The ARID study is a prospective cohort study of people who suffered an acute kidney injury (AKI) during a hospital stay.
The ARID study includes people who had a non-elective hospital stay, but did not suffer an AKI. This is to take account of the natural aging effect causing a reduction in kidney function in some people.
Recruitment to the ARID Pilot Study ran from November 2011 to January 2013 and the final data review after five years took place in November 2017. Work on the ARID Pilot Study is now closed. The main aim of this study was to identify whether a full study was viable. The ARID Pilot Study is therefore considered to be successful.
Recruitment to the ARID Main Study began in April 2013 and was closed in April 2016. The first year follow-ups were completed in January 2017.
Third year follow-ups will continue until January 2019. Five year follow-ups started in February 2018 and will run until January 2021.
There is an increasing recognition that episodes of AKI may have profound longer term effect on renal function and patient outcomes. However, the majority of studies in this area are retrospective and many only focus on specific patient groups. There is therefore a need to examine the long term effects of AKI on patient outcomes in a prospective, UK based study that includes general hospitalised patients from across the entire spectrum of AKI severity.
We set up a long-term, observational case-control study to investigate the effects of AKI on patient outcomes. Cases (patients with AKI) and controls (those screened for AKI but who did not sustain it) were identified from a hospital-wide electronic reporting system for AKI based on the AKIN criteria.
Potential participants were contacted via post and invited to participate; all participants gave informed consent. The control group was matched to AKI patients on a 1:1 basis in terms of baseline eGFR (within the same CKD stage but as closely as possible) and age ± 5yrs. Renal function and proteinuria were measured at 3 months after AKI (or index hospital admission for controls) and will also be measured at 1 and 3 years. Baseline demographics, AKI data (baseline renal function, peak serum creatinine/AKI stage), co-morbidity and hospital stay data were extracted from electronic records.
|AKI||Acute Kidney Injury
Not an actual injury but a sudden reduction in kidney function.
|CKD||Chronic Kidney Disease
A gradual decline in kidney function over time.
|Prospective Cohort Study||A study to which participants are recruited and then data collected over time.|
|Retrospective Cohort Study||A study which data previously collected for a defined group of patients.
Retrospective studies have limitations as the subject data is historic and cannot be extended as the study develops. However, prospective studies require additional organisation; time has to elapse for the data to be collected and the participant cohort can diminish throughout the duration of the study.
|Cohort||Group or sub-group of participants in a study.|
|Primary care||Health care provided by your GP in the community.|
Health care provided by the hospital.