JMIR Publications

ABSTRACT

Background:

Chronic kidney disease (CKD) and diabetes are major causes of death and disability. They are associated with high health service utilisation persisting over many years. Their slow progression and wide clinical variation makes them eminently suitable for study in population-based cohorts. However, current understanding of their prevalence, incidence and progression is largely based on studies conducted in clinical populations.

Objective:

To establish a novel link between an existing population-based cohort (the 45 and Up Study) and routinely-collected laboratory and administrative data to facilitate research across the full disease spectrum of CKD and diabetes.

Methods:

In the EXamining OuTcomEs in chroNic Disease in the 45 and Up Study (EXTEND45) Study, baseline questionnaire responses of over 260,000 45 and Up Study participants aged ≥45 years living in New South Wales (NSW), collected between January 2006 and December 2009, are linked to data from laboratory service providers as well as national and state-based administrative data sets via probabilistic linkage. Routinely-collected data were obtained for participants who could be linked between January 2005 and July 2013. Laboratory data will enable identification of early cases of chronic disease and assessment of clinically relevant biochemical targets during the disease course. Health administrative data sets will allow examination of health service use, pharmacological management and clinical outcomes.

Results:

The study received ethics approval from the NSW Population and Health Services Research Ethics Committee (PHSREC) in February 2014. Data linkage for 267,153 45 and Up Study participants was completed in June 2016, with congruent linkage achieved for 265,086 (99.2%) individuals. To date, the CKD and diabetes cohorts have been identified (published elsewhere) and a diverse portfolio of research projects relating to disease burden, risk factors, health outcomes and health service utilisation is in development.

Conclusions:

The EXTEND45 Study represents an unparalleled opportunity to perform extensive research into diseases of considerable public health and clinical importance. Strengths include the population-based nature of the cohort and the availability of longitudinal information on the complete disease pathway for affected individuals. Clinical Trial: This study has been registered in australianclinicaltrials.gov.au (Trial ID: ACTRN12615001366549)