CAN CARETAKERS OF CHILDREN WITH IDDM ACCURATELY MEASURE SMALL INSULINDOSES AND DOSE CHANGES

OBJECTIVE - To determine if caretakers of young children with IDDM cou ld consistently reproduce small incremental measurements of insulin (U 100). RESEARCH DESIGN END METHODS - Fifteen caretakers of children wit h IDDM were asked to deliver repealed small doses of insulin, includin g doses separated by only 0.25 U of insulin. A sensitive gravimetric t echnique was used to determine the error in measurement of these low d oses of insulin. Statistical analysis was used to evaluate accuracy an d internal consistency of each caretaker at each dose. RESULTS - The m eans +/- SD at each dose level were as follows: 2.75 +/- 0.13 U at 2.5 U, 3.19 +/- 0.13 U at 3.0 U, 3.55 +/- 0.13 U at 3.25 U, and 3.70 +/- 0.11 U at 3.5 U. All doses were biased toward overadministration. Ther e was a statistically significant difference in the dose delivered whe n the target doses were varied by only 0.25 U. The average differences and standard errors between 2.5 U and 3.0 U, 3.0 U and 3.25 U, and 3. 25 U and 3.5 U were 0.44 +/- 0.20 U, 0.36 +/- 0.018 U, and 0.15 +/- 0. 017 U, respectively. CONCLUSIONS - Participants were not accurate in m easuring small insulin doses, consistently overdrawing insulin by an a verage of 0.22 U. Caretakers are reasonably internally consistent with a given dose, since participants were able to measure statistically s ignificant differences in 0.25 U dose changes. The error in insulin me asurement does not vary with the intended dose level. Caretakers in th e same family deliver insulin doses as variable from each other as the y are from the population as a whole; however, when two or more indivi duals are responsible for one insulin dose in a child with IDDM, they have a combined variability that is similar to 40% greater than a sing le individual's variability.