Table 6. Correlations and regressions between duration of experience/exposure and pulmonary function test results.

	Correlation		Regression
Parameter	ρ coefficient	p‑value	Coefficient	p‑value	95% CI	Adjusted R2
FEV1 (L)	–0.560	<0.001*	–0.248	<0.000†	–0.355 - –140	0.371
FVC (L)	–0.437	<0.001*	–0.235	0.001†	–0.027 - 0.005	0.211
FEV1/FVC (%)	–0.498	<0.001*	–0.001	0.160	–0.027 - 0.005	0.226
PEFR (L/min)	–0.438	<0.001*	–29.768	0.001†	–46.685 - –12.851	0.204

CI = confidence interval

FEV₁ = forced expiratory volume in 1 second

FVC = forced vital capacity

PEFR = peak expiratory flow rate

* Significant (p<0.05) according to Spearman’s correlation.

^† Significant (p<0.05). The regression models were also adjusted for age and body mass index; however, duration of experience/exposure was the only significant variable