| Level I | Good quality evidence |
Systematic review of RCTs with consistent findings High quality individual RCT |
| Level II |
Limited quality patient orientated evidence |
Systematic review of lower quality studies or studies with inconsistent findings Low quality clinical trial Cohort studies Case-control studies |
| Level III | Other |
Consensus guidelines, extrapolations from bench research, usual practice, opinion, disease-oriented evidence (intermediate or physiologic outcomes only), or case series |
[5] Haloperidol, oral/parenteral: Digges M, Hussein A, Wilcock A, Crawford GB, Boland JW, Agar MR, Sinnarajah A, Currow DC, Johnson MJ. Pharmacovigilance in Hospice/Palliative Care: Net Effect of Haloperidol for Nausea or Vomiting. J Palliat Med. 2018 Jan;21(1):37-43. https://www.ncbi.nlm.nih.gov/pubmed/28772094
Haloperidol, oral/parenteral: Doyle D, Woodruff R. The IAHPC Manual of Palliative Care. 3rd ed. IAHPC Press, 2013. Available from: https://hospicecare.com/what-we-do/publications/manual-of-palliative-care/[Accessed August 2019]