Relationship of plasma and urine composition to recurrence of calcium urinary stones in patients on drug therapy.

Factors relating alterations in plasma and urine composition to recurrence of urinary stones during drug therapy were investigated by using a multiple regression analysis technique. These factors were influenced not only by the efficacy of the drugs but also by other factors (plasma or urinary constituents and overall health of the patients, etc.). In order to study the effect of drug therapy or other treatment on the alteration of plasma and urine constituents, multiple regression analysis is more appropriate than Student's paired t-test which has been used by some workers. These two analytical methods yield different results even if used on the same data.