Epidemiology

Asthma affects about 300 million people around the world with 250,000 deaths annually due to the condition.

Due to the lack of a precise and universally accepted definition, the global prevalence of asthma varies from a range of 1% to 18% (2)

• specific groups in the population are considered to have a higher rate than the general population -
  • higher in urban areas than in rural areas
  • in the US
    • race and ethnicity strongly affect the prevalence of asthma
    • more common in children and people on a low income than in the general population - 7% of African-American children and 13.5% of children from low-income families have asthma (1).

There is a geographical variation in incidence of asthma -

• it is rare in Far Eastern countries such as Malaysia, but common in countries such as New Zealand
• it seems likely that in developing countries, the disease increases in prevalence as they become more westernised

In the UK, 5.4 million people were receiving treatment for asthma in 2011 out of which 1.1 million were children (1 in 11) and 4.3 million were adults (1 in 12)

• in Northern Ireland, 182,000 people (1 in 10) were receiving treatment for asthma (36,000 children and 146,000 adults)
• in Scotland, 368,000 were receiving treatment for asthma (72,000 children and 296,000 adults)
• in Wales, 314,000 were receiving treatment for asthma (59,000 children and 256,000 adults)
• in England, 4,500,000 people (1 in 11) were receiving treatment for asthma (932,000 children and 3,600,000 adults). (3).

The UK has among the highest prevalence rates of asthma symptoms in children worldwide.

• asthma is the most common long-term medical condition with one in 11 children being affected
• on average there are two children with asthma in every classroom
• the chance of a child developing asthma when one parent has asthma is approximately double that of a child whose parents do not have asthma
• one in 8 children under 15 with asthma symptoms experience attacks so severe they can't speak
• asthma attacks hospitalise someone every 8 minutes; 185 people are admitted to hospital because of asthma attacks every day in the UK (a child is admitted to hospital every 20 minutes because of an asthma attack) (3)

Occupational asthma, e.g. due to allergens from animals, flour or grain; may afflict up to 20% of the workforce exposed to the sensitiser.

Reference:

1. Olin JT, Wechsler ME. Asthma: pathogenesis and novel drugs for treatment. BMJ. 2014;349:g5517.
2. Global Initiative For Asthma (GINA) 2023. Global strategy for asthma management and prevention
3. Asthma UK. Asthma facts and statistics (Accessed March 2024)