Effects on HbA1c of referral of type 2 diabetes patients to secondary care.

Aim: To study trajectories of HbA1c in type 2 diabetes (T2D) patients referred to diabetes outpatient clinics (DOCs), and to explore characteristics of referrals and patient pathways in patients treated in DOCs.

Methods: We retrospectively followed T2D patients from the Norwegian population-based ROSA 4 study to identify persons with T2D who were referred to a DOC. We used latent class trajectory modelling to identify subgroups of patients with similar patterns of HbA1c one year before to one year after the first consultation at a DOC. We performed multinomial regression analyses to identify baseline characteristics associated with group membership.

Results: Four hundred and two of 6716 T2D patients started treatment at a DOC, constituting a yearly starting rate of 1.5%. We identified three classes of HbA1c trajectories: (1) stable moderate hyperglycaemia (75%); (2) severe hyperglycaemia with a decline in HbA1c around referral (14%) and (3) severe hyperglycaemia with a decline in HbA1c after starting treatment at the DOC (11%). HbA1c trajectories were associated with diabetes duration RRR 0.92, CI (0.87, 0.97) in class 2 vs. 1 and 0.93 (0.88, 0.98) in class 3 vs. 1. Some differences were found between clinics in rejection rate, processes of care, and duration of follow-up.

Conclusions: Norwegian GPs handle most T2D patients themselves. Those with T2D and severe hyperglycaemia had a considerable benefit from being referred to a DOC, though with two separate trajectories: One where HbA1c improved around the time of referral, and another that improved after starting in a DOC.