Table 3 Relative risk (RR) and 95% confidence interval (CI) of NPC for males and females by age-period-cohort analysis in Sihui County, Guangdong Province, South China

Age (years)

30-34

1.00 (Ref)

1.00 (Ref)

35-39

1.64

1.24–2.20

2.25

1.59–3.23

40-44

2.73

2.05–3.68

3.08

2.07–4.71

45-49

3.21

2.36–4.45

3.08

1.93–5.23

50-54

3.60

2.53–5.28

5.00

2.93–9.48

55-59

4.15

2.75–6.51

6.82

3.65–14.77

60-64

3.52

2.16–6.04

5.74

2.68–14.57

65-69

2.89

1.60–5.49

5.62

2.31–16.65

70-74

2.90

1.41–6.26

5.31

2.55–15.00

Period

1987-1991

1.00 (Ref)

1.00 (Ref)

1992-1996

1.01

0.80–1.28

0.92

0.68–1.26

1997-2001

0.93

0.70–1.23

0.77

0.51–1.14

2002-2006

0.89

0.63–1.25

0.56

0.33–0.92

2007-2011

1.01

0.68–1.45

0.59

0.31–1.01

Cohort

1920-1924

0.58

0.26–1.24

0.62

0.25–1.45

1925-1929

1.05

0.62–1.77

0.53

0.26–1.06

1930-1934

0.97

0.64–1.47

0.59

0.34–1.00

1935-1939

1.12

0.82–1.55

0.56

0.36–0.87

1940-1944

1.00 (Ref)

1.00 (Ref)

1945-1949

1.18

0.91–1.54

1.10

0.77–1.58

1950-1954

1.36

1.03–1.79

1.54

1.06–2.30

1955-1959

1.38

1.02–1.91

1.53

0.97–2.56

1960-1964

1.27

0.88–1.89

1.39

0.79–2.69

1965-1969

1.18

0.75–1.89

1.75

0.90–3.89

1970-1974

1.23

0.73–2.17

2.40

1.11–6.14