Hospital Harm - Acute Kidney Injury

Sex and Age.

First vital signs since the encounter start:

- Heart Rate

- Respiratory Rate

- Systolic Blood Pressure

- Temperature.

The estimated glomerular filtration rate (eGFR) which is calculated using the index serum creatinine, patient sex, and age-based formula.

Patient sex collected for risk adjustment and to calculate the eGFR is determined by the

AdministrativeGender codes 'F' (female) and 'M' (male). These codes make up the "ONC Administrative

Sex" value set and are also used to derive the supplemental data element of patient sex for the measure.

All encounter diagnoses along with their present on admission (POA) indicators are being collected for the development of baseline risk adjustment model with initial focus on any encounter diagnoses captured for:

- Cancer (leukemia, lymphoma, or metastatic cancer)

- Diabetes

- Heart failure

- Hypertension

- Obesity

Encounter length of stay.

Please see the Hospital Harm - Acute Kidney Injury Risk Adjustment Methodology Report on the eCQM-specific page on the eCQI Resource Center website: https://ecqi.healthit.gov/

This measure focuses on stage 2 or greater acute kidney injury as an outcome in the hospital inpatient setting. The incidence of AKI in general hospitalized patients is 10%–20%, and among critically ill patients, the incidence of AKI has been reported as high as 45–50%; in cardiac surgery patients it ranges from 30%-50% (Thongprayoon et al., 2020). Less severe acute kidney injury and acute kidney injury requiring dialysis affect approximately 2,000 to 3,000 and 200 to 300 per million population per year, respectively. Acute kidney injury may result in the need for dialysis, and is associated with an increased risk of mortality (Schwager et al., 2023; Wilson et al., 2013).

While not all instances of acute kidney injury are avoidable and may be due to natural progression of underlying illness or a complication of a necessary treatment such as chemotherapy, a proportion of acute kidney injury cases are preventable and treatable. The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines suggest careful management of hemodynamic status, fluids, and vasoactive medications for the prevention of acute kidney injury (KDIGO, 2012). Several studies identified through systematic literature searches developed or evaluated the effectiveness of acute kidney injury electronic alert systems (Schwager et al., 2023; Selby et al., 2012; Ahmed et al., 2015; Porter et al., 2014; Wilson et al., 2014; Kirkendall et al., 2014; Cho et al., 2012). These studies used data elements for defining acute kidney injury that were already present and populated in the electronic health record (EHR). For acute kidney injury diagnosis, all except two were limited to using serum creatinine levels, suggesting that this is the most reliable and consistently available electronic data element for defining acute kidney injury.

Serum creatinine is an accepted proxy for acute kidney disease (Ostermann et al., 2020; KDIGO, 2012). It is cited by many guidelines for defining and monitoring acute kidney injury (Lameire et al., 2021; Ostermann et al., 2020; Lopes & Jorge, 2013; KDIGO, 2012). eGFR equations that incorporate creatinine and cystatin C but omit race are more accurate and lead to smaller differences between Black participants and non-Black participants than new equations without race with either creatinine or cystatin C alone (Inker et al., 2021). As a result, a new race-neutral eGFR equation that that measures serum creatinine or cystatin C incorporate age, sex, and race to estimate measured GFR has been developed and is recommended by the Task Force from the National Kidney Foundation and American Society of Nephrology (Inker et al., 2021; Diao et al., 2021; Delgado et al., 2021; Delgado et al., 2022). It was recommended by the Task Force to use within the measure a Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation refit without the race variable. This functionality has been available to all laboratories in the United States (Delgado et al., 2021; Delgado et al., 2022), and has acceptable performance characteristics and potential consequences that do not disproportionately affect any one group of individuals.

The KDIGO offers clinical practice guidelines for preventing and managing acute kidney injury:

FLUIDS

3.1.1: In the absence of hemorrhagic shock, we suggest using isotonic crystalloids rather than colloids (albumin or starches) as initial management for expansion of intravascular volume in patients at risk for acute kidney injury or with acute kidney injury. (Level 2, grade B)

VASOPRESSORS

3.1.2: We recommend the use of vasopressors in conjunction with fluids in patients with vasomotor shock with, or at risk for, acute kidney injury. (Level 1, grade C)

PROTOCOLIZED HEMODYNAMIC MANAGEMENT

3.1.3: We suggest using protocol-based management of hemodynamic and oxygenation parameters to prevent development or worsening of acute kidney injury in high-risk patients in the perioperative setting (2C) or in patients with septic shock. (Level 2, grade C)

In April 2019, KDIGO held a follow-up conference (Ostermann et al., 2020). The effectiveness of the 2012 KDIGO recommendations in preventing AKI was also noted to have been confirmed in small single-center randomized controlled trials (RCTs), such as the Prevention of AKI (PrevAKI) and the Biomarker Guided Intervention for Prevention of AKI (BigpAK) studies (Meersch et al., 2017; Göcze et al., 2018). In addition, results of RCTs have provided new data relevant to several facets of preventing and managing AKI, including early resuscitation, fluid therapy, prevention of contrast-associated AKI, and timing of acute renal replacement therapy (RRT) (Kellum et al., 2016; Nijssen et al., 2017; Self et al., 2018; Zarbock et al, 2016; Gaudry et al., 2016; Barbar et al., 2018).

Inpatient hospitalizations: Includes time in the emergency department and observation when the transition between these encounters (if they exist) and the inpatient encounter are within an hour or less of each other.

The numerator harm, AKI (stage 2 or greater), is defined as a substantial increase in serum creatinine value during the encounter, as evidenced by a subsequent increase in value at least 2 times higher than the lowest serum creatinine value, and the increased value is greater than the highest sex-specific normal value for serum creatinine. The following steps are performed to determine if this criterion for AKI is met:

- To identify AKI, evaluate if any serum creatinine value obtained between 48 hours after the start of the encounter and either 30 days after the start of the encounter or discharge, whichever is sooner, is at least 1.5 times higher than the lowest value obtained within the prior 7 days. If yes, then:

- Evaluate if the increased serum creatinine is greater than the highest sex-specific normal value for serum creatinine. If yes, then:

- To stage AKI, evaluate if any serum creatinine value obtained between 48 hours after the start of the encounter and either 30 days after the start of the encounter or discharge, whichever is sooner, is at least 2 times higher than the lowest prior value (at any prior time) during that encounter. If yes, then:

- Evaluate if the increased serum creatinine value is greater than the highest sex-specific normal value for serum creatinine. If yes, then a harm (AKI stage 2 or greater) has been identified.

The highest normal serum creatinine value for females is defined as 1.02 mg/dL.

The highest normal serum creatinine value for males is defined as 1.18 mg/dL.

The eGFR values are calculated using the CKD-EPI Creatinine Equation, recommended by the National Kidney Foundation (Delgado et al., 2022). This is a sex-specific, race-neutral formula.

The CKD-EPI Creatinine Equation used for females: 142 x [min((Serum Creatinine)/0.7,1)] raised to the power of (-0.241) x max [((Serum Creatinine)/0.7,1) raised to the power of (-1.200)] x [0.9938] raised to the power of Age x 1.012.

The CKD-EPI Creatinine Equation used for males: 142 x [min((Serum Creatinine)/0.9,1)] raised to the power of (-0.302) x max [((Serum Creatinine)/0.9,1) raised to the power of (-1.200)] x [0.9938] raised to the power of Age.

The "index" serum creatinine is defined as the lowest serum creatinine value within the first 24 hours of encounter start. If there are no serum creatinine values within the first 24 hours, then the index is the first serum creatinine value within the first 48 hours of the encounter start. This serum creatinine value is used to identify and exclude patients with AKI at the start of the encounter.

The "index" eGFR is calculated using the "index" serum creatinine, patient sex, and patient age based on the CKD-EPI Creatinine Equation.

"Initiation" of kidney dialysis (CRRT, hemodialysis and peritoneal) during hospitalization is defined as documentation that kidney dialysis (CRRT, hemodialysis or peritoneal) was started during the encounter.

In addition to clinical electronic health record data, this measure uses Present on Admission (POA) indicators (e.g., POA = U) as found in billing/claims system within the measure criteria.

The POA Indicator is intended to differentiate conditions present at the time of admission from those conditions that develop during the inpatient admission.

- A POA Indicator of Y = yes (Diagnosis was present at time of inpatient admission)

- A POA Indicator of N = no (Diagnosis was not present at time of inpatient admission)

- A POA Indicator of W = clinically undetermined

- A POA Indicator of U = documentation insufficient to determine if the condition was present at the time of inpatient admission

Per CMS and the Agency for Healthcare Research and Quality (AHRQ) convention, POA indicators of Y and W are accepted indicators of a diagnosis present on admission. POA indicators of N and U are accepted indicators of a diagnosis that is not present on admission.

Inpatient hospitalizations that end during the measurement period for patients 18 years of age or older without an obstetrical or pregnancy related condition, with a length of stay of 48 hours or longer, and who had at least one serum creatinine value after 48 hours from the start of the hospitalization