Issues in the construction of wealth indices for the measurement of socio-economic position in low-income countries

BACKGROUND: Epidemiological studies often require measures of socio-economic position (SEP). The application of principal components analysis (PCA) to data on asset-ownership is one popular approach to household SEP measurement. Proponents suggest that the approach provides a rational method for weighting asset data in a single indicator, captures the most important aspect of SEP for health studies, and is based on data that are readily available and/or simple to collect. However, the use of PCA on asset data may not be the best approach to SEP measurement. There remains concern that this approach can obscure the meaning of the final index and is statistically inappropriate for use with discrete data. In addition, the choice of assets to include and the level of agreement between wealth indices and more conventional measures of SEP such as consumption expenditure remain unclear. We discuss these issues, illustrating our examples with data from the Malawi Integrated Household Survey 2004-5. METHODS: Wealth indices were constructed using the assets on which data are collected within Demographic and Health Surveys. Indices were constructed using five weighting methods: PCA, PCA using dichotomised versions of categorical variables, equal weights, weights equal to the inverse of the proportion of households owning the item, and Multiple Correspondence Analysis. Agreement between indices was assessed. Indices were compared with per capita consumption expenditure, and the difference in agreement assessed when different methods were used to adjust consumption expenditure for household size and composition. RESULTS: All indices demonstrated similarly modest agreement with consumption expenditure. The indices constructed using dichotomised data showed strong agreement with each other, as did the indices constructed using categorical data. Agreement was lower between indices using data coded in different ways. The level of agreement between wealth indices and consumption expenditure did not differ when different consumption equivalence scales were applied. CONCLUSION: This study questions the appropriateness of wealth indices as proxies for consumption expenditure. The choice of data included had a greater influence on the wealth index than the method used to weight the data. Despite the limitations of PCA, alternative methods also all had disadvantages

Issues in the construction of wealth indices for the measurement of socio-economic position in low-income countries-0

<p><b>Copyright information:</b></p><p>Taken from "Issues in the construction of wealth indices for the measurement of socio-economic position in low-income countries"</p><p>http://www.ete-online.com/content/5/1/3</p><p>Emerging Themes in Epidemiology 2008;5():3-3.</p><p>Published online 30 Jan 2008</p><p>PMCID:PMC2248177.</p><p></p

Issues in the construction of wealth indices for the measurement of socio-economic position in low-income countries-2

<p><b>Copyright information:</b></p><p>Taken from "Issues in the construction of wealth indices for the measurement of socio-economic position in low-income countries"</p><p>http://www.ete-online.com/content/5/1/3</p><p>Emerging Themes in Epidemiology 2008;5():3-3.</p><p>Published online 30 Jan 2008</p><p>PMCID:PMC2248177.</p><p></p

Issues in the construction of wealth indices for the measurement of socio-economic position in low-income countries-1

<p><b>Copyright information:</b></p><p>Taken from "Issues in the construction of wealth indices for the measurement of socio-economic position in low-income countries"</p><p>http://www.ete-online.com/content/5/1/3</p><p>Emerging Themes in Epidemiology 2008;5():3-3.</p><p>Published online 30 Jan 2008</p><p>PMCID:PMC2248177.</p><p></p

An intervention for the promotion of hygienic feces disposal behaviors in a shanty town of Lima, Peru.

This paper describes the design, implementation and evaluation of an intervention to promote improved hygiene practices in a shanty town area of Lima, Peru. Following formative research, the intervention focused on behaviors associated with the hygienic use of potties by children aged 15-47 months and keeping the home environment free from feces. A health communications strategy was developed involving delivery through routine health services, and using video presentations, leaflets and counseling by health staff during consultations. Intervention activities occurred during a 6-month period in health centers and posts of four intervention communities; four other communities acted as a comparison group. Process and impact indicators were measured through questionnaires and 4-h structured observations conducted in over 600 households both pre- and post-intervention implementation, and through intervention monitoring activities. The intervention materials and approach were well received by the study community; however, in the time-frame of the project only limited coverage of the target audience was achieved, which was insufficient to result in an impact on behaviors. Nevertheless sufficient positive features existed to suggest that with higher coverage, an impact on target behaviors might have been achieved. Reasons for the intervention's shortcomings are discussed and suggestions made for more effective implementation

Improved cognitive and motor development in a community-based intervention of psychosocial stimulation in northeast Brazil.

The aim of the study was to compare the development of children with and without a programme of psychosocial stimulation in 'control' and 'intervention' sites in a poorly resourced area of northeast Brazil. The sample (n = 156, born 1998) was from a larger cohort. The cohort was tested at 12 months (baseline) with the Bayley Scales of Infant Development. All children in the intervention site with a mental development index (MDI) and/or psychomotor development index (PDI) < or = 100 were enrolled. Each time such a child was enrolled, the next child tested in that site of the same sex and with an index of 101 to 115 was also enrolled, and the next two children matched for sex and scores of < or = 100 and 101 to 115 in the control sites were recruited in parallel. The intervention comprised 14 contacts between 13 and 17 months of age. All children were tested again at age 18 months. The intervention and control groups were similar at baseline for a range of socioeconomic, demographic, environmental, and biological variables, and their MDI and PDI were also similar. At 18 months, the mean differences between the intervention and control groups were + 9.4 points for MDI and + 8.2 points for PDI (p < 0.001 in each case). For children with an initial score of < or = 100, the mean difference between the intervened and control groups was + 11.2 points for MDI (p < 0.001), and + 10.8 points for PDI (p = 0.001). The intervention was thus associated with significant improvements in cognitive and motor development