Lipid Control in Patients With Type 2 Diabetes Mellitus: A Continuous Quality Improvement Study

Introduction Type 2 diabetes mellitus (T2DM) is highly prevalent in Portugal, ranking among the highest in Europe, according to Organisation for Economic Co-operation and Development (OECD) data. Cardiovascular risk (CVR) control, particularly dyslipidemia management, is a key contributor to long-term health outcomes. This study aims to improve lipid management in T2DM patients, with the primary objective of achieving a 25% lipid control rate. Methodology A continuous quality improvement study was conducted in a Portuguese family health unit, involving independent random samples of patients with T2DM at each assessment period. The assessments were performed at three distinct time periods: January-June 2022, November 2023-April 2024, and May-October 2024. Interventions included team-based training workshops, monthly electronic reminders, visual aids, anonymous performance feedback, and collaborative consultations with nurses to support guideline-based lipid management. Low-density lipoprotein cholesterol (LDL-C) targets were less than 100, 70, or 55 mg/dL for moderate, high, or very high CVR. Non-high-density lipoprotein cholesterol (non-HDL-C) was used to assess lipid control when triglyceride levels were above 200 mg/dL, targeting below 135, 100, and 85 mg/dL for moderate, high, or very high CVR, respectively. Therapeutic inertia was defined as the absence of treatment adjustment despite evidence of inadequate lipid control, excluding cases where non-intensification was due to documented treatment refusal or poor adherence. Results Lipid control was achieved in 55 (20.4%) of 270 patients at baseline, rising to 60 (21.7%) of 276 in the second assessment and 90 (32.5%) of 277 in the final period, representing a 12.1 percentage point improvement (p<0.001). Among patients with high CVR, control increased from 45 (23.9%) to 61 (38.6%) and from 10 (12.2%) to 29 (24.4%) in those with very high CVR. A significant reduction in median LDL-C levels was also observed (p<0.001). Therapeutic inertia affected 199 (93.9%) patients initially, decreasing to 104 (73.8%) in the third assessment (p<0.001). Despite progress, a relevant proportion of patients remained without lipid-lowering therapy, although they did not meet recommended targets: 54 (25.2%) at baseline and 29 (15.5%) in the final period. Prescription of combination therapy with ezetimibe remained infrequent. Additionally, documentation of non-adherence and treatment refusal improved throughout the study. Conclusion The intervention showed improvement in lipid control and reduction in therapeutic inertia. Despite this progress, lipid control remained suboptimal, requiring ongoing education of healthcare professionals and patients to enhance CVR management and reduce cardiovascular events. Extending the intervention with further evaluations would help monitor long-term effectiveness. To enhance outcomes, future strategies should promote greater use of combination therapy, implement patient-specific approaches to improve adherence, and integrate clinical decision support tools to reduce therapeutic inertia. Biases such as inter-observer variability and the Hawthorne effect may have influenced the findings.