A 2009 Weill Cornell Medical College study concluded that patients switched to generic oxybutynin experienced a degradation in therapeutic value: "In women, there was a doubling of daytime frequency of urination, a slight 20% increase in nocturia, and a 46.3% increase in urge incontinence. In men, there was a 2.4-fold increase in daytime frequency, a 40% increase in nocturia, and a 40.6% increase in urge incontinence," Steven A. Kaplan said of the findings.