Table 5

Estimated incidence rates and relative risks for mild or greater AR. The number of expected cases were based on estimated incidence rates utilizing the pooled control (unexposed) groups of these studies. Relative risks and z statistics were calculated within each study.
Author, year
 Duration (months)
 "Incident" cases
 Expected cases
 p-value by Poisson
 Relative Risk (RR)
 Lower 95% CI of RR
 Upper 95% CI of RR
 z
 p-value
Khan, 1998
 26.5
 38.9
 1.939
 <0.00001
 59.5
 31.6
 112.1
 12.7
 <0.00001

4.9
 3.5
 0.086
 <0.00001
 69.1
 31.1
 153.4
 10.4
 <0.00001

9.0
 5.6
 0.125
 <0.00001
 108.0
 57.1
 204.4
 14.4
 <0.00001
Weissman, 1998
 2.4
 11.6
 0.696
 <0.00001
 15.3
 8.4
 27.9
 8.9
 <0.00001
Shively, 1999
 6.9
 9.3
 0.685
 <0.00001
 38.4
 18.9
 78.0
 10.1
 <0.00001
Hensrud, 1999
 9.6
 3.3
 0.075
 <0.00001
 7.8
 1.2
 51.8
 2.1
 0.016
Ryan, 1999
 16.7
 13
 0.600
 <0.00001
 -
 -
 -
 -
 -
Gardin, 2000
 2.0
 0.03
 0.042
 0.96
 0.7
 0.0
 61295
 -0.1
 0.52

4.5
 10.3
 0.226
 <0.00001
 47.8
 31.3
 73.0
 17.9
 <0.00001

9.0
 8.2
 0.459
 <0.00001
 18.8
 10.6
 33.3
 10.0
 <0.00001

15.0
 10.5
 0.563
 <0.00001
 19.5
 11.6
 32.9
 11.2
 <0.00001

22.0
 14.5
 0.816
 <0.00001
 18.7
 11.6
 30.0
 12.1
 <0.00001

2.0
 0
 0.080
 0.92
 0.0
 0.0
 -
 -0.3
 0.60

4.5
 7.5
 0.359
 <0.00001
 26.1
 15.0
 45.2
 11.6
 <0.00001

9.0
 16.2
 0.652
 <0.00001
 31.0
 20.6
 46.7
 16.5
 <0.00001

15.0
 2.8
 0.190
 0.0010
 18.5
 7.6
 45.1
 6.4
 <0.00001
Jollis, 2000
 2.0
 0.10
 0.022
 0.022
 5.1
 0.0
 1233
 0.6
 0.28

4.5
 2.8
 0.618
 0.026
 4.8
 1.6
 14.9
 2.8
 0.0029

9.0
 14.1
 1.638
 <0.00001
 9.3
 5.4
 15.9
 8.1
 <0.00001

18.0
 31.7
 2.486
 <0.00001
 13.8
 9.2
 20.6
 12.7
 <0.00001

30.0
 11.9
 1.131
 <0.00001
 11.4
 6.6
 19.7
 8.7
 <0.00001
Davidoff, 2001
 2.5
 5.0
 0.300
 <0.00001
 20.8
 9.9
 43.4
 8.1
 <0.00001
Summary, 2002
 8.78
 220.8
 14.01
 <0.00001
 19.6
 16.3
 23.5
 31.7
 <0.00001

Hopkins and Polukoff BMC Cardiovascular Disorders 2003 3:5   doi:10.1186/1471-2261-3-5