Therapeutic inertia or individualization? Delay in clinical management of type 2 diabetes mellitus

Recently, therapeutic strategies for type 2 diabetes mellitus (T2DM) have focused on individualization: medical care should be adjusted to patient preferences, comorbidities and other, individual factors¹. One of the reasons why individualization of medical care is being required is that clinical trials targeting lower glycemic control with intensive therapy recently failed to demonstrate a beneficial effect on cardiovascular diseases in type 2 diabetes². However, because a glycemic level as close as possible to the nondiabetic range has been demonstrated to exert powerful beneficial effects on diabetic microvascular complications, including neuropathy, retinopathy and nephropathy not only in type 1 diabetes but also in type 2 diabetes mellitus³, glycemic goals for patients should be adjusted according to individual preferences and specific factors, including patient age, duration of diabetes, life expectancy, comorbidities, resources and support.

Clinical inertia can be recognized in the treatment of hypertension, dyslipidemia and diabetes mellitus⁴. Healthcare providers often do not initiate or intensify therapy appropriately, although the recommended treatment goals are well defined, effective therapies are readily available and practice guidelines for the diseases are widely distributed. Clinical inertia is defined as recognition of the problem but failure to act⁴.

Watson et al. evaluated clinical inertia in the management of patients with T2DM: patients who were given intensified second-line therapy within one year achieved maintained reduction in HbA1c sooner than those with delayed intensification or no second-line therapy⁵. In that retrospective, longitudinal database analysis, patients who failed to achieve a glycemic target of HbA1c <7.0% with metformin monotherapy but were given intensified second-line treatment within one year from the index date (Group A) showed a better rate of HbA1c <7.0% than those with second-line therapy delayed more than one year (Group B) or those without intensification (Group C). The authors mention clinical inertia in the background of delayed treatment intensification.

The causal factors of clinical inertia are debatable, but are generally thought to be induced by both provider and patient factors⁶. Providers may not have enough information regarding therapeutic goals, strategies, values or guidelines. They may be concerned, especially about adverse events such as hypoglycemia, which could result in an increase of cardiovascular risk. Intensification might be postponed to give their patients time to implement life-style modification and better glycemic control. On the other hand, patients can refuse intensification due to lack of knowledge, general non-adherence practice or economic burden. Furthermore, the relationship between providers and patients can result in clinical inertia. Comorbidities such as inability of self-care behavior due to dementia or lack of social support can also affect the decision making of healthcare providers.

While clinical inertia appears to be a factor in clinical care, it is difficult from this retrospective database analysis to distinguish a delay of intensification due to oversights by general practitioners (GPs) from their individualization of therapy. At baseline, patients in Group A were younger, had higher HbA1c, were more obese, and had fewer comorbidities than patients in Group B and C. Thus, there is ample rationale to intensify treatment for patients in Group A. Patients in Groups B and C might have been subject to delay of intensification of treatment not only due to inertia of individual GPs but to clinical disinterest in individualization of therapeutic strategies.

Recently Paul et al.⁷ investigated whether delay of intensification of treatment for one year resulted in development of complications related to diabetes. They reported that patients with HbA1c >7% who received intensified treatment within one year were reported post-diagnosis to have 38% lower risk for cardiovascular events compared to those who had delayed treatment intensification.

To avoid clinical inertia and promote adjusted medical care for individual patients, specific strategies should be taken into consideration. First, healthcare providers should acknowledge clinical inertia in clinical practice. Second, healthcare providers should communicate with their patients regarding suitable glycemic targets, treatment strategies and alternative options, risks and benefits. Whether and how individualization of glycemic targets can result in better outcomes with respect to patient quality of life should also be discussed. Further investigation is necessary to clarify the longitudinal outcomes of individualized diabetes therapeutic strategy.

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Declaration of funding

This editorial was written independently and received no professional help.

Acknowledgement

We thank Ms Michiko Yamane in Kansai Electric Power Hospital for her secretarial assistance.

Declaration of financial/other relationships

N.T. has disclosed that he has no significant relationships with or financial interests in any commercial companies related to this study or article. T.K. has disclosed that he has received consulting and/or speaker fees from Astellas, Boehringer Ingelheim, Sanofi, Novo Nordisk, MSD, Takeda, Kowa, Tanabe Mitsubishi, Kaken Pharm, AstraZeneca, Daiichi-Sankyo, and Kyowa Kirin; he has also received clinical commissioned/joint research grants from Boehringer Ingelheim, Novo Nordisk, Merck, Sharp and Dohme, Takeda, Ono Pharm, Eli Lilly, Teijin, and Sanofi. Y.S. has disclosed that he has received consulting and/or speaker fees from Eli Lilly, Sanofi, Novo Nordisk, GlaxoSmithKline, Taisho Pharmaceutical, Astellas Pharma, BD, Boehringer Ingelheim, Johnson & Johnson and Takeda.

The CMRO peer reviewer on this manuscript has no relevant financial or other relationships to disclose.