Are patients with type 2 diabetes reluctant to start insulin therapy? An examination of the scope and underpinnings of psychological insulin resistance in a large, international population

Objective: To examine the scope and underpinnings of psychological insulin resistance (PIR) across eight Western nations, with special attention to the potential influence of beliefs about insulin and broader patient beliefs regarding medications and diabetes. Methods: A total of 1400 subjects with insulin-naive, type 2 diabetes across eight nations completed an online survey. The survey assessed willingness to start insulin, beliefs about insulin and current medications, and diabetes-related emotional distress. Results: The majority of respondents were male (59.3%), mean age was 51.6 years and mean diabetes duration was 6.1 years. A total of 17.2% reported they would be unwilling to start insulin (the PIR group), while 34.7% were ambivalent and 48.1% indicated they would be willing to do so. Marked differences by country were apparent, with PIR ranging from 5.9% (Spain) to 37.3% (Italy). Both unwilling and ambivalent patients reported significantly more negative (p<0.001; p<0.05) and fewer positive beliefs (p<0.001; p<0.01) about starting insulin, more negative feelings about their current medications (p<0.01, p<0.001), and more diabetes-related distress (p<0.001; p<0.05) than willing patients. Unwilling patients also reported significantly more negative (p<0.05) and fewer positive beliefs (p<0.001) about starting insulin than ambivalent patients. Conclusion: These are the first data demonstrating the prevalence of PIR across Western nations. PIR is strongly linked to positive and negative insulin beliefs, and may also reflect a broader discomfort with medications and with diabetes in general. Of note, however, PIR is a marker of behavioral intent only; it is not known whether this predicts actual behavior at the time when insulin is prescribed. When addressing patients who are reluctant to initiate insulin therapy, clinicians may find it valuable to inquire about their beliefs about insulin and their current medications.