. 2022 Aug 25;130(8):087008. doi: 10.1289/EHP10734

Table 3.

Association between exposure to residential wood burning and pulmonary function measure by asthma status among $lowercase italic n equals 2815$ participants in the Agricultural Lung Health Study (2009–2013).

Asthma status	Residential wood burning exposure	$n$	$uppercase f e v begin subscript 1 end subscript$ (mL)^a	FVC (mL)^a	$uppercase f e v begin subscript 1 end subscript per uppercase f v c$ (%)^a
Noncase	Unexposed	1,378	Ref	Ref	Ref
Noncase	Some	145	1 ( $negative 80$ , 82)	37 ( $negative 62$ , 135)	$negative 0.2$ ( $negative 1$ , 1)
Noncase	Frequent	209	10 ( $negative 62$ , 82)	$negative 1$ ( $negative 87$ , 84)	$negative 0.2$ ( $negative 1$ , 0.8)
Case	Unexposed	839	Ref	Ref	Ref
Case	Some	105	$negative 14$ ( $negative 122$ , 95)	$negative 31$ ( $negative 153$ , 91)	$negative 0.3$ ( $negative 2$ , 2)
Case	Frequent	139	$negative 164$ ( $negative 261$ , $negative 66$ )	$negative 125$ ( $negative 230$ , $negative 20$ )	$negative 2$ ( $negative 4$ , $negative 0.4$ )
Case	$p_{i n t e r a c t i o n}$ ^b	—	0.0044	0.068	0.049

Note: —, not applicable; FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; Ref, reference: .

^{^a}

Regression coefficients (beta estimate and 95% confidence interval) representing the difference in mean response between participants exposed to wood burning vs. unexposed individuals, holding all covariates constant. Analyses conducted using sample weighted linear regression with wood $burning \times asthma$ interaction term. Models adjusted for age, $age begin superscript 2 end superscript$ , gender, height, $height begin superscript 2 end superscript$ , weight (for FVC only), race/ethnicity, state, smoking status, and pack-years. In parentheses, lower and upper bounds for 95% confidence intervals.

^{^b}

$p$ -Value for difference in the effect of frequent wood burning exposure by asthma status, from frequent wood $burning \times asthma$ case interaction product term, after accounting for main effects of wood burning exposure and asthma status.