Study (dates)

Number of study subjects

Type A number

Type B number

Type C number

Type D number

Type E number

German, et al. [9] (1964-1974)

102

6

2

83

9

2

Sillen, et al. [10] (1967-1984)

110

7

1

100

1

1

Holder, et al. [11] (1973-1986)

100

2

1

85

6

6

Poenaru, et al. [12] (1969-1989)

95

8

0

80

1

6

Engum, et al. [3] (1971-1993)

227

29

2

178

5

13

Spitz, et al. [1] (1988-1994)

410

27

4

353

9

17

Total

1044

79 (8%)

10 (1%)

879 (84%)

31 (3%)

45 (4%)