Table 4.

Studies evaluating critical inhaler steps for MDIs as defined by lung deposition or disease control

Preparatory step	Affects drug delivery	Affects symptoms or disease control
Inhaler step
Expose mouthpiece/remove cap
Cannister shaken (if medication in suspension)	Everard (1995)9
If first use or if several days have elapsed since last use, prime inhaler by releasing actuations into the air	Dewsbury (1996)30
	Kenyon (1998)32
	Janssens (1999)36
	Mitchell (2007)35
Head tilted so that chin is slightly upward
Hold inhaler upright		Price (2017)56*
Exhale before actuating inhaler	Hindle (1993)90
Does not exhale into inhaler		Price (2017)56*
Actuate inhaler at the start of inhalation	Newman (1991)91	Price (2017)56
	Farr (1995)92
Inhalation takes place over 3–5 seconds, or slow and deep inhalation		Al-Showair (2007)102
	Newman (1980)93
	Newman (1981)94
	Dolovich (1981)95
	Newman (1982)96
	Lawford (1983)97
	Hindle (1993)90
	Newman (1995)98
	Pavia (1995)99
	Farr (1995)92
	Heyder (2004)100
	Tomlinson (2005)101
Hold breath for 5–10 seconds	Newman (1980)93
	Newman (1982)96
	Hindle (1993)90
Correct second dose preparation and timing		Price (2017)56†
Replace cap after use

^*study combined the errors “exhaled into the inhaler or did not hold inhaler upright”

^†study combined the errors “lack of device knowledge or incorrect second dose preparation, timing or inhalation”