Professor Ruth Gilbert of University College London presents "Could a systematic review have prevented the epidemic of sudden infant death syndrome?" at the opening of the Austrian Cochrane Branch in Krems, Austria, on December 14th 2010.

1. "Could a systematic review have
prevented the epidemic of sudden
infant death syndrome?"
Ruth Gilbert
Centre for Evidence-based Child Health
UCL Institute of Child Health, London,
UK

2. 1947 – book on parent craft

3. Advice on infant sleeping position
“Avoid prone (front)
sleeping, particularly
at night.” (review of
139 deaths)
–Abramson 1944
1944 1950 1960 1970 1980 1990 2000 2005
Rubber sheet
experiment.
- “suffocation
unlikely”
Woolley 1945

4. Advice on infant sleeping position
1944 1950 1960 1970 1980 1990 2000 2005
SIDS
Infection/inhalation?
Front sleeping
Scoliosis, rounded heads
Apnoeas, oxygenation
Sleeps better

5. UK
How did practice change?
Netherlands
Norw ay
Prevalence of prone sleeping
New Zealand
75 Australia
Hong Kong
USA
65
55
USA NTL
45
% prone
35
25
15
5
1955 1960 1965 1970 1975 1980 1985 1990 1995 2000
-5
midpoint date

6. How did SIDS
incidence
change?
Arch Dis Child
1995;72:478-82.

7. Clinical studies timeline
Comparative clinical studies
Case control/cohort
1944 1950 1960 1970 1980 1990 2000 2005
???
?

8. Front vs back

9. Front vs other positions

10. Can we infer causality?
• RCTs feasible in 1970 but not after
• Evidence only from systematic review of
observational studies
• But….
– Strong association
– Not explained by confounders
– Dose effect (side, front vs back)
– SIDS reduced when front sleeping declined

11. Change in SIDS incidence as front sleeping declined
Postneonatal SIDS: England & Wales
2.5
deaths/1000 live births
2
1.5
1
0.5 Avon
campaign National
campaign
0
74
76
78
80
82
84
86
88
90
92
94
96
98
19
19
19
19
19
19
19
19
19
19
19
19
19
year
Source: Office of National Statistics

12. SIDS incidence: Europe 1987-1997
Change in 5
Austria E&W NTL Norway Scotland Switz
SIDS 4
rate/1000
3
incidence 2
1
0
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997
SIDS incidence 1987-1997
Excess death toll Australia NZ USA
due to prone 5
sleeping in 20y 4
rate/1000
3
USA>40,000
2
UK >10,000 1
0
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997

13. Lessons
1) Clinical practice requires clinical evidence
2) Delays in systematically reviewing evidence can
cost lives
3) Systematic reviews – can help to explain
conflicting results

14. "Could a systematic review have
prevented the epidemic of sudden
infant death syndrome?"
Possibly!

15. Why did it take so long to change advice?
De Jonge (NTL)
1944 1950 1960 1970 1980 1990 2000 2005
SIDS foundation (UK)
Government advice
USA

16. Acknowledgements
• Georgia Salanti, Sarah See, Melissa Harden
(co-authors), Chris Hiley, Iain Chalmers
Gilbert, Salanti, Harden, See. Int J Epid 2005
r.gilbert@ich.ucl.ac.uk