In clinical trials,patient name,date of birth,and sex are items of medical information used to refer to patients.Generally speaking,patient names are indicated by their initials.However,there are doubts as to whether patients may remain completely unidentified when initials are used.
In this study,we investigated the identification levels of patients through the combination of the above three patient data items in post marketing surveillance data.We also investigated the necessity of items recorded in case registration forms for pharmaceutical companies and medical institutions.
We investigated combinations of“K.K”and“Jan.2,1947”which were assumed to relate to the largest populations in the database of patient medical information at Kanazawa University Hospital.The total number of patients in the database with combinations of the above was 358,251.The number of patients with the initials“K.K.”was 7,892(1/45),that with the initials“K.K”and“1947”was 173(1/2000),and that with the initials“K.K”,“1947" and“Jan”was 23,while there were only 4 patients(1/8500)with the initials“K.K.”“1947”,“Jan”and ”2”.
These results indicate that it would be possible to identify patients from the combination of their initials and their date of birth(DD/MM/YY).However,the size of the patient population in each medical institution’s database would be an important factor since it would determine the extent to which this could be done.From the point of view of protecting personal information,it is thus necessary to consider whether it is appropriate to use patients' initials and dates of birth based on the size of patient population.
