Asthma. Intermittent or persistent?

Those suffering from intermittent asthma do not need daily medications to maintain good control. On the other hand, those with persistent asthma will need daily maintenance medications to prevent exacerbations. Luckily for us, there is a rule of thumb that will help make the clinical distinction between intermittent and persistent asthma easier.

This rule of thumb is the “rule of twos” (abbreviated as Ro2). This is a quick and easy checklist to go through with your patients. If they answer “yes” to any of the rules of two, asthma is considered to be “persistent” or inadequately controlled.

  • Are they symptomatic more than 2 days a week?
  • Are they requiring their rescue inhaler more than 2 days per week?
  • Are they experiencing nighttime symptoms more than 2 days per month?
  • Are they requiring a course of oral steroids more than 2 times a year?

Hopefully some of you can put the Ro2 to use in practice!


Have a great week! Good luck to those studying for exams.

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