Off-Label Use of Atypical Antipsychotics: An Update
Modes of Results Reporting and Statistical Analysis in the Comparative Effectiveness Review (2 of 2)
Absolute Risk Difference: The absolute value of the mathematical difference between the rates (risk) of an event in the treatment and comparison groups.
ARD = | ARC–ART |
Number Needed To Treat or Harm (NNT, NNH): The number of patients to be treated to observe benefit or harm in one patient more than seen in the comparison group. The number of patients to be treated in order to find a benefit or harm attributable to the intervention.
NNT or NNH = | ARC–ART |-1 for a benefit or adverse event, respectively
Number of attributable events per 1,000 = 1,000 x | ARC–ART |
- Higgins JPT, Green S, eds. Cochrane handbook for systematic reviews of interventions. Version 5.1.0. London: The Cochrane Collaboration; March 2011. Available at www.cochrane handbook.org.
- Cohen J. Statistical power analysis for the behavioral sciences. 2nd ed. London: Routledge Academic; 1988.
- Maglione M, Ruelaz Maher A, Hu J, et al. Off-Label Use of Atypical Antipsychotics: An Update. Comparative Effectiveness Review No. 43 (Prepared by the Southern California RAND Evidence-based Practice Center under Contract No. HHSA 290-2007-10062-I). Rockville, MD: Agency for Healthcare Research and Quality; September 2011. AHRQ Publication No. 11(12)-EHC087-EF. Available at www.effectivehealthcare.ahrq.gov/offlabelantipsych.cfm.
Your slide tray is being processed.