Purpose: Treatment guidelines recommend insulin progression (switching from basal to a premixed insulin regimen, adding bolus doses, and/or increasing dosing frequency) to achieve A1C targets as type 2 diabetes progresses, but fewer patients are being progressed than would be indicated based on their disease status. This systematic review proposes 2 questions regarding insulin progression among patients with type 2 diabetes: (1) What are the patient, provider, and health system barriers to insulin progression? (2) Do insulin progression barriers differ between insulin-naive and insulin-experienced patients?
Methods: We conducted a systematic review in the MEDLINE, EMBASE, Science Citation Index, PsycINFO, CINAHL, and Cochrane Library databases through July 2011.
Results: Of 745 potentially relevant articles, 10 met inclusion criteria: 7 evaluated patient and 2 evaluated provider barriers, and 1 was an intervention to reduce barriers among physicians. Patients with prior insulin experience had fewer barriers arising from injection-related concerns and worries about the burden of insulin progression than did insulin-naive patients. Physician barriers included concerns about patients' ability to follow more complicated regimens as well as physicians' own inexperience with insulin and progression algorithms. The cross-sectional nature, narrow scope, and failure of all studies to examine patient, provider, and health systems barriers concurrently limited both barrier identification and an assessment of their impact on progression.
Conclusions: Patient and physician experience with insulin and diabetes/insulin education were associated with fewer perceived barriers to insulin progression. Future studies should use multilevel longitudinal designs to quantify the relative impact of potential patient, provider, and health system factors on progression and health outcomes.