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Statistical Methods in Medical Research 4ed

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Table 19.5 Comb<strong>in</strong>ation of relative risks from 10 retrospective surveys on smok<strong>in</strong>g and lung cancer (Cornfield, 1956; Gart 1962).<br />

Study<br />

number<br />

Lung cancer<br />

patients Control patients<br />

Smokers<br />

ai<br />

Nonsmokers<br />

bi<br />

Smokers<br />

ci<br />

Nonsmokers<br />

di ^c i ln ^c i<br />

Woolf 's method Mantel±Haenszel<br />

(1)<br />

1=ai ‡<br />

1=bi ‡<br />

1=ci ‡<br />

1=di<br />

wi ˆ 1<br />

…1† wi ln ^c i ni aidi=ni bici=ni E…ai† var…ai†<br />

1 83 3 72 14 5 38 1 683 0 4307 2 3 3 87 172 6 756 1 256 77 50 3 85<br />

2 90 3 227 43 5 68 1 737 0 3721 2 7 4 69 363 10 661 1 876 81 21 7 68<br />

3 129 7 81 19 4 32 1 463 0 2156 4 6 6 73 236 10 386 2 403 121 02 5 67<br />

4 412 32 299 131 5 64 1 730 0 0447 22 4 38 75 874 61 753 10 947 361 19 33 18<br />

5 1350 7 1296 61 9 08 2 206 0 1608 6 2 13 68 2714 30 343 3 343 1323 00 16 58<br />

6 60 3 106 27 5 09 1 627 0 3965 2 5 4 07 196 8 265 1 622 53 36 5 57<br />

7 459 18 534 81 3 87 1 353 0 0720 13 9 18 81 1092 34 047 8 802 433 76 22 17<br />

8 499 19 462 56 3 18 1 157 0 0747 13 4 15 50 1036 26 973 8 473 480 50 17 41<br />

9 451 39 1729 636 4 25 1 447 0 0300 33 3 48 19 2855 100 468 23 619 374 15 73 30<br />

10 260 5 259 28 5 62 1 726 0 2434 4 1 7 08 522 13 188 2 346 249 16 7 76<br />

Total 3793 136 5065 1096 105 4 161 37 302 840 64 687 3554 85 193 17<br />

19.5 Relative risk 679

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