Do Treatment Quality Indicators Predict Cardiovascular Outcomes in Patients with Diabetes?

Abstract

BackgroundLandmark clinical trials have led to optimal treatment recommendations for patients with diabetes. Whether optimal treatment is actually delivered in practice is even more important than the efficacy of the drugs tested in trials. To this end, treatment quality indicators have been developed and tested against intermediate outcomes. No studies have tested whether these treatment quality indicators also predict hard patient outcomes.MethodsA cohort study was conducted using data collected from >10.000 diabetes patients in the Groningen Initiative to Analyze Type 2 Treatment (GIANTT) database and Dutch Hospital Data register. Included quality indicators measured glucose-, lipid-, blood pressure- and albuminuria-lowering treatment status and treatment intensification. Hard patient outcome was the composite of cardiovascular events and all-cause death. Associations were tested using Cox regression adjusting for confounding, reporting hazard ratios (HR) with 95% confidence intervals.ResultsLipid and albuminuria treatment status, but not blood pressure lowering treatment status, were associated with the composite outcome (HR = 0.77, 0.67–0.88; HR = 0.75, 0.59–0.94). Glucose lowering treatment status was associated with the composite outcome only in patients with an elevated HbA1c level (HR = 0.72, 0.56–0.93). Treatment intensification with glucose-lowering but not with lipid-, blood pressure- and albuminuria-lowering drugs was associated with the outcome (HR = 0.73, 0.60–0.89).ConclusionTreatment quality indicators measuring lipid- and albuminuria-lowering treatment status are valid quality measures, since they predict a lower risk of cardiovascular events and mortality in patients with diabetes. The quality indicators for glucose-lowering treatment should only be used for restricted populations with elevated HbA1c levels. Intriguingly, the tested indicators for blood pressure-lowering treatment did not predict patient outcomes. These results question whether all treatment indicators are valid measures to judge quality of health care and its economics.

Therapeutic inertia in the treatment of hyperglycaemia in patients with type 2 diabetes: A systematic review

“…Out of 7698 combined search results, 53 articles were identified that reported at least 1 measure of therapeutic inertia in the management of hyperglycaemia in individuals with type 2 diabetes . The main reasons for exclusion of publications other than duplicates and those covering irrelevant topics were that they reported non‐original research (eg, editorials, letters, comments and guidelines) or they were congress abstracts (Figure ).…”

“…Three studies were carried out in Asia, and a single study was conducted in Israel . Articles mainly reported data from cohort studies, using data from medical records or chart reviews, or from claims, clinical research or administrative databases. Four articles reported results from cross‐sectional studies, and the data were collected using provider questionnaires or surveys .…”

“…Patients were managed by primary care providers in 21 studies, by both primary care providers and secondary care specialists in 6 studies, and by secondary care specialists alone in 1 study . The healthcare providers responsible for patient care were not described in 25 studies .…”

“…A single study considered 3 different treatment groups (OADs alone, insulin alone, and diet and exercise alone), and 2 others investigated patients treated with OADs and/or injectable drugs . Another group of studies included only patients who were not treated with insulin but did not describe their therapies in more detail (ie, glucagon‐like peptide‐1 [GLP‐1] receptor agonists were not explicitly excluded) . By contrast, a study by Khunti et al assessed treatment intensification in patients whose therapies included basal insulin .…”

“…There is no accepted measure to describe clinical or therapeutic inertia. For the purpose of this systematic review, studies were classified into 4 categories based on the measurement(s) used to quantify clinical/therapeutic inertia: (1) the mean or median length of time between at least one HbA1c measurement above a certain threshold and treatment intensification; (2) the proportion of patients with at least 1 HbA1c measurement above a certain threshold who received treatment intensification within a given time frame; (3) the glycaemic burden, defined as the length of time during which a patient had an HbA1c level above a certain threshold during a given period of time; and (4) all other measurements . HbA1c thresholds and the lengths of time to assess therapeutic inertia varied widely across the 53 studies, making comparisons difficult.…”