Detecting chronic kidney disease in population-based administrative databases using an algorithm of hospital encounter and physician claim codes

Prevalence of chronic kidney disease in France: methodological considerations and pitfalls with the use of Health claims databases

Background

Health policy-making require careful assessment of chronic kidney disease (CKD) epidemiology to develop efficient and cost-effective care strategies. The aim of the present study was to use the RENALGO-EXPERT algorithm to estimate the global prevalence of CKD in France.

Methods

An expert group developed the RENALGO-EXPERT algorithm based on healthcare consumption. This algorithm has been applied to the French National Health claims database (SNDS), where no biological test findings are available to estimate a national CKD prevalence for the years 2018-2021. The CONSTANCES cohort (+219 000 adults aged 18-69 with one CKD-EPI eGFR) was used to discuss the limit of using health claims data.

Results

Between 2018 and 2021, the estimated prevalence in the SNDS increased from 8.1% to 10.5%. The RENALGO-EXPERT algorithm identified 4.5% of the volunteers in the CONSTANCES as CKD. The RENALGO-EXPERT algorithm had a positive predictive value of 6.2% and negative predictive value of 99.1% to detect an eGFR<60 ml/min/1.73 m². Half of 252 false positive cases (ALGO+, eGFR > 90) had been diagnosed with kidney disease during hospitalization, and the other half based on healthcare consumption suggestive of a 'high-risk' profile; 95% of the 1661 false negatives (ALGO-, eGFR < 60) had an eGFR between 45 and 60 ml/min, half had medication and two-thirds had biological exams possibly linked to CKD. Half of them had a hospital stay during the period but none had a diagnosis of kidney disease.

Conclusions

Our result is in accordance with other estimations of CKD prevalence in the general population. Analysis of diverging cases (FP and FN) suggests using health claims data have inherent limitations. Such an algorithm can identify patients whose care pathway is close to the usual and specific CKD pathways. It does not identify patients who have not been diagnosed or whose care is inappropriate or at early stage with stable GFR.

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%).

Association Between Age at Diagnosis of Type 2 Diabetes and Hospitalization for Heart Failure: A Population-Based Study

BACKGROUND

The relation between age at diagnosis of type 2 diabetes (T2D) and hospitalization for heart failure (HHF) is unclear. We assessed the association between age at diagnosis of T2D and HHF.

METHODS AND RESULTS

We conducted a population-based cohort study using administrative health databases from the Canadian province of Ontario, including participants without prior heart failure. We identified people with new-onset T2D between April 1, 2005 and March 31, 2015, and matched each person with 3 diabetes-free adults, according to birth year and sex. We estimated adjusted hazard ratios (HRs) and rate ratios (RRs) for the association between age at T2D diagnosis and incident HHF, which was assessed until March 31, 2020. Among 743 053 individuals with T2D and 2 199 539 matched individuals without T2D, 126 241 incident HHF events occurred over 8.9 years. T2D was associated with a greater adjusted hazard of HHF at younger ages (eg, HR at age 30 years: 6.94 [95% CI, 6.54-7.36]) than at older ages (eg, HR at age 60 years: 2.50 [95% CI, 2.45-2.56]) relative to matched individuals. Additional adjustment for mediators (hypertension, coronary artery disease, and chronic kidney disease) marginally attenuated this relationship. Age at T2D diagnosis was associated with a greater number of HHF events relative to matched individuals at younger ages (eg, RR at age 30 years: 6.39 [95% CI, 5.76-7.08]) than at older ages (eg, RR at age 60 years: 2.65 [95% CI, 2.54-2.76]).

CONCLUSIONS

Younger age at T2D diagnosis is associated with a disproportionately elevated HHF risk relative to age-matched individuals without T2D.

Patterns of multiple chronic conditions in pregnancy: Population-based study using latent class analysis

BACKGROUND

Adults with multiple chronic conditions (MCC) are a heterogeneous population with elevated risk of future adverse health outcomes. Yet, despite the increasing prevalence of MCC globally, data about MCC in pregnancy are scarce.

OBJECTIVES

To estimate the population prevalence of MCC in pregnancy and determine whether certain types of chronic conditions cluster together among pregnant women with MCC.

METHODS

We conducted a population-based cohort study in Ontario, Canada, of all 15-55-year-old women with a recognised pregnancy, from 2007 to 2020. MCC was assessed from a list of 22 conditions, identified using validated algorithms. We estimated the prevalence of MCC. Next, we used latent class analysis to identify classes of co-occurring chronic conditions in women with MCC, with model selection based on parsimony, clinical interpretability and statistical fit.

RESULTS

Among 2,014,508 pregnancies, 324,735 had MCC (161.2 per 1000, 95% confidence interval [CI] 160.6, 161.8). Latent class analysis resulted in a five-class solution. In four classes, mood and anxiety disorders were prominent and clustered with one additional condition, as follows: Class 1 (22.4% of women with MCC), osteoarthritis; Class 2 (23.7%), obesity; Class 3 (15.8%), substance use disorders; and Class 4 (22.1%), asthma. In Class 5 (16.1%), four physical conditions clustered together: obesity, asthma, chronic hypertension and diabetes mellitus.

CONCLUSIONS

MCC is common in pregnancy, with sub-types dominated by co-occurring mental and physical health conditions. These data show the importance of preconception and perinatal interventions, particularly integrated care strategies, to optimise treatment and stabilisation of chronic conditions in women with MCC.

The validity of hospital diagnostic and procedure codes reflecting morbidity in preterm neonates born <32 weeks gestation

OBJECTIVE

To determine the validity of diagnostic hospital billing codes for complications of prematurity in neonates <32 weeks gestation.

STUDY DESIGN

Retrospective cohort data from discharge summaries and clinical notes (n = 160) were reviewed by trained, blinded abstractors for the presence of intraventricular hemorrhage (IVH) grades 3 or 4, periventricular leukomalacia (PVL), necrotizing enterocolitis (NEC), stage 3 or higher, retinopathy of prematurity (ROP), and surgery for NEC or ROP. Data were compared to diagnostic billing codes from the neonatal electronic health record.

RESULTS

IVH, PVL, ROP and ROP surgery had strong positive predictive values (PPV > 75%) and excellent negative predictive values (NPV > 95%). The PPVs for NEC (66.7%) and NEC surgery (37.1%) were low.

CONCLUSION

Diagnostic hospital billing codes were observed to be a valid metric to evaluate preterm neonatal morbidities and surgeries except in the instance of more ambiguous diagnoses such as NEC and NEC surgery.

Retrospective cohort analysis of outpatient antibiotic prescribing for community-acquired pneumonia in Canadian older adults

BACKGROUND

This retrospective cohort study is the first in North America to examine population-level appropriate antibiotic use for community-acquired pneumonia (CAP) in older adults, by agent, dose and duration. With the highest rates of CAP reported in the elderly populations, appropriate antibiotic use is essential to improve clinical outcomes. Given the ongoing crisis of antimicrobial resistance, understanding inappropriate antibiotic prescribing is integral to direct community stewardship efforts.

METHODS

All outpatient primary care visits for CAP (aged ≥65 years) were identified using physician billing codes between January 1 2014 to December 31 2018 in British Columbia (BC) and Ontario (ON). Categories of prescribing were derived from existing literature, and constructed for clinical relevance using Canadian and international guidelines available during the study period. Categories were mutually exclusive and included: guideline adherent (first-line agent, adherent dose/duration), clinically appropriate (non-first line agent, presence of comorbidities), effective but unnecessary (first-line agent, excess dose/duration), undertreatment (first-line agent, subtherapeutic dose/duration), and not recommended (non-first line agent, absence of comorbidities). Proportions of prescribing were examined by category. Temporal trends in prescribing were examined using Poisson regression.

RESULTS

A total of 436,441 episodes of CAP were identified, with 46% prescribed an antibiotic in BC, and 52% in Ontario. Guideline adherent prescribing was minimal for both provinces (BC: 2%; ON: 1%) however the largest magnitude of increase was reported in this category by the final study year (BC-Rate Ratio [RR]: 3.4, 95% Confidence Interval [CI]: 2.7-4.3; ON-RR: 4.62, 95% CI: 3.4-6.5). Clinically appropriate prescribing accounted for the most antibiotics issued, across all study years (BC: 61%; ON: 74%) (BC-RR: 0.8, 95% CI: 0.8-0.8; ON-RR: 0.9, 95% CI: 0.8-0.9). Excess duration of therapy was the hallmark characteristic for effective but unnecessary prescribing (BC: 92%; ON: 99%). The most common duration prescribed was 7 days, followed by 10. Not recommended prescribing was minimal in both provinces (BC: 4%; ON: 7%) and remained stable by the final study year (BC-RR: 1.1, 95% CI: 0.9-1.2; ON-RR: 0.9, 95% CI: 0.9-1.1).

CONCLUSION

Three quarters of antibiotic prescribing for CAP was appropriate in Ontario, but only two thirds in BC. Shortening durations-in line with evidence for 3 to 5-day treatment presents a focused target for stewardship efforts.

Physical disability and venous thromboembolism during pregnancy and the postpartum period: a population-based cohort study

BACKGROUND

Pregnancy and the postpartum period are a high-risk time for venous thromboembolism (VTE). Decreased mobility is also a major risk factor. However, the risk of peripregnancy VTE among individuals with physical disabilities is unknown.

OBJECTIVES

To compare the risk of peripregnancy VTE between people with a physical disability and those without a physical disability.

METHODS

This population-based cohort study comprised all births in Ontario, Canada, from 2007 to 2018. Physical disability was defined as a condition diagnosed before conception that was likely to result in restricted mobility. Modified Poisson regression was used to compare the risk of VTE during pregnancy and up to 6 weeks postpartum between people with a physical disability and those without a physical disability. Adjusted relative risks (aRRs) were calculated, controlling for demographics, history of VTE, thrombophilia, and other comorbidities. An additional analysis was used to evaluate the risk of peripregnancy VTE among people with physical disabilities who used a mobility aid.

RESULTS

Of 1 220 822 eligible people, 13 791 (1.1%) had a physical disability. VTE occurred during pregnancy or up to 6 weeks of the postpartum period in 0.85% of the individuals with a physical disability and 0.47% of those without a physical disability (aRR, 1.52; 95% CI, 1.26-1.83). The rate of VTE was notably higher in those with a physical disability requiring a mobility aid (3.0%), generating an aRR of 3.05 (95% CI, 1.45-6.41), than in those without a physical disability.

CONCLUSION

Pregnant people with a physical disability, especially those using a mobility aid, are at an increased risk of VTE. Anticoagulant prophylaxis could be considered in this group, especially in the presence of additional risk factors.

Associations between modest reductions in kidney function and adverse outcomes in young adults: retrospective, population based cohort study

OBJECTIVE

To study age specific associations of modest reductions in estimated glomerular filtration rate (eGFR) with adverse outcomes.

DESIGN

Retrospective, population based cohort study.

SETTING

Linked healthcare administrative datasets in Ontario, Canada.

PARTICIPANTS

Adult residents (18-65 years) with at least one outpatient eGFR value (categorized in 10 unit increments from 50 mL/min/1.73m2 to >120 mL/min/1.73m2), with no history of kidney disease.

MAIN OUTCOME MEASURES

eGFRs and hazard ratios of composite adverse outcome (all cause mortality, any cardiovascular event, and kidney failure) stratified by age (18-39 years, 40-49 years, and 50-65 years), and relative to age specific eGFR referents (100-110 mL/min/1.73m2) for ages 18-39 years, 90-100 for 40-49 years, 80-90 for 50-65 years).

RESULTS

From 1 January 2008 to 31 March 2021, among 8 703 871 adults (mean age 41.3 (standard deviation 13.6) years; mean index eGFR 104.2 mL/min/1.73m2 (standard deviation 16.1); median follow-up 9.2 years (interquartile range 5.7-11.4)), modestly reduced eGFR measurements specific to age were recorded in 18.0% of those aged 18-39, 18.8% in those aged 40-49, and 17.0% in those aged 50-65. In comparison with age specific referents, adverse outcomes were consistently higher by hazard ratio and incidence for ages 18-39 compared with older groups across all eGFR categories. For modest reductions (eGFR 70-80 mL/min/1.73m2), the hazard ratio for ages 18-39 years was 1.42 (95% confidence interval 1.35 to 1.49), 4.39 per 1000 person years; for ages 40-49 years was 1.13 (1.10 to 1.16), 9.61 per 1000 person years; and for ages 50-65 years was 1.08 (1.07 to 1.09), 23.4 per 1000 person years. Results persisted for each individual outcome and in many sensitivity analyses.

CONCLUSIONS

Modest eGFR reductions were consistently associated with higher rates of adverse outcomes. Higher relative hazards were most prominent and occurred as early as eGFR <80 mL/min/1.73m2 in younger adults, compared with older groups. These findings suggest a role for more frequent monitoring of kidney function in younger adults to identify individuals at risk to prevent chronic kidney disease and its complications.

Incidence of Heart Failure Related to Co-Occurrence of Gestational Hypertensive Disorders and Gestational Diabetes

BACKGROUND

The extent to which their co-occurrence of gestational hypertensive disorders (GHTD) and gestational diabetes mellitus (GDM) influences heart failure (HF) risk is unclear.

OBJECTIVES

The purpose of this study was to characterize the risk of HF related to concomitant GHTD and GDM.

METHODS

We conducted a population-based cohort study using the Ministry of Health and Long-Term Care of Ontario (Canada) health care administrative databases. We included women with a livebirth singleton delivery between July 1, 2007, and March 31, 2018, and excluded those with prepregnancy diabetes, hypertension, HF, or coronary artery disease. GDM, GHTD, peripartum cardiomyopathy (at index pregnancy) were identified using diagnosis coding. Incident HF was assessed from index pregnancy until March 31, 2020. We estimated associations of GDM and/or GHTD with peripartum cardiomyopathy and incident HF.

RESULTS

Among 885,873 women (mean age: 30 years, 54,015 with isolated GDM, 43,750 with isolated GHTD, 4,960 with GDM and GHTD), there were 489 HF events over 8 years. Compared to no-GDM and no-GHTD, isolated GDM (adjusted hazard ratio [aHR]: 1.44; 95% CI: 1.02-2.04) and isolated GHTD (aHR: 1.65; 95% CI: 1.17-2.31) were associated with a higher risk of incident HF. The co-occurrence of GDM and GHTD was associated with a higher HF risk (aHR: 2.64; 95% CI: 1.24-5.61). GDM and GHTD increased the risk of peripartum cardiomyopathy (adjusted risk ratio [aRR]: 7.30; 95% CI: 6.92-7.58), similarly to isolated GHTD (aRR: 7.40; 95% CI: 7.23-7.58).

CONCLUSIONS

The co-occurrence of GDM and GHTD was associated with a significantly high risk of incident HF.

The Association of Sodium-Glucose Cotransporter 2 Inhibitors With Cardiovascular Outcomes in Anthracycline-Treated Patients With Cancer

Background

Sodium glucose cotransporter-2 inhibitors (SGLT2is) are hypothesized to reduce the risk of anthracycline-associated cardiotoxicity.

Objectives

This study sought to determine the association between SGLT2is and cardiovascular disease (CVD) after anthracycline-containing chemotherapy.

Methods

Using administrative data sets, we conducted a population-based cohort study of people >65 years of age with treated diabetes and no prior heart failure (HF) who received anthracyclines between January 1, 2016, and December 31, 2019. After estimating propensity scores for SGLT2i use, the average treatment effects for the treated weights were used to reduce baseline differences between SGLT2i-exposed and -unexposed controls. The outcomes were hospitalization for HF, incident HF diagnoses (in- or out-of-hospital), and documentation of any CVD in future hospitalizations. Death was treated as a competing risk. Cause-specific HRs for each outcome were determined for SGLT2i-treated people relative to unexposed controls.

Results

We studied 933 patients (median age 71.0 years, 62.2% female), 99 of whom were SGLT2i treated. During a median follow-up of 1.6 years, there were 31 hospitalizations for HF (0 in the SGLT2i group), 93 new HF diagnoses, and 74 hospitalizations with documented CVD. Relative to controls, SGLT2i exposure was associated with HR of 0 for HF hospitalization (P < 0.001) but no significant difference in incident HF diagnosis (HR: 0.55; 95% CI: 0.23-1.31; P = 0.18) or CVD diagnosis (HR: 0.39; 95% CI: 0.12-1.28; P = 0.12). There was no significant difference in mortality (HR: 0.63; 95% CI: 0.36-1.11; P = 0.11).

Conclusions

SGLT2is may reduce the rate of HF hospitalization after anthracycline-containing chemotherapy. This hypothesis warrants further testing in randomized controlled trials.

Comorbidity-stratified estimates of 30-day mortality risk by age for unvaccinated men and women with COVID-19: a population-based cohort study

BACKGROUND

The mortality risk following COVID-19 diagnosis in men and women with common comorbidities at different ages has been difficult to communicate to the general public. The purpose of this study was to determine the age at which unvaccinated men and women with common comorbidities have a mortality risk which exceeds that of 75- and 65-year-old individuals in the general population (Phases 1b/1c thresholds of the Centre for Disease Control Vaccine Rollout Recommendations) following COVID-19 infection during the first wave.

METHODS

We conducted a population-based retrospective cohort study using linked administrative datasets in Ontario, Canada. We identified all community-dwelling adults diagnosed with COVID-19 between January 1 and October 31st, 2020. Exposures of interest were age (modelled using restricted cubic splines) and the following conditions: major cardiovascular disease (recent myocardial infarction or lifetime history of heart failure); 2) diabetes; 3) hypertension; 4) recent cancer; 5) chronic obstructive pulmonary disease; 6) Stages 4/5 chronic kidney disease (CKD); 7) frailty. Logistic regression in the full cohort was used to estimate the risk of 30-day mortality for 75- and 65-year-old individuals. Analyses were repeated after stratifying by sex and medical condition to determine the age at which 30-day morality risk in strata exceed that of the general population at ages 65 and 75 years.

RESULTS

We studied 52,429 individuals (median age 42 years; 52.5% women) of whom 417 (0.8%) died within 30 days. The 30-day mortality risk increased with age, male sex, and comorbidities. The 65- and 75-year-old mortality risks in the general population were exceeded at the youngest age by people with CKD, cancer, and frailty. Conversely, women aged < 65 years who had diabetes or hypertension did not have higher mortality than 65-year-olds in the general population. Most people with medical conditions (except for Stage 4-5 CKD) aged < 45 years had lower predicted mortality than the general population at age 65 years.

CONCLUSION

The mortality risk in COVID-19 increases with age and comorbidity but the prognostic implications varied by sex and condition. These observations can support communication efforts and inform vaccine rollout in jurisdictions with limited vaccine supplies.

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.

The influence of diabetes on temporal trends in lower extremity revascularisation and amputation for peripheral artery disease: A population-based repeated cross-sectional analysis

AIM/HYPOTHESIS

To describe the influence of diabetes on temporal changes in rates of lower extremity revascularisation and amputation for peripheral artery disease (PAD) in Ontario, Canada.

METHODS

In this population-based repeated cross-sectional study, we calculated annual rates of lower extremity revascularisation (open or endovascular) and amputation (toe, foot or leg) related to PAD among Ontario residents aged ≥40 years between 2002 and 2019. Annual rate ratios (relative to 2002) adjusted for changes in diabetes prevalence alone, as well as fully adjusted for changes in demographics, diabetes and other comorbidities, were estimated using generalized estimating equation models to model population-level effects while accounting for correlation within units of observation.

RESULTS

Compared with 2002, the Ontario population in 2019 exhibited a significantly higher prevalence of diabetes (18% vs. 10%). Between 2002 and 2019, the crude rate of revascularisation increased from 75.1 to 90.7/100,000 person-years (unadjusted RR = 1.10, 95% CI = 1.07-1.13). However, after adjustment, there was no longer an increase in the rate of revascularisation (diabetes-adjusted RR = 0.98, 95% CI = 0.96-1.01, fully-adjusted RR = 0.94, 95% CI = 0.91-0.96). The crude rate of amputation decreased from 2002 to 2019 from 49.5 to 45.4/100,000 person-years (unadjusted RR = 0.78, 95% CI = 0.75-0.81), but was more pronounced after adjustment (diabetes-adjusted RR = 0.62, 95% CI = 0.60-0.64; fully-adjusted RR = 0.58, 95% CI = 0.56-0.60).

CONCLUSIONS/INTERPRETATION

Diabetes prevalence rates strongly influenced rates of revascularisation and amputation related to PAD. A decrease in amputations related to PAD over time was attenuated by rising diabetes prevalence rates.

System-level performance measures of access to rheumatology care: a population-based retrospective study of trends over time and the impact of regional rheumatologist supply in Ontario, Canada, 2002-2019

OBJECTIVE

To determine whether there were improvements in rheumatology care for rheumatoid arthritis (RA) between 2002 and 2019 in Ontario, Canada, and to evaluate the impact of rheumatologist regional supply on access.

METHODS

We conducted a population-based retrospective study of all individuals diagnosed with RA between January 1, 2002 and December 31, 2019. Performance measures evaluated were: (i) percentage of RA patients seen by a rheumatologist within one year of diagnosis; and (ii) percentage of individuals with RA aged 66 years and older (whose prescription drugs are publicly funded) dispensed a disease modifying anti-rheumatic drug (DMARD) within 30 days after initial rheumatologist visit. Logistic regression was used to assess whether performance improved over time and whether the improvements differed by rheumatology supply, dichotomized as < 1 rheumatologist per 75,000 adults versus ≥1 per 75,000.

RESULTS

Among 112,494 incident RA patients, 84% saw a rheumatologist within one year: The percentage increased over time (adjusted odds ratio (OR) 2019 vs. 2002 = 1.43, p < 0.0001) and was consistently higher in regions with higher rheumatologist supply (OR = 1.73, 95% CI 1.67-1.80). Among seniors who were seen by a rheumatologist within 1 year of their diagnosis the likelihood of timely DMARD treatment was lower among individuals residing in regions with higher rheumatologist supply (OR = 0.90 95% CI 0.83-0.97). These trends persisted after adjusting for other covariates.

CONCLUSION

While access to rheumatologists and treatment improved over time, shortcomings remain, particularly for DMARD use. Patients residing in regions with higher rheumatology supply were more likely to access care but less likely to receive timely treatment.

Association of Concomitant Gestational Hypertensive Disorders and Gestational Diabetes With Cardiovascular Disease

IMPORTANCE

Accruing evidence suggests that gestational hypertensive disorders (GHTD) and gestational diabetes (GD) are each associated with an increased risk of cardiovascular disease (CVD). However, the extent to which the co-occurrence of GHTD and GD is associated with the risk of CVD remains largely unknown.

OBJECTIVE

To estimate the individual and joint associations of GHTD and GD with incident CVD.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used the Ministry of Health and Long-Term Care of Ontario (Canada) health care administrative databases. All women in Ontario with a GHTD and/or GD diagnosis, and a live-birth singleton delivery between July 1, 2007, and March 31, 2018, were considered for inclusion. Women with pregravid diabetes, hypertension, or cardiovascular disease were excluded. Statistical analysis was performed from November 2021 to September 2022.

EXPOSURES

GD and/or GHTD, defined using diagnosis coding.

MAIN OUTCOMES AND MEASURES

Individual and joint associations of GHTD and GD with incident CVD (including a composite of myocardial infarction, acute coronary syndrome, stroke, coronary artery bypass grafting, percutaneous coronary intervention, or carotid endarterectomy), estimated using Cox regression models, adjusting for relevant cardiometabolic risk factors. The follow-up extended from the index pregnancy until March 31, 2020.

RESULTS

Among 886 295 eligible women (mean [SD] age, 30 [5.6] years; 43 861 [4.9%] with isolated GHTD, 54 061 [6.1%] with isolated GD, and 4975 [0.6%] with GHTD and GD), there were 1999 CVD events over 12 years of follow-up. In the early postpartum phase (first 5 years post partum), there was no association of co-occurrence of GTHD and GD (adjusted hazard ratio [aHR], 1.42, 95% CI, 0.78-2.58) or GD alone (aHR, 0.80; 95% CI, 0.60-1.06) with CVD; there was an association between isolated GTHD and incident CVD compared with no GTHD and no GD (aHR, 1.90; 95% CI, 1.51-2.35). In the late postpartum period (after the initial 5 years post partum), compared with no GD and no GHTD, isolated GHTD (aHR, 1.41, 95% CI, 1.12-1.76) and co-occurrence of GHTD and GD (aHR, 2.43, 95% CI, 1.60-3.67) were each associated with a higher risk of incident CVD. There was no association between isolated GD and incident CVD.

CONCLUSIONS AND RELEVANCE

In this cohort study, GHTD was associated with a high risk of CVD post partum, and the co-occurrence of GD and GHTD was associated with a much greater postpartum CVD risk. These findings suggest that CVD preventive care is particularly needed in the aftermath of combined GD and GHTD.

Fracture Risk of Sodium-Glucose Cotransporter-2 Inhibitors in Chronic Kidney Disease

BACKGROUND AND OBJECTIVES

Sodium-glucose cotransporter-2 (SGLT2) inhibitors have been associated with a higher risk of skeletal fractures in some randomized, placebo-controlled trials. Secondary hyperparathyroidism and increased bone turnover (also common in CKD) may contribute to the observed fracture risk. We aimed to determine if SGLT2 inhibitor use associates with a higher risk of fractures compared with dipeptidyl peptidase-4 (DPP-4) inhibitors, which have no known association with fracture risk. We hypothesized that this risk, if present, would be greatest in patients with lower eGFR.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a population-based cohort study in Ontario, Canada between 2015 and 2019 using linked provincial administrative data to compare the incidence of fracture between new users of SGLT2 inhibitors and DPP-4 inhibitors. We used inverse probability of treatment weighting on the basis of propensity scores to balance the two groups of older adults (≥66 years of age) on indicators of baseline health. We compared the 180- and 365-day cumulative incidence rates of fracture between groups. Prespecified subgroup analyses were conducted by eGFR category (≥90, 60 to <90, 45 to <60, and 30 to <45 ml/min per 1.73 m²). Weighted hazard ratios were obtained using Cox proportional hazard regression.

RESULTS

After weighting, we identified a total of 38,994 new users of a SGLT2 inhibitor and 37,449 new users of a DPP-4 inhibitor and observed a total of 342 fractures at 180 days and 689 fractures at 365 days. The weighted 180- and 365-day risks of a fragility fracture did not significantly differ between new users of a SGLT2 inhibitor versus a DPP-4 inhibitor: weighted hazard ratio, 0.95 (95% confidence interval, 0.79 to 1.13) and weighted hazard ratio, 0.88 (95% confidence interval, 0.88 to 1.00), respectively. There was no observed interaction between fracture risk and eGFR category (P=0.53).

CONCLUSIONS

In this cohort study of older adults, starting a SGLT2 inhibitor versus DPP-4 inhibitor was not associated with a higher risk of skeletal fracture, regardless of eGFR.

Comorbid conditions as risk factors for West Nile neuroinvasive disease in Ontario, Canada: a population-based cohort study

West Nile neuroinvasive disease (WNND) is a severe neurological illness that can result from West Nile virus (WNV) infection, with long-term disability and death being common outcomes. Although WNV arrived in North America over two decades ago, risk factors for WNND are still being explored. The objective of this study was to identify WNND comorbid risk factors in the Ontario population using a retrospective, population-based cohort design. Incident WNV infections from laboratory records between 1 January 2002 – 31 December 2012 were individually-linked to health administrative databases to ascertain WNND outcomes and comorbid risk factors. WNND incidence was compared among individuals with and without comorbidities using risk ratios (RR) calculated with log binomial regression.

Three hundred and forty-five individuals developed WNND (18.3%) out of 1884 WNV infections. West Nile encephalitis was driving most associations with comorbidities. Immunocompromised (aRR 2.61 [95% CI 1.23–4.53]) and male sex (aRR 1.32 [95% CI 1.00–1.76]) were risk factors for encephalitis, in addition to age, for which each 1-year increase was associated with a 2% (aRR 1.02 [95% CI 1.02–1.03]) relative increase in risk. Our results suggest that individuals living with comorbidities are at higher risk for WNND, in particular encephalitis, following WNV infection.

Trends in basal insulin prescribing in older adults with chronic kidney disease in Ontario, Canada: A population-based analysis from 2010 to 2020

AIM

To examine trends in basal insulin prescribing in older adults with chronic kidney disease (CKD).

MATERIALS AND METHODS

We conducted a population-based study of adults aged 66 years or older with treated diabetes from 1 January 2010 to 30 September 2020 in Ontario, Canada. We examined prevalent and incident prescriptions for human NPH, Levemir, glargine-100, Basaglar, glargine-300, and degludec insulin over 43 study intervals. We present trends in those with CKD, and in a subgroup, by estimated glomerular filtration rate (eGFR). To provide context for prescribing, we provide demographics, co-morbidities, and the healthcare utilization of included patients.

RESULTS

In CKD, use of basal insulin was about 2-fold higher than in the general treated diabetes cohort. Prescriptions for NPH declined over time, while prescriptions for Levemir and glargine-100 increased until 2018 then decreased. Following drug formulary approval (September 2018), prescriptions for glargine-300 and degludec increased substantially. Incident prescriptions for basal insulin in CKD declined over time; however, in those with an eGFR of less than 30 ml/min/1.73m² , rates remained stable. In recent years, rates of degludec and glargine-300 have rivalled glargine-100.

CONCLUSIONS

In an era of new oral and injectable diabetes medications, the use of basal insulin has declined in older adults with CKD. However, in those with more advanced CKD, basal insulin, particularly newer analogues, remain a mainstay treatment.

Perinatal Mental Illness and Risk of Incident Autoimmune Disease: A Population-Based Propensity-Score Matched Cohort Study

Background

Studies have demonstrated elevated risk for autoimmune disease associated with perinatal mental illness, but the extent to which this risk is specific to mental illness arising perinatally, and not mental illness generally, is unknown. Our objective was to compare the risk of autoimmune disease in women with mental illness arising within the perinatal period to (1) women with mental illness arising outside the perinatal period and (2) women who did not develop mental illness.

Methods

We conducted a population-based matched cohort study of women aged 15–49 years with no history of mental illness or autoimmune disease in Ontario, Canada, 1998–2018. The exposed, 60,701 women with mental illness arising between conception and 365 days postpartum were propensity score-matched to (1) 264,864 women with mental illness arising non-perinatally and (2) 469,164 women who did not develop mental illness. Hazard ratios (HR) for autoimmune disease were generated using Cox proportional hazards models.

Results

The incidence of autoimmune disease was similar among women with mental illness arising perinatally compared to those with mental illness arising non-perinatally (138.4 vs 140.7 per 100,000 person-years; HR 0.98, 95% CI 0.92–1.05), and elevated among women with mental illness arising perinatally compared to those who did not develop mental illness (138.4 vs 88.9 per 100,000 person-years; HR 1.54, 95% CI 1.44–1.64). The HR for the latter comparison was more pronounced for autoimmune disease with brain-reactive antibodies than other autoimmune disease.

Conclusion

Perinatal mental illness is associated with increased risk of autoimmune disease that is no different than that of mental illness arising non-perinatally. Women with mental illness, regardless of the timing of onset, could benefit from early detection of autoimmune disease.

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

BACKGROUND

Prior validation studies of claims-based definitions of chronic kidney disease (CKD) using ICD-9 codes reported overall low sensitivity, high specificity, and variable but reasonable PPV. No studies to date have evaluated the accuracy of ICD-10 codes to identify a US patient population with CKD.

METHODS

We assessed the accuracy of claims-based algorithms to identify adults with CKD Stages 3-5 compared with laboratory values in a subset (~40%) of a US commercial insurance claims database (Optum's de-identified Clinformatics® Data Mart Database). We calculated the positive predictive value (PPV) of one or two ICD-9 (2012-2014) or ICD-10 (2016-2018) codes for CKD compared with a lab-based estimated glomerular filtration rate (eGFR) occurring within prespecified windows (±90 days, ±180 days, ±365 days) of the ICD-based CKD code(s).

RESULTS

The study population ranged between 104 774 and 161 305 patients (ICD-9 cohorts) and between 285 520 and 373 220 patients (ICD-10 cohorts). The mean age was 74.4 years (ICD-9) and 75.6 years (ICD-10) and the median eGFR was 48 ml/min/1.73 m² . The algorithm of two CKD codes compared with a lab value ±90 days of the first code achieved the highest PPV (PPV 86.36% [ICD-9] and 86.07% [ICD-10]). Overall, ICD-10 based codes had comparable PPVs to ICD-9 based codes and all ICD-10 based algorithms had PPVs >80%. The algorithm of one CKD code compared with laboratory value ±180 days maintained the PPV above 80% but still retained a large number of patients (PPV 80.32% [ICD-9] and 81.56% [ICD-10]).

CONCLUSION

An ICD-10-based definition of CKD identified with sufficient accuracy a patient population with CKD Stages 3-5. Our findings suggest that claims databases could be used for future real-world research studies in patients with CKD Stages 3-5.

Cardiovascular outcomes after initiating GLP-1 receptor agonist or basal insulin for the routine treatment of type 2 diabetes: a region-wide retrospective study

Aim

We aimed to compare cardiovascular outcomes of patients with type 2 diabetes (T2D) who initiated GLP-1 receptor agonists (GLP-1RA) or basal insulin (BI) under routine care.

Methods

We accessed the administrative claims database of the Veneto Region (Italy) to identify new users of GLP-1RA or BI in 2014–2018. Propensity score matching (PSM) was implemented to obtain two cohorts of patients with superimposable characteristics. The primary endpoint was the 3-point major adverse cardiovascular events (3P-MACE). Secondary endpoints included 3P-MACE components, hospitalization for heart failure, revascularizations, and adverse events.

Results

From a background population of 5,242,201 citizens, 330,193 were identified as having diabetes. PSM produced two very well matched cohorts of 4063 patients each, who initiated GLP-1RA or BI after an average of 2.5 other diabetes drug classes. Patients were 63-year-old and only 15% had a baseline history of cardiovascular disease. During a median follow-up of 24 months in the intention-to-treat analysis, 3P-MACE occurred less frequently in the GLP-1RA cohort (HR versus BI 0.59; 95% CI 0.50–0.71; p < 0.001). All secondary cardiovascular endpoints were also significantly in favor of GLP-1RA. Results were confirmed in the as-treated approach and in several stratified analyses. According to the E-value, confounding by unmeasured variables were unlikely to entirely explain between-group differences in cardiovascular outcomes.

Conclusions

Patients with T2D who initiated a GLP-1RA experienced far better cardiovascular outcomes than did matched patients who initiated a BI in the same healthcare system. These finding supports prioritization of GLP-1RA as the first injectable regimen for the management of T2D.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01414-3.

Chronic disease surveillance in Alberta's tomorrow project using administrative health data

Introduction

Alberta’s Tomorrow Project (ATP) is the largest population-based prospective cohort study of cancer and chronic diseases in Alberta, Canada. The ATP cohort data were primarily self-reported by participants on lifestyle behaviors and disease risk factors at the enrollment, which lacks sufficient and accurate data on chronic disease diagnosis for longer-term follow-up.

Objectives

To characterize the occurrence rate and trend of chronic diseases in the ATP cohort by linking with administrative healthcare data.

Methods

A set of validated algorithms using ICD codes were applied to Alberta Health (AH) administrative data (October 2000-March 2018) linked to the ATP cohort to determine the prevalence and incidence of common chronic diseases.

Results

There were 52,770 ATP participants (51.2±9.4 years old at enrollment and 63.7% females) linked to the AH data with average follow-up of 10.1±4.4 years. In the ATP cohort, hypertension (18.5%), depression (18.1%), chronic pain (12.8%), osteoarthritis (10.1%) and cardiovascular diseases (8.7%) were the most prevalent chronic conditions. The incidence rates varied across diseases, with the highest rates for hypertension (22.1 per 1000 person-year), osteoarthritis (16.2 per 1000 person-year) and ischemic heart diseases (13.0 per 1000 person-year). All chronic conditions had increased prevalence over time (p < for trend tests), while incidence rates were relatively stable. The proportion of participants with two or more of these conditions (multi-morbidity) increased from 3.9% in 2001 to 40.3% in 2017.

Conclusions

This study shows an increasing trend of chronic diseases in the ATP cohort, particularly related to cardiovascular diseases and multi-morbidity. Using administrative health data to monitor chronic diseases for large population-based prospective cohort studies is feasible in Alberta, and our approach could be further applied in a broader research area, including health services research, to enhance research capacity of these population-based studies in Canada.

Cardiovascular Risk Associated With Ibrutinib Use in Chronic Lymphocytic Leukemia: A Population-Based Cohort Study

PURPOSE

Ibrutinib reduces mortality in chronic lymphocytic leukemia (CLL). It increases the risk of atrial fibrillation (AF) and bleeding and there are concerns about heart failure (HF) and central nervous system ischemic events. The magnitude of these risks remains poorly quantified.

METHODS

Using linked administrative databases, we conducted a population-based cohort study of Ontario patients who were treated for CLL diagnosed between 2007 and 2019. We matched ibrutinib-treated patients with controls treated with chemotherapy but unexposed to ibrutinib on prior AF, age ≥ 66 years, anticoagulant exposure, and propensity for receiving ibrutinib. Study outcomes were AF-related health care contact, hospital-diagnosed bleeding, new diagnoses of HF, and hospitalizations for stroke and acute myocardial infarction (AMI). The cumulative incidence function was used to estimate absolute risks. We used cause-specific regression to study the association of ibrutinib with bleeding rates, while adjusting for anticoagulation as a time-varying covariate.

RESULTS

We matched 778 pairs of ibrutinib-treated and unexposed patients with CLL (N = 1,556). The 3-year incidence of AF-related health care contact was 22.7% (95% CI, 19.0 to 26.6) in ibrutinib-treated patients and 11.7% (95% CI, 9.0 to 14.8) in controls. The 3-year risk of hospital-diagnosed bleeding was 8.8% (95% CI, 6.5 to 11.7) in ibrutinib-treated patients and 3.1% (95% CI, 1.9 to 4.6) in controls. Ibrutinib-treated patients were more likely to start anticoagulation after the index date. After adjusting for anticoagulation as a time-varying covariate, ibrutinib remained positively associated with bleeding (HR, 2.58; 95% CI, 1.76 to 3.78). The 3-year risk of HF was 7.7% (95% CI, 5.4 to 10.6%) in ibrutinib-treated patients and 3.6% (95% CI, 2.2 to 5.4) in controls. There was no significant difference in the risk of ischemic stroke or AMI.

CONCLUSION

Ibrutinib is associated with higher risk of AF, bleeding, and HF, but not AMI or stroke.

Data Consult Service: Can we use observational data to address immediate clinical needs?

OBJECTIVE

A number of clinical decision support tools aim to use observational data to address immediate clinical needs, but few of them address challenges and biases inherent in such data. The goal of this article is to describe the experience of running a data consult service that generates clinical evidence in real time and characterize the challenges related to its use of observational data.

MATERIALS AND METHODS

In 2019, we launched the Data Consult Service pilot with clinicians affiliated with Columbia University Irving Medical Center. We created and implemented a pipeline (question gathering, data exploration, iterative patient phenotyping, study execution, and assessing validity of results) for generating new evidence in real time. We collected user feedback and assessed issues related to producing reliable evidence.

RESULTS

We collected 29 questions from 22 clinicians through clinical rounds, emails, and in-person communication. We used validated practices to ensure reliability of evidence and answered 24 of them. Questions differed depending on the collection method, with clinical rounds supporting proactive team involvement and gathering more patient characterization questions and questions related to a current patient. The main challenges we encountered included missing and incomplete data, underreported conditions, and nonspecific coding and accurate identification of drug regimens.

CONCLUSIONS

While the Data Consult Service has the potential to generate evidence and facilitate decision making, only a portion of questions can be answered in real time. Recognizing challenges in patient phenotyping and designing studies along with using validated practices for observational research are mandatory to produce reliable evidence.

Association of pediatric cardiac surgery-associated acute kidney injury with post-discharge healthcare utilization, mortality and kidney outcomes

BACKGROUND

Acute kidney Injury (AKI) in children undergoing cardiac surgery (CS) is strongly associated with hospital morbidity. Post-discharge CS AKI outcomes are less clear. We evaluated associations between AKI and post-discharge (a) healthcare utilization, (b) chronic kidney disease (CKD) or hypertension and (c) mortality.

METHODS

This is a retrospective two-centre cohort study of children surviving to hospital discharge after CS. Primary exposures were post-operative ≥Stage 1 AKI and ≥Stage 2 AKI defined by Kidney Disease Impoving Global Outcomes. Association of AKI with time to outcomes was determined using multivariable Cox-Proportional Hazards analysis.

RESULTS

Of 350 participants included (age 3.1 (4.5) years), 180 [51.4%] developed AKI and 60 [17.1%] developed ≥Stage 2 AKI. Twenty-eight (9%) participants developed CKD or hypertension (composite outcome), and 17 (5%) died within 5 years of discharge. Post-operative ≥Stage 1 and ≥Stage 2 AKI were not associated with post-discharge hospitalizations, emergency room (ER) visits, physician visits or CKD or hypertension in adjusted analyses. A trend was observed between ≥Stage 2 AKI and mortality but was not statistically significant. In unadjusted stratified analyses, AKI was associated with post-discharge hospitalizations in children with RACHS-1 score ≥3, complex chronic disease classification and children living in urban areas.

CONCLUSIONS

Post-CS AKI is not associated with post-discharge healthcare utilization, death and CKD or hypertension, though it may be associated with healthcare utilization in more complex paediatric CS children. Studies should aim to better understand post-CS healthcare utilization patterns and non-AKI risk factors for CKD, hypertension and mortality, to reduce adverse long-term outcomes after CS.

Gestational Diabetes and Incident Heart Failure: A Cohort Study

OBJECTIVE

To assess whether gestational diabetes mellitus (GDM) is associated with an increased risk of heart failure (HF).

RESEARCH DESIGN AND METHODS

We conducted a population-based cohort study using information from the Ministry of Health and Long-Term Care of Ontario (Canada) health care administrative databases. We identified all women in Ontario with a GDM diagnosis with a live birth singleton delivery between 1 July 2007 and 31 March 2018. Women with diabetes or HF before pregnancy were excluded. GDM was defined based on laboratory test results and diagnosis coding. The primary outcome was incident HF hospitalization over a period extending from the index pregnancy until 31 March 2019. The secondary outcome was prevalent peripartum cardiomyopathy at index pregnancy. Estimates of association were adjusted for relevant cardiometabolic risk factors.

RESULTS

Among 906,319 eligible women (mean age 30 years [SD 5.6], 50,193 with GDM [5.5%]), there were 763 HF events over a median follow-up period of 7 years. GDM was associated with a higher risk of incident HF (adjusted hazard ratio [aHR] 1.62 [95% CI 1.28, 2.05]) compared with no GDM. This association remained significant after accounting for chronic kidney disease, postpartum diabetes, hypertension, and coronary artery disease (aHR 1.39 [95% CI 1.09, 1.79]). GDM increased the odds of peripartum cardiomyopathy (adjusted odds ratio 1.83 [95% CI 1.45, 2.33]).

CONCLUSIONS

In a large observational study, GDM was associated with an increased risk of HF. Consequently, diabetes screening during pregnancy is suggested to identify women at risk for HF.

Evaluation of the Risk of Stroke Without Anticoagulation Therapy in Men and Women With Atrial Fibrillation Aged 66 to 74 Years Without Other CHA2DS2-VASc Factors

Importance

There are limited clinical trial data and discrepant recommendations regarding use of anticoagulation therapy in patients with atrial fibrillation (AF) aged 65 to 74 years without other stroke risk factors.

Objectives

To evaluate the risk of stroke without anticoagulation therapy in men and women with AF aged 66 to 74 years without other CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, stroke, vascular disease, age 65-74 years, female sex) risk factors and examine the association of stroke incidence with patient age.

Design, Setting, and Participants

A population-based retrospective cohort study was conducted using linked administrative databases. The population included 16 351 individuals aged 66 to 74 years who were newly diagnosed with AF in Ontario, Canada, between April 1, 2007, and March 31, 2017. Exclusion criteria included long-term care residence, prior anticoagulation therapy, valvular disease, heart failure, hypertension, diabetes, stroke, and vascular disease. The cumulative incidence function was used to estimate the 1-year incidence of stroke in patients who did not receive anticoagulation therapy. Fine-Gray regression was used to study the association of patient characteristics with stroke incidence and derive estimates of stroke risk at each age. Death was treated as a competing risk and patients were censored if they initiated anticoagulation therapy. Inverse probability of censoring weights was used to account for patient censoring. Data analysis was performed from May 26, 2019, to December 9, 2020.

Exposures

Atrial fibrillation and age.

Main Outcomes and Measures

Hospitalizations for stroke.

Results

Of the 16 351 individuals with AF (median [interquartile range] age, 70 [68-72] years), 8352 (51.1%) were men; 6314 individuals (38.6%) started anticoagulation therapy during follow-up. The overall 1-year stroke incidence among patients who did not receive anticoagulation therapy was 1.1% (95% CI, 1.0%-1.3%) and the incidence of death without stroke was 8.1% (95% CI, 7.7%-8.5%). The incidence of stroke was not significantly associated with sex. The estimated 1-year stroke risk increased with patient age from 66 years (0.7%; 95% CI, 0.5%-0.9%) to 74 years (1.7%; 95% CI, 1.3%-2.1%).

Conclusions and Relevance

The risk of stroke more than doubled in this study as men and women with AF but no other CHA2DS2-VASc risk factors aged from 66 to 74 years. These data suggest that anticoagulation therapy is more likely to benefit older individuals within this group of patients, whereas younger individuals are less likely to gain net clinical benefit from anticoagulation therapy.

Rivaroxaban vs. warfarin and renal outcomes in non-valvular atrial fibrillation patients with diabetes

AIMS

Vascular calcification is common in diabetic patients. Warfarin has been associated with renovascular calcification and worsening renal function; rivaroxaban may provide renopreservation by decreasing vascular inflammation. We compared the impact of rivaroxaban and warfarin on renal outcomes in diabetic patients with non-valvular atrial fibrillation (NVAF).

METHODS AND RESULTS

Using United States IBM MarketScan data from January 2011 to December 2017, we identified adults with both NVAF and diabetes, newly-initiated on rivaroxaban or warfarin with ≥12-month insurance coverage prior to anticoagulation initiation. Patients with Stage 5 chronic kidney disease (CKD) or undergoing haemodialysis at baseline were excluded. Differences in baseline covariates between cohorts were adjusted using inverse probability-of-treatment weighting (IPTW) based on propensity scores (absolute standardized differences <0.1 achieved for all after adjustment). Outcomes included incidence rates of emergency department/hospital admissions for acute kidney injury (AKI) and the composite of the development of Stage 5 CKD or need for haemodialysis. Patients were followed until an event, index anticoagulant discontinuation/switch, insurance disenrollment, or end-of-data availability. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox regression. We assessed 10 017 rivaroxaban (22.6% received a reduced dose) and 11 665 warfarin users. In comparison to warfarin, rivaroxaban was associated with lower risks of AKI (HR = 0.83, 95% CI = 0.74-0.92) and development of Stage 5 CKD or need for haemodialysis (HR = 0.82, 95% CI = 0.70-0.96). Sensitivity and subgroup analyses had similar effects as the base-case analysis.

CONCLUSION

Rivaroxaban appears to be associated with lower risks of undesirable renal outcomes vs. warfarin in diabetic NVAF patients.

Clinical outcomes among patients with chronic kidney disease hospitalized with diabetic foot disorders: A nationwide retrospective study

INTRODUCTION

Diabetic foot ulcerations or infections (DFUs/DFIs) are common complications of patients with diabetes. This study aimed to explore the impact of non-dialysis and dialysis CKD on hospitalized patients with DFUs/DFIs.

METHODS

A retrospective cohort study was conducted using the National Inpatient Sample database for the years 2017 and 2018. Patients hospitalized for DFUs/DFIs were included in the study. The primary outcome was lower limb amputations. The secondary outcomes were inpatient mortality, sepsis, length of stay (LOS), total hospitalization charges (THC) and disposition.

RESULTS

A total of 121,815 hospitalizations were included (26.1% non-dialysis CKD; 8.4% dialysis CKD). There was no significant difference in amputation rates between those on non-dialysis CKD (adjusted odds ratio [aOR]: 0.96; 95% confidence interval [CI]: 0.87-1.06) and dialysis CKD (aOR: 1.04, [95% CI: 0.91-1.12]) when compared to non-CKD group. Dialysis CKD group had increased odds of undergoing major amputation (aOR: 1.74, [95% CI: 1.32-2.29]), in-hospital mortality (aOR: 3.77 [95% CI: 1.94-7.31]), sepsis (aOR: 1.83 [95% CI: 1.27-2.62]), longer LOS (adjusted mean difference [aMD]: 1.46 [95 CI: 1.12-1.80) and higher THC (adjusted mean difference [aMD]: $20,148 [95% CI: $15,968-$24,327]). Non-dialysis CKD group had increased odds of sepsis (aOR: 1.36 [95% CI: 1.02-1.82]), less likely to be discharged home (aOR: 0.87 [95% CI: 0.80-0.95]), longer LOS (aMD: 0.91 [95% CI 0.69-1.13]) and higher THC (aMD: $20,148 [95% CI: $15,968-$24,327]).

CONCLUSION

Patients with CKD on dialysis had higher odds of undergoing major amputation. CKD increased the odds of in-hospital morbidity and resource utilization, with the most significant is for those on dialysis.

Characteristics and Outcomes of Women Developing Heart Failure After Early Stage Breast Cancer Chemotherapy: A Population-Based Matched Cohort Study

BACKGROUND

The prognosis of heart failure (HF) after early stage breast cancer (EBC) treatment with anthracyclines or trastuzumab is not well-characterized.

METHODS

Using administrative databases, women diagnosed with HF after receiving anthracyclines or trastuzumab for EBC in Ontario during 2007 to 2017 (the EBC-HF cohort) were categorized by cardiotoxic exposure (anthracycline alone, trastuzumab alone, sequential therapy with both agents) and matched on age with ≤3 cancer-free HF controls to compare baseline characteristics. To study prognosis after HF onset, we conducted a second match on age plus important HF prognostic factors. The cumulative incidence function was used to describe risk of hospitalization or emergency department visits (hospital presentations) for HF and cardiovascular death.

RESULTS

A total of 804 women with EBC developed HF after anthracyclines (n=312), trastuzumab (n=112), or sequential therapy (n=380); they had significantly fewer comorbidities than 2411 age-matched HF controls. After the second match, the anthracycline-HF cohort had a similar 5-year incidence of HF hospital presentations (16.5% [95% CI, 12.0%-21.7%]) as controls (17.1% [95% CI, 14.4%-20.1%]); the 5-year incidence was lower than matched controls for the trastuzumab-HF (9.7% [95% CI, 4.7%-16.9%]; controls 16.4% [95% CI, 12.1%-21.3%]; P=0.03) and sequential-HF cohorts (2.7% [95% CI, 1.4%-4.8%]; controls 10.8% [95% CI, 8.9%-13.0%]; P<0.001). At 5 years, the incidence of cardiovascular death was 2.9% (95% CI, 1.2%-5.9%) in the anthracycline-HF cohort vs. 9.5% (95% CI, 6.9%-12.6%) in controls, and 1.7% (0.6%-3.7%) for women developing HF after trastuzumab vs. 4.3% (95% CI, 3.1-5.8%) for controls.

CONCLUSIONS

Women developing HF after cardiotoxic EBC chemotherapy have fewer comorbidities than cancer-free women with HF; trastuzumab-treated women who develop HF have better prognosis than matched HF controls.

Perinatal Complications as a Mediator of the Association Between Chronic Disease and Postpartum Mental Illness

Background: Chronic disease is associated with increased risk of postpartum mental illness, but the mechanisms underlying this association are unclear. Our aim was to explore the mediating role of perinatal complications in the association between chronic disease and postpartum mental illness. Materials and Methods: This was a population-based retrospective cohort study of all women in Ontario, Canada, from 2005 to 2015 with a singleton live birth and no recent history of mental illness during or 2 years before pregnancy. The outcome was mental illness diagnosis between delivery and 365 days postpartum, with perinatal complications, including pregnancy, delivery, and neonatal complications. Modified Poisson regression models were used to examine the association between chronic disease and perinatal mental illness, with generalized estimating equations for the calculation of total, direct, and indirect effects. All models were adjusted for sociodemographic characteristics and remote history of mental health care. Results: Of the 792,972 women, 21.1% had a chronic disease. Chronic disease was associated with an increased risk of postpartum mental illness (adjusted relative risk [aRR] 1.15 [95% confidence interval, CI 1.14-1.16]). There was no evidence of an indirect effect of chronic disease on postpartum mental illness via perinatal complications (aRR 1.003, 95% CI 1.002-1.003). Perinatal complications explained only 1.5% of the association between chronic disease and postpartum mental illness. Results were consistent by type of perinatal complication and chronic disease diagnosis. Conclusion: We observed no clinically meaningful mediating effect of perinatal complications in the association between chronic disease and postpartum mental illness. Future research should investigate alternative mechanisms explaining this association.

The validity of Dutch health claims data for identifying patients with chronic kidney disease: a hospital-based study in the Netherlands

BACKGROUND

Health claims data may be an efficient and easily accessible source to study chronic kidney disease (CKD) prevalence in a nationwide population. Our aim was to study Dutch claims data for their ability to identify CKD patients in different subgroups.

METHODS

From a laboratory database, we selected 24 895 adults with at least one creatinine measurement in 2014 ordered at an outpatient clinic. Of these, 15 805 had ≥2 creatinine measurements at least 3 months apart and could be assessed for the chronicity criterion. We estimated the validity of a claim-based diagnosis of CKD and advanced CKD. The estimated glomerular filtration rate (eGFR)-based definitions for CKD (eGFR < 60 mL/min/1.73 m2) and advanced CKD (eGFR < 30 mL/min/1.73 m2) satisfying and not satisfying the chronicity criterion served as reference group. Analyses were stratified by age and sex.

RESULTS

In general, sensitivity of claims data was highest in the population with the chronicity criterion as reference group. Sensitivity was higher in advanced CKD patients than in CKD patients {51% [95% confidence interval (CI) 47-56%] versus 27% [95% CI 25-28%]}. Furthermore, sensitivity was higher in young versus elderly patients. In patients with advanced CKD, sensitivity was 72% (95% CI 62-83%) for patients aged 20-59 years and 43% (95% CI 38-49%) in patients ≥75 years. The specificity of CKD and advanced CKD was ≥99%. Positive predictive values ranged from 72% to 99% and negative predictive values ranged from 40% to 100%.

CONCLUSION

When using health claims data for the estimation of CKD prevalence, it is important to take into account the characteristics of the population at hand. The younger the subjects and the more advanced the stage of CKD the higher the sensitivity of such data. Understanding which patients are selected using health claims data is crucial for a correct interpretation of study results.

Trends in Anticoagulant Use at Nursing Home Admission and Variation by Frailty and Chronic Kidney Disease Among Older Adults with Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is relatively common among nursing home residents, and decisions regarding anticoagulant therapy in this setting may be complicated by resident frailty and other factors.

OBJECTIVES

The aim of this study was to examine trends and correlates of oral anticoagulant use among newly admitted nursing home residents with AF following the approval of direct-acting oral anticoagulants (DOACs).

METHODS

We conducted a retrospective cohort study of all adults aged > 65 years with AF who were newly admitted to nursing homes in Ontario, Canada, between 2011 and 2018 (N = 36,466). Health administrative databases were linked with comprehensive clinical assessment data captured shortly after admission, to ascertain resident characteristics. Trends in prevalence of anticoagulant use (any, warfarin, DOAC) at admission were captured with prescription claims and examined by frailty and chronic kidney disease (CKD). Log-binomial regression models estimated crude percentage changes in use over time and modified Poisson regression models assessed factors associated with anticoagulant use and type.

RESULTS

The prevalence of anticoagulant use at admission increased from 41.1% in 2011/2012 to 58.0% in 2017/2018 (percentage increase = 41.1%, p < 0.001). Warfarin use declined (- 67.7%, p < 0.001), while DOAC use increased. Anticoagulant use was less likely among residents with a prior hospitalization for hemorrhagic stroke (adjusted risk ratio [aRR] 0.65, 95% confidence interval [CI] 0.60-0.70) or gastrointestinal bleed (aRR 0.80, 95% CI 0.78-0.83), liver disease (aRR 0.78, 95% CI 0.69-0.89), severe cognitive impairment (aRR 0.89, 95% CI 0.85-0.94), and non-steroidal anti-inflammatory drug (aRR 0.76, 95% CI 0.71-0.81) or antiplatelet (aRR 0.25, 95% CI 0.23-0.27) use, but more likely for those with a prior hospitalization for ischemic stroke or thromboembolism (aRR 1.30, 95% CI 1.27-1.33). CKD was associated with a reduced likelihood of DOAC versus warfarin use in both the early (aRR 0.62, 95% CI 0.54-0.71) and later years (aRR 0.79, 95% CI 0.76-0.83) of our study period. Frail residents were significantly less likely to receive an anticoagulant at admission, although this association was modest (aRR 0.95, 95% CI 0.92-0.98). Frailty was not associated with anticoagulant type.

CONCLUSIONS

While the proportion of residents with AF receiving oral anticoagulants at admission increased following the approval of DOACs, over 40% remained untreated. Among those treated, use of a DOAC increased, while warfarin use declined. The impact of these recent treatment patterns on the balance between benefit and harm among residents warrant further investigation.

Data Challenges in Addressing Chronic Kidney Disease in Low- and Lower-Middle-Income Countries

The burden of chronic kidney disease (CKD) is growing globally, particularly in low- and lower-middle-income countries (LLMICs) where access to treatment is poor and the largest increases in disease burden will occur. The individual and societal costs of kidney disease are well recognized, especially in developed health care systems where treatments for the advanced stages of CKD are more readily available. The consequences of CKD are potentially more catastrophic in developing health care systems where such resources are often lacking. Central to addressing this challenge is the availability of data to understand disease burden and ensure that investments in treatments and health resources are effective at a local level. Use of routinely collected administrative data is helpful in this regard, however, the barriers to developing a more systematic focus on data collection should not be underestimated. This article reviews the current tools that have been used to measure the burden of CKD and considers limitations regarding their use in LLMICs. A review of the literature investigating the use of registries, disease specific databases and administrative data to identify populations with CKD in LLMICs, which indicate these to be underused resources, is included. Suggestions regarding the potential use of administrative data for measuring CKD burden in LLMICs are explored.

Risk of Chronic Kidney Disease and Estimated Glomerular Filtration Rate Decline in Patients with Chronic Hypoparathyroidism: A Retrospective Cohort Study

INTRODUCTION

Chronic hypoparathyroidism, treated with conventional therapy of oral calcium supplements and active vitamin D, may increase the risk of kidney complications. This study examined risks of development and progression of chronic kidney disease (CKD) and estimated glomerular filtration rate (eGFR) decline in patients with chronic hypoparathyroidism.

METHODS

A retrospective cohort study using a managed care claims database in the United States from January 2007 to June 2017 included patients with chronic hypoparathyroidism (excluding those receiving parathyroid hormone) and randomly selected patients without hypoparathyroidism followed for up to 5 years. Main outcome measures were (1) development of CKD, defined as new diagnosis of CKD stage 3 and higher or ≥ 2 eGFR measurements < 60 ml/min/1.73 m² ≥ 3 months apart, (2) progression of CKD, defined as increase in baseline CKD stage, (3) progression to end-stage kidney disease (ESKD), and (4) eGFR decline ≥ 30% from baseline. Time-to-event analyses included Kaplan-Meier analyses with log-rank tests, and both unadjusted and adjusted Cox proportional hazards models were used to compare outcomes between cohorts.

RESULTS

The study included 8097 adults with and 40,485 without chronic hypoparathyroidism. In Kaplan-Meier analyses, patients with chronic hypoparathyroidism had higher risk of developing CKD and CKD progression and higher rates of eGFR decline (all P < 0.001). In multivariable Cox models adjusted for baseline characteristics, hazard ratios (95% confidence intervals [CIs]) were 2.91 (2.61-3.25) for developing CKD, 1.58 (1.23-2.01) for CKD stage progression, 2.14 (1.51-3.04) for progression to ESKD, and 2.56 (1.62-4.03) for eGFR decline (all P < 0.001) among patients with chronic hypoparathyroidism compared with those without hypoparathyroidism.

CONCLUSION

Patients with chronic hypoparathyroidism have increased risk of development and progression of CKD and eGFR decline compared with those without hypoparathyroidism. Further studies are warranted to understand underlying mechanisms for the associations between chronic hypoparathyroidism and kidney disease.

Acute Kidney Injury in Critically Ill Children Is Not all Acute: Lessons Over the Last 5 Years

Acute kidney injury (AKI) in the pediatric intensive care unit (PICU) is an important risk factor for increased morbidity and mortality during hospitalization. Over the past decade, accumulated data on children and young people indicates that acute episodes of kidney dysfunction can have lasting consequences on multiple organ systems and health outcomes. To date, there are no guidelines for follow-up of surviving children that may be at risk of long-term sequelae following AKI in the PICU. This narrative review aims to describe literature from the last 5 years on the risk of medium and long-term kidney and non-kidney outcomes after AKI in the PICU. More specifically, we will focus on outcomes in children and young people following AKI in the general PICU population and children undergoing cardiac surgery. These outcomes include mortality, hypertension, proteinuria, chronic kidney disease, and healthcare utilization. We also aim to highlight current gaps in knowledge in medium and long-term outcomes in this pediatric population. We suggest a framework for future research to develop evidence-based guidelines for follow-up of children surviving an episode of critical illness and AKI.

Statin Exposure and Risk of Heart Failure After Anthracycline- or Trastuzumab-Based Chemotherapy for Early Breast Cancer: A Propensity Score‒Matched Cohort Study

Background Statins are hypothesized to reduce the risk of cardiotoxicity associated with anthracyclines and trastuzumab. Our aim was to study the association of statin exposure with hospitalization or emergency department visits (hospital presentations) for heart failure (HF) after anthracycline- and/or trastuzumab-containing chemotherapy for early breast cancer. Methods and Results Using linked administrative databases, we conducted a retrospective cohort study of women aged ≥66 years without prior HF who received anthracyclines or trastuzumab for newly diagnosed early breast cancer in Ontario between 2007 to 2017. Statin-exposed and unexposed women were matched 1:1 using propensity scores. Trastuzumab-treated women were also matched on anthracycline exposure. We matched 666 statin-discordant pairs of anthracycline-treated women and 390 pairs of trastuzumab-treated women (median age, 69 and 71 years, respectively). The 5-year cumulative incidence of HF hospital presentations after anthracyclines was 1.2% (95% CI, 0.5%-2.6%) in statin-exposed women and 2.9% (95% CI, 1.7%-4.6%) in unexposed women (P value, 0.01). The cause-specific hazard ratio associated with statins in the anthracycline cohort was 0.45 (95% CI, 0.24-0.85; P value, 0.01). After trastuzumab, the 5-year cumulative incidence of HF hospital presentations was 2.7% (95% CI, 1.2%-5.2%) in statin-exposed women and 3.7% (95% CI, 2.0%-6.2%) in unexposed women (P value 0.09). The cause-specific hazard ratio associated with statins in the trastuzumab cohort was 0.46 (95% CI, 0.20-1.07; P value, 0.07). Conclusions Statin-exposed women had a lower risk of HF hospital presentations after early breast cancer chemotherapy involving anthracyclines, with non-significant trends towards lower risk following trastuzumab. These findings support the development of randomized controlled trials of statins for prevention of cardiotoxicity.

Specificity of International Classification of Diseases codes for bronchopulmonary dysplasia: an investigation using electronic health record data and a large insurance database

OBJECTIVE

International Classification of Diseases (ICD) codes in electronic health records (EHRs) are increasingly used for health services research, in spite of unknown diagnostic accuracy. The accuracy of ICD codes to identify bronchopulmonary dysplasia (BPD) is unknown.

STUDY DESIGN

Retrospective cohort study in a single-center NICU (n = 166) to evaluate sensitivity and specificity of ICD-10 codes for the diagnosis of BPD. Analysis of large insurance claims database (n = 7887) to determine date of assignment of the code.

RESULTS

The sensitivity of any BPD-related ICD codes ranged from 0.82 to 0.95, while the specificity ranged from 0.25 to 0.36. In a large national insurance database, the most common date of ICD-9 or ICD-10 code assignment was the day of birth, which is inconsistent with the clinical definition.

CONCLUSIONS

ICD codes registered for BPD are unlikely to accurately reflect the current clinical definition and should be interpreted with caution.

Association Between Chronic Medical Conditions and Acute Perinatal Psychiatric Health-Care Encounters Among Migrants: A Population-Based Cohort Study

OBJECTIVES

To examine the relationship between prepregnancy chronic medical conditions (CMCs) and the risk of acute perinatal psychiatric health-care encounters (i.e., psychiatric emergency department visits, hospitalizations) among refugees, nonrefugee immigrants, and long-term residents in Ontario.

METHODS

We conducted a population-based study of 15- to 49-year-old refugees (N = 29,189), nonrefugee immigrants (N = 187,430), and long-term residents (N = 641,385) with and without CMC in Ontario, Canada, with a singleton live birth in 2005 to 2015 and no treatment for mental illness in the 2 years before pregnancy. Modified Poisson regression was used to estimate the relative risk of a psychiatric emergency department visit or hospitalization from conception until 1 year postpartum among women with versus without CMC, stratified by migrant status. An unstratified model with an interaction term between CMC and migrant status was used to test for multiplicativity of effects.

RESULTS

The association between CMC and risk of a psychiatric emergency department visit or hospitalization was stronger among refugees (adjusted relative risk [aRR] = 1.87; 95% confidence interval [CI], 1.36 to 2.58) compared to long-term residents (aRR = 1.39; 95% CI, 1.30 to 1.48; interaction P = 0.047). The strength of the association was no different in nonrefugee immigrants (aRR = 1.26; 95% CI, 1.05 to 1.51) compared to long-term residents (interaction P = 0.45).

CONCLUSION

Our study identifies refugee women with CMC as a high-risk group for acute psychiatric health care in the perinatal period. Preventive psychosocial interventions may be warranted to enhance supportive resources for all women with CMC and, in particular refugee women, to reduce the risk of acute psychiatric health care in the perinatal period.

Development and validation of a multivariable prediction model for major adverse cardiovascular events after early stage breast cancer: a population-based cohort study

AIMS

Develop a score to predict the risk of major adverse cardiovascular events (MACE) after early stage breast cancer (EBC) to facilitate personalized decision-making about potentially cardiotoxic treatments and interventions to reduce cardiovascular risk.

METHODS AND RESULTS

Using administrative databases, we assembled a cohort of women diagnosed with EBC in Ontario between 2003 and 2014, with follow-up through 2015. Two-thirds of the cohort were used for risk score derivation; the remainder were reserved for its validation. The outcome was a composite of hospitalizations for acute myocardial infarction, unstable angina, transient ischaemic attack, stroke, peripheral vascular disease, heart failure (HF), or cardiovascular death. We developed the score by regressing MACE incidence against candidate predictors in the derivation sample using a Fine-Gray model. Discrimination was assessed in the validation sample using Wolber's c-index for prognostic models with competing risks, while calibration was assessed by comparing predicted and observed MACE incidence. The risk score was derived in 60 294 women and validated in 29 810 women. Age, hypertension, diabetes, ischaemic heart disease, atrial fibrillation, HF, cerebrovascular disease, peripheral vascular disease, chronic obstructive pulmonary disease, and chronic kidney disease were significantly associated with MACE incidence and incorporated into the score. Ten-year MACE incidence was >40-fold higher for patients in the highest score decile compared to the lowest. The c-index was 81.9% (95% confidence interval 80.9-82.9%) at 5 years and 79.8% (78.8-80.8%) at 10 years in the validation cohort, with good agreement between predicted and observed MACE incidence.

CONCLUSION

Cardiovascular prognosis after EBC can be estimated using patients' pre-treatment characteristics.

Validity of Hospital Codes for Obesity in Ontario, Canada

BACKGROUND

Obesity has a significant impact on population health and health care. Administrative databases may be a useful tool to study obesity at a population level. In this work, we aimed to determine the validity of hospital codes for obesity in Ontario, Canada.

METHODS

Using linked health-care databases (ICES), we conducted a validation study in adults ≥18 years of age who had their height and weight recorded during a hospitalization in southwestern Ontario. We considered a body mass index ≥30 kg/m² as our gold standard definition for obesity. We then examined the validity of 2 International Classification of Diseases---10th revision (ICD-10) coding algorithms for obesity (Algorithm 1, ICD-10 E66.X; and Algorithm 2, ICD-10 E65.X-68.X). As additional analyses, we examined the validity of algorithms in different obesity classes (i.e. obese classes 1, 2 and 3), and in patients with diagnosed diabetes and hypertension.

RESULTS

There were 34,588 patients included in our study (mean age, 62 years; 47% female). Algorithm 1 performed best, with a sensitivity, specificity, positive predictive value and negative predictive value of 8.8%, 99.8%, 95.4% and 65.1%, respectively. The sensitivity of this algorithm was highest in patients with obesity class 3 (27.4%) and in those with diagnosed diabetes.

CONCLUSIONS

Hospital codes for obesity have a high positive predictive value and specificity. These codes can be used to build and study cohorts of patients with obesity in administrative database studies. However, given their limited sensitivity, administrative codes provide inaccurate incidence and prevalence estimates.

The prevalence of chronic kidney disease in Iceland according to KDIGO criteria and age-adapted estimated glomerular filtration rate thresholds

Most epidemiological studies on chronic kidney disease (CKD) are based solely on estimated glomerular filtration rate (eGFR). Few studies have included proteinuria, while the chronicity criterion is usually omitted. To explore this, we examined the prevalence of CKD stages 1-5 in Iceland based on multiple markers of kidney damage. All serum creatinine values, urine protein measurements and diagnostic codes for kidney diseases and comorbid conditions for people aged 18 years and older were obtained from electronic medical records of all healthcare institutions in Iceland in 2008-2016. CKD was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline using diagnoses indicative of a chronic kidney disease, proteinuria and/or an eGFR under 60 mL/min/1.73 m² for over three months. Mean annual age-standardized prevalence of CKD stages 1-5 was calculated based on the KDIGO criteria and age-adapted eGFR thresholds from 2,120,147 creatinine values for 218,437 individuals, 306,531 proteinuria measurements for 86,364 individuals and 6973 individuals carrying a kidney disease diagnosis. Median age was 63 years (range, 18-106) and 47% were male. The mean annual age standardized CKD prevalence was 5.13% for men and 6.75% for women using the KDIGO criteria but by age-adapted eGFR cut-offs, the prevalence was 3.27% for men and 4.01% for women. Thus, our nationwide study, defining CKD in Iceland with strict adherence to the KDIGO criteria, demonstrates a lower prevalence of CKD than anticipated from most previous studies.

Health claims databases used for kidney research around the world

Health claims databases offer opportunities for studies on large populations of patients with kidney disease and health outcomes in a non-experimental setting. Among others, their unique features enable studies on healthcare costs or on longitudinal, epidemiological data with nationwide coverage. However, health claims databases also have several limitations. Because clinical data and information on renal function are often lacking, the identification of patients with kidney disease depends on the actual presence of diagnosis codes only. Investigating the validity of these data is therefore crucial to assess whether outcomes derived from health claims data are truly meaningful. Also, one should take into account the coverage and content of a health claims database, especially when making international comparisons. In this article, an overview is provided of international health claims databases and their main publications in the area of nephrology. The structure and contents of the Dutch health claims database will be described, as well as an initiative to use the outcomes for research and the development of the Dutch Kidney Atlas. Finally, we will discuss to what extent one might be able to identify patients with kidney disease using health claims databases, as well as their strengths and limitations.

Acute mental health service use is increased in rheumatoid arthritis and ankylosing spondylitis: a population-based cohort study

Background

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are associated with mental illness. Whether acute mental health (MH) service utilization (i.e. emergency visits or hospitalizations) is increased in RA or AS is not known.

Methods

Two population-based cohorts were created where individuals with RA (n = 53,240) or AS (n = 13,964) were each matched by age, sex, and year to unaffected comparators (2002-2016). Incidence rates per 1000 person-years (PY) were calculated for a first MH emergency department (ED) presentation or MH hospitalization. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated, adjusting for demographic, clinical, and health service use variables.

Results

Individuals with RA had higher rates of ED visits [6.59/1000 person-years (PY) versus 4.39/1000 PY in comparators] and hospitalizations for MH (3.11/1000 PY versus 1.80/1000 PY in comparators). Higher rates of ED visits (7.92/1000 PY versus 5.62/1000 PY in comparators) and hospitalizations (3.03/1000 PY versus 1.94/1000 PY in comparators) were also observed in AS. Overall, RA was associated with a 34% increased risk for MH hospitalization (HR 1.34, 95% CI 1.22-1.47) and AS was associated with a 36% increased risk of hospitalization (HR 1.36, 95% CI 1.12-1.63). The risk of ED presentation was attenuated, but remained significant, after adjustment in both RA (HR 1.08, 95% CI 1.01-1.15) and AS (HR 1.14, 95% CI 1.02-1.28).

Conclusions

RA and AS are both independently associated with a higher rate and risk of acute ED presentations and hospitalizations for mental health conditions. These findings underscore the need for routine evaluation of MH as part of the management of chronic inflammatory arthritis. Additional research is needed to identify the underlying individual characteristics, as well as system-level variation, which may explain these differences, and to help plan interventions to make MH service use more responsive to the needs of individuals living with RA and AS.

The Risk of Heart Failure and Other Cardiovascular Hospitalizations After Early Stage Breast Cancer: A Matched Cohort Study

Background

Data are limited regarding the risk of heart failure (HF) requiring hospital-based care after early stage breast cancer (EBC) and its relationship to other types of cardiovascular disease (CVD).

Methods

We conducted a population-based, retrospective cohort study of EBC patients (diagnosed April 1, 2005–March 31, 2015) matched 1:3 on birth-year to cancer-free control subjects. We identified hospitalizations and emergency department visits for CVD through March 31, 2017. We used cumulative incidence function curves to estimate CVD incidence and cause-specific regression models to compare CVD rates between cohorts. All statistical tests were two-sided.

Results

We identified 78 318 EBC patients and 234 954 control subjects. The 10-year incidence of CVD hospitalization was 10.8% (95% confidence interval [CI] = 10.5% to 11.1%) after EBC and 9.1% (95% CI = 8.9% to 9.2%) in control subjects. Ischemic heart disease was the most common reason for CVD hospitalization after EBC. After regression adjustment, the relative rates compared with control subjects remained statistically significantly elevated for HF (hazard ratio [HR] = 1.21, 95% CI = 1.14 to 1.29, P < .001), arrhythmias (HR = 1.31, 95% CI = 1.23 to 1.39, P < .001), and cerebrovascular disease (HR 1.10, 95% CI = 1.04 to 1.17, P = .002) hospitalizations. It was rare for HF hospital presentations (2.9% of cases) to occur in EBC patients without recognized risk factors (age >60 years, hypertension, diabetes, prior CVD). Anthracycline and/or trastuzumab were used in 28 950 EBC patients; they were younger than the overall cohort with lower absolute rates of CVD, hypertension, and diabetes. However, they had higher relative rates of CVD in comparison with age-matched control subjects.

Conclusions

Atherosclerotic diagnoses, rather than HF, were the most common reasons for CVD hospitalization after EBC. HF hospital presentations were often preceded by risk factors other than chemotherapy, suggesting potential opportunities for prevention.

Risk of rhabdomyolysis with donepezil compared with rivastigmine or galantamine: a population-based cohort study

BACKGROUND

Donepezil, rivastigmine and galantamine are popular cholinesterase inhibitors used to manage the symptoms of Alzheimer disease and other dementias; regulatory agencies in several countries warn about a possible risk of rhabdomyolysis with donepezil, based on information from case reports. Our goal was to investigate the 30-day risk of admission to hospital with rhabdomyolysis associated with initiating donepezil versus other cholinesterase inhibitors.

METHODS

We conducted a retrospective cohort study in Ontario, Canada, from 2002 to 2017. Participants were adults aged 66 years or older with a newly dispensed prescription for donepezil compared with rivastigmine or galantamine. The primary outcome was hospital admission with rhabdomyolysis (assessed using hospital diagnostic codes) within 30 days of a new prescription of a cholinesterase inhibitor. Odds ratios were estimated using logistic regression, with inverse probability of treatment weights calculated from propensity scores.

RESULTS

The average age in our 2 groups was 81.1 years, and 61.4% of our population was female. Donepezil was associated with a higher risk of hospital admission with rhabdomyolysis compared with rivastigmine or galantamine (88 events in 152 300 patients [0.06%] v. 16 events in 68 053 patients [0.02%]; weighted odds ratio of 2.21, 95% confidence interval [CI] 1.52-3.22). Most hospital admissions with rhabdomyolysis after donepezil use were not severe, and no patient was treated with acute dialysis or mechanical ventilation.

INTERPRETATION

Initiating donepezil is associated with a higher 30-day risk of admission to hospital with rhabdomyolysis compared with initiating rivastigmine or galantamine. The proportion of patients who develop severe rhabdomyolysis within 30 days of initiating donepezil is very low.

Incidence, Risk Factors, and Outcomes of Neonatal Renal Vein Thrombosis in Ontario: Population-Based Cohort Study

Background

There are limited data at a population level on the burden, risk factors, and long-term outcomes of neonatal renal vein thrombosis (nRVT). We conducted a population-based cohort study to understand the epidemiology and outcomes of nRVT over a 25-year period in Ontario.

Methods

Using linked administrative health databases, all hospitalized neonates ≤28 days born in Ontario between 1992 and 2016 with nRVT were identified. The primary outcome was to calculate the incidence of nRVT and trend over time in Ontario. We also determined the risk factors associated with nRVT as well as the risk of long-term outcomes after nRVT, including CKD, ESKD, all-cause mortality, and hypertension (HTN) compared with the healthy neonatal population without nRVT.

Results

The annual incidence rate of nRVT was 2.6 per 100,000 live births (n=85). Presence of respiratory distress syndrome (OR, 8.01; 95% CI, 4.90 to 13.1), congenital heart disease (OR, 9.1; 95% CI, 5.05 to 16.4), central venous catheterization (OR, 3.9; 95% CI, 1.89 to 7.93), maternal preeclampsia (OR, 2.8; 95% CI, 1.6 to 4.79), and maternal diabetes (OR, 2.36; 95% CI, 1.36 to 4.07) conferred the highest risk for nRVT. Over a median follow-up of 15 years and after adjusting for confounders, neonates with nRVT versus the comparator cohort had a 15.5-fold risk of CKD, HTN, or death (n=49 [58%] versus n=90,050 [3%]; 95% CI, 11.7 to 20.6); 12.3-fold increased risk of CKD or death (n=39 [46%] versus n=32,016 [1%]; 95% CI, 8.9 to 16.8); and a 15.7-fold increased risk of HTN (n=33 [39%] versus n=64,458 [2%]; 95% CI, 11.1 to 21.1). None of the nRVT cohort developed ESKD. The median time to composite outcome of CKD, HTN, or death was 11.1 years.

Conclusions

Patients with a history of nRVT remain at higher risk than the general population for long-term morbidity or mortality, indicating the need for long-term follow-up.