BACKGROUND: Hyperglycaemia in people with diabetes is associated with increased risk of micro- and macrovascular complications and all-cause mortality.  The risk of micro- and macrovascular compilations are increased by delaying the intensification of treatment in people with poor glycaemic control, a condition occurring not only as a result of the complexity of the disease, long duration of diabetes or non-adherence, but also due to inertia on the part of healthcare professionals (HCPs).  Therapeutic inertia has recently been suggested to refer to the failure of HCPs changing (either intensifying or de-intensifying) diabetes medications if it is clinically indicated.

AIMS: The aim of this survey is to evaluate trends in therapeutic inertia among 3 groups of interest in a primary care physician (PCP) and diabetes specialist setting over the past 4 years.
METHODS: Data were drawn from 4 waves of the Adelphi Diabetes Disease Specific Programme (DSP) conducted from 2013 to 2016 across 5EU/US. Although not longitudinal in nature, each DSP survey provides independent point-in-time data, which can be used to explore patterns over time. Specialists and PCPs completed physician-reported forms for 10 consecutive patients with T2DM. Data were collected on patients’ demographics, clinical assessments including HbA1c, clinical outcomes, medication use and history including duration of therapy and concomitant conditions. Patients were classified into 3 groups of interest: (1) Adequately controlled: >65 years, >2 comorbidities, HbA1c >7.0%, duration of diabetes >15 years and high risk of hypoglycaemia; (2) Candidates for de-intensification of therapy: >65 years, >2 comorbidities, HbA1c <7.0%, duration of diabetes >15 years  and high risk of hypoglycaemia; (3) Candidates for intensification of therapy: <65 years, <2 comorbidities, HbA1c >7.0%, duration of diabetes <15 years and no risk of hypoglycaemia. High risk of hypoglycaemia was defined by occurrence of one or more of the following: >1 severe hypogylcaemic episode in last year, moderate chronic renal failure or exposure to insulin >5 years. Therapeutic inertia was defined by no treatment change in past 12 months.
RESULTS: 3,414 physicians included 33,203 patients across 4 DSP waves. On average, stable (S) patients accounted for 3.1%, candidates for de-intensification (DE) 1.2% and candidates for intensification (IN) 10.8% with no change in size of patient groups since 2013. Of these, in 2016, therapeutic inertia accounted for approximately half of patients within each group (S 47%; DE  56%; IN 41%),  with fewer patients than in 2013 (S 39%; DE  47%; IN 30%). Of these inertia groups, in 2016, PCPs were more likely to be managing the potential de-intensification and intensification patients ( 62% and 63% respectively), with little change since 2013 ( 62% and 65% respectively). Stable inert patients were more likely to be managed by PCPs in 2013 (56% vs. 44% specialist) with a move towards specialist involvement in 2016 (49% vs. 51% specialist). 85% of patients did not qualify for one of the 3 groups of interest, highlighting several other potential patient groups for future analysis.

DISCUSSION: This analysis highlights patients managed in a primary care setting are more likely to experience therapeutic inertia, especially amongst those patients who are potential candidates for de-intensification and intensification of therapy. As the prevalence of diabetes continuously rises, specialist centres are unable to cope with a gradual shifting of care to primary and community care settings, so-called “left-shifting”. Simultaneously, there has been a proliferation of new antidiabetic medications, with over four new classes since 2005, all with different extra-glycaemic benefits and side-effects. Keeping on top of the “left-shift” could be a daunting task for the generalist physician in primary care. Limited exposure to education emphasizing treating to target levels and the need to act each time intensification of therapy is clinically indicated is believed to be what leads to therapeutic inertia in the primary care setting.

Therapeutic inertia among real world population with T2DM from 2013-2016: data from 33,203 patients across Europe and US