Tuesday 04 November 2014 Health insurance company Zilveren Kruis has apologised to policyholders after sending them a survey about their hospital treatment using the details of another patient . The mistake meant policyholders received a form containing the initials and surname , hospital department and length of treatment of someone one else . The forms did not include details of the ailment . Something went wrong when the file was being compiled and the information was wrongly linked to the address list , director of customer services Annemiek Heijer told Radio 1 news . The mistake , she said , is down to human error . In total , 2643 people were sent the forms a patient satisfaction survey using someone elses details . ;