest knowledge scores were highest for the 10 - and 15-question formats ( 75.7 [ 1.1 ] and 74.4 [ 1.0 ] , respectively ) and lower for 0 - , 1 - , and 5-question formats ( 73.1 [ 1.3 ] , 72.9 [ 1.0 ] , and 72.8 [ 1.5 ] , respectively ) ; P = .04 for differences across all modules .