IN RECENT studies of the growth of lung function, exponential equations were found to describe the relationships of the test results to body size. In general, standing height was the best anthropomorphic measurement (in reducing the variance) and little was gained by the use of more than one independent variable. In order to provide easy calculations of the predicted values, a simple nomograph has been constructed. A second way of calculating predicted values is to base them upon the vital capacity. The derived formulas for the relationships of the test results to vital capacity were also exponential ones. In most cases, first degree equations can be substituted for the exponential equations with excellent approximations. These simpler equations provide another easy method of obtaining predicted results.
The characteristics of the children and details of the testing methods are given elsewhere.1-4 The children ranged in age from 4 to 18