What are the Treatable Traits
Treatable traits are phenotypic or endotypic characteristics which can include comorbidities (such as anxiety, vocal cord dysfunction and reflux), risk factors (such as smoking and bone density) and self-management skills (such as adherence and inhaler technique). To be considered a trait each characteristic must be clinically relevant, identifiable and measurable using validated trait identification markers, and treatable. Treatable Traits are recognised within three domains: pulmonary traits, extrapulmonary traits and behavioural/risk-factors. With advances in research and knowledge, new traits are always being considered and added.
Pulmonary traits
| Trait | Trait identification marker/diagnostic criteria | Possible treatments | Evidence level I–IV # |
| Airway smooth muscle contraction | Bronchodilator reversibility, peak expiratory flow variability, airway hyperresponsiveness | Bronchodilators: Maintenance: LABA/LAMA; Rescue: SABA/SAMA/rapid-acting LABA | I |
| Systemic allergic inflammation | Elevated serum IgE | Anti-IgE monoclonal antibody therapy | I |
| Dyspnoea | Dyspnoea score ≥2, modified Medical Research Council scale | Pulmonary rehabilitation, breathing retraining | I |
| Emphysema (loss of elastic recoil) | Chest CT, plethysmography, lung compliance | Smoking cessation, lung volume reduction surgery, lung transplantation, α1-antitrypsin replacement if deficient | I |
| Airway inflammation (eosinophilic) | Sputum eosinophils ≥3% and/or FENO ≥30 ppb and/or blood eosinophils ≥0.3×109 cells·L−1 | Corticosteroids, anti-IL-5, -13, -4 monoclonal antibody therapy | I-II |
| Pulmonary hypertension | Doppler echocardiography, brain natriuretic peptide, right heart catheterisation | Oxygen therapy, pulmonary vasodilator therapy, lung transplantation | I-II |
| Bronchiectasis | High-resolution chest CT | Physiotherapy, mucociliary clearance techniques, macrolides, pulmonary rehabilitation, vaccination | I–II¶ |
| Bacterial colonisation | Presence of a recognised bacterial pathogen in sputum (sputum culture, quantitative PCR) | Antibiotics and tailored antibiotic written action plan for infections | II |
| Airway inflammation (neutrophilic) | Sputum neutrophils ≥61% | Macrolides, tetracyclines, roflumilast | II |
| Cough reflex hypersensitivity | Capsaicin challenge, cough counts, cough questionnaire | Speech pathology intervention, gabapentin | II |
| Mucus hypersecretion/ Chronic Bronchitis | Volume ≥25 mL of mucus produced daily for the past week in the absence of an infection/ COPD assessment tool: CAT 1 (cough) and 2 (sputum) items scores ≥3 | Mucociliary clearance techniques with a physiotherapist, inhaled hypertonic saline, macrolides | II |
Hypoxaemia | PaO2 ≤55 mmHg; PaO2 56–59 mmHg and evidence of complications of hypoxaemia (e.g. pulmonary hypertension, polycythaemia, right-sided heart failure) | Domiciliary oxygen therapy | II |
LABA: long-acting β2-agonists; LAMA: long-acting muscarinic antagonist; SABA: short-acting β2-agonists; SAMA: short-acting muscarinic antagonist; IgE: immunoglobulin E; CT: computed tomography; IL: interleukin; PaO2: partial pressure of oxygen. #: National Health and Medical Research Council (NHMRC) level of evidence currently available for the management/treatment of each trait; ¶: studies examining the effectiveness of different treatments in bronchiectasis in general, not specifically in chronic airways disease patients with coexisting bronchiectasis.
Extrapulmonary traits
| Trait | Trait identification marker/diagnostic criteria | Possible treatments | Evidence level I–IV # |
| Depression | Questionnaires (e.g. HADS depression domain score ≥8, GADS score >5), psychologist/liaison psychiatrist assessment | CBT, pharmacotherapy | I |
| Anxiety | Questionnaires (e.g. HADS anxiety domain score ≥8), psychologist/liaison psychiatrist assessment | Pharmacotherapy (i.e., anxiolytics/antidepressants), breathing retraining, CBT | I |
| Dysfunctional breathing | Nijmegen Questionnaire Total score ≥23, B-PAT (breathing pattern assessment tool) score >4, breath holding time, manual assessment of respiratory motion (MARM) | Breathing retraining | I |
| Physical inactivity and sedentary behaviour | Actigraphy, International Physical Activity Questionnaire | Pulmonary rehabilitation, physical activity, breaking bouts of sedentary activity | I |
| Overweight/obesity | Overweight: BMI 25–29.9 kg·m−2 Obesity: BMI ≥30 kg·m−2 | Caloric restriction, exercise, bariatric surgery, pharmacotherapy | I–II |
| Deconditioning | Cardiopulmonary exercise testing, 6MWT | Structured exercise programme, rehabilitation | I+, II |
| Rhinosinusitis | History and examination, imaging (sinus CT), Sino-Nasal Outcome Test (SNOT-22) | Topical corticosteroids, leukotriene receptor antagonists, antihistamines, surgery, intranasal saline lavage | II |
| VCD | Questionnaires (e.g. Pittsburgh ≥4), laryngoscopy, dynamic neck CT, inspiratory flow–volume curve | Speech pathology intervention, laryngeal botulinum toxin, gabapentin/pregabalin, psychology/psychiatry | II |
| Systemic inflammation | Leukocyte count >9×109 cells·L−1or high-sensitivity CRP >3 mg·L−1 | Statins¶ | II |
| Anaemia | Males: Hb <140 g·L−1 Females: Hb <120 g·L−1 | Haematinic (iron/B12) supplementation | I+, IV |
| Cardiovascular disease | Doppler echocardiography, Electrocardiogram, brain natriuretic peptide | Pharmacotherapy (β-blockers, diuretics, angiotensin-converting enzyme inhibitors), surgery | II |
| GORD | Questionnaires, gastrointestinal endoscopy, pH monitoring | Anti-reflux lifestyle measures, antacids, proton pump inhibitors, fundoplication surgery | II |
| OSA | Questionnaires (i.e., STOP-Bang Questionnaire), polysomnography | CPAP, mandibular advancement splint, positional therapy, weight loss | III-2 |
HADS: hospital anxiety and depression scale; GADS: Goldberg Anxiety and Depression Scale; CBT: cognitive behavioural therapy; BMI: body mass index; 6MWT: 6-min walk test; VCD: vocal cord dysfunction; CRP: C-reactive protein; Hb: haemoglobin; GORD: gastro-oesophageal reflux disease; OSA: obstructive sleep apnoea; CPAP: continuous positive airway pressure. #: NHMRC level of evidence currently available for the management/treatment of each trait; ¶: currently research only; +: evidence from the general population
Behaviour/risk-factor traits
| Trait | Trait identification marker/diagnostic criteria | Possible treatments | Evidence level I–IV # |
| Suboptimal inhaler technique | Direct observation and standardised assessment checklists, assessment via chipped inhalers | Education including demonstration and regular reassessment | I |
| Suboptimal adherence | Prescription refill rates, self-reported use of <80% of prescribed medication, chipped inhalers, FENO suppression test, measurement of drug concentrations | Self-management support, education, simplification of medication regime (i.e., reduce number of medications, frequency of doses and number of devices) | I |
| Smoking | Self-reported current smoking, elevated exhaled carbon monoxide, urinary cotinine | Smoking cessation counselling ± pharmacotherapy | I |
| Side-effects of treatments | Patient report, monitored withdrawal | Optimisation of treatment, alternative therapy, change device | I |
| Absence of a written action plan | Patient does not possess a written action plan, or reports not using the prescribed plan during exacerbations | Individualised self-management education with a written action plan | I |
| Exercise intolerance | <350 m on 6MWT | Pulmonary rehabilitation | I |
| Decreased bone mineral density (osteoporosis) | T-score ≤−2.5 | Pharmacotherapy based on osteoporosis guidelines, vitamin D supplementation, resistance training | I¶, II |
| Sarcopenia | Appendicular skeletal muscle mass index: Males <7.26 kg·m−2 Females <5.45 kg·m−2 | Diet (high protein), resistance training | I¶, II |
#: NHMRC level of evidence currently available for the management/treatment of each trait; ¶: evidence from the general population.