Key Summary Points

  • The phenomenon of clinical inertia is defined as the failure to start a therapy or its intensification/non-intensification when appropriate, in diabetology.

  • Despite the introduction of many glucose-lowering therapies that have proved to be efficacious in clinical trials, glycaemic control remains suboptimal in many patients globally, at all stages of treatment intensification.

  • There is a clear need to encourage earlier intensification and address issues around therapeutic inertia to make health systems more sustainable and improve the quality of life of diabetic patients.

  • Three classes of factors emerge as causes of clinical inertia: factors related to the healthcare professionals, to the patients and to the National Healthcare System.

  • Through adequate training, clinicians can evaluate their own performances, identify critical areas and adopt suitable strategies, in a virtuous quality cycle able to increase knowledge, and modify behaviors.

  • A structured and continuous educational activity, able to improve patients’ self-management abilities and responsibility, is fundamental.

  • The creation of multi-professional teams able to work with a common and shared language, the planning of educational activities, the presence and implementation of specific and shared diagnostic-therapeutic paths, the creation of pathology registers, and the evaluation of performances with the use of indicators, are all plausibly effective organizational strategies to improve the clinical-care outcomes and reduce clinical inertia.

Causes of clinical inertia in diabetes care

The causes of therapeutic inertia are multifactorial and complex and this phenomenon is becoming increasingly important in the management of diabetes also because it exposes patients to long periods of hyperglycemia which in turn foster an high risk of developing several complications and reduced life expectancy [63].

The causes of therapeutic inertia have been long debated, with the main goal of implementing strategies able to resolve and/or mitigate the problem.

From the careful analysis of the data currently available in the literature, three classes of factors have emerged as possible causes of clinical inertia, that is, factors related to the healthcare professionals, to the patients and to the National Healthcare System (Table 1). Almost all authors agree on the clinician’s greater responsibility as a cause of inertia [64]. Frequently, in fact, health professionals tend to delay the initiation and/or intensification of the treatment, in particular with insulin, because they are concerned that this procedure may entail clinical consequences and increased risk of hypoglycemic events, weight gain, difficulty in managing more complex injection therapies or at least the perception that the patient may have more difficulty in managing them. As for the patients, it is not uncommon for them to reject the doctor’s proposal to initiate or intensify insulin therapy, mainly because insulin therapy is perceived either as a “final stage” therapy, or as a punishment due to poor patient compliance [65]. These responsibilities will be examined extensively in the following section, bearing in mind, however, that if we want to try to solve the problem, it should be considered as a unique multifaceted phenomenon rather than a cluster of separate entities [66].

Table 1 Causes of clinical inertia

The barriers related to healthcare professionals (Table 1)

The barriers related to healthcare professionals include: lack of time, poor training, and lack of familiarity with the efficacy and safety of therapeutic regimens. These factors lead to an abuse of conventional drugs, such as metformin, sulfonylureas and insulin, therefore neglecting the new options of combined therapies or the new hypoglycemic molecules, either oral or injective, which present a window of efficacy and safety greater than the classic hypoglycemic agents [57].

Other important physician-related barriers are the recognition and management of side effects, the lack of awareness of the need to adopt a new therapeutic regime and the failure to establish and/or monitor all progresses achieved with respect to the set objectives. For this issue, the role of hypoglycemia is central: a study has shown that for 75.5% of healthcare professionals fear of hypoglycemia is a barrier to insulin therapy [67]. Zafar et al. also recognized other key factors, such as doctors’ misperception of improved glycemic control [68]. Parchman’s research team monitored 211 diabetological outpatient visits [69] and observed that the likelihood of a change in treatment decreased proportionally with the increasing degree of patient’s concern during the visit. This effect was independent from the duration of the visit, the value of HbA1c and its trend in time, the time elapsed since the previous evaluation, and the number of discussion points raised by the doctor.

One of the causes of clinical inertia, often declared by the same doctor, is the lack of awareness of the guidelines, which are frequently updated on the latest evidence resulting from clinical studies. The goals of treatment are not clear, the level of HbA1c to be achieved based on the patient’s characteristics is not known. Indeed, in recent years, based on scientific evidence, it has emerged that not all patients must reach a glycated hemoglobin level < 7% and this can lead to uncertainty in the healthcare professionals [70].

Equally important when talking about the physician’s responsibility as a cause of therapeutic inertia is their concern and/or conviction about certain patients compliance with the therapy, whom the doctor might perceive as incapable or reluctant to therapy changes and/or regimes ever more complex. Finally, one of the causes that is always declared by the doctor when it comes to therapeutic inertia is the heavy workload, often without an adequate organization and with high risk of burnout. In a chronic disease such as diabetes, where the patient is at the center of an articulated path focused on the recognition and satisfaction of clinical needs, the diabetologist is actually the main actor of the patient-centered approach. It is the diabetologist who must manage the therapeutic relationship with clinical, empathic, communication and organizational skills. Some neuroscientists have stated that clinicians often consider guidelines as treatment strategies based on clinical or experimental studies involving strict patient groups, which do not apply to particular patients (and each patient is particular) and with limited information. This increases the doubt in accepting the guidelines and generates overconfidence, aversion to risk or uncertainty, and herding [53]. Studies on decision-making theories by D. Kahneman have suggested that individuals, in the concrete act of making a decision, do not respond to optimizing logics but use a limited number of heuristics, or mental shortcuts. This could be attributed to the presence of cognitive bias, manifesting in situations of uncertainty [71]. For this reason, it is important to explore the conscious and unconscious mental processes at the base of the therapeutic choices in order to identify and highlight the factors related to therapeutic inertia.

Patient-related factors (Table 1)

The patient-related factors that favor clinical inertia include drug side effects, inability to follow complex treatment regimens, poor awareness of the true severity of the disease, limited doctor-patient communication and low level of education, collectively accounting for about 30% of the cases of clinical inertia [23]. Furthermore, poor compliance with an adequate diet, socioeconomic status, presence of acute and terminal illnesses are barriers that can be difficult to overcome, but must be managed. Patients sometimes can feel discouraged and frustrated, and such feelings can push them to stop their medications, resulting in failure to reach the glycemic target [72].

The data from the PANORAMA study [Efficacy and Safety of Intravitreal (IVT) Aflibercept for the Improvement of Moderately Severe to Severe Nonproliferative Diabetic Retinopathy (NPDR)], carried out in France, showed that the HbA1c targets set by French doctors for their patients reflected a good knowledge of type 2 diabetes care guidelines. Nevertheless, over two-thirds of patients failed to reach their intended goal, and this issue was attributed to the reluctance of the patients to intensify their treatments [73]: a phenomenon defined as “psychological resistance to insulin”, present in about 25% of the population to which this drug was prescribed [74].

The patient’s perception of non-adherence may contribute to clinical inertia in intensifying oral hypoglycemic agents. According to an analysis carried out in the United States, in fact, the clinician is led to make changes in therapy (dosage or pharmaceutical formulation), in patients who show greater compliance [75]. It is also possible that the association between delayed treatment intensification and poor adherence, as reported by Grant [75], may represent a tactic to tackle the problem with adherence at first, and only subsequently proceed with the intensification of the treatment. However, the author confirmed an overall slower rate of intensification: even in the cohort with the highest adherence, intensification was delayed on average for 2 years. However, when the doctor believes that the patient might not have good compliance, it would be good clinical practice to not address the problem in a step-wise manner, but to discuss it with the patient in conjunction with the intensification of therapy.

Other factors inherent to specific treatments used for type 2 diabetes can also contribute to clinical inertia by affecting compliance. These factors are mainly related to the side effects of a treatment (hypoglycemia, weight gain, edema, gastrointestinal symptoms), to the perceived complexity of treatment administration or to poor efficacy of treatment on glycemic control [76].

Another reason why patients do not achieve their goals is called “educational inertia”, defined as the learning of clinically inaccurate or obsolete information by doctors and health professionals [77]. This misinformation is implemented in patient care, resulting in poor outcomes. Since educational inertia is a subjective concept, it is impossible to measure it. It would be desirable that, during congresses, conventions or annual events proposed by scientific associations, healthcare professionals be given the real information they need, to successfully help their patients and guide them in achieving personalized therapeutic goals [77].

Factors related to the National Healthcare System (Table 1)

The evaluation of the barriers generated by the National Healthcare System cannot be generalized, because it variates according to the individual legislation and realities of each Country/Region. Among the numerous possible indicators of therapeutic inertia, a pivotal role is played by a poor coordination between planning and data exchange between the members of a health team, inadequate support technologies, the need for reimbursements, insurance coverage, and the great difference in regional norms [23]. The bureaucratic difficulties deriving from the use of therapeutic plans, for which expensive and complicated processes are required, lead doctors to adopt cheaper and more easily accessible drugs [78]. Resource constraints that limit staff time and predisposition to develop individual patient care plans can also limit the provision of in-depth diabetes education. The lack of an adequate care plan, including appropriate instructions on the use of medicines, can lead to delays in treatment intensification [64]. In situations where changes in health systems may be needed to improve care, the inertia of the system can make reform difficult. Clinical inertia can therefore be exacerbated by the inherent resistance to change within establishments facing barriers and competing demands [79]. More fundamental changes, such as a person-centered care model, can help find ways to address the challenges of patient non-compliance and clinical inertia.

Use of indicators

The analysis of the literature does not clearly outline the indicators of therapeutic inertia, but it rather identifies the methods for measuring inertia itself. In particular, some authors measure it by evaluating the appropriateness of the care process in relation to reference standards (guidelines, care paths) and therefore through a methodology that can be equated with the use of process indicators (Table 2). In other instances, therapeutic inertia is measured by evaluating the effects on welfare outcomes, either clinical and economic (direct and indirect costs), through a methodology equated with the use of outcome indicators (Table 3).

Table 2 Process indicators employed in the literature to assess clinical inertia
Table 3 Outcome indicators employed in the literature to assess clinical inertia

In several cases the appropriateness of the care process has been evaluated as “failure to intensify the therapy in the presence of a clinical situation that made it necessary”. As part of diabetes therapy, intensification was intended as the addition of a new drug, the increase in the dosage of the existing therapy, or the initiation of insulin in the presence of non-target HBA1c values. As part of the intensification, failure to titrate the basal insulin after initiation was also included. This method of measuring inertia was also used for hypotensive and normolipemic therapy. In some instances, the time elapsed before intensification was evaluated, instead of the percentage of patients assigned to a specific care process.

The consequences of therapeutic inertia have been evaluated more frequently on clinical care outcomes as a percentage of target subjects for glycemic, lipid and blood pressure parameters or as time elapsed before clinical optimization. The impact of therapeutic inertia on more severe outcomes such as life expectancy and progression of retinopathy was also assessed. For the economic aspect, the focus was on the impact of therapeutic inertia on the costs of complications.

Discussion and proposals to overcome clinical inertia

Therapeutic inertia, particularly in the management of chronic diseases such as diabetes, is a very complex phenomenon that recognizes multiple causes, largely dependent on the health professionals, but also on the patient and on national healthcare, with significant impact on health outcomes, welfare and social costs. In the past, the balance between hypoglycemia and strict metabolic control was difficult to assess with a limited therapeutic arsenal, and inertia was somewhat explained by fear of hypoglycemia. Nowadays, we have drugs with a very-low risk of hypoglycemia, able to minimize cardiovascular and renal burden. Therefore, we have entered an era where inertia is ethically unacceptable. In this manuscript we have analyzed the whole phenomenon, also trying to identify indicators to quantitatively and qualitatively measure inertia.

One of the possible approaches identified in the literature is to adopt monitoring systems to assess the quality of care as a whole. Through an analysis of process and outcome indicators and above all through a comparison among diverse care realities, clinicians can evaluate their own performances, identify critical areas and adopt suitable strategies, in a virtuous quality cycle. An attentive evaluation of behaviors and results could be instrumental for a real evolution of the entire class of professionals. From a practical point of view, it is crucial to implement discussions and comparisons in the various local realities to analyze the results obtained in each clinical practice and to make corrective actions.

Among the possible causes of therapeutic inertia, the main observations regarding health operators are the lack of familiarity with the new drugs, which are associated with a very-low risk of hypoglycemia and cardiovascular and renal events, the inadequate knowledge of Guidelines and up-to-date scientific evidences and the uncertainty about clinical objectives. From here it clearly emerges how training is fundamental to increase knowledge, but also for behavior modification: frontal readings, workshops and in-depth peer reviews, should be supplied alongside more accessible and interactive hands-on experiences combined with distance learning and evaluations.

Ideally, the therapeutic decision making could be guided by the implementation of software or algorithms embedded in the informatics clinical folders, able to stratify patients according to previous cardiovascular events, presence of chronic kidney disease, age, fragilities, etc., therefore identifying the most appropriate decision aligned with the current recommendations and candidates for new therapies [80].

Training courses at all levels of care (including general practitioners) and specialization (cardiologists, nephrologists, geriatricians, etc.) involved in the treatment of diabetes and its complications are essential to reach the greatest number of potentially treatable patients with new drugs since the early stages of illness. This, in addition to raising awareness among professionals and creating a common cultural base, would reassure patients who would receive uniform information shared by various professionals. Large-scale training projects might also help to overcome cognitive biases, indeed, it is necessary to identify the mental maps underlying therapeutic choices in order to recognize and reduce the inappropriate behavior [81].

Alongside a structured and continuous educational activity, able to improve patients’ self-management abilities and responsibility, all strategies able to increase adherence to therapy are important for antagonizing inertia: the simplification of therapeutic schemes, the preference for using drugs burdened by a lower impact on weight and hypoglycemic risk, the choice of therapy taking into account the patient’s preferences and lifestyle, sharing of the therapeutic objectives, the recognition of the cognitive, emotional and behavioral obstacles put in place by the patient as conscious and unconscious defenses to the therapy, an effective communication.

The clinical skills and up-to-date scientific knowledge of the professional must therefore be associated with relational, communicative and pedagogical skills. Recently, the skills required for a chronicity professional were examined and described in a Core Competence Curriculum, [82] through a correlation between activities/knowledge/skills and their impact on the Diabetology outcomes. The presence of an increasing number of professionals with “certified” skills is likely to foster a reduction of therapeutic inertia and an improvement in the quality of care and in the achievement of therapeutic goals.

Other effective organizational strategies to improve the clinical-care outcomes and reduce clinical inertia would be the creation of multi-professional teams able to work with a common and shared language, the planning of educational activities, the presence and implementation of specific and shared diagnostic-therapeutic paths, the creation of pathology registers, and the evaluation of performances with the use of indicators.


In conclusion, only through a multifactorial approach able to affect all the elements at the basis of therapeutic inertia and through complex and complementary organizational, educational and training strategies, it will be possible to reduce this phenomenon and thus improve care outcomes, with a significant impact on health outcomes, on reduction of complications and health costs of diabetes.