Long term outcomes and mortality among patients enrolled in a structured primary care-led diabetes programme

Problem

Limited data exists, internationally and in Ireland, on long-term outcomes among people with diabetes who are managed in primary care. The Midlands Diabetes Structured Care Programme takes a multifaceted approach to primary care-led management, including patient registration and recall, regular diabetes review visits, multidisciplinary specialist access (e.g. nurse specialists, dietetics, ophthalmology, chiropody), professional education, and remuneration. Our aim was to examine clinical parameters, complications and mortality among patients with diabetes enrolled in the programme since its establishment in 1998.

Approach

Data were collected in 1999, 2003, 2008 and 2015, on outcomes (clinical parameters, complications and mortality) among patients with diabetes (≥18 years) registered with participating practices. Data were extracted from patient notes by clinical nurse specialists using a paper-based data collection form. Cause and date of death were obtained from national death records. Using Stata, chi-square tests were used to test differences in clinical outcomes over time. Cox proportional hazards regression was used to examine the association of baseline factors with mortality.

Findings

Patients from 1999 (n=376), were followed up in 2003 (n=229), 2008 (n=96) and 2016 (n=376).The proportion of patients with a recommended blood pressure target (<130/80mmHg) increased from 9% in 1999 to 26% in 2016 (P<0.001), as did the proportion with a total cholesterol of <4.5mmol/L (22% vs.71%, P<0.001), and triglycerides <2.0mmol/L (47% vs.81%, P<0.001). The percentage achieving optimal glycaemic control (HbA1c <7.0%) declined (52% vs. 34%). Between 1999–2016, 22% (n=81) of patients had ever experienced a macrovascular complication; primarily CVA (n=21, 6%), MI (n=16, 4%), or heart failure (n=11, 3%), and 1% (n=5) ever had a minor amputation. In 1999, 18% (n=33) had retinopathy, increasing to 57% (n=59) by 2016. In total, 184 (49%) had died. Only 25% of patients (n=46) had cause of death recorded in their GP record. Of 163 patients for whom cause of death was obtained from national records, the main causes were MI (n=24, 15%) and pneumonia (n=22, 14%). Mean age at death was 77.7±9.3 years. Decedents were older at baseline (69.5±11.2 years) than survivors (56.6±11.7 years), and mortality was significantly higher among patients who were older in 1999. Gender, diabetes type, smoking status and clinical parameters at baseline were not significant predictors of mortality.

Consequences

Improvements in the clinical profile of patients enrolled in the programme since its inception suggests primary-care-led diabetes management can perform favourably in the long-term. The high incidence of macrovascular complications and prevalence of retinopathy indicates the importance of effective management and achieving clinical outcome targets in this group.