How long do you try an inhaler before increasing the dose because it was inadequate/failed to control the patients asthma?

How long do you try an inhaler before increasing the dose because it was inadequate/failed to control the patient's asthma?

• 1-2 months
• 2-3 months
• 3-4 months
• 4-5 months
• 5-6 months
• 6-9 months
• 9-12 months
• >1 year
• Other