Table 3

Carbon footprint associated with excess SABA inhaler use in asthma

APrevalence of clinically-diagnosed asthma3 800 000 people
SABA overuse
Mild overuse: >150 to 375 uses (doses)of SABA per year*
MDI
BNumber of people in ‘A’ who use a SABA MDI >150 to 375 times per year750 120 people
CCarbon footprint associated with excess SABA MDI use in people in ‘B’22 194 MT CO2e
Moderate overuse: >375 to 750 uses of SABA per year*
MDI
DNumber of people in ‘A’ who use a SABA MDI >375 to 750 times per year250 040 people
ECarbon footprint associated with excess SABA MDI use in people in ‘D’27 126 MT CO2e
Severe overuse: >750 usesof SABA per year*
MDI
FNumber of people in ‘A’ who use a SABA MDI>750 times per year71 440 people
GCarbon footprint associated with excess SABA MDI use in people in ‘F’11 273 MT CO2e
Total
HCarbon footprint of SABA MDI overuse60 594 MT CO2e
ICarbon footprint of SABA DPI overuse – online supplemental appendix B, table S1132 MT CO2e
JTotal carbon footprint of SABA inhaler overuse60 726 MT CO2e

  • Detailed calculations, supportive information and additional data on DPIs are presented in online supplemental material 1, appendix B, table S1

  • *Overuse is defined as requiring >150 uses (doses) of a SABA over a year.31 This reflects a conservative definition, given that guidelines define well-controlled asthma as no more than two uses (doses) of SABA per week.24 25 Note that a typical use (dose) of a SABA MDI consists of two medication actuations, and of a SABA DPI consists of one medication actuation). Categories of people overusing SABA are derived from Nwaru, Ekstrom.31 We calculated the mid-point estimate for mild and moderate SABA overuse categories, and the low-point estimate for the severe overuse category. We did not count the first 150 uses (doses) in any category, as those doses are considered within the acceptable limit for good asthma control.

  • DPI, dry powder inhaler; MDI, metred-dose inhaler; MT CO2e, metric tons of CO2 equivalent; SABA, short-acting beta2-agonist.