How to Calculate ED50

ED50 is a medical term that stands for "effective dose."

ED50 is a medical term that stands for "effective dose." The 50 stands for 50 percent, which is the amount of people who experience a positive therapeutic effect of the treatment in order for it to be deemed to be effective. While ED50 is occasionally used to describe the effectiveness of drugs, most often it's used in radiology to describe the effects of radiation treatment. If a treatment does not reach the ED50 threshold, physicians tend to focus their energies on finding a different method of treatment, if available.

Instructions

1. Find the total number of people that have undergone the treatment. You can find this out by consulting the medical records of a hospital or specific doctor, although you may need to get written legal permission to examine these records--most are confidential.

2. Find the number of people who experienced therapeutic effects from the treatment. Whether or not they experienced positive effects from the treatment will be listed on the person's medical chart. However, once again, it may be difficult to gain access to this material without going through the proper channels and getting the needed authorization.

3. Divide the number people who experienced therapeutic effects from the treatment by the number of total patients who underwent the treatment. For example, if 100 patients underwent treatment and 50 had therapeutic effects, then it would be 50 divided by 100, or 0.5. Multiply your answer by 100 to get the percentage, in this case 50 percent. If the number is over 50 percent, then the treatment can be said to have ED50. If the number is less than 50 percent, then the treatment does not qualify for ED50.

References

• PubMed.goc
• Medical Physics