Table 2.

Interactions for PM2.5 and Physical Activity on the Risk of Cardiovascular Disease Among 5‐Year Cancer Survivors

	Moderate‐to‐vigorous physical activity, times/wk
	0	1–2	3–4	≥5	Ptrend	Pinteraction
Cardiovascular disease						0.041
Low PM2.5
Events	220	52	49	92
Person‐y	27 561	10 021	9204	15 485
aHR (95% CI)	1.00 (reference)	0.91 (0.67–1.23)	0.82 (0.60–1.13)	0.77 (0.60–0.99)	0.028
High PM2.5
Events	247	62	60	138
Person‐y	27 283	10 128	8957	14 921
aHR (95% CI)	1.00 (reference)	0.88 (0.66–1.17)	0.86 (0.64–1.14)	0.98 (0.79–1.21)	0.711
Coronary heart disease						0.281
Low PM2.5
Events	93	31	23	48
Person‐y	27 561	10 021	9204	15 485
aHR (95% CI)	1.00 (reference)	1.27 (0.79–2.04)*	0.88 (0.52–1.49)*	0.91 (0.61–1.36)*	0.472
High PM2.5
Events	106	37	27	77
Person‐y	27 283	10 128	8957	14 921
aHR (95% CI)	1.00 (reference)	1.22 (0.79–1.89)*	0.89 (0.55–1.45)*	1.26 (0.89–1.77)*	0.229
Stroke						0.078
Low PM2.5
Events	127	21	26	44
Person‐y	27 561	10 021	9204	15 485
aHR (95% CI)	1.00 (reference)	0.64 (0.37–1.09)*	0.78 (0.48–1.27)*	0.67 (0.45–0.99)*	0.020
High PM2.5
Events	141	25	33	61
Person‐y	27 283	10 128	8957	14 921
aHR (95% CI)	1.00 (reference)	0.63 (0.39–1.03)*	0.84 (0.54–1.30)*	0.76 (0.53–1.08)*	0.090

aHR calculated by Cox proportional hazards regression after adjustments for age, sex, household income, area of residence, smoking, alcohol intake, body mass index, systolic blood pressure, fasting serum glucose, total cholesterol, and Charlson comorbidity index. PM2.5 range: low, 19.8–25.6 μg/m³; high, 25.8–33.8 μg/m³. MVPA determined by adding the frequency of moderate PA and vigorous PA per week, each ranging between 0–7 times per week. aHR indicates adjusted hazard ratio; MVPA, moderate‐to‐vigorous physical activity; and PM2.5, particulate matter with particles ≤2.5 µm.

^*95% CI calculated after Bonferroni correction (P<0.025 for significance).