Without exactly knowing what your implementation is for, I would think that
future use of the data for any other output or processing would be better
served by making the structure something like this:

 <data>
     <newRecord>
 	...
        <DifferentialDiagnosis>
		<Diagnosis>Sick</Diagnosis>
		<Diagnosis>Sicker</Diagnosis>
		<Diagnosis>Sickest</Diagnosis>
        </DifferentialDiagnosis>

	...

Certainly when processing for XSL FO or HTML, it would be easier. Especially
if the input data changes and you have to add 4,5,6,...10...more? 

Kevin Brown
RenderX