Gaps in Diagnosis and Treatment of Patients With Laboratory-Confirmed Diabetes: A National Cohort Study

OBJECTIVE To characterize gaps in diagnostic coding and pharmacologic treatment among adults with laboratory-confirmed diabetes. RESEARCH DESIGN AND METHODS We conducted a retrospective cohort study using national commercial and Medicare claims (2017–2023) linked to laboratory results. Adults with laboratory-confirmed diabetes and no prior diabetes/prediabetes were observed for 1 year. Outcomes were type 2 diabetes diagnostic coding and pharmacologic treatment initiation. RESULTS Among 27,650 adults with laboratory-confirmed diabetes, 66.6% received both a diagnosis code and pharmacologic treatment within 1 year; 19.7% received a diagnosis only, 4.1% received treatment only, and 9.6% received neither. Compared with HbA1c 6.5–6.9%, higher HbA1c was associated with progressively higher probabilities of diagnostic coding and treatment initiation, whereas greater comorbidity burden was associated with lower probabilities of both outcomes. CONCLUSIONS One-third of adults with laboratory-confirmed diabetes lacked claims-documented diagnostic coding, treatment, or both, with patterns of care defined by glycemic severity and comorbidity burden.