eAppendix
Child socioeconomic conditions (CHSEC) and oral cancer
1. Syntax:
Model 1: Total effect
TITLE "TOTAL EFFECT OF CHSEC";
PROC GENMOD DATA=OCMSM DESCENDING;
CLASS CENTRE;
MODEL CASE_I= OCCP_CH_C2 PAT_ALC/ DIST=BINOMIAL LINK=LOG;
REPEATED SUBJECT= CENTRE / TYPE= cs corrw covb;
RUN;
Model 2: Conventional regression
TITLE "ADJUSTED EFFECT";*USED POISSON BECAUSE THE MODEL WAS NOT CONVERGING
FOR DIST=BINOMIAL;
PROC GENMOD DATA=OCMSM DESCENDING;
CLASS CENTRE;
MODEL CASE_I= OCCP_CH_C2 PAT_ALC SMK_NSMK CHW_NCHW DRNK_NDRNK SELF_EDU_C2
OCCP_ADLT_C2 AGE_2 SEX / DIST=POISSON LINK=LOG;
REPEATED SUBJECT= CENTRE / TYPE= cs corrw covb;
RUN;
Model 4: Estimating CDE using marginal structural model
Estimating weight for child socioeconomic condition
Stabilized weight for CHSEC
TITLE "CALCULATING DENOMINATOR OF WEIGHT FOR CHSEC DEPENDENT ON PATERNAL
ALCOHOL";
PROC LOGISTIC DATA=CNTRLDTA DESCENDING OUTEST=PARAMS1;
MODEL OCCP_CH_C2= PAT_ALC ;STRATA CENTRE;
OUTPUT OUT=OCMSM P=PHAT;
RUN;
PROC LOGISTIC DATA=OCMSM DESCENDING INEST=PARAMS1;
MODEL OCCP_CH_C2= PAT_ALC ;STRATA CENTRE;
OUTPUT OUT=OCMSM P=PHAT;
RUN;
TITLE "CALCULATING NUMERATOR OF WEIGHT FOR CHSEC DEPENDENT ON PATERNAL
ALCOHOL";
PROC LOGISTIC DATA=CNTRLDTA DESCENDING OUTEST=PARAMS2;
MODEL OCCP_CH_C2=;
RUN;
PROC LOGISTIC DATA=OCMSM DESCENDING INEST=PARAMS2;
MODEL OCCP_CH_C2=;
OUTPUT OUT=OCMSM P=PHAT1;
RUN;
1
TITLE "CALCULATING STABILIZED WEIGHT FOR CHSEC";
DATA OCMSM;
SET OCMSM;
IF OCCP_CH_C2=1 THEN SW=PHAT1/PHAT;
ELSE IF OCCP_CH_C2=0 THEN SW=(1-PHAT1)/(1-PHAT);
RUN;
Stabilized weight for smoking
TITLE "CALCULATING DENOMINATOR OF WEIGHT FOR SMOKING";
PROC LOGISTIC DATA=CNTRLDTA DESCENDING OUTEST=PARAMS3;
MODEL SMK_NSMK= OCCP_CH_C2 SELF_EDU_C2 OCCP_ADLT_C2 AGE_2 SEX PAT_ALC
CHW_NCHW DRNK_NDRNK ;STRATA CENTRE;
RUN;
PROC LOGISTIC DATA=OCMSM DESCENDING INEST=PARAMS3;
MODEL SMK_NSMK= OCCP_CH_C2 SELF_EDU_C2 OCCP_ADLT_C2 AGE_2 SEX PAT_ALC
CHW_NCHW DRNK_NDRNK;
OUTPUT OUT=OCMSM P=PHAT2;STRATA CENTRE;
RUN;
TITLE "CALCULATING NUMERATOR OF WEIGHT FOR SMOKING";
PROC LOGISTIC DATA=CNTRLDTA DESCENDING OUTEST=PARAMS4;
MODEL SMK_NSMK=OCCP_CH_C2;STRATA CENTRE;
RUN;
PROC LOGISTIC DATA=OCMSM DESCENDING INEST=PARAMS4;
MODEL SMK_NSMK=OCCP_CH_C2 ;
OUTPUT OUT=OCMSM P=PHAT3;STRATA CENTRE;
RUN;
DATA OCMSM;
SET OCMSM;
IF SMK_NSMK=1 THEN SWS=PHAT3/PHAT2;
ELSE IF SMK_NSMK=0 THEN SWS=(1-PHAT3)/(1-PHAT2);
RUN;
DATA OCMSM;
SET OCMSM;
SW_SWS=SW*SWS;
RUN;
CDE of CHSEC controlled for smoking
TITLE "SMOKING CONTROLLED DIRECT EFFECT OF CHSEC-CLUSTER";
PROC GENMOD DATA=OCMSM DESCENDING;
CLASS CENTRE;WEIGHT SW_SWS;
MODEL CASE_I= OCCP_CH_C2 SMK_NSMK / DIST=BINOMIAL LINK=LOG;
REPEATED SUBJECT= CENTRE / type=cs corrw covb;
RUN;
Stabilized weight for chewing quid/alcohol
TITLE "CALCULATING DENOMINATOR OF WEIGHT FOR CHEWING";
PROC LOGISTIC DATA=CNTRLDTA DESCENDING OUTEST=PARAMS5;
2
MODEL CHW_NCHW=OCCP_CH_C2 SELF_EDU_C2 OCCP_ADLT_C2 AGE_2 SEX PAT_ALC SMK_NSMK
DRNK_NDRNK;STRATA CENTRE;
RUN;
PROC LOGISTIC DATA=OCMSM DESCENDING INEST=PARAMS5;
MODEL CHW_NCHW=OCCP_CH_C2 SELF_EDU_C2 OCCP_ADLT_C2 AGE_2 SEX PAT_ALC SMK_NSMK
DRNK_NDRNK;STRATA CENTRE;
OUTPUT OUT=OCMSM P=PHAT4;
RUN;
TITLE "CALCULATING NUMERATOR OF WEIGHT FOR CHEWING";
PROC LOGISTIC DATA=CNTRLDTA DESCENDING OUTEST=PARAMS6;
MODEL CHW_NCHW=OCCP_CH_C2;STRATA CENTRE;
RUN;
PROC LOGISTIC DATA=OCMSM DESCENDING INEST=PARAMS6;
MODEL CHW_NCHW=OCCP_CH_C2 ;STRATA CENTRE;
OUTPUT OUT=OCMSM P=PHAT5;
RUN;
DATA OCMSM;
SET OCMSM;
IF CHW_NCHW=1 THEN SWC=PHAT5/PHAT4;
ELSE IF CHW_NCHW=0 THEN SWC=(1-PHAT5)/(1-PHAT4);
SW_SWC=SW*SWC;
RUN;
CDE of CHSEC controlled for chewing
TITLE "CHEWING CONTROLLED DIRECT EFFECT OF CHSEC-CLUSTER";
PROC GENMOD DATA=OCMSM DESCENDING;
CLASS CENTRE ;WEIGHT SW_SWC;
MODEL CASE_I= OCCP_CH_C2 CHW_NCHW / DIST=BINOMIAL LINK=LOG;
REPEATED SUBJECT= CENTRE / type=cs corrw covb;
RUN;
Stabilized weight for alcohol
TITLE "CALCULATING DENOMINATOR OF WEIGHT FOR ALCOHOL";
PROC LOGISTIC DATA=CNTRLDTA DESCENDING OUTEST=PARAMS7;
MODEL DRNK_NDRNK= OCCP_CH_C2 SELF_EDU_C2 OCCP_ADLT_C2 AGE_2 SEX PAT_ALC
CHW_NCHW SMK_NSMK;STRATA CENTRE;
RUN;
PROC LOGISTIC DATA=OCMSM DESCENDING INEST=PARAMS7;
MODEL DRNK_NDRNK= OCCP_CH_C2 SELF_EDU_C2 OCCP_ADLT_C2 AGE_2 SEX PAT_ALC
CHW_NCHW SMK_NSMK;STRATA CENTRE;
OUTPUT OUT=OCMSM P=PHAT6 ;
RUN;
TITLE "CALCULATING NUMERATOR OF WEIGHT FOR ALCOHOL";
PROC LOGISTIC DATA=CNTRLDTA DESCENDING OUTEST=PARAMS8;
MODEL DRNK_NDRNK=OCCP_CH_C2;STRATA CENTRE;
RUN;
3
PROC LOGISTIC DATA=OCMSM DESCENDING INEST=PARAMS8;
MODEL DRNK_NDRNK=OCCP_CH_C2 ;STRATA CENTRE;
OUTPUT OUT=OCMSM P=PHAT7;
RUN;
DATA OCMSM;
SET OCMSM;
IF DRNK_NDRNK=1 THEN SWA=PHAT7/PHAT6;
ELSE IF DRNK_NDRNK=0 THEN SWA=(1-PHAT7)/(1-PHAT6);
SW_SWA=SW*SWA;
RUN;
CDE of CHSEC controlled for alcohol
TITLE "ALCOHOL CONTROLLED DIRECT EFFECT OF CHSEC-CLUSTER";
PROC GENMOD DATA=OCMSM DESCENDING;
CLASS CENTRE; WEIGHT SW_SWA;
MODEL CASE_I= OCCP_CH_C2 DRNK_NDRNK/ DIST=BINOMIAL LINK=LOG;
REPEATED SUBJECT= CENTRE / type=cs corrw covb;
RUN;
CDE of CHSEC controlled for smoking, chewing and alcohol (Final model)
Final tabilized weights
DATA OCMSM;
SET OCMSM;
SWSCA=.;
SWSCA=SW*SWS*SWC*SWA;
RUN;
TITLE "CONTROLLED DIRECT EFFECT OF CHSEC-CONTROLLED FOR SMOKING, CHEWING AND
ALCOHOL";
PROC GENMOD DATA=OCMSM DESCENDING;
CLASS CENTRE; WEIGHT SWSCA;
MODEL CASE_I= OCCP_CH_C2 SMK_NSMK CHW_NCHW DRNK_NDRNK/ DIST=BINOMIAL
LINK=LOG;
REPEATED SUBJECT= CENTRE / type=cs corrw covb;
RUN;
Additive interaction on risk ratio scale:
Interaction between CHSEC and smoking:
TITLE "RERI CHSEC SMK ON RR SCALE";
PROC NLMIXED DATA=OCMSM;
4
*LOGISTIC REGRESSION MODEL;
ODDS = EXP(B0 +B1*OCCP_CH_C2 + B2*SMK_NSMK + B3*OCCP_CH_C2*SMK_NSMK);
PI = ODDS/(1+ODDS);
MODEL CASE_I~BINARY(PI);
ESTIMATE 'P00' EXP(B0)/(1+EXP(B0));
ESTIMATE 'P01' EXP(B0+B1)/(1+EXP(B0+B1));
ESTIMATE 'P10' EXP(B0+B2)/(1+EXP(B0+B2));
ESTIMATE 'P11' EXP(B0+B1+B2+B3)/(1+EXP(B0+B1+B2+B3));
ESTIMATE 'ICR= RERI USING RR = P11/P00 - P10/P00 - P01/P00 + 1'
EXP(B0+B1+B2+B3)/(1+EXP(B0+B1+ B2+B3))/ (EXP(B0)/(1+EXP(B0)))
- EXP(B0+B2)/(1+EXP(B0+B2))/ (EXP(B0)/(1+EXP(B0)))
- EXP(B0+B1)/(1+EXP(B0+B1)) / (EXP(B0)/(1+EXP(B0))) + 1;
REPLICATE SW_SWS;
RUN;
Interaction between CHSEC and chewing;
TITLE "RERI CHSEC CHW ON RR SCALE";
PROC NLMIXED DATA=OCMSM;
*LOGISTIC REGRESSION MODEL;
ODDS = EXP(B0 +B1*OCCP_CH_C2 + B2*CHW_NCHW + B3*OCCP_CH_C2*CHW_NCHW);
PI = ODDS/(1+ODDS);
MODEL CASE_I~BINARY(PI);
ESTIMATE 'P00' EXP(B0)/(1+EXP(B0));
ESTIMATE 'P01' EXP(B0+B1)/(1+EXP(B0+B1));
ESTIMATE 'P10' EXP(B0+B2)/(1+EXP(B0+B2));
ESTIMATE 'P11' EXP(B0+B1+B2+B3)/(1+EXP(B0+B1+B2+B3));
ESTIMATE 'ICR= RERI USING RR = P11/P00 - P10/P00 - P01/P00 + 1'
EXP(B0+B1+B2+B3)/(1+EXP(B0+B1+ B2+B3))/ (EXP(B0)/(1+EXP(B0)))
- EXP(B0+B2)/(1+EXP(B0+B2))/ (EXP(B0)/(1+EXP(B0)))
- EXP(B0+B1)/(1+EXP(B0+B1)) / (EXP(B0)/(1+EXP(B0))) + 1;
REPLICATE SW_SWC;
RUN;
Interaction between CHSEC and alcohol
TITLE "RERI CHSEC ALC ON RR SCALE";
PROC NLMIXED DATA=OCMSM;
*LOGISTIC REGRESSION MODEL;
ODDS = EXP(B0 +B1*OCCP_CH_C2 + B2*DRNK_NDRNK + B3*OCCP_CH_C2*DRNK_NDRNK);
PI = ODDS/(1+ODDS);
MODEL CASE_I~BINARY(PI);
ESTIMATE 'P00' EXP(B0)/(1+EXP(B0));
ESTIMATE 'P01' EXP(B0+B1)/(1+EXP(B0+B1));
ESTIMATE 'P10' EXP(B0+B2)/(1+EXP(B0+B2));
ESTIMATE 'P11' EXP(B0+B1+B2+B3)/(1+EXP(B0+B1+B2+B3));
ESTIMATE 'ICR= RERI USING RR = P11/P00 - P10/P00 - P01/P00 + 1'
EXP(B0+B1+B2+B3)/(1+EXP(B0+B1+ B2+B3))/ (EXP(B0)/(1+EXP(B0)))
- EXP(B0+B2)/(1+EXP(B0+B2))/ (EXP(B0)/(1+EXP(B0)))
- EXP(B0+B1)/(1+EXP(B0+B1)) / (EXP(B0)/(1+EXP(B0))) + 1;
REPLICATE SW_SWA;
RUN;
Multiplicative interaction on risk ratio scale
5
CHSEC and smoking;
TITLE "INTERACTION B/W CHSEC*SMOKING";
PROC GENMOD DATA=OCMSM DESCENDING;
CLASS CENTRE ;WEIGHT SW_SWS;
MODEL CASE_I= OCCP_CH_C2 SMK_NSMK OCCP_CH_C2*SMK_NSMK / DIST=BINOMIAL
LINK=LOG;
REPEATED SUBJECT= CENTRE / type=cs corrw covb;
RUN;
CHSEC and chewing;
TITLE " INTERACTION B/W CHSEC*CHEWING";
PROC GENMOD DATA=OCMSM DESCENDING;
CLASS CENTRE ;WEIGHT SW_SWC;
MODEL CASE_I= OCCP_CH_C2 CHW_NCHW OCCP_CH_C2*CHW_NCHW / DIST=BINOMIAL
LINK=LOG;
REPEATED SUBJECT= CENTRE / type=cs corrw covb;
RUN;
CHSEC and alcohol;
TITLE " INTERACTION B/W CHSEC*ALCOHOL";
PROC GENMOD DATA=OCMSM DESCENDING;
CLASS CENTRE ;WEIGHT SW_SWA;
MODEL CASE_I= OCCP_CH_C2 DRNK_NDRNK OCCP_CH_C2*DRNK_NDRNK/ DIST=BINOMIAL
LINK=LOG;
REPEATED SUBJECT= CENTRE / type=cs corrw covb;
RUN;
6
2. Tables
eTable 1 Joint distribution of Child SEC (CHSEC) and Smoking among cases and controls
Cases (n)
64
76
11
26
CHSEC1 SMOKING1
CHSEC1SMOKING0
CHSEC0SMOKING1
CHSEC0SMOKING0
Controls (n)
39
131
15
87
eTable 2 RERI between child SEC and smoking
‡
Estimate
Parameter
Parameter Estimates
Standard DF t Value
Error
Pr > |t|
Alpha
Lower
Upper
b0
b1
b2
b3
-1.01
0.46
0.84
0.30
0.21
0.26
0.56
0.64
433
433
433
433
-4.76
1.78
1.50
0.47
<.0001
0.076
0.135
0.638
0.05
0.05
0.05
0.05
-1.42
-0.05
-0.26
-0.95
-0.59
0.97
1.94
1.55
p00
p01
p10
p11
0.27
0.37
0.46
0.64
0.04
0.03
0.13
0.06
433
433
433
433
6.44
10.71
3.55
10.81
<0.001
<0.001
<0.001
<0.001
0.05
0.05
0.05
0.05
0.19
0.30
0.20
0.53
0.349
0.433
0.712
0.760
RERI using RR = p11/p00 p10/p00 - p01/p00 + 1
0.32
0.56
433
0.58
0.561
0.05
-0.77
1.420
Z
Pr> |Z|
-6.40
3.97
7.52
0.60
<.0001
<.0001
<.0001
0.5480
‡Beta estimates for CHSEC =b1, Smoking =b2 and CHSEC*Smoking =b3
eTable 3 Multiplicative interaction between child SEC and smoking
Parameter
Intercept
Child SEC
Smoking
Child SEC*Smoking
Estimate
-1.3352
0.3211
0.5363
0.0319
Standard
Error
0.2085
0.0809
0.0714
0.0531
7
95% CI
-1.7439
0.1625
0.3965
-0.0722
-0.9264
0.4796
0.6762
0.1360
eTable 4 Joint distribution of CHSEC and Chewing quid/tobacco (CHEWING) among
cases and controls
Cases (n)
101
39
20
17
CHSEC1 CHEWING1
CHSEC1 CHEWING0
CHSEC0 CHEWING1
CHSEC0 CHEWING0
Controls (n)
50
120
13
89
eTable 5 RERI between Child SEC and Chewing
‡
Estimate
Parameter
Parameter Estimates
Standard
DF t Value
Error
0.25
433
-5.82
0.31
433
1.02
0.44
433
3.93
0.51
433
0.19
Pr > |t|
Alpha
Lower
Upper
<.0001
0.307
<.0001
0.851
0.05
0.05
0.05
0.05
-1.94
-0.29
0.87
-0.91
-0.96
0.93
2.60
1.10
b0
b1
b2
b3
-1.45
0.32
1.73
0.10
p00
p01
p10
p11
0.19
0.24
0.57
0.67
0.04
0.03
0.09
0.04
433
433
433
433
4.97
7.07
6.41
17.03
<.001
<.001
<.001
<.001
0.05
0.05
0.05
0.05
0.12
0.18
0.40
0.59
0.27
0.31
0.75
0.74
RERI using RR = p11/p00 p10/p00 - p01/p00 + 1
0.23
0.56
433
0.4
0.687
0.05
-0.88
1.33
‡
Beta estimates for CHSEC =b1, Chewing =b2 and CHSEC*Chewing =b3
eTable 6 Multiplicative interaction between child SEC and chewing
Parameter
Intercept
Child SEC
Chewing
Child SEC*Chewing
Estimate
-1.6769
0.2938
1.1284
-0.1447
Standard
Error
0.4652
0.3261
0.6989
0.6011
95% CI
-2.5887
-0.3453
-0.2414
-1.3228
-0.7651
0.9330
2.4982
1.0334
eTable 7 Joint distribution of CHSEC and alcohol among cases and controls
8
Z
Pr> |Z|
-3.60
0.90
1.61
-0.24
0.0003
0.3676
0.1064
0.8098
CHSEC1ALCOHOL1
CHSEC1ALCOHOL0
CHSEC0ALCOHOL1
CHSEC0ALCOHOL0
Cases (n)
74
66
19
18
Controls (n)
43
127
14
88
eTable 8 RERI between Child SEC and Alcohol
Parameter‡
Estimate
Parameter Estimates
Standard
DF
t Value
Error
0.28
433
-6.32
0.32
433
3.99
0.55
433
3.68
0.61
433
-1.32
Pr > |t|
Alpha
Lower
Upper
<0.001
<0.001
<0.001
0.187
0.05
0.05
0.05
0.05
-2.34
0.65
0.94
-2.00
-1.23
1.91
3.08
0.39
b0
b1
b2
b3
-1.78
1.28
2.01
-0.81
p00
p01
p10
p11
0.14
0.38
0.56
0.67
0.04
0.04
0.12
0.05
433
433
433
433
4.14
10.63
4.83
13.32
<.001
<.001
<.001
<.001
0.05
0.05
0.05
0.05
0.08
0.31
0.33
0.57
0.21
0.45
0.78
0.77
RERI using RR =
p11/p00 - p10/p00 p01/p00 + 1
-0.84
1.01
433
-0.83
0.668
0.05
-2.82
1.15
‡
Beta estimates for CHSEC=b1, Alcohol=b2 and CHSEC*Alcohol=b3
eTable 9 Multiplicative interaction between child SEC and alcohol
Parameter
Intercept
Child SEC
Alcohol
Child SEC*Alcohol
Estimate
-1.9427
0.9673
1.3365
-0.7733
Standard
Error
0.3528
0.1747
0.3917
0.2662
9
95% CI
-2.6342
0.6250
0.5687
-1.2950
-1.2513
1.3097
2.1043
-0.2515
Z
Pr> |Z|
-5.51
5.54
3.41
-2.90
<.0001
<.0001
0.0006
0.0037
eTable 10 Sensitivity analysis for unmeasured confounding considering three estimates of
controlled direct effect (CDE) of early-life socioeconomic condition (SEC) on oral cancer
Sensitivity analysis for unmeasured
confounder that would invalidate
CDE not mediated by smoking
𝜸1a P11b P21c P11-P21d RR1e
Sensitivity analysis for unmeasured
confounder that would invalidate
CDE not mediated by chewing
𝜸2f P12g P22h P12-P22i RR2j
Sensitivity analysis for unmeasured
confounder that would invalidate
CDE not mediated by drinking
𝜸3k P13l P23m P13-P23n RR3
o
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
0.50
0.51
0.52
0.53
0.55
0.62
0.77
0.90
0.27
0.28
0.30
0.31
0.39
0.53
0.68
0.83
0.02
0.03
0.03
0.04
0.05
0.10
0.20
0.29
0.02
0.03
0.04
0.05
0.11
0.20
0.30
0.40
0.48
0.48
0.49
0.49
0.50
0.52
0.57
0.61
0.25
0.25
0.26
0.26
0.28
0.33
0.38
0.43
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
4
4
4
4
4
4
4
4
4
4
-
0.19
0.20
0.21
0.22
0.24
0.31
0.46
0.60
0.75
0.90
-
0.02
0.03
0.04
0.04
0.06
0.10
0.21
0.30
0.40
0.50
-
0.17
0.17
0.17
0.18
0.18
0.21
0.25
0.30
0.35
0.40
-
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
-
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
4
0.26
0.27
0.28
0.30
0.36
0.48
0.61
0.60
0.14
0.15
0.16
0.17
0.18
0.24
0.37
0.49
0.61
0.74
0.86
0.11
0.11
0.12
0.13
0.14
0.20
0.33
0.45
0.57
0.70
0.82
0.02
0.03
0.04
0.05
0.10
0.20
0.30
0.30
0.02
0.03
0.04
0.04
0.05
0.10
0.21
0.30
0.40
0.50
0.60
0.03
0.03
0.04
0.04
0.05
0.10
0.21
0.30
0.40
0.50
0.60
0.24
0.24
0.24
0.25
0.26
0.28
0.31
0.30
0.12
0.12
0.12
0.13
0.13
0.14
0.16
0.19
0.21
0.24
0.26
0.08
0.08
0.08
0.09
0.09
0.10
0.12
0.15
0.17
0.20
0.22
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
3
3
3
3
3
3
3
4
4
4
4
4
4
4
-
0.51
0.52
0.53
0.55
0.57
0.66
0.86
0.35
0.36
0.37
0.39
0.41
0.70
0.90
-
0.02
0.03
0.03
0.04
0.05
0.10
0.20
0.02
0.03
0.03
0.04
0.05
0.20
0.31
-
Note: Bias formula for CDE given by VanderWeeleTJ48 was used by specifying sensitivity parameters 𝛾, P1 and P2 to calculate RR;
a 𝛾1 = conditional increase in the risk for oral cancer when smoking is the mediator in model 4;
b P11= prevalence in smokers; c P21= prevalence in non-smokers; d P11-P21= Calculated differences in the probability of U;
e RR1 = direct effect of child SEC controlled for smoking;
f 𝛾2 = conditional increase in the risk for oral cancer when chewing is the mediator in model 4;
g P12= prevalence in chewers; h P22= prevalence in non-chewers; i P12-P22= Calculated differences in the probability of U ;
j RR2 = direct effect of child SEC controlled for chewing;
10
0.49
0.49
0.50
0.51
0.52
0.56
0.66
0.33
0.33
0.34
0.35
0.36
0.50
0.59
-
1.9
1.9
1.9
1.9
1.9
1.9
1.9
1.9
1.9
1.9
1.9
1.9
1.9
1.9
-
k 𝛾3 = conditional increase in the risk for oral cancer when drinking is the mediator in model 4;
l P13= prevalence in drinkers; m P23 = prevalence in non-drinkers; n P13-P23= Calculated differences in the probability of U;
o RR3 = direct effect of child SEC controlled for drinking;
eTable 11 Naive and Misclassification-corrected mediation analysis in the absence of
mediator exposure interaction (Specificity = (0.75, 0.80, 0.85, 0.90, 0.95), Sensitivity = (0.75,
0.80, 0.85, 0.90, 0.95)), 95%CI obtained from bootstrap, effects not adjusted for clustering.
Estimates (95%CI)
Naïve
CDEc (M= Smoking)b
1.38 (1.02-1.86)
CDEc (M=Alcohol)b
1.89 (1.30-2.75)
CDEc (M=Chewing)b
1.21 (0.92-1.59)
SP=SN=0.95a
1.35 (0.98-1.82)
1.86 (1.24-2.75)
1.20 (0.90-1.56)
SP=SN=0.90 a
1.33 (0.97-1.84)
1.84 (1.27-2.70)
1.19 (0.90-1.52)
SP=SN=0.85 a
1.32 (0.98-1.84)
1.83 (1.27-2.70)
1.19 (0.90-1.52)
SP=SN=0.80 a
1.31 (0.95-1.87)
1.82 (1.26-2.70)
1.19 (0.87-1.51)
SP=SN=0.75 a
1.29 (0.95-1.79)
1.82 (1.26-2.70)
1.17 (0.87-1.54)
a
SP indicates Specificity and SN indicates Sensitivity
M indicates mediator
c
CDE indicates controlled direct effect
b
11
3. Life grid
The life grid method was developed by Blane (1996) and validated by Berney and Blane (1997). It is very
useful in collecting life-course information by recalling where cross-referencing with personal life events
or historical events act as triggers in temporal referencing. In the present study, there were 12 columns in
the life grid chart, arranged from left to right in order: year, external events, age, life events, area of
residence, occupation, income, diet, smoking, Smokeless tobacco, quid and alcohol use. Crossreferencing each of the aspects along the columns with the participant’s own life events (marriage, birth
of a child, death of a family member) and major external events during their lifetime (for example
political events, a natural disaster) were used as triggers to improve the accuracy in recall (Blane, 1996;
Berney and Blane, 2003). Initially changes in residential areas, occupational, dietary and behavioural
histories were recorded with a life-grid that was later utilised as a guide throughout the structured part of
the interview to keep a track of the timeline. Below is an example of the life grid used in the study.
12
ವರ್ಷ
ಬಾಹ್ಯ ಘಟನೆಗಳು
ವಯಸ್ಸು
ಜೀವನದ ಘಟನೆಗಳು ವಾಸ್ಸ್ಥಳ
ಉದೆ್ಯೀಗ
ಆದಾಯ
Year
1930
1931
External events
Age
Life events
Born
Occupation
Income
1940
1947
Indian independence
1950
1960
1962
1970
1980
1984
Married
Drought
Assasination of
Indira Gandhi
1990
2000
2010
13
Residence
ವರ್ಷ
ಆಹಾರ
ಧೂಮಪಾನ
ತಂಬಾಕು
Year
1930
Diet
Smoking
Smokeless tobaccoQuid
1940
1950
1960
1970
1980
1990
2000
2010
14
ಎಲೆ-ಅಡಿಕೆ
ಮದ್ಯಪಾನ
Alcohol