I am specifically interested in any challenges faced regarding implementing such a study in a resource limited setting, and any challenges with community education or challenges obtaining regulatory approval.
Flavia I am not sure whether you mean cash to do research or cash incentives as in public works programmes. In the latter, cash is used e.g in Food for Work programmes, some programmes were converted into Cash for Work because of the logistics of distributing food (its quality) which is more difficult to sustain; If the incentives are for studies, ethical issues come to play - while you will enjoy the high retention rates as suggested by Mwambi, other researchers without the same resources will find it difficult to do their studies in the same location if they cannot match your incentive.