Association between Air Pollution and Hemoptysis

Table 2

Poisson regression exponentiated coefficients of the relationship between concentration of air contaminants and monthly number of embolizations.

Relationship between number of embolizations in a given month and …	… concentration of the contaminant in the same month ()	… concentration of the contaminant in the previous month ()	… increase (from the previous month) in the concentration of the contaminant ()
Contaminants
SO2 (per 1 g/m^3)	1.010 ()	1.070 ()	0.961 ()
NO (per 15 g/m^3)	1.169 ()	0.958 ()	1.445 ()
NO2 (per 10 g/m^3)	1.135 ()	0.945 ()	1.292 ()
O3 (per 20 g/m^3)	0.868 ()	0.900 ()	0.839 ()
CO (per 0.1 g/m^3)	1.073 ()	0.923 ()	1.253 ()
PM10 (per 10 g/m^3)	1.029 ()	0.991 ()	1.097 ()
Potential confounds
Temperature (per 10°C)	0.987 (0.933)	1.118 (0.511)	0.596 (0.101)
Influenza (per 500 searches)	0.808 (0.182)	0.857 (0.339)	0.993 (0.959)

Each cell shows the Poisson regression exponentiated coefficient and the value of the relationship. The exponentiated coefficient shows the amount by which the expected number of embolizations is multiplied per each unit increase in the contaminant (e.g., for the right-most NO cell, 1.169, the expected number of embolizations in a given month is 16.9% higher if the concentration of NO is 15 g/m³ higher). The measurement units were semiconventionally chosen (round numbers with similar standard deviations ~ 0.5–1), but statistics were conducted considering the variables as continuous for which   values do not depend on these measure units.
Statistically significant after correction for multiple comparisons.
Only statistically significant before correction for multiple comparisons.