This study aims to increase the understanding of Hyperkalemia (HK) management, treatment patterns, and the treatment decision-making process for the management of patients with HK over a period of up to 12 months. The generation of real-world evidence (RWE) to understand the treatment management decision rationale and to prospectively describe patient characteristics, treatment management patterns among patients with HK is of importance to improve adherence to guidelines and improve patient care.

The primary objective:

• Describe HK management decisions, their rationale and treatment expectations.

The secondary objective:

• Describe baseline characteristics and longitudinal clinical variables in patients with HK.

The exploratory objective:

• Describe patient awareness and satisfaction with their HK treatment management across the study period.

This study is a multinational, observational, prospective, longitudinal, cohort study that will include primary and secondary data collection. Secondary data, collected as per routine clinical practice will be extracted from electronic health records (EHR) and manually entered into the electronic case report form (eCRF). Primary data will be collected directly from patients and Health Care Providers (HCPs). Prospective data collection will be performed for a period of 12 months and will include data collection at baseline, that is, the date of enrollment, and at 3-, 6-, 9-, and 12-months following baseline. The data collection timepoints in this study is irrespective of when the patient's medical visits are scheduled. There are no study specific patient visits mandated by protocol and study may be fully virtual.

Patients meeting all the following inclusion criteria will be eligible for inclusion into the study:

1. Age ≥18 years on the date of signing informed consent
2. HK with serum potassium (K+) level(s) greater than 5.0 mmol/L, collected during Standard of Care, within 21 days prior to the date of enrollment*
3. Provision of signed and dated informed consent

(*enrollment in study is defined as the date of Informed consent and confirmation of study eligibility, whichever occurs later).

Patients will be excluded from the study if they meet any of the following criteria:

1. Concurrent participation in any trial that includes the use of K+ binders as an investigational medicinal product (IMP)
2. Patients with pseudohyperkalemia
3. A life expectancy of less than six months, based on physician judgement
4. Acute causes of HK such as infections and/or trauma to be determined by the principal investigator
5. Scheduled renal transplant
6. Involvement in the planning and/or conduct of the study

Patients with established HK (K+ levels >5.0 mmol/L) at selected sites distributed across USA and Europe will be recruited by the principal investigators to participate in the study.

This is a non-interventional study. As such, patients will undergo clinical assessments and receive standard medical care as determined by their treating physicians. Patients will not receive any experimental disease management intervention or experimental treatment because of their participation in the study.

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment:

https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

When a request has been approved AstraZeneca will provide access to the de-identified individual patient-level data in an approved sponsored tool . Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.