Some considerations in the design of a nutrition intervention trial in Linxian, People's Republic of China.

摘要: Various issues pertaining to the design of a nutrition intervention trial in Linxian, county North Central China where esophageal cancer rates are extraordinarily high among population with chronic deficiencies multiple nutrients, addressed. Two target populations identified: One is group patients diagnosed severe dysplasia, other general high-risk area. Interventions involving supplementation each vitamins and minerals described, rationale provided for selection nutrients choice dose levels. Several potential statistical designs evaluated, particular emphasis on balancing gains specificity afforded by full fractional factorial against their loss sensitivity compared simplest placebo versus vitamin mineral supplement.