The results confirm the large clinical and economic burden of chronic kidney disease, particularly in patients with type 2 diabetes. Patients were observed to be “sicker” and used more healthcare resources in the ascending order of: type 2 diabetes < chronic kidney disease < chronic kidney disease+type 2 diabetes. This observation may be in part related to the older age (years) observed among those with chronic kidney disease alone (72.6) or chronic kidney disease+type 2 diabetes (72.2) vs. type 2 diabetes alone (63.0). Emergency department visits and hospitalizations were highest in those with both chronic kidney disease+type 2 diabetes. While the percentage of patients with a primary care visit was observed to be very similar across groups, more patients with chronic kidney disease and type 2 diabetes had cardiology visits, not surprising since the prevalence of cardiovascular disease was observed to be highest in this group (18.3%). The prevalence of other specialty visits was observed to be rather low. Nephrology visits were observed in only 7.6% of patients with chronic kidney disease or chronic kidney disease+type 2 diabetes, and endocrinology visits were observed in only 9.0% and 8.6% of patients with type 2 diabetes or chronic kidney disease+type 2 diabetes respectively. Perhaps a higher rate of specialty referral and management, as well as an increase in outpatient primary care visits, would lead to a reduction in the number of emergency department visits and hospitalizations in patients with chronic kidney disease+type 2 diabetes.
The utilization of ACEi/ARB therapy was observed to be low in our cohorts of patients with chronic kidney disease alone (27.7%), chronic kidney disease+type 2 diabetes (42.4%), and type 2 diabetes alone (31.5%). This is much lower than has been previously reported by Vupputuri et.al. with 54-65% depending on the stage of chronic kidney disease14, but similar to other reports which have characterized the utilization of ACEi or ARB therapy among patients with type 2 diabetes15,16 Low ACEi/ARB use in chronic kidney disease alone may be explained, in part, by non-diabetic kidney disease or chronic kidney disease without proteinuria or resulting hyperkalemia. In addition, prescriptions for SGLT-2i therapy in patients with type 2 diabetes or chronic kidney disease+type 2 diabetes were observed to be rather low, and only modestly higher when compared to data from 2017.15 Lastly, the assessment of proteinuria was observed to be disappointingly low among our three cohorts of patients, and this is consistent with data that has been previously published.17 These observations highlight the opportunity that exits to improve the frequency of albuminuria testing to guideline-recommended standards since albuminuria levels are highly predictive of all-cause mortality, end stage kidney disease and risk of fatal and non-fatal cardiovascular events.18,19 Dedicated kidney outcome randomized controlled trials have demonstrated the benefits of SGLT-2is4,5 and the non-steroidal mineralocorticoid antagonist finerenone6 on the risk of chronic kidney disease progression and associated outcomes, particularly in patients with type 2 diabetes. Thus, recognizing the presence of chronic kidney disease in patients with type 2 diabetes will become ever-more important, and the choice of therapies will need to include those which may provide additional benefits, beyond those afforded by adequate blood pressure and glycemic control, as well as ACEi/ARB therapy.
The strengths of this study include the large number of participants identified, the use of the validated EMERGE algorithm to properly identify patients with type 2 diabetes, and the robust amount of clinical data which allowed for an extensive depiction of subjects. While there are numerous strengths of our analysis, it is not without limitations. Our study is limited by its use of only structured data to document both chronic kidney disease and type 2 diabetes, which relies heavily on provider coding practices and adequate documentation of lab results which may have occurred outside our health system. Adding the use of natural language processing of chart notes may better capture these disease states vs. using the ICD codes alone. In addition, our record of medication utilization was based upon EHR documentation of prescriptions, not based on pharmacy data; thus, medication compliance could not be ascertained. As is typical of cross-sectional data in general, full interpretation of the observed medication use and comorbidity burden is limited by the lack of longitudinal data. Further, cross-sectional data cannot capture the complexities of clinical care on a patient level. However, our intent was primarily to understand the prevalence of these conditions and overall care patterns in a large cohort of patients with both type 2 diabetes and chronic kidney disease, purposes for which cross sectional data are particularly useful. While we limited our analysis to active patients in our health system by requiring at least one outpatient encounter in 2019, this likely resulted in bias by selecting “sicker” patients as they are the ones likely to seek or require care. Lastly, our report only contains data from one integrated delivery system so generalizability of our findings may be limited.
Characterizing the population of patients with chronic kidney disease and type 2 diabetes will become ever-more important in routine clinical practice to ensure that appropriate treatment strategies are initiated. A tremendous opportunity exists to improve the utilization of ACEi or ARB therapy, particularly in patients with chronic kidney disease or chronic kidney disease+type 2 diabetes. In addition, routine measurement of urine protein, particularly urine albumin to creatinine ratio, was observed to be very low. For type 2 diabetes patients, guidelines recommend at least annual urine albumin to creatinine ratio testing to thoroughly characterize the chronic kidney disease burden and to monitor for chronic kidney disease progression. Furthermore, employing strategies to mitigate chronic kidney disease progression may help to offset costs associated with the disease thereby freeing up resources for other high valued needs. This study, leveraging real-world data, helps to expand our knowledge about the burden of chronic kidney disease in patients with and without type 2 diabetes and the opportunities that exist to improve the quality of care rendered to these populations.