English to Spanish Medical Medical (general)

Estoy traduciendo un estudio clínico sobre medicamentos para aliviar los síntomas asociados a la acidez:

"Data Analysis

The total amount (milliequivalents) of sodium hydroxide infused to maintain a gastric pH of 4.0 was tabulated for 15-minute intervals throughout each 10-hour study. The number of milliequivalents of sodium hydroxide required to maintain a gastric pH of 4.0 was asumed to be equal to the number of milliequivalents of gastric acid secreted. The predefined primary comparisons between groups were the total milliequivalents of sodium hydroxide infused during the first hour following dosing with study medication (indicative of onset of action) and during hours 6 to 8 in the post-treatment period (indicative of duration of effect). For both of these time intervals, the four treatments were compared using an analysis of variance (ANOVA) model appropriate for a crossover design and a logaritmic transformation of data was used to satisfy assumptions of the analysis. The **predefined treatment comparisons of primary interest** were those between the famotidine/antacid combination and ranitidine 75 mg treatments for the 0 to 1 hour postdose interval and between the famotidine/antacid combination and calcium carbonate 1000 mg treatments for the 6 to 8 hour postdose interval."

Me parece que debe ser un término de uso común en este tipo de estudios y me imagino que significa los mismo que "predefined primary comparisons". ¿Las comparaciones de tratamiento predefinidas de interés principal?