Participants with an abnormal test result were randomized to 1 of 3 message formats designed to evaluate trade-offs between clarity and privacy : ( 1 ) an SMS text message that stated results were abnormal and requested return to clinic ( `` direct '' ) , ( 2 ) the same message protected by a 4-digit PIN code ( `` PIN '' ) , and ( 3 ) the message `` ABCDEFG '' explained at enrollment to indicate abnormal results ( `` coded '' ) .