Computerised linking of medical records: methodological guidelines.
OBJECTIVE
To report on the development of computer assisted methods for linking medical records and record abstracts.


METHODS
The methods include file blocking, to put records in an order which makes searching efficient; matching, which is the process of comparing records to determine whether they do or do not relate to the same person; linkage, which is the process of assembling correctly matched records into a time sequenced composite record for the individual; and validation checks and corrections, in which any inconsistencies between different records for the same person are identified and corrected.


METHODS
The dataset comprising the Oxford record linkage study which includes hospital inpatient records and vital records.


CONCLUSIONS
Probability matching, using an array of identifiers, achieves much higher levels of correct matching than is generally achievable by exact character by character comparisons. The increasing use of information technology to store data about health and health care means that there is increasing scope to link records for research and for patient care. Sophisticated methods to achieve this on a large scale are now available.
Gill
L
L
Department of Public Health and Primary Care, University of Oxford, Oxford Regional Health Authority, Headington.
Goldacre
M
M
Simmons
H
H
Bettley
G
G
Griffith
M
M
D004739:England; D006801:Humans; D008498:Medical Record Linkage; D016347:Medical Records Systems, Computerized; D012984:Software