La Trobe

File(s) stored somewhere else

Please note: Linked content is NOT stored on La Trobe and we can't guarantee its availability, quality, security or accept any liability.

Patient-specific record linkage between emergency department and hospital admission data for a cohort of people who inject drugs: methodological considerations for frequent presenters

journal contribution
posted on 2021-01-18, 03:12 authored by R Di Rico, D Nambiar, B Gabbe, M Stoové, Paul DietzePaul Dietze
© 2020, The Author(s). Background: People who inject drugs (PWID) have been identified as frequent users of emergency department (ED) and hospital inpatient services. The specific challenges of record linkage in cohorts with numerous administrative health records occurring in close proximity are not well understood. Here, we present a method for patient-specific record linkage of ED and hospital admission data for a cohort of PWID. Methods: Data from 688 PWID were linked to two state-wide administrative health databases identifying all ED visits and hospital admissions for the cohort between January 2008 and June 2013. We linked patient-specific ED and hospital admissions data, using administrative date-time timestamps and pre-specified linkage criteria, to identify hospital admissions stemming from ED presentations for a given individual. The ability of standalone databases to identify linked ED visits or hospital admissions was examined. Results: There were 3459 ED visits and 1877 hospital admissions identified during the study period. Thirty-four percent of ED visits were linked to hospital admissions. Most links had hospital admission timestamps in-between or identical to their ED visit timestamps (n = 1035, 87%). Allowing 24-h between ED visits and hospital admissions captured more linked records, but increased manual inspection requirements. In linked records (n = 1190), the ED ‘departure status’ variable correctly reflected subsequent hospital admission in only 68% of cases. The hospital ‘admission type’ variable was non-specific in identifying if a preceding ED visit had occurred. Conclusions: Linking ED visits with subsequent hospital admissions in PWID requires access to date and time variables for accurate temporal sorting, especially for same-day presentations. Selecting time-windows to capture linked records requires discretion. Researchers risk under-ascertainment of hospital admissions if using ED data alone.


The Melbourne Injecting Drug User Cohort Study (MIX) was funded by The Colonial Foundation Trust and the National Health and Medical Research Council (NHMRC Grants #545891, 1126090, and the Centre for Research Excellence into Injecting Drug Use, #1001144). The Burnet Institute receives valuable support from the Victorian Operational Infrastructure Support Program. The funders had no role in the study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication. PD has received funding from Gilead Sciences Inc. for an investigator-driven grant and an untied educational grant from Indivior for work unrelated to this study. MS has received funding from Gilead Sciences Inc. and Bristol-Myers Squibb for investigatordriven grants. BG was supported by an Australian Research Council Future Fellowship (FT170100048). PD (#1163908) and MS (#1136970) are supported by NHMRC Senior Research Fellowships.


Publication Date



BMC Medical Research Methodology





Article Number

ARTN 283







Rights Statement

The Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.