Laura C . Rodrigues, Jonathan A . C . Sterne, Ines Nobre Guedes
D oes the efficacy of
B e G
decrease w ith tim e
since vaccination? A m eta analyis
E stim a te s o f th e p ro te c tiv e e ffic a c y o f B C G v a c c in a tio n (B C G P E ) a g a in st tu b e rc u lo sis fro m d iffe re n t stu d ie s ra n g e fro m n e g a tiv e to o v e r 9 0 % . T h e se e stim a te s a re h e te ro g e n o u s to a sta -tistic a lly sig n ific a n t d e g re e . T h is stu d y in v e stig a te s th e h y p o th e sis
th a t B C G P E d e c re a se s w ith tim e sin c e v a c c in a tio n , b y p e rfo rm -in g a m e ta -a n a lisy s o f th e c h a n g e -in B C G -P E a g a -in st tu b e rc u lo sis o v e r tim e o b se rv e d in a ll n in e ra n d o rn ise d c o n tro lle d tria ls w h ic h p re se n te d d a ta se p a ra te ly fo r d isc re te tim e p e rio d s. F o r e a c h tria l,
w e d e riv e d lo g ra te ra tio s fo r a n n u a l c h a n g e in th e ra te o f T B in
Trials reviewed
London School of Hygiene and Tropical Medicine
c o n tro ls a n d . th e a n n u a l c h a n g e in B C G P E . W e a lso c o m p a re d
B C G P E in th e first tw o y e a rs, a n d th e la st 1 0 y e a rs, to th a t in th e re st o f th e tria l, T h e re w a s sta tistic a lly sig n ific a n t h e te ro g e n e ity b e tw e e n tria ls in th e a n n u a l c h a n g e in B C G P E . In six tria ls B C G P E d e c re a se d o v e r ti m e (in o n e o f th e tria ls th is d e c re a se w a s sta
-tistic a lly sig n ific a n t) w h ile in th re e o f th e tria ls it in c re a se d . T h e a n n u a l c h a n g e in P E w a s n o t re la te d to o v e ra ll P E . B e c a u se o f th e h e te ro g e n e ity , it w o u ld n o t b e a p p ro p ria te to c a lc u la te a n o v e ra ll tre n d in B C G P E w ith tim e .
S tu d y - a c u m u la tio n
3 0 0 8 A m e ric a n In d ia n s In d iv id u a ls
3 3 8 1 ? 4 8 3 9 c h ild re n
7 7 9 2 7 c h ild re n
3 4 5 6 7 in d iv id u a ls o f 5 + y e a rs
2 6 4 6 5 a d o le s c e n ts a n d e a rly a d u lts
1 0 8 7 2 n ig e rs
9 0 0 0 0 g e rs
S ta rt d a te
M a x im u m Y e a rs
o f F o llo w -u p
1 1
23
20
2 0 20
20
2 1 1 5
R e fe re n c e s
Trials reviewed
S u m m a ry p ro te c tio n In tria ls :
P E (9 5 % C I)
7 8 .5 (4 6 .6 , 9 2 .8 )
8 0 .8 (7 3 .6 , 8 6 .2 )
7 2 .5 (5 1 .6 , 8 5 .3 )
-5 6 .3 (-9 0 5 .0 ,6 9 .6 )
2 7 .9 (9 .6 , 4 2 .4 )
6 .2 (-5 5 .5 , 4 3 .6 )
7 6 .7 (6 9 .2 , 8 2 ,6 )
1 9 -4 (-2 8 ,4 ,5 0 .0 )
.2 .9 (-2 4 .0 ,1 4 .4 )
0 .9 1 9
(0 .8 6 8 ,0 .9 7 3 )
0 .9 3 3 (0 .8 5 7 ,1 .0 1 6 )
1 .0 4 4
(0 .9 9 5 , 1 .0 9 5 )
2 2 .8 5 (9 d f) =0 .0 0 4
E ffe c t a fte r th e firs t 1 0 y e a rs , c o m p a re d
to th e firs t 1 0 y e a rs
o f th e tria l
0 .5 2 2 (0 .0 4 4 , 6 .1 5 7 )
0 .3 3 3 (0 .0 1 7 , 6 .6 4 8 )
1 .2 0 8 (0 .7 6 8 , 1 .8 9 9 )
0 .8 1 0 (0 .3 1 0 ,2 .1 1 4 )
0 ,3 5 9 (0 .1 6 9 , 0 .7 8 5 )
0 .1 6 3 (0 .0 3 4 , 0 .7 8 2 )
1 .0 3 1 (0 .7 1 7 ,1 .4 8 2 )
1 3 .0 5 (7 d f)
=0 .0 4 2
