Table 1 MEDLINE systematic review search strategy

 1. older adults/

 2. elderly/

 3. aged/

 4. (older$ adj1 (person$ or adult$)).tw.

 5. (elderly$ adj2 (adult$ or person$)).tw.

 6. 1 or 2 or 3 or 4 or 5

 7. baths/

 8. shower$.tw.

 9. (bath$ adj3 (independ$ or depend$ or disab$)).tw.

 10. 7 or 8 or 9

 11. 6 and 10

 12. randomized controlled trial.pt.

 13. controlled clinical trial.pt.

 14. (control$ adj2 trial).tw.

 15. intervention study/

 16. experiment$.tw.

 17. (time adj1 series).tw.

 18. (pre test or pretest or posttest or post test).tw.

 19. random allocation/

 20. intervention?.tw.

 21. evaluation studies/

 22. comparative study.pt.

 23. 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22

 24. 11 and 23

 25. nursing home/

 26. 24 not 25

 27. radon/

 28. 26 not 27

 29. limit to adults