1. ((plan* or develop* or institution or institute? or organi#ation* or organi#e* or designat* or stipulat* or dedicat* or implement*) adj2 (trauma* or polytrauma*)).ti,ab.

2. ((polytrauma* or trauma*) adj2 (system? or network?)).ti,ab.

3. traumatology/og

4. (trauma* or polytrauma*).ti,ab.

5. Regional Medical Programs/

6. 4 and 5

7. ((impact* or effect* or evaluat* or implement* or develop* or assess* or outcome* or centrali#ation or centrali#ed or regionali#ation or regionali#ed) adj5 (trauma centre* or trauma center* or trauma service? or trauma care)).ti,ab.

8. trauma centers/og

9. or/1‐3,6‐8

10. randomized controlled trial.pt.

11. controlled clinical trial.pt.

12. multicenter study.pt.

13. pragmatic clinical trial.pt.

14. (randomis* or randomiz* or randomly).ti,ab.

15. groups.ab.

16. (trial or multicenter or multi center or multicentre or multi centre).ti.

17. (intervention? or effect? or impact? or controlled or control group? or (before adj5 after) or (pre adj5 post) or ((pretest or pre test) and (posttest or post test)) or quasiexperiment* or quasi experiment* or pseudo experiment* or pseudoexperiment* or evaluat* or time series or time point? or repeated measur*).ti,ab.

18. non‐randomized controlled trials as topic/

19. interrupted time series analysis/

20. controlled before‐after studies/

21. or/10‐20

22. exp animals/

23. humans/

24. 22 not (22 and 23)

25. review.pt.

26. meta analysis.pt.

27. news.pt.

28. comment.pt.

29. editorial.pt.

30. cochrane database of systematic reviews.jn.

31. comment on.cm.

32. (systematic review or literature review).ti.

33. or/24‐32

34. 21 not 33

35. 9 and 34