Table 7 The output size of the original and simplified Boolean queries in the drug collection after re-running on Ovid MEDLINE (1950 - Week 3, Nov 2008).

1

2,153

1,986

29,074

15,027

7,654

2

1,378

1,347

120,420

111,653

1,596

3

101

101

1,857

1,799

1,568

4

994

897

12,857

11,924

81,371

5

1,526

1,343

63,494

53,319

8,093

6

276

276

159,772

153,121

36,686

7

1,200

1,117

109,584

104,743

308,329

8

309

230

106,154

81,018

64,704

9

1,464

1,464

41,544

35,618

17,686

10

64

64

2,260

2,205

243,733

11

930

540

6,420

6,172

23,896

12

140

140

3,215

3,058

1,599

13

5,578

5,378

21,332

20,588

13,491

14

1,969

1,782

39,446

36,487

24,230

15

997

997

9,859

9,568

5,189