Accuracy of identifying diagnosis of moderate to severe chronic kidney disease in administrative claims data

Development and validation of a medication-based risk prediction model for acute kidney injury in older outpatients

BACKGROUND

Older adults are at an increased risk of acute kidney injury (AKI), particularly in community settings, often due to medications. Effective prevention hinges on identifying high-risk patients, yet existing models for predicting AKI risk in older outpatients are scarce, particularly those incorporating medication variables. We aimed to develop an AKI risk prediction model that included medication-related variables for older outpatients.

METHODS

We constructed a cohort of 2,272,257 outpatients aged ≥65 years using a national claims database. This cohort was split into a development (70%) and validation (30%) groups. Our primary goal was to identify newly diagnosed AKI within one month of cohort entry in an outpatient context. We screened 170 variables and developed a risk prediction model using logistic regression.

RESULTS

The final model integrated 12 variables: 2 demographic, 4 comorbid, and 6 medication-related. It showed good performance with acceptable calibration. In the validation cohort, the area under the receiver operating characteristic curve value was 0.720 (95% confidence interval, 0.692-0.748). Sensitivity and specificity were 69.9% and 61.9%, respectively. Notably, the model identified high-risk patients as having a 27-fold increased AKI risk compared with low-risk individuals.

CONCLUSION

We have developed a new AKI risk prediction model for older outpatients, incorporating critical medication-related variables with good discrimination. This tool may be useful in identifying and targeting patients who may require interventions to prevent AKI in an outpatient setting.

Associations between long-term exposure to air pollution and kidney function utilizing electronic healthcare records: a cross-sectional study

BACKGROUND

Chronic kidney disease (CKD) affects more than 38 million people in the United States, predominantly those over 65 years of age. While CKD etiology is complex, recent research suggests associations with environmental exposures.

METHODS

Our primary objective is to examine creatinine-based estimated glomerular filtration rate (eGFRcr) and diagnosis of CKD and potential associations with fine particulate matter (PM2.5), ozone (O3), and nitrogen dioxide (NO2) using a random sample of North Carolina electronic healthcare records (EHRs) from 2004 to 2016. We estimated eGFRcr using the serum creatinine-based 2021 CKD-EPI equation. PM2.5 and NO2 data come from a hybrid model using 1 km2 grids and O3 data from 12 km2 CMAQ grids. Exposure concentrations were 1-year averages. We used linear mixed models to estimate eGFRcr per IQR increase of pollutants. We used multiple logistic regression to estimate associations between pollutants and first appearance of CKD. We adjusted for patient sex, race, age, comorbidities, temporality, and 2010 census block group variables.

RESULTS

We found 44,872 serum creatinine measurements among 7,722 patients. An IQR increase in PM2.5 was associated with a 1.63 mL/min/1.73m2 (95% CI: -1.96, -1.31) reduction in eGFRcr, with O3 and NO2 showing positive associations. There were 1,015 patients identified with CKD through e-phenotyping and ICD codes. None of the environmental exposures were positively associated with a first-time measure of eGFRcr < 60 mL/min/1.73m2. NO2 was inversely associated with a first-time diagnosis of CKD with aOR of 0.77 (95% CI: 0.66, 0.90).

CONCLUSIONS

One-year average PM2.5 was associated with reduced eGFRcr, while O3 and NO2 were inversely associated. Neither PM2.5 or O3 were associated with a first-time identification of CKD, NO2 was inversely associated. We recommend future research examining the relationship between air pollution and impaired renal function.

Chronic kidney disease and outcomes in hospitalized sickle cell disease patients: A National Inpatient Sample analysis

OBJECTIVES

To examine the association between chronic kidney disease (CKD) and outcomes in sickle cell disease (SCD) patients.

METHODS

Patients ≥18 years with SCD in the National Inpatient Sample database between 2016 and 2018 were identified using ICD-10-CM diagnosis codes. A 1:1 propensity-score matched analysis was performed to compare in-hospital outcomes of patients with and without CKD.

RESULTS

Of the 366 240 SCD admissions, 19 365 (5.3%) had CKD. The CKD group had higher odds of in-hospital mortality (odds ratio [OR] 2.59, 95% confidence interval [CI]: 1.63-4.12, p = <.01), blood transfusion (OR 1.67, 95% CI: 1.47-1.90, p < .01), mechanical ventilation (OR 2.20, 95% CI: 1.56-3.12, p = <.01), sepsis (OR 1.75, 95% CI: 1.46-2.10, p < .01), incurred higher costs ($53 255 vs. $47 294, p < .001), but had lower odds of acute chest syndrome (OR 0.71, 95% CI: 0.54-0.95, p = 0.02) and pulmonary embolism (OR 0.45, 95% CI: 0.31-0.67, p < .01).

CONCLUSIONS

CKD was associated with higher mortality, higher costs, blood transfusion, sepsis, and mechanical ventilation in SCD patients. Further studies are needed to explore the reasons for the reduced odds of pulmonary embolism and acute chest syndrome.

Risk of incident chronic kidney disease among patients with urolithiasis: a nationwide longitudinal cohort study

Background

Urolithiasis has been infrequently implicated to have a causal association with chronic kidney disease (CKD). Recently, several studies have demonstrated the relationship between urolithiasis and CKD. However, the generalizability of their results is limited. This study aimed to investigate the association between urolithiasis and the risk of incident CKD.

Methods

This longitudinal cohort study used the National Health Insurance Service data, including 219 570 Korean adults with incident urolithiasis requiring procedural interventions and without prior kidney disease and 219 570 age- and sex-matched controls without urolithiasis between 1 January 2002 and 31 December 2020. Primary outcome was the development of CKD, defined by an estimated glomerular filtration rate <60 ml/min/1.73 m2 for at least two consecutive measurements at least 90 days apart. The risk for incident CKD was further examined using the outcome defined by newly occurring diagnostic codes indicating CKD.

Results

Over a mean follow-up of 6 years, 12 338 (2.8%) primary outcome events of CKD were observed (incidence rate 4.6/1000 person-years). Per multivariable Cox analysis, urolithiasis was associated with a higher risk of incident CKD [adjusted hazard ratio 1.41 (95% confidence interval 1.36-1.46)]. This association remained consistent across all clinically relevant subgroups and when the CKD outcome was defined based on the diagnostic codes in the sensitivity analysis.

Conclusions

In this large national cohort study, patients with urolithiasis were associated with a higher risk of incident CKD than those without urolithiasis. Further studies are warranted to establish the benefits of preventing urolithiasis in reducing CKD development.

A population-based cohort defined risk of hyperkalemia after initiating SGLT-2 inhibitors, GLP1 receptor agonists or DPP-4 inhibitors to patients with chronic kidney disease and type 2 diabetes

Hyperkalemia is a common adverse event in patients with chronic kidney disease (CKD) and type 2 diabetes and limits the use of guideline-recommended therapies such as renin-angiotensin system inhibitors. Here, we evaluated the comparative effects of sodium-glucose cotransporter-2 inhibitors (SGLT-2i), glucagon-like peptide-1 receptor agonists (GLP-1RA) and dipeptidyl peptidase-4 inhibitors (DPP-4i) on the risk of hyperkalemia. We conducted a population-based active-comparator, new-user cohort study using claims data from Medicare and two large United States commercial insurance databases (April 2013-April 2022). People with CKD stages 3-4 and type 2 diabetes who newly initiated SGLT-2i vs. DPP-4i (141671 patients), GLP-1RA vs. DPP-4i (159545 patients) and SGLT-2i vs. GLP-1RA (93033 patients) were included. The primary outcome was hyperkalemia diagnosed in inpatient or outpatient settings. Secondary outcomes included hyperkalemia diagnosed in inpatient or emergency department setting, and serum potassium levels of 5.5 mmol/L or more. Pooled hazard ratios and rate differences were estimated after propensity score matching to adjust for over 140 potential confounders. Initiation of SGLT-2i was associated with a lower risk of hyperkalemia compared with DPP-4i (hazard ratio 0.74; 95% confidence interval 0.68-0.80) and contrasted to GLP-1RA (0.92; 0.86-0.99). Compared with DPP-4i, GLP-1RA were also associated with a lower risk of hyperkalemia (0.80; 0.75-0.86). Corresponding absolute rate differences/1000 person-years were -24.8 (95% confidence interval -31.8 to -17.7), -5.0 (-10.9 to 0.8), and -17.7 (-23.4 to -12.1), respectively. Similar findings were observed for the secondary outcomes, among subgroups, and across single agents within the SGLT-2i and GLP-1RA classes. Thus, SGLT-2i and GLP-1RA are associated with a lower risk of hyperkalemia than DPP-4i in patients with CKD and type 2 diabetes, further supporting the use of these drugs in this population.

Diagnostic Validity of Chronic Kidney Disease in Health Claims Data Over Time: Results from a Cohort of Community-Dwelling Older Adults in Germany

Purpose

The validity of ICD-10 diagnostic codes for chronic kidney disease (CKD) in health claims data has not been sufficiently studied in the general population and over time.

Patients and Methods

We used data from the Berlin Initiative Study (BIS), a prospective longitudinal cohort of community-dwelling individuals aged ≥70 years in Berlin, Germany. With estimated glomerular filtration rate (eGFR) as reference, we assessed the diagnostic validity (sensitivity, specificity, positive [PPV], and negative predictive values [NPV]) of different claims-based ICD-10 codes for CKD stages G3-5 (eGFR <60mL/min/1.73m²: ICD-10 N18.x-N19), G3 (eGFR 30-<60mL/min/1.73m²: N18.3), and G4-5 (eGFR <30mL/min/1.73m²: N18.4-5). We analysed trends over five study visits (2009-2019).

Results

We included data of 2068 participants at baseline (2009-2011) and 870 at follow-up 4 (2018-2019), of whom 784 (38.9%) and 440 (50.6%) had CKD G3-5, respectively. At baseline, sensitivity for CKD in claims data ranged from 0.25 (95%-confidence interval [CI] 0.22-0.28) to 0.51 (95%-CI 0.48-0.55) for G3-5, depending on the included ICD-10 codes, 0.20 (95%-CI 0.18-0.24) for G3, and 0.36 (95%-CI 0.25-0.49) for G4-5. Over the course of 10 years, sensitivity increased by 0.17 to 0.29 in all groups. Specificity, PPVs, and NPVs remained mostly stable over time and ranged from 0.82-0.99, 0.47-0.89, and 0.66-0.98 across all study visits, respectively.

Conclusion

German claims data showed overall agreeable performance in identifying older adults with CKD, while differentiation between stages was limited. Our results suggest increasing sensitivity over time possibly attributable to improved CKD diagnosis and awareness.

The ICD-9 to ICD-10 transition has not improved identification of rapidly progressing stage 3 and stage 4 chronic kidney disease patients: a diagnostic test study

BACKGROUND

The International Classification of Diseases (ICD) coding system is the industry standard tool for billing, disease classification, and epidemiology purposes. Prior research has demonstrated ICD codes to have poor accuracy, particularly in relation to rapidly progressing chronic kidney disease (CKD) patients. In 2016, the ICD system moved to revision 10. This study examines subjects in a large insurer database to determine the accuracy of ICD-10 CKD-staging codes to diagnose patients rapidly progressing towards end-stage kidney disease (ESKD).

PATIENTS AND METHODS

Serial observations of outpatient serum creatinine measurements from 2016 to 2021 of 315,903 patients were transformed to estimated glomerular filtration rate (eGFR) to identify CKD stage-3 and advanced patients diagnosed clinically (eGFR-CKD). CKD-staging codes from the same time period of 59,386 patients and used to identify stage-3 and advanced patients diagnosed by ICD-code (ICD-CKD). eGFR-CKD and ICD-CKD diagnostic accuracy was compared between a total of 334,610 patients.

RESULTS

5,618 patients qualified for the progression analysis; 72 were identified as eGFR rapid progressors; 718 had multiple codes to qualify as ICD rapid progressors. Sensitivity was 5.56%, with positive predictive value (PPV) 5.6%. 34,858 patients were diagnosed as eGFR-CKD stage-3 patients; 17,549 were also diagnosed as ICD-CKD stage-3 patients, for a sensitivity of 50.34%, with PPV of 58.71%. 4,069 patients reached eGFR-CKD stage-4 with 2,750 ICD-CKD stage-4 patients, giving a sensitivity of 67.58%, PPV of 42.43%. 959 patients reached eGFR-CKD stage-5 with 566 ICD-CKD stage-5 patients, giving a sensitivity of 59.02%, PPV of 35.85%.

CONCLUSION

This research shows that recent ICD revisions have not improved identification of rapid progressors in diagnostic accuracy, although marked increases in sensitivity for stage-3 (50.34% vs. 24.68%), and PPV in stage-3 (58.71% vs. 40.08%), stage-4 (42.43% vs. 18.52%), and stage-5 (35.85% vs. 4.51%) were observed. However, sensitivity in stage-5 compares poorly (59.02% vs. 91.05%).

Cardiorenal effectiveness of empagliflozin vs. glucagon-like peptide-1 receptor agonists: final-year results from the EMPRISE study

BACKGROUND

No randomized clinical trials have directly compared the cardiorenal effectiveness of empagliflozin and GLP-1RA agents with demonstrated cardioprotective effects in patients with a broad spectrum of cardiovascular risk. We reported the final-year results of the EMPRISE study, a monitoring program designed to evaluate the cardiorenal effectiveness of empagliflozin across broad patient subgroups.

METHODS

We identified patients ≥ 18 years old with type 2 diabetes who initiated empagliflozin or GLP-1RA from 2014 to 2019 using US Medicare and commercial claims databases. After 1:1 propensity score matching using 143 baseline characteristics, we evaluated risks of outcomes including myocardial infarction (MI) or stroke, hospitalization for heart failure (HHF), major adverse cardiovascular events (MACE - MI, stroke, or cardiovascular mortality), a composite of HHF or cardiovascular mortality, and progression to end-stage kidney disease (ESKD) (in patients with chronic kidney disease stages 3-4). We estimated hazard ratios (HR) and rate differences (RD) per 1,000 person-years, overall and within subgroups of age, sex, baseline atherosclerotic cardiovascular disease (ASCVD), and heart failure (HF).

RESULTS

We identified 141,541 matched pairs. Compared with GLP-1RA, empagliflozin was associated with similar risks of MI or stroke [HR: 0.99 (0.92, 1.07); RD: -0.23 (-1.25, 0.79)], and lower risks of HHF [HR: 0.50 (0.44, 0.56); RD: -2.28 (-2.98, -1.59)], MACE [HR: 0.90 (0.82, 0.99); RD: -2.54 (-4.76, -0.32)], cardiovascular mortality or HHF [HR: 0.77 (0.69, 0.86); RD: -4.11 (-5.95, -2.29)], and ESKD [0.75 (0.60, 0.94); RD: -6.77 (-11.97, -1.61)]. Absolute risk reductions were larger in older patients and in those with baseline ASCVD/HF. They did not differ by sex.

CONCLUSIONS

The cardiovascular benefits of empagliflozin vs. cardioprotective GLP-1RA agents were larger in older patients and in patients with history of ASCVD or HF, while they did not differ by sex. In patients with advanced CKD, empagliflozin was associated with risk reductions of progression to ESKD.

Prevalent diabetes and long-term cardiovascular outcomes in adult sepsis survivors: a population-based cohort study

BACKGROUND

Sepsis survivors are at elevated risk for cardiovascular disease during long-term follow-up. Whether diabetes influences cardiovascular risk after sepsis survival remains unknown. We sought to describe the association of diabetes with long-term cardiovascular outcomes in adult sepsis survivors.

METHODS

Population-based cohort study in the province of Ontario, Canada (2008-2017). Adult survivors of a first sepsis-associated hospitalization, without pre-existing cardiovascular disease, were included. Main exposure was pre-existing diabetes (any type). The primary outcome was the composite of myocardial infarction, stroke, and cardiovascular death. Patients were followed up to 5 years from discharge date until outcome occurrence or end of study period (March 2018). We used propensity score matching (i.e., 1:1 to patients with sepsis but no pre-existing diabetes) to adjust for measured confounding at baseline. Cause-specific Cox proportional hazards models with robust standard errors were used to estimate hazard ratios (HR) alongside 95% confidence intervals (CI). A main secondary analysis evaluated the modification of the association between sepsis and cardiovascular disease by pre-existing diabetes.

RESULTS

78,638 patients with pre-existing diabetes who had a sepsis-associated hospitalization were matched to patients hospitalized for sepsis but without diabetes. Mean age of patients was 71 years, and 55% were female. Median duration from diabetes diagnosis was 9.8 years; mean HbA1c was 7.1%. Adult sepsis survivors with pre-existing diabetes experienced a higher hazard of major cardiovascular disease (HR 1.25; 95% CI 1.22-1.29)-including myocardial infarction (HR 1.40; 95% CI 1.34-1.47) and stroke (HR 1.24; 95% CI 1.18-1.29)-during long-term follow-up compared to sepsis survivors without diabetes. Pre-existing diabetes modified the association between sepsis and cardiovascular disease (risk difference: 2.3%; 95% CI 2.0-2.6 and risk difference: 1.8%; 95% CI 1.6-2.0 for the effect of sepsis-compared to no sepsis-among patients with and without diabetes, respectively).

CONCLUSIONS

Sepsis survivors with pre-existing diabetes experience a higher long-term hazard of major cardiovascular events when compared to sepsis survivors without diabetes. Compared to patients without sepsis, the absolute risk increase of cardiovascular events after sepsis is higher in patients with diabetes (i.e., diabetes intensified the higher cardiovascular risk induced by sepsis).

A Novel Chronic Kidney Disease Phenotyping Algorithm Using Combined Electronic Health Record and Claims Data

Purpose

Because chronic kidney disease (CKD) is often under-coded as a diagnosis in claims data, we aimed to develop claims-based prediction models for CKD phenotypes determined by laboratory results in electronic health records (EHRs).

Patients and Methods

We linked EHR from two networks (used as training and validation cohorts, respectively) with Medicare claims data. The study cohort included individuals ≥65 years with a valid serum creatinine result in the EHR from 2007 to 2017, excluding those with end-stage kidney disease or on dialysis. We used LASSO regression to select among 134 predictors for predicting continuous estimated glomerular filtration rate (eGFR). We assessed the model performance when predicting eGFR categories of <60, <45, <30 mL/min/1.73m2 in terms of area under the receiver operating curves (AUC).

Results

The model training cohort included 117,476 patients (mean age 74.8 years, female 58.2%) and the validation cohort included 56,744 patients (mean age 73.8 years, female 59.6%). In the validation cohort, the AUC of the primary model (with 113 predictors and an adjusted R2 of 0.35) for predicting eGFR <60, eGFR<45, and eGFR <30 mL/min/1.73m2 categories was 0.81, 0.88, and 0.92, respectively, and the corresponding positive predictive values for these 3 phenotypes were 0.80 (95% confidence interval: 0.79, 0.81), 0.79 (0.75, 0.84), and 0.38 (0.30, 0.45), respectively.

Conclusion

We developed a claims-based model to determine clinical phenotypes of CKD stages defined by eGFR values. Researchers without access to laboratory results can use the model-predicted phenotypes as a proxy clinical endpoint or confounder and to enhance subgroup effect assessment.

Safety of Sodium-Glucose Cotransporter-2 Inhibitors in Patients with CKD and Type 2 Diabetes: Population-Based US Cohort Study

BACKGROUND

Limited information exists regarding the safety of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in patients with CKD treated in routine care. We evaluated the safety of SGLT2i in patients with CKD and type 2 diabetes treated in US routine practice.

METHODS

Using claims data from Medicare and two large US commercial databases (April 2013-December 2021), we included 96,128 adults with CKD stages 3-4 and type 2 diabetes who newly filled prescriptions for SGLT2i versus glucagon-like peptide-1 receptor agonists (GLP-1RA). Safety outcomes included diabetic ketoacidosis (DKA), lower limb amputations, nonvertebral fractures, genital infections, hypovolemia, AKI, hypoglycemia, and severe urinary tract infections (UTIs). Hazard ratios (HRs) and incidence rate differences per 1000 person-years were estimated after 1:1 propensity score matching, adjusted for >120 baseline characteristics.

RESULTS

Compared with GLP-1RA, SGLT2i initiators had a higher risk of nonvertebral fractures (HR, 1.30; 95% confidence interval [CI], 1.03 to 1.65]; incidence rate difference, 2.13 [95% CI, 0.28 to 3.97]), lower limb amputations (HR, 1.65 [95% CI, 1.22 to 2.23]; incidence rate difference, 2.46 [95% CI, 1.00 to 3.92]), and genital infections (HR, 3.08 [95% CI, 2.73 to 3.48]; incidence rate difference, 41.26 [95% CI, 37.06 to 45.46]). Similar risks of DKA (HR, 1.07 [95% CI, 0.74 to 1.54]; incidence rate difference, 0.29 [95% CI, -0.89 to 1.46]), hypovolemia (HR, 0.99 [95% CI, 0.86 to 1.14]; incidence rate difference, 0.20 [95% CI, -2.85 to 3.25]), hypoglycemia (HR, 1.08 [95% CI, 0.92 to 1.26]; incidence rate difference, 1.46 [95% CI, -1.31 to 4.23]), and severe UTI (HR, 1.02 [95% CI, 0.87 to 1.19]; incidence rate difference, 0.35 [95% CI, -2.51 to 3.21]) were observed. SGLT2i had lower risk for AKI (HR, 0.93 [95% CI, 0.87 to 0.99]; incidence rate difference, -6.75 [95% CI, -13.69 to 0.20]).

CONCLUSIONS

In US patients with CKD and type 2 diabetes receiving routine care, SGLT2i use was associated with higher risks of genital infections and potentially lower limb amputations and nonvertebral fractures.

Clinical characteristics and disease outcomes in non-diabetic chronic kidney disease: retrospective analysis of a US healthcare claims database

BACKGROUND

The observational, real-world evidence FLIEDER study aimed to describe patient clinical characteristics and investigate clinical outcomes in non-diabetic patients with chronic kidney disease (CKD) using data collected from routine clinical practice in the United States.

METHODS

Between 1 January, 2008-31 December, 2018, individuals aged ≥ 18 years, with non-diabetic, stage 3-4 CKD were indexed in the Optum^® Clinformatics^® Data Mart US healthcare claims database using International Classification of Diseases-9/10 codes for CKD or by laboratory values (estimated glomerular filtration rate [eGFR] 15-59 mL/min/1.73 m²). The primary outcomes were hospitalization for heart failure, a composite kidney outcome of end-stage kidney disease/kidney failure/need for dialysis and worsening of CKD stage from baseline. The effects of the intercurrent events of a sustained post-baseline decline in eGFR ≥ 30%, ≥ 40%, and ≥ 57% on the subsequent risk of the primary outcomes were also assessed.

RESULTS

In the main study cohort (N = 504,924), median age was 75.0 years, and 60.5% were female. Most patients (94.7%) had stage 3 CKD at index. Incidence rates for hospitalization for heart failure, the composite kidney outcome, and worsening of CKD stage from baseline were 4.0, 10.3, and 4.4 events/100 patient-years, respectively. The intercurrent event analysis demonstrated that a relative decline in kidney function from baseline significantly increased the risk of cardiorenal events.

CONCLUSIONS

This real-world study highlights that patients with non-diabetic CKD are at high risk of serious adverse clinical outcomes, and that this risk is amplified in patients who experienced greater post-baseline eGFR decline.

Defining measures of kidney function in observational studies using routine health care data: methodological and reporting considerations

The availability of electronic health records and access to a large number of routine measurements of serum creatinine and urinary albumin enhance the possibilities for epidemiologic research in kidney disease. However, the frequency of health care use and laboratory testing is determined by health status and indication, imposing certain challenges when identifying patients with kidney injury or disease, when using markers of kidney function as covariates, or when evaluating kidney outcomes. Depending on the specific research question, this may influence the interpretation, generalizability, and/or validity of study results. This review illustrates the heterogeneity of working definitions of kidney disease in the scientific literature and discusses advantages and limitations of the most commonly used approaches using 3 examples. We summarize ways to identify and overcome possible biases and conclude by proposing a framework for reporting definitions of exposures and outcomes in studies of kidney disease using routinely collected health care data.

Childhood diabetes mellitus and early-onset kidney diseases later in life: a nationwide population-based matched cohort study

BACKGROUND

The empirical evidence remains inconclusive for an association between diabetes mellitus (DM) in children and early-onset kidney disease later in life, and little is known about the effects of DM types (i.e., type 1 diabetes [T1DM] and type 2 diabetes [T2DM]) in childhood on type-specific kidney diseases. We aimed to evaluate the association of childhood DM with overall and type-specific early-onset kidney diseases later in life.

METHODS

The population-based matched cohort study included 9356 individuals with DM (T1DM: 8470, T2DM: 886) diagnosed in childhood (&lt; 18 years) who were born between 1977 and 2016, and 93,560 individuals without DM matched on sex and year of birth in Denmark. The main outcomes were overall and type-specific early-onset kidney diseases. The follow-up period of all included participants was from the date of DM diagnosis in the exposure group until the first diagnosis of kidney disease, emigration, or 31 December 2018, whichever came first.

RESULTS

During a median follow-up of 13 years, children with DM had a 154% increased risk of early-onset kidney diseases than children without DM (adjusted hazard ratios 2.54, 95% confidence intervals 2.38-2.72), and T1DM (2.48, 2.31-2.67) and T2DM (2.75, 2.28-3.31) showed similar results. Children with DM also had a higher risk of multiple specific kidney diseases including glomerular diseases, renal tubulo-interstitial diseases, renal failure, and urolithiasis. The risks of type-specific kidney diseases including glomerular diseases and renal failure tended to be higher for children with T2DM (glomerular diseases: 5.84, 3.69-9.24; renal failure: 14.77, 8.53-25.59) than those with T1DM (glomerular diseases: 3.14, 2.57-3.83; renal failure: 8.24, 6.66-10.20).

CONCLUSIONS

Children with DM had a higher increased risk of early-onset overall and specific kidney diseases later in life. Early prevention and treatment of both T1DM and T2DM in childhood may significantly reduce the risk of kidney diseases later in life.

Validation of a Classification Algorithm for Chronic Kidney Disease Based on Health Information Systems

Background: Chronic kidney disease (CKD) is a common condition, characterized by high burden of comorbidities, mortality and costs. There is a need for developing and validating algorithm for the diagnosis of CKD based on administrative data. Methods: We validated our previously developed algorithm that used administrative data of the Lazio Region (central Italy) to define the presence of CKD on the basis of serum creatinine measurements performed between 2012 and 2015 at the Policlinico Gemelli Hospital. CKD and advanced CKD were defined according to eGFR (<60 and <30 mL/min/1.73 m2, respectively). Sensitivity, specificity, positive and negative predictive values (PPV/NPV) were computed. Results: During the time span of the study, 30,493 adult participants residing in the Lazio Region had undergone at least 2 serum creatinine measurements separated by at least 3 months. CKD and advanced CKD were present in 11.1% and 2.0% of the study population, respectively. The performance of the algorithm in the identification of CKD was high, with a sensitivity of 51.0%, specificity of 96.5%, PPV of 64.5% and NPV of 94.0%. Using advanced CKD, sensitivity was 62.9% (95% CI 59.0, 66.8), specificity 98.1%, PPV 40.4% and NPV 99.3%. Conclusion: The algorithm based on administrative data has high specificity and adequate performance for more advanced CKD; it can be used to obtain estimates of prevalence of CKD and to perform epidemiological research.