Type of cigarette smoked
|
Statisticb
|
All lung cancerc
|
Squamousd
|
Adenoe
|
---|
Only filter vs. only plainf
|
n
|
42
|
13
|
10
|
|
F
|
0.67 (0.64-0.72)
|
0.58 (0.52-0.64)
|
0.88 (0.75-1.03)
|
|
R
|
0.69 (0.61-0.78)
|
0.52 (0.40-0.68)
|
0.84 (0.66-1.08)
|
|
H, PH
|
3.18, p < 0.001
|
4.73, p < 0.001
|
1.90, p < 0.05
|
Ever filter vs. only plaing
|
n
|
42
|
11
|
10
|
|
F
|
0.79 (0.75-0.83)
|
0.85 (0.79-0.91)
|
1.00 (0.89-1.12)
|
|
R
|
0.73 (0.65-0.82)
|
0.55 (0.41-0.74)
|
0.99 (0.84-1.16)
|
|
H, PH
|
3.60, p < 0.001
|
7.73, p < 0.001
|
1.35, NS
|
Only filter vs. ever plainh
|
n
|
42
|
13
|
10
|
|
F
|
0.67 (0.63-0.71)
|
0.87 (0.81-0.92)
|
1.05 (0.93-1.18)
|
|
R
|
0.70 (0.62-0.78)
|
0.69 (0.57-0.83)
|
0.98 (0.80-1.21)
|
|
H, PH
|
3.30, p < 0.001
|
3.15, p < 0.001
|
1.88, p < 0.05
|
Handrolled vs. manufacturedi
|
n
|
20
|
5
|
4
|
|
F
|
1.27 (1.16-1.40)
|
1.47 (1.24-1.76)
|
2.12 (1.53-2.96)
|
|
R
|
1.29 (1.12-1.49)
|
1.62 (1.18-2.21)
|
2.09 (0.83-5.25)
|
|
H, PH
|
1.81, p < 0.05
|
2.61, p < 0.05
|
6.54, p < 0.001
|
Mentholated vs. non-mentholated
|
n
|
6
|
1
|
1
|
|
F
|
0.99 (0.86-1.14)
|
1.04 (0.75-1.44)
|
0.96 (0.73-1.27)
|
|
R
|
0.98 (0.80-1.20)
|
1.04 (0.75-1.44)
|
0.96 (0.73-1.27)
|
|
H, PH
|
1.89, p < 0.1
|
NA
|
NA
|
-
a Within each study, results for the relevant smoking product and smoking status are selected in the following preference order, within each sex, for:
- cigarette type – see notes f to i;
- unexposed group – see notes f to i;
- smoking product – any, cigarettes (ignoring other products), cigarettes only;
- smoking status – ever, current;
- lung cancer type – see notes c to e;
- race – all or nearest available, otherwise by race;
- follow-up period – longest available;
- overlapping studies – principal, subsidiary;
- age – whole study, widest available age group;
- Results are then selected for:
- sex – single sex results, combined sex results;
- adjustment for potential confounders – most available.
-
b n = number of estimates combined, F = fixed-effect meta-analysis RR (95% CI), R = random-effects meta-analysis RR (95% CI), H = heterogeneity chisquared per degree of freedom, PH = probability value for heterogeneity expressed as p < 0.001, p < 0.05, p < 0.1 or NS (p ≥ 0.1), PB = probability value for between levels (see Methods) similarly expressed.
-
c All or nearest available, must include at least squamous cell carcinoma and adenocarcinoma.
-
d Squamous cell carcinoma or nearest available, but not including adenocarcinoma.
-
e Adenocarcinoma or nearest available, but not including squamous cell carcinoma.
-
f Or nearest available.
- Preference order for cigarette type – filter only/NOS, always, mainly, both, equally, ever.
- Preference order for comparison group – plain only/NOS, always, mainly, ever.
-
g Or nearest available.
- Preference order for cigarette type – filter ever, equally, both, mainly, always, only/NOS.
- Preference order for comparison group – plain only/NOS, always, mainly, ever.
-
h Or nearest available.
- Preference order for cigarette type – filter only/NOS, always, mainly, both, equally, ever.
- Preference order for comparison group – plain ever, mainly, always, only/NOS.
-
i Preference order for cigarette type – handrolled any, both, mainly, only.
- Preference order for comparison group – manufactured only ever, only current, any, ever.