Clinical inertia: focusing on type 2 diabetes patients in tertiary care hospital

Abstract

Clinical inertia was described as failing to adequately escalate therapy when treatment targets are not achieved. Clinical inertia mostly occurs in patients with chronic noncontagious diseases such as diabetes, hypertension, and dyslipidaemia. In developed countries, the prevalence of clinical inertia in type 2 diabetes mellitus (T2DM) was 28.4-73.0%. However, studies on the relationship between clinical inertia and diabetes-related complications in Thailand remain limited. This study attempted to 1. determine the prevalence of clinical inertia and associated factors, 2. investigate the impact of clinical inertia on diabetes-related complications and 3. evaluate the association between time to treatment intensification and diabetes-related complications. For each objective, this study was split into 3 phases. In Phase I, this study comprised an observational study to find the prevalence and associated factors of clinical inertia. Patients with T2DM attending the outpatient department of Maharaj Nakorn Chiang Mai Hospital in 2017 with glycated hemoglobin (HbA1c) levels ≥7.0% and ages from 40 to 65 were included to be evaluated for clinical inertia. Clinical inertia in this study meant having HbA1c levels of ≥7.0% and failing to receive treatment intensification at the index date and consequence visit. Prevalence and factors affecting the occurrence of clinical inertia were analysed using the logistic regression model. The study found that patients with T2DM attending the outpatient department at Maharaj Nakorn Chiang Mai Hospital in 2017 totalled 5,756 patients. Of these, 3,089 patients had HbA1c levels ≥7.0%. Age outside the range of 40-65 years 1,109 patients. Patients passing the inclusion criteria totalled 994 patients. In 2017, patients with T2DM 261 (26.2%) experienced clinical inertia. Factors associated with clinical inertia included the baseline of HbA1c levels, the amount of medication that the patient received, insulin use and the type of physician performing the treatment. In Phase II, this study was a retrospective cohort study. Patients with T2DM attending the outpatient department at Maharaj Nakorn Chiang Mai Hospital from January 1, 2011 to December 31, 2011 and then followed up to December 31, 2017 were selected for this study. The primary outcome was diabetes-related complications. Secondary outcomes were a composite of macrovascular complications, myocardial infarction, stroke, heart failure, a composite of microvascular complications, diabetic nephropathy or diabetic retinopathy. An analysis of the effect of clinical inertia on diabetes-related complications was carried out using survival analysis. The propensity score method was used to control confounding by indication. The study found that patients with T2DM attending the outpatient department at Maharaj Nakorn Chiang Mai Hospital from January 1, 2011 to December 31, 2011 were 6,033 patients. Of these, 2,786 patients had HbA1c greater than or equal to 7.0%. One thousand five hundred fifteen patients had age range out of the 40-65 years. The number of patients passing the inclusion criteria totalled 686 patients. In 2017, patients experiencing clinical inertia totalled 165 (24.0%). During 6.5 years of median follow-up, our study found that clinical inertia was insignificantly associated with diabetes-related complications (adjusted HR 1.09, 95%CI 0.82–1.45) and secondary outcomes except for diabetic nephropathy (adjusted HR 1.51, 95%CI 1.01–2.27). The results of the study were consistent with the propensity score method. In Phase III, this study was a retrospective study. Included patients in the Phase II study were categorized into three groups based on time to intensified treatment: 1. patients with no delayed intensified treatment, 2. the group receiving intensified treatment within six months and 3. the group receiving intensified treatment after six months. After dividing them into 3 groups, participants were followed by clinical outcomes. Primary outcome was diabetes-related complications. Secondary outcomes were a composite of macrovascular complications, myocardial infarction, stroke, heart failure, a composite of microvascular complications, diabetic nephropathy, or diabetic retinopathy. Survival analysis was used to analyse the association between time to intensified treatment and diabetes-related complications. The number of patients passing the inclusion criteria totalled 686 patients. Of these, 521 patients had no delayed treatment intensification, 53 patients receiving treatment intensification within six months and 112 patients receiving treatment intensification after six months. During 6.5 years of median follow-up, delayed treatment intensification was not associated with primary and secondary outcomes. Conversely, patients receiving treatment intensification by even six months exhibited an association with diabetic nephropathy (adjusted HR 2.35; 95%CI 1.35-4.09). In 2017, clinical inertia in a tertiary hospital in Thailand occurred at 26.2%. Factors affecting clinical inertia were baseline HbA1c level, the amount of medication the patient received, insulin use and the type of physician performing treatment. Clinical inertia increased the incidence of diabetic nephropathy. Treatment intensification by even six months resulted in statistically significant diabetic nephropathy. Thus, the patients presented blood sugar levels higher than the target, they should be intensified treatment immediately to reduce the incidence of kidney complications.