Table 5.

Effect modification of the association of cumulative average fine particulate matter (PM_2.5) ≥ 12µg/m³ and mortality among adolescent and young adult cancer patients by stage at diagnosis

	1 year post-diagnosis			5 years post-diagnosis			10 years post-diagnosis
	HR	95% CI	Joint test p-value	HR	95% CI c	Joint test p-value	HR	95% CI	Joint test p-value
Cancer mortality
Local	1.15	0.82–1.60	<0.001c	1.44b	1.29–1.61	<0.001c	1.44b	1.24–1.66	<0.0001c
Regional	1.46	0.95–2.25		1.25b	1.04–1.49		1.07	0.96–1.19
Distant	0.95	0.78–1.16		1.09	0.93–1.26		1.16b	1.03–1.30
Unstaged	0.62b	0.45–0.87		0.82	0.57–1.18		0.88	0.67–1.17
All-cause mortality
Local	1.30	0.92–1.83	<0.001c	1.54b	1.37–1.73	<0.001c	1.43b	1.22–1.67	<0.0001c
Regional	1.63b	1.05–2.53		1.32b	1.09–1.60		1.17b	1.03–1.32
Distant	0.89	0.75–1.05		1.05	0.85–1.29		1.11	0.94–1.32
Unstaged	0.78	0.55–1.10		1.05	0.75–1.48		1.06	0.80–1.41

HR=hazard ratio; 95% CI=95% confidence interval; Models used 5- and 10-year average PM_2.5 for all residential ZIP codes categorized by EPA yearly standard of 12 µg/m³ PM_2.5; 95% confidence interval ratio is ≤2 for all analyses; Models adjusted for sex, age at diagnosis, race/ethnicity, census tract SES at diagnosis clustered by county; Separate baseline hazard for cancer type included, leukemias excluded from this analysis; Estimates rounded to the nearest hundredth;

^aHazard ratios significant if null value not included in the 95% CI;

^bRatio of upper-to-lower 95% confidence interval is ≥3;

^cp-value for effect modification significant at p<0.05.