Treatable traits and their application in high-, middle- and low-income countries

Change is in the air: key questions on the 'Treatable Traits' model for chronic airway diseases in primary care

Despite great advancements in the treatment of chronic airway diseases, improvements in morbidity and mortality have stalled in recent years. Asthma and chronic obstructive pulmonary disease are complex and heterogeneous diseases that require tailored management based on individual patient characteristics and needs. The Treatable Traits (TTs) approach aims to personalise and improve patient care through the identification and targeting of clinically relevant and modifiable pulmonary, extra-pulmonary and behavioural traits. In this article, we outline the rationale for TTs-based management and provide practical guidance for its application in primary care. To aid implementation, seven potential 'prime' traits are proposed: airflow obstruction, eosinophilic inflammation, adherence, inhaler technique, smoking, low body mass index/obesity and anxiety and depression-selected for their prevalence, recognisability and feasibility of use. Some of the key questions among healthcare professionals, that may be roadblocks to widespread application of a TTs model of care, are also addressed.

Treatable traits in pre-COPD: Time to extend the treatable traits paradigm beyond established disease

To date, the treatable traits (TTs) approach has been applied in the context of managing diagnosed diseases. TTs are clinical characteristics and risk factors that can be identified clinically and/or biologically, and that merit treatment if present. There has been an exponential increase in the uptake of this approach by both researchers and clinicians. Realizing the potential of the TTs approach to pre-clinical disease, this expert review proposes that it is timely to consider acting on TTs present before a clinical diagnosis is made, which might help to prevent development of the full disease. Such an approach is ideal for diseases where there is a long pre-clinical phase, such as in chronic obstructive pulmonary disease (COPD). The term 'pre-COPD' has been recently proposed to identify patients with respiratory symptoms and/or structural or functional abnormalities without airflow limitation. They may eventually develop airflow limitation with time but patients with pre-COPD are likely to have traits that are already treatable. This review first outlines the contribution of recently generated knowledge into lifetime lung function trajectories and the conceptual framework of 'GETomics' to the field of pre-COPD. GETomics is a dynamic and cumulative model of interactions between genes and the environment throughout the lifetime that integrates information from multi-omics to understand aetiology and mechanisms of diseases. This review then discusses the current evidence on potential TTs in pre-COPD patients and makes recommendations for practice and future research. At a broader level, this review proposes that introducing the TTs in pre-COPD may help reenergize the preventive approaches to health and diseases.

Treatable traits models of care

Treatable traits is a personalized approach to the management of respiratory disease. The approach involves a multidimensional assessment to understand the traits present in individual patients. Traits are phenotypic and endotypic characteristics that can be identified, are clinically relevant and can be successfully treated by therapy to improve clinical outcomes. Identification of traits is followed by individualized and targeted treatment to those traits. First proposed for the management of asthma and chronic obstructive pulmonary disease (COPD) the approach is recommended in many other areas of respiratory and now immunology medicine. Models of care for treatable traits have been proposed in different diseases and health care setting. In asthma and COPD traits are identified in three domains including pulmonary, extrapulmonary and behavioural/lifestyle/risk-factors. In bronchiectasis and interstitial lung disease, a fourth domain of aetiological traits has been proposed. As the core of treatable traits is personalized and individualized medicine; there are several key aspects to treatable traits models of care that should be considered in the delivery of care. These include person centredness, consideration of patients' values, needs and preferences, health literacy and engagement. We review the models of care that have been proposed and provide guidance on the engagement of patients in this approach to care.

The treatable traits approach to adults with obstructive airways disease in primary and secondary care

The treatable traits approach is based on the recognition that the different clinical phenotypes of asthma and chronic obstructive airways disease (COPD) are a heterogeneous group of conditions with different underlying mechanisms and clinical manifestations, and that the identification and treatment of the specific clinical features or traits facilitates a personalised approach to management. Fundamentally, it recognises two important concepts. Firstly, that treatment for obstructive lung disease can achieve better outcomes if guided by specific clinical characteristics. Secondly, that in patients with a diagnosis of asthma, and/or COPD, poor respiratory health may also be due to numerous overlapping disorders that can present with symptoms that may be indistinguishable from asthma and/or COPD, comorbidities that might require treatment in their own right, and lifestyle or environmental factors that, if addressed, might lead to better control rather than simply increasing airways directed treatment. While these concepts are well accepted, how best to implement this personalised medicine approach in primary and secondary care within existing resource constraints remains uncertain. In this review, we consider the evidence base for this management approach and propose that the priority now is to assess different prototype templates for the identification and management of treatable traits in both asthma and COPD, in primary, secondary and tertiary care, to provide the evidence that will guide their use in clinical practice in different health care systems.

Treatable traits, combination inhaler therapy and the future of asthma management

The landscape of asthma has considerably changed in the last decade. Effective medications and inhaler devices have been developed and integrated into the asthma pharmacopoeia, but unfortunately, the proportion of uncontrolled patients remains unacceptably high. This is now recognized to be mainly due to the inappropriate use of medications or inhaler devices, heterogeneity of the disease or other factors contributing to the disease. Currently, inhaled corticosteroids (ICS), with or without long-acting beta agonists (LABA), are the cornerstone of asthma management, and recently international guidelines recognized the importance of combination inhaler therapy (ICS/LABA) even in mild asthma. In future, ultra-long-acting personalized medications and smart inhalers will complement combination inhaler therapy in order to effectively addresses issues such as adherence, inhaler technique and polypharmacy (both of drugs and devices). Asthma is now acknowledged as a multifaceted cluster of disorders and the treatment model has evolved from one-size-fits-all to precision medicine approaches such as treatable traits (TTs, defined as measurable and treatable clinically important factors) which encourages the quality use of medications and identification and management of all underlying behavioural and biological treatable risk factors. TT requires research and validation in a clinical context and the implementation strategies and efficacy in various settings (primary/secondary/tertiary care, low-middle income countries) and populations (mild/moderate/severe asthma) are currently evolving. Combination inhaler therapy and the TTs approach are complementary treatment approaches. This review examines the current status of personalized medicine and combination inhaler therapy, and describes futuristic views for these two strategies.

Treatable Traits in Airway Disease: From Theory to Practice

Chronic airway diseases such as asthma and chronic obstructive pulmonary disease are prevalent and complex conditions that often coexist in the same patient. To address this complexity in clinical practice, and to move forward toward personalized and precision medicine of airway diseases, a strategy based on the identification and treatment of so-called "treatable traits" (TTs) has been proposed. A TT is a recognizable phenotypic or endotypic characteristic that can be assessed and successfully targeted by therapy to improve a clinical outcome in a patient with airway disease. Importantly, TTs can coexist in the same patient, so they are not mutually exclusive. The TT strategy proposes to investigate in each individual patient with chronic airway disease the number and type of TTs present and to treat each of them according to guideline recommendations. This strategy is agnostic (ie, independent) to the traditional diagnostic labels (asthma, chronic obstructive pulmonary disease), so it can be applied to any patient with airway disease. Currently, there is firm evidence supporting the adequacy and validity of the TT strategy. Here, we review the current state of the art of this topic, first by presenting its theoretical background and then by discussing how to best implement it in clinical practice.

Multidisciplinary care in chronic airway diseases: the Newcastle model

Chronic airway diseases including, asthma and chronic obstructive pulmonary disease (COPD) are prevalent and high burden conditions with the majority of patients successfully managed in the primary care setting. However, some patients with more complex disease such as difficult-to-treat or severe asthma, or complex COPD, tertiary care is required. This review provides an overview of the successful tertiary care multidisciplinary respiratory service that operates in Newcastle, New South Wales, Australia, which has been integrated into the tertiary care outpatient clinics for almost three decades. The service is multifaceted in terms of the clinical care it provides, and includes an “Inpatient service”, “Asthma Management Service”, “Difficult Airway Clinic”, “Drug Administration Clinic”, “Rapid Access Clinic”, “Pulmonary Rehabilitation” and has an integrated research programme. The core of the multidisciplinary approach to airway diseases is a person-centred model of care, the “Treatable Traits” approach. The staffing of this service comprises of consultant physicians, respiratory advanced trainees, respiratory scientists, physiotherapists, speech pathologists, nurse specialists and a nurse consultant. Patients that present to this service undergo an initial assessment and clinical review by team members, synthesis of relevant data, and development of a diagnosis and management plan. Based on this review specific interventions are determined according to the traits identified. Overtime the service has evolved to accommodate the increasing numbers of patients requiring access to the “Difficult Airways Clinic” assessment and therapies. This has been facilitated by partnered with the Centres of Excellence in Severe Asthma and Treatable Traits to develop educational and practice management tools.

The use of treatable traits to address COPD complexity and heterogeneity and to inform the care

COPD is complex and heterogeneous with respect to its aetiology, clinical presentation, phenotypes and biological mechanisms. Despite this, COPD is still diagnosed and treated according to simple clinical measures, including airflow limitation, symptoms and exacerbation frequency, leading to failure to recognise the disease's heterogeneity and/or to provide targeted interventions. COPD continues to have a very large burden of disease with suboptimal outcomes for people with the disease, including frequent hospitalisation with exacerbations, rapid lung function decline, multimorbidity and death from respiratory failure. In light of this, there have been increasing calls for a renewed taxonomy with better characterisation of COPD phenotypes and endotypes. This would allow the unravelling of COPD's complexity and heterogeneity, the implementation of targeted interventions and improved patient outcomes. The treatable traits strategy is a proposed vehicle for the implementation of precision medicine in chronic airway diseases. In this review, in addition to summarising the key knowledge on the heterogeneity of COPD, we refer to the existing evidence pertaining to the treatable traits strategy as applied in COPD and discuss implementation in different settings.

COPD is a heterogeneous clinical syndrome, which requires deconstruction of its individual components to facilitate targeted treatment and improve individual patient outcomes. 
https://bit.ly/2YXWgHN

Moving towards a Treatable Traits model of care for the management of obstructive airways diseases

Asthma and chronic obstructive pulmonary disease (COPD) are two prevalent chronic airways diseases. Both are complex and heterogeneous. Traditionally, clinical guidelines have advocated a stepwise approach to pharmacotherapy of asthma and COPD, but there is increasing realization that both require a more personalized and precise management approach. To this end, a management strategy based on the so-called Treatable Traits has been proposed. Emerging evidence suggests that this model improves relevant outcomes in patients with chronic airway diseases but further research is needed to guide implementation. This review discusses the challenges, opportunities, and hurdles that its implementation will have to face.