Among 3,334 eligible general practitioners , significantly higher response rates were achieved in the unconditional group ( 167 of 1,101 , 15 % ) compared with the conditional group ( 118 of 1,111 , 11 % ) ( P = 0.0014 ) , and both were significantly higher than the control group ( 74 of 1,122 , 7 % ; both P < 0.001 ) .