Use of proxy measures in estimating socioeconomic inequalities in malaria prevalence.
OBJECTIVE
To present and compare socioeconomic status (SES) rankings of households using consumption and an asset-based index as two alternative measures of SES; and to compare and evaluate the performance of these two measures in multivariate analyses of the socioeconomic gradient in malaria prevalence.


METHODS
Data for the study come from a survey of 557 households in 25 study villages in Tanzania in 2004. Household SES was determined using consumption and an asset-based index calculated using Principal Components Analysis on a set of household variables. In multivariate analyses of malaria prevalence, we also used two other measures of disease prevalence: parasitaemia and self-report of malaria or fever in the 2 weeks before interview.


RESULTS
Household rankings based on the two measures of SES differ substantially. In multivariate analyses, there was a statistically significant negative association between both measures of SES and parasitaemia but not between either measure of SES and self-reported malaria. Age of individual, use of a mosquito net, and wall construction were negatively and significantly associated with parasitaemia, whilst roof construction was positively associated with parasitaemia. Only age remained significant when malaria self-report was used as the measure of disease prevalence.


CONCLUSIONS
An asset index is an effective alternative to consumption in measuring the socioeconomic gradient in malaria parasitaemia, but self-report may be an unreliable measure of malaria prevalence for this purpose.
Somi
Masha F
MF
Australian Centre for Economic Research on Health, Australian National University, Canberra, Australia. masha.somi@anu.edu.au
Butler
James R
JR
Vahid
Farshid
F
Njau
Joseph D
JD
Kachur
S P
SP
Abdulla
Salim
S
D000328:Adult; D005191:Family Characteristics; D006801:Humans; D008288:Malaria / Q000191:economics / Q000453:epidemiology*; D015999:Multivariate Analysis; D015995:Prevalence; D012650:Self Disclosure; D012923:Social Class; D013636:Tanzania / Q000453:epidemiology