Linked cross-sectional study for evaluating the effect on the microfilarial load of the onchocerciasis control...

When analysing incomplete longitudinal data (ie data which includes complete longitudinal results plus cross-sectional results plus partially longitudinal results) one can increase the sensitivity of the data by taking the correlation structure of the data into account. For the described data on onchocerciasis, the adapted method of Rao and Rao, called the Linked Cross-Sectional method, which estimates the mean microfilarial load for each passage and hence the differences between passages, taking into account the correlation between the same individuals measured at different times is such a method that reduces significantly the standard deviations of the mean responses and hence increases their sensitivity. The method takes into account the missing data nature of the results. It can be simply generalized to any number of passages.