No. of MC

0

1

2

3

β + ve

193 (65)

67 (34)^*

12 (13)^†

9 (14)^†

β − ve

105 (35)

127 (66)^*

83 (87)^†

54 (86)^†

Total

298 (100)

194 (100)

95 (100)

63 (100)

β − ve/β + ve

0.65

1.9^*

6.7

6.2

RR ± CI^‡

3.0 ± 0.22^*

10.3 ± 0.77^†

9.5 ± 0.65^†