Informed consent to record linkage: A systematic review

Background: Record linkage methods have been widely used in public health research but its use demands the discussion of privacy issues. Purposes: To systematically review studies which address informed consent and record linkage. Methods: A computer-assisted search of the PubMed electronic databases up to November 2008 was performed using the following terms: “record linkage” and “consent”. We included articles published in the following languages: Portuguese, Spanish, English and French. Study selection and data extraction was conducted independently by two reviewers. Results: Out of 52 citations, we identified 49 studies eligible for inclusion. 71.4% of articles were published after 2000, coinciding with the introduction of laws addressing privacy of health information in different countries. Articles were published in Medical (26; 53.1%), Public Health (12; 24.5%); Law – (6; 10.2%) and Informatics (5; 10.2%) journals. With regard to the country of the main author's institution of affiliation, there is a predominance of UK, USA and Canada, countries with longer running traditions in using record linkage techniques and where the oldest integrated health record registries using such methods are located. The majority of the studies are theoretical, with no empirical data about the actual proportion of participant consent. Conclusion: Despite the increasing utilization of record linkage techniques in research, the issues related to participant consent are not yet adequately addressed.