The 1500/1800 Rule provides a way to estimate blood sugar drop caused by each unit of short acting insulin. See the description at DiabetesNet.com for a more detailed discussion of the 1500/1800 Rule.
Since this method only estimates the Blood Sugar/Insulin ratio, you may wish to actually measure your blood sugar ratios to get a more accurate figure. For more information on how to do this see the Other Blood Sugar related HOWTO's listed below.
Data collected from the members of the Insulin Pumpers mail list about their actual Blood Sugar / Insulin ratios, indicates that the 1500 Rule may predict ratios that are VERY DIFFERENT from the actual measured ratios of many adults, children, and adolescents. Great care should be used when applying the results prededicted by this rule.
You should consult with your physician and health care team when making changes to your insulin regimen.
The 1500 Rule was developed by Paul Davidson, M.D., Medical Director of the Diabetes Treatment Center at HCA West Paces Ferry Hospital in Atlanta, GA.