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Supplemental Material 

Chronic (xposure to )ine 3articles and 0ortality: $n (xtended )ollow-8p of the Harvard Six Cities 

Study from 1974 to 2009 

Johanna Lepeule, Francine Laden, Douglas Dockery, Joel Schwartz. 

Table of contents: 

Supplemental Material, Table 1: Association between different PM2.5 moving averages and 

mortality among participants who survived at least 5 years after enrolment (n=7805 participants, 

180106 person-years 4209 deaths), Harvard Six Cities study, 1974-2009. 

Supplemental Material, Figure 1: The estimated concentration-response fonction and 95% 

confidence interval between PM2.5 and mortality in the Six Cities Study (1974-2009), using 

penalized splines. 
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Supplemental Material, Table 1: Association between different PM2.5 moving averages and 

mortality among participants who survived at least 5 years after enrolment (n=7805 participants, 

180106 person-years 4209 deaths), Harvard Six Cities study, 1974-2009. 

Cox regressiona

Poisson regressionb

Cause of 

death 

PM2.5 

moving 

average 

(years) 

Rate Ratio 

(95%CI) 

AIC Rate Ratio 

 (95%CI) 

AIC 

All-cause 1 1.15 (1.06-1.24) 31161.772 1.14 (1.05-1.23) 42347.57 

 1-2 1.15 (1.06-1.23) 31161.996 1.13 (1.05-1.22) 42347.94 

 1-3 1.14 (1.06-1.23) 31161.907 1.13 (1.05-1.21) 42347.92 

 1-4 1.13 (1.05-1.21) 31162.989 1.12 (1.04-1.20) 42348.95 

 1-5 1.13 (1.05-1.21) 31162.675 1.12 (1.04-1.20) 42348.74 

 

Cardiovascular 1 1.32 (1.17-1.48) 12369.478 1.31 (1.17-1.47) 19739.23 

1-2 1.31 (1.17-1.47) 12369.591 1.31 (1.17-1.46) 19739.20 

 1-3 1.30 (1.16-1.45) 12369.546 1.30 (1.16-1.45) 19739.16 

 1-4 1.29 (1.15-1.43) 12370.363 1.28 (1.15-1.43) 19740.06 

 1-5 1.28 (1.15-1.42) 12370.088 1.27 (1.15-1.41) 19739.84 

 

Lung 

cancer 

1 1.28 (0.97-1.69) 2229.420 1.38 (1.06-1.80) 4751.03 

1-2 1.29 (0.98-1.70) 2229.091 1.40 (1.07-1.82) 4750.41 

1-3 1.29 (0.99-1.69) 2229.013 1.39 (1.07-1.80) 4750.51 

 1-4 1.26 (0.97-1.64) 2229.490 1.35 (1.05-1.74) 4751.18 

 1-5 1.24 (0.96-1.61) 2229.696 1.33 (1.03-1.70) 4751.61 

 

COPD 1 1.18 (0.83-1.67) 1568.151 1.12 (0.81-1.56) 3600.23 

 1-2 1.18 (0.84-1.68) 1568.122 1.13 (0.81-1.58) 3600.20 

 1-3 1.16 (0.83-1.64) 1568.248 1.11 (0.80-1.54) 3600.32 

 1-4 1.17 (0.84-1.63) 1568.166 1.11 (0.81-1.53) 3600.28 

1-5 1.17 (0.85-1.62) 1568.105 1.11 (0.81-1.51) 3600.29

AIC: Akaike Information Criterion 

Results in bold are those with the lowest AIC value. 

a Cox proportional hazard model stratified by sex, age, and time in the study and adjusted for 

body mass index, education, and smoking history 

b Poisson survival analysis adjusted for sex, age, body mass index, education, smoking history, 

and time in the study (dummy variables for each year) 
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Supplemental Material, Figure 1: The estimated concentration-response fonction and 95% 

confidence interval between PM2.5 and mortality in the Six Cities Study (1974-2009), using 

penalized splines. Log hazard ratio

Log hazard ratio

10 15 20 25 30 35 40

Log hazard ratio

PM2.5 (μg/m3)-moving average 

1-3 years

10 15 20 25 30 35 40

PM2.5 (μg/m3)-lag 1

10 15 20 25 30 35 40

PM2.5 (μg/m3)-moving average 

1-3 years

All cause mortality Cardiovascular mortality

Lung cancer mortality