'How poor are you?' -- a comparison of four questionnaire delivery modes for assessing socio-economic position in rural zimbabwe.

BACKGROUND: Assessing socio-economic position can be difficult, particularly in developing countries. Collection of socio-economic data usually relies on interviewer-administered questionnaires, but there is little research exploring how questionnaire delivery mode (QDM) influences reporting of these indicators. This paper reports on results of a trial of four QDMs, and the effect of mode on poverty reporting. METHODS: This trial was nested within a community-randomised trial of an adolescent reproductive health intervention conducted in rural Zimbabwe. Participants were randomly allocated to one of four QDMs (three different self-administered modes and one interviewer-administered mode); a subset was randomly selected to complete the questionnaire twice. Questions covered three socio-economic domains: i) ownership of sellable and fixed assets; ii) ability to afford essential items; and iii) food sufficiency. Statistical analyses assessed the association between QDM and reporting of poverty, and compared the extent of response agreement between questionnaire rounds. RESULTS: 96% (n = 1483) of those eligible took part; 395 completed the questionnaire twice. Reported levels of poverty were high. Respondents using self-administered modes were more likely to report being unable to afford essential items and having insufficient food. Among those completing the questionnaire twice using different modes, higher levels of poverty and food insufficiency were reported when they completed the questionnaire using a self-administered mode. CONCLUSION: These data suggest that QDM plays a significant role in how different socio-economic indicators are reported, and reminds us to consider the mode of collection when identifying indicators to determine socio-economic position.