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Taking guesswork out of asthma: risk factors for future attacks


Published online: December 22, 2016

Asthma affects people of all ages in different ways, but anyone with asthma can experience an asthma attack. An attack is a sudden narrowing of the airways that worsens symptoms and cannot be resolved by usual inhaled reliever treatment. The periods of worsening cause physical and psychological distress, and can lead to serious outcomes such as hospitalization, mechanical ventilation, and even death. Despite the availability of efficacious medicines and international guidelines, asthma attacks remain common. In the United Kingdom, the number of people dying as a result of asthma attacks is at a 10-year high despite >75% of these episodes being preventable. The uncomfortable realities are in part due to asthma management being largely guided by patient-reported symptoms rather than by objective measurements. Assessment of objective measures and addressing risk factors has been a successful strategy in reducing acute adverse events in other disciplines (e.g. heart attacks and deaths in the field of cardiology). Motivated by such successes, an international group of asthma experts were brought together by the Respiratory Effectiveness Group (REG, www.effectivenessevaluation.org) to identify objective risk factors for asthma attacks and to explore how these findings might be used in clinical practice to reduce risk at the individual patient level.

Blakey and colleagues, writing in The Journal of Allergy and Clinical Immunology: In Practice report common clinical and demographic characteristics of patients who go on to experience multiple attacks. The retrospective cohort study involved almost 120,000 adults with asthma from the Optimum Patient Care Research Database (OPCRD, www.optimumpatientcare.org). The OPCRD is a research quality primary care database containing anonymized records for over 1.7 million people in the UK. The authors collected potential risk factors over a 1-year period and related these factors to asthma attacks in the subsequent 2-year period. The risk factors were analyzed individually, then collectively, to see which were the most instructive markers of risk of future attacks. The most influential factors were then incorporated into an online risk prediction tool that illustrates how healthcare professionals could use such information in clinical practice to quantify risk and identify practical opportunities for its reduction (http://effectivenessevaluation.org/ARC/).

The research team included over 16 potential risk predictors in their mathematical models, which looked specifically at the risk of a minimum of two or four asthma attacks in the following 2 years. Independent predictors associated with future attacks included baseline-year markers of attacks (acute oral corticosteroid [OCS] courses, emergency visits), more frequent reliever use and healthcare
utilization, worse lung function, current smoking, blood eosinophilia, rhinitis, nasal polyps, eczema, gastroesophageal reflux disease, obesity, older age, and being female. The resultant prediction models were consistently able to identify patients with an increased risk profile and compared favorably with other routine tests used to guide medical decision-making (e.g. C-reactive protein to assess if an infection is bacterial in origin).

The study shows that data routinely collected within primary care can be used to quantify the risk of future asthma attacks for individual patients and may have a role to play in informing future asthma service planning. The development of such evidence-based tools may help clinicians to identify at-risk patients through automated record searches, thereby encouraging appropriately informed decision-making during consultations.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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