This is a prospective observational parallel group cohort study that will aim to recruit 220 participants who were admitted to the hospital with COVID-19 between 1st March 2020 and 30th June 2020 (Group A - 110 participants who had COVID-19 with AKI; Group B - 110 participants who had COVID-19 without AKI). Data from groups A and B will be compared with AKI and non-AKI groups from an existing study database (ARID study, n=1125) who were recruited before the outbreak of the COVID-19 pandemic (recruitment 2013-2016) and who have all completed at least three years of follow up. Participants who have recovered from COVID-19 will be matched for analysis to participants from the ARID study for AKI status, baseline estimated glomerular filtration rate (eGFR) stage, age (± 5 years) and presence of diabetes. Potential participants will receive a letter of invitation along with a comprehensive participant information sheet (PIS).

After the participants have read and understand the PIS, and had sufficient time (at least 24 hours) to consider their participation in this study, the investigators will ask them to sign a consent form, which shows their willingness to take part. The investigators will then collect information from their medical records about their hospital admission with COVID-19, including their age, ethnicity, medical conditions, length of hospital stay, tablets or any other treatments they received, as well as details of their stay in the intensive care unit.

For the two groups - COVID AKI and COVID non-AKI, telephone follow-up with a study questionnaire will be performed at recruitment, 6-9 months and 12-15 months after hospital discharge. The study questionnaire will include the following:

1. Details of any medical event and date of medical event since last study follow-up.
2. Details of any hospital re-admission.
3. Details of current medication.

In addition, at the same time points, participants will be asked to attend their general practitioner surgery or other clinic to have simple clinical measurements (height, weight and blood pressure), blood and urine tests.

Inclusion Criteria:

1. Adult patients greater or equal to 18 years of age.
2. Swab results positive for SARS-CoV-2.
3. Patients admitted to the hospital for ≥24hrs.

Exclusion Criteria:

1. Paediatric patients as defined by age of <18 years of age.
2. Patients >90 years of age.
3. Swab results negative for SARS-CoV-2.
4. Patients on haemodialysis or peritoneal dialysis, pre-existing CKD stage 5 (eGFR <15ml/min/1.73m2), solid organ transplant.
5. Inability/refusal to give informed consent to participate.
6. Death during the same hospital admission that AKI occurred.

People who were admitted to the hospital with COVID-19:

• Group A: people who had COVID-19 with AKI.
• Group B: people who had COVID-19 without AKI.