This is a retrospective, multinational, non-interventional, observational study. A series of cohort studies will be conducted to assess the prevalence of undiagnosed stage 3 CKD in each region. The study will also assess the current state of CKD management in patients with undiagnosed CKD

This study is a retrospective, multinational, non-interventional observational study. The study does not attempt to test any specific a priori hypothesis; it is descriptive only and will collect data under conditions of routine medical care. Relevant secondary databases will be identified, and a series of cohort studies will be conducted to assess the prevalence of undiagnosed CKD. The study will also assess the current state of CKD management in patients with undiagnosed CKD.

Primary Objectives

1. Estimate the point prevalence of undiagnosed stage 3 CKD (proportion of patients with eGFR measurements indicating stage 3 CKD with no corresponding CKD diagnostic code either before or up to six months after the second abnormal eGFR value)
2. Describe time to CKD diagnosis in patients with no prior CKD diagnosis code at index date (time of second qualifying eGFR), overall and by patient characteristics

Secondary Objectives

1. Assess trends in the prevalence (point prevalence) of undiagnosed CKD by calendar year
2. Describe baseline characteristics among those with undiagnosed versus diagnosed CKD
3. Assess CKD management and monitoring practices (post index date) in patients with diagnosed versus undiagnosed CKD

Exploratory objectives (pending feasibility)

1. Describe the risk of selected adverse clinical outcomes longitudinally among those with undiagnosed versus diagnosed CKD

2. Describe HCRU associated with undiagnosed versus diagnosed CKD

3. Assess association between the timing of the CKD diagnosis and the risk of selected adverse clinical outcomes and HCRU in patients with no CKD diagnosis code prior to the index date

4. Describe health care costs associated with undiagnosed versus diagnosed CKD

5. For CKD patients with eGFR 25-75 mL/min/1.73m2 and urine albumin creatinine ratio (UACR) 200 - 5000 mg/g (DAPA-CKD trial-like population):

   1. Estimate the point prevalence of undiagnosed CKD
   2. Describe the risk of selected adverse clinical outcomes longitudinally among those with undiagnosed CKD
   3. Describe HCRU and costs associated with undiagnosed CKD

Inclusion Criteria:

• At least two consecutive eGFR laboratory tests with values ≥30 and <60 mL/min/1.73 m2 (Stage 3A or 3B) that are >90 and ≤730 days apart. The index date is the date of the second eGFR measure meeting the criteria for stage 3 CKD
• At least 12 months of continuous presence in the database or registration in the data prior to the first qualifying eGFR (for data sources with information on enrolment)
• Age ≥18 years at index date

Exclusion Criteria:

• Solid organ transplant before the study index date
• Any evidence of advanced CKD (stage 4, 5) based on CKD diagnostic codes, or renal replacement therapy before the index date

Patients ≥18 years old with two consecutive eGFR measurements indicating stage 3 CKD (≥30 and <60 mL/min/1.73m2 using CKD-EPI (preferred) or MDRD equation) recorded more than 90 days apart (max. 730 days), meeting the inclusion criteria will be included in the study (from 2015 onwards).

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. Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.

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 deidentified 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.