1. Morbidity and regional anesthesia RCT vs. Big data
Markus F. Stevens
Academic Medical Center Amsterdam
Morbidity and regional anesthesia RCT vs. Big data

2. Faculty Disclosure DARA/ESRA instructor x Company Name Honoraria/
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DARA/ESRA instructor x
     

3. RCT vs. Big Data
3798 m
VAALSERBERG
-2 m
322 m 3

4. RCT vs. Big Data
The problem
History
Take home message

5. RCT vs. Big Data The problem Is RA safer than GA?
Memtsoudis et al. Anesthesiology 2013 n=
Mortality of GA increased (OR 1.8)
Guay et al. Cochrane Syst Rev 2016
n=2152
No differences in mortality, morbidity or any other outcome

6. RCT vs. Big Data

7. RCT vs. Big Data
Rodgers BMJ 2000

8. RCT vs. Big Data
Rodgers BMJ 2000

9. RCT vs. Big Data
Ballantyne J Clin Anesth 2005

10. RCT vs. Big Data
Ballantyne J Clin Anesth 2005

11. RCT vs. Big Data
Ballantyne J Clin Anesth 2005

12. RCT vs. Big Data The meta-analysis is the holy grail of EBM
But the quality of a meta-analysis highly depends on the included/excluded studies

13. RCT vs. Big Data The meta-analysis of meta-analysis
“Overall, there is insufficient evidence to confirm or deny the ability of postoperative analgesic techniques to affect major postoperative mortality or morbidity. This is primarily due to typically insufficient subject numbers to detect differences in currently low incidences of postoperative complications.”
Liu SS Anesth Analg 2007

14. RCT vs. Big Data What are the advantages of big data?
Less artificial/experimental than RCT
High numbers in reasonable time
Represents the “reality”
Lots of possibilities for statistical analysis

15. RCT vs. Big Data 259.037 patients undergoing surgery
patients received epidural
used as matched pairs
30 day mortality
Wijeysundera DN Lancet 2008

16. RCT vs. Big Data
Wijeysundera DN Lancet 2008

17. RCT vs. Big Data
Wijeysundera DN Lancet 2008

18. RCT vs. Big Data Statistically significant ≠ clinically meaningful
Wijeysundera DN Lancet 2008

19. RCT vs. Big Data
Guay J Cochrane Database syst Rev 2016

20. RCT vs. Big Data
Johnson RL BJA 2016

21. RCT vs. Big Data
Johnson RL BJA 2016

22. RCT vs. Big Data n=
Memtsoudis S Anesthesiology 2013

23. RCT vs. Big Data 0.1% => 0.18% => NNT?
Memtsoudis S Anesthesiology 2013

24. RCT vs. Big Data
Memtsoudis S Anesthesiology 2013

25. RCT vs. Big Data Retrospective data just shows associations
Speculations over effect
Patients with RA were less healthy
More RA at big hospitals
More RA by certified anesthesiologists
More RA in recent years
Memtsoudis S Anesthesiology 2013

26. RCT vs. Big Data Retrospective study
2.135 SpA for TKA with matched controls
30 d mortality SpA: 0.19%; GA: 0.8%
Perlas A Anesthesiology 2016

27. Take home message
Meta-analysis are fallible
Big Data are still retrospective data
Retrospective data are about associations not causation
Statistically significant ≠ clinically meaningful
Regional anesthesia has never been associated with increased mortality or morbidity

28. Thank you for your attention