Insulin initiation in patients with type 2 diabetes is often delayed, but access to a diabetes nurse may help—insights from Norwegian general practice

Abstract

Objective: We opted to study how support staff operational capacity and diabetes competences may impact the timeliness of basal insulin-initiation in general practice patients with type 2 diabetes (T2D).

Design/Setting/Outcomes: This was an observational and retrospective study on Norwegian primary care patients with T2D included from the ROSA4-dataset. Exposures were (1) support staff size, (2) staff size relative to number of GPs, (3) clinic access to a diabetes nurse and (4) share of staff with diabetes course (1 and 2 both relate to staff operational capacity, whereas 3 and 4 are both indicatory of staff diabetes competences). Outcomes were ‘timely basal insulin-initiation’ (primary) and ‘attainment of HbA_1c<7%’ after insulin start-up (secondary). Associations were analyzed using multiple linear regression, and directed acyclic graphs guided statistical adjustments.

Subjects: Insulin naïve patients with ‘timely’ (N = 294), ‘postponed’ (N = 219) or ‘no need of’ (N = 3,781) basal insulin-initiation, respectively.

Results: HbA_1c [median (IQR)] increased to 8.8% (IQR, 8.0, 10.2) prior to basal insulin-initiation, which reduced HbA_1c to 7.3 (6.8–8.1) % by which only 35% of the subjects reached HbA_1c <7%. Adjusted risk of ‘timely basal insulin-initiation’ was more than twofold higher if access to a diabetes nurse (OR = 2.40, [95%CI, 1.68, 3.43]), but related only vaguely to staff size (OR = 1.01, [95%CI, 1.00, 1.03]). No other staff factors related significantly to neither the primary nor the secondary outcome.

Conclusion: In Norwegian general practice, insulin initiation in people with T2D may be affected by therapeutic inertia but access to a diabetes nurse may help facilitating more timely insulin start-up.

KEY POINTS

• In patients with type 2 diabetes (T2D) cared for by their general practice physician (GP), insulin therapy was susceptible to therapeutic inertia.

• In Norwegian general practice, chance of timely basal insulin-initiation was found more than two-fold higher if the GP had access to a diabetes nurse.

• In contrast, the timeliness of basal insulin-initiation in general practice patients with T2D seemed unaffected by share of support staff with diabetes course and by factors indicatory of support staff overall operational capacity.

• In Norwegian general practice, a diabetes nurse seems to offer unique clinical benefits to the care of insulin treated patients with T2D.

Keywords:

• Type 2 diabetes mellitus
• general practice
• primary care
• therapeutic inertia
• basal insulin
• insulin initiation
• diabetes nurse

Authors’ contributions

I.M. and E.SB. analyzed the data and I.M. and E.S.B. drafted the paper. T.J.B., T.C., J.G.C., K.F.L., S.S. and A.K.J. organized the ROSA 4 data collection. All authors contributed to data discussion and interpretation, and reviewed and edited the manuscript.

Ethics approval and consent to participate

Data were assembled without consent but subjects were informed via the Norwegian Diabetes Association about their right to withdraw. The regional ethics committee, REK- Vest approved the study (reference 2014/1374/REK vest).

Disclosure statement

E.S.B has received fees for lectures and advising to Novo Nordisk, Sanofi Aventis and MundiPharma.

Notes

1 NOKLUS: “The NOKLUS diabetes form” which was launched in 2008, and after that time was gradually implemented in most general practice electronic patient record systems in Norway. The form collects national data on the quality of diabetes treatment in Norway, it is well suited for carrying out an annual diabetes control in a structured manner, it has been shown to associate to better quality of care and it’s usage is strongly recommended by Norwegian health authorities. NOKLUS includes the following variables: diabetes type and year of diagnosis, HbA1c, blood pressure, LDL cholesterol, possible history and status of retinopathy and nephropathy, possible history of CHD, stroke, limb amputations and foot ulcers, monofilament tests, foot pulse status, smoking status and history, hypoglycemia frequency, body weight, height, Body Mass Index (BMI), driver’s license status, frequency of retinopathy screening, and current anti-diabetic, anti-hyperlipidemic and anti-hypertensive medications (https://www.noklus.no/norsk-diabetesregister-for-voksne/variabeloversikt/).

2 FTE: abbreviation for Full-Time-Equivalent. FTE is computed as number of total hours worked by an individual employee divided by the maximum number of compensable hours in a full-time schedule as defined by law in Norway. In Norway 1 FTE, also often referred to as one 100% employment position, equals an employment of 37.5 hours per week.

Additional information

Funding

The data collection of the ROSA 4 study was supported financially with grants from the Norwegian Diabetes Association, a consortium of six pharmaceutical firms (AstraZeneca, Boehringer Ingelheim, Eli Lilly, MSD, Novo Nordisk, Sanofi-Aventis), the Northern Norway Regional Health Authority, the Endocrinology Research Foundation, Stavanger and the University of Oslo.