217-LB: Associations between Multimorbidity and HbA1c in People with Type 2 Diabetes in Australian Family Practice

Introduction: Multimorbidity (MM) is common in people with T2D (PwT2D) who in Australia, receive medical care predominantly in family practice (FP). We explored the association between MM condition count and HbA1c in PwT2D attending Australian FP, using electronic health record (EHR) data. Methods: Cross-sectional study of 69,718 PwT2D who had a FP encounter between 2013-15 captured in the NPS MedicineInsight dataset (EHR data from >500 family practices and 3.5 million patients across Australia). MM condition count was based on coded and free text conditions in the reason for visit, prescription or medical history fields. Primary outcome: HbA1c. Multivariable mixed-effects linear regression examined associations between MM counts (total, concordant (T2D-related) and discordant (unrelated)) and HbA1c (%). Results: We found statistically significant associations between HbA1c and total and discordant MM counts. Mean HbA1c (95% CI) was lower for those having 1, 2, 3 and 4+ total conditions compared to T2D only, -0.065 (-0.089, -0.041), -0.097 (-0.128, -0.066), -0.089 (-0.133, -0.046), and -0.097 (-0.146, -0.047) respectively, and for discordant conditions -0.085 (-0.108, -0.061), -0.100 (-0.134, -0.065), -0.141 (-0.195, -0.087), and -0.204 (-0.276, -0.133). There was no statistically significant association between HbA1c and increasing concordant count. Conclusions: While EHR counts of MM and discordant conditions are associated with lower HbA1c, this is not likely to be clinically significant, suggesting the impact of MM on HbA1c remains unclear. The NPS dataset uses routine data entered by clinicians for the purpose of patient care, rather than epidemiological studies and may thus underestimate the number of conditions experienced by PwT2D. While clinicians need to consider the MM burden of PwT2D, the NPS MedicineInsight dataset needs further validation, eg through combining with other data sources, in the study of MM.