title: Use of proxy measures in estimating socioeconomic inequalities in malaria prevalence.
abstract: 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.
authors.affiliation: Australian Centre for Economic Research on Health, Australian National University, Canberra, Australia. masha.somi@anu.edu.au
authors.forename: Masha F
authors.initials: MF
authors.lastname: Somi
authors.forename: James R
authors.initials: JR
authors.lastname: Butler
authors.forename: Farshid
authors.initials: F
authors.lastname: Vahid
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Njau
authors.forename: S P
authors.initials: SP
authors.lastname: Kachur
authors.forename: Salim
authors.initials: S
authors.lastname: Abdulla
mesh_terms: 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