Table 1.

Risk factors for potentially fatal asthma

Risk factor	Level of evidence
Control and severity of asthma
Poor control of asthma27,36–43	II-2
History of admission to hospital for asthma38,39,41,42,44,45	II-2
Previous admission to an intensive care unit for asthma27,38,42	II-2
Previous need for mechanical ventilation for asthma27,38	II-2
History of multiple visits to the emergency department for asthma38,39,46	II-2
Failure to consult family physician for worsening asthma27,29,40,42,47	II-2
Pattern of sudden attacks29,30,48	II-2
History of previous hypercapnic asthma attack2,49,50	II-2
Use of medications
Poor adherence with medications for asthma31,36,39,40,42	II-2
Excessive or increasing reliance on short-acting β2-adrenergic bronchodilators38,51–53	II-2
Underuse of inhaled corticosteroids27,31,54	II-2
History of need for oral corticosteroids27,31,38,41,44,45	II-2
Monotherapy with a long-acting β2-adrenergic bronchodilator55–58	I
Prescription of multiple types of asthma medications44	II-2
Increased use of oral theophylline27,38,42	II-2
Asthma that is worsened by acetylsalicylic acid or nonsteroidal anti-inflammatory drugs59–61	II-3
Psychosocial profile
Older age27,42	II-2
Poor perception of breathlessness27,36,62–64	II-2
Psychological dysfunction (psychosis, anxiety, depression, denial)36,37,45,46,63,65–69	II-2
Socio-economic factors (family discord, low income, ethnicity)6,43,61,70,71	II-2
Continued smoking38,72,73	II-2
Failure to use a written asthma action plan73	II-2
Poor understanding of asthma and its treatment	III
Frequent missed appointments	III
Substantial lifestyle alterations because of asthma	III
Self-discharge from hospital	III
Learning difficulties	III
Abuse of alcohol or drugs73,74	II-3
Physician-related factors
Failure to initiate (or delay in initiating) appropriately aggressive therapy40,47,75,76	II-2
Failure to initiate mechanical ventilation when appropriate47	II-2
Failure to objectively evaluate the severity of airflow obstruction47	II-3
Failure to recommend appropriate strategies for avoidance of allergens, irritants and workplace-related factors	III