Compliance and nutritional status during feasibility study for an intervention trial in China

As part of a pilot study to assess the feasibility of a long-term intervention trial to be done in Linxian, People's Republic of China, nutritional status and compliance were assessed in villagers taking daily multivitamin pills containing the U.S. Recommended Dietary Allowances (RDA). Before the start of the trial and again during its 4th month, nutritional status was assessed by laboratory tests and a dietary interview. Compliance was assessed in all subjects by pill counts and in a subset by urinary riboflavin loading-dose tests. At the outset of the trial, the study population had widespread biochemical and dietary deficiencies of ascorbic acid and riboflavin. As expected, subjects taking a daily pill had significantly improved status for these vitamins during the study. Compliance as measured by pill counts was excellent, with over 90% of the subjects taking at least 80% of their daily pills. Mean urinary excretion of a riboflavin loading dose entered and remained in the normal range after 3 weeks of supplementation, indicating that compliance did not fall off over time. Compliance was similar in normal subjects and in those with a prior diagnosis of esophageal dysplasia. Compliance also was nearly as good in subjects receiving monthly home visits as in those receiving weekly home visits from the barefoot doctor (village paramedical worker). The results of this pilot study indicated that a long-term intervention trial was feasible in Linxian and that the RDA dose level of vitamins was effective in ameliorating certain nutritional deficiencies prevalent in the study population.