Table 2

Age-specific incidence (cases per thousand) of herpes zoster and trends, Massachusetts, 1999–2003

Year

Parameter

Age group in years

1–24

25–44

45–64

65+

All ages, crude

All ages, standardized ^a

1999

n^b

5655

4230

2214

911

13010

Cases

5

14

11

10

40

Incidence

0.87

1.87

4.82

6.9

2.23

2.77

95% CI

0.25–3.05

0.90–3.88

2.36–9.86

2.97–16.05

1.46–3.43

1.82–4.20

2000

n^b

3668

3449

2211

1121

10449

Cases

2

12

13

8

35

Incidence

0.46

3.74

6.45

6.45

3.57

3.54

95% CI

0.11–1.91

2.04–6.76

3.60–11.29

3.04–13.16

2.50–5.08

2.48–5.03

2002

n^b

3469

3234

2451

1303

10457

Cases

6

14

20

23

63

Incidence

1.70

5.13

7.42

20.03

6.51

6.47

95% CI

0.71–4.03

2.65–9.70

4.39–12.28

12.46–30.59

4.86–8.67

4.92–8.47

2003

n^b

3698

3260

2700

1278

10936

Cases

8

16

18

14

56

Incidence

2.19

4.88

6.79

11.74

5.38

5.25

95% CI

1.05–4.50

2.86–8.20

4.02–11.23

6.57–20.12

4.03–7.14

3.96–6.94

1999–2003

% change for period

152%

161%

41%

70%

141%

90%

p for trend test

0.10

0.03

0.42

0.03

0.0001

0.0009

^a Incidence is standardized using the standard 2000 U.S. population. The p-value is from age-adjusted analysis for trend using logistic regression.

^b N's exclude individuals for whom age or herpes zoster status was missing. The number excluded for these reasons was 1011, 513, 887, and 506 in 1999, 2000, 2002, and 2003, respectively. Values for n's and numbers of cases are unweighted, whereas incidence rates and 95% confidence intervals are based on weighted analysis.

Yih et al. BMC Public Health 2005 5:68   doi:10.1186/1471-2458-5-68