Notes Concerning the IOPI Iowa Database Model

The data underlying the model results shown below were collected from normal subjects in and around Iowa City, Iowa. The vast majority were Caucasians of northern European ancestry. They were all healthy. The curved lines represent the 95% confidence limits of a linear model applied to these data.  These curves show a region into where one would expect the strength or endurance of a normal healthy individual to fall, given knowledge of their age and gender.  A model of this type is affected by the number of subjects at different ages, which is why all the model results are “pinched” in the middle.  There were far more subjects in the middle than at the extremes of these curves.