Clinical utility of two-dimensional Doppler echocardiographic techniques for estimating pulmonary to systemic blood flow ratios in children with left to right shunting atrial septal defect, ventricular septal defect or patent ductus arteriosus

Range gated two-dimensional Doppler echocardiographic methods were evaluated for quantifying pulmonary (QP) to systemic (QS) blood flow ratios. Twenty-one patients were studied, 4 with patent ductus arteriosus, 6 with atrial septal defect and 11 with ventricular septal defect. The Doppler pulmonary to systemic flow (QP:QS) estimation method involved calculating volume flow (liters/min) at a variety of intracardiac sites by using imaging information for flow area and Doppler outputs to calculate mean flow velocity as a function of time. Area volume flows were combined to yield QP:QS ratios. The sites sampled were main pulmonary artery, ascending aorta, mitral valve orifice and subpulmonary right ventricular outflow tract. The overall correlation between Doppler QP:QS estimates and those obtained at cardiac catheterization (n = 18) or radionuclide angiography (n = 3) was r = 0.85 (standard error of the estimate = 0.48:1). These preliminary results suggest that clinical application of this Doppler echocardiographic method should allow noninvasive estimation of the magnitude of cardiac shunts

Micro-econometric and Micro-Macro Linked Models: Sequential Macro-Micro Modelling with Behavioral Microsimulations

Analyzing the poverty and distributional impact of macro events requires understanding how shocks or policy changes on the macro level affect household income and consumption. It is clear that this poses a formidable task, which of course raises the question of the appropriate methodology to address such questions. This paper presents one possible approach: A sequential methodology that combines a macroeconomic model with a behavioral micro-simulation. We discuss the merits and shortcomings of this approach with a focus on developing country applications with a short to medium run time horizon. - This chapter is a re-print of: Lay, J. (2010). Sequential macro-micro modelling with behavioural microsimulations. International Journal of Microsimulation, 3(1), 24-34

Who uses outpatient healthcare services under Ghana’s health protection scheme and why?

Background: The National Health Insurance Scheme (NHIS) was launched in Ghana in 2003 with the main objective of increasing utilisation to healthcare by making healthcare more affordable. Previous studies on the NHIS have repeatedly highlighted that cost of premiums is one of the major barriers for enrollment. However, despite introducing premium exemptions for pregnant women, older people, children and indigents, many Ghanaians are still not active members of the NHIS. In this paper we investigate why there is limited success of the NHIS in improving access to healthcare in Ghana and whether social exclusion could be one of the limiting barriers. The study explores this by looking at the Social, Political, Economic and Cultural (SPEC) dimensions of social exclusion. Methods: Using logistic regression, the study investigates the determinants of health service utilisation using SPEC variables including other variables. Data was collected from 4050 representative households in five districts in Ghana covering the 3 ecological zones (coastal, forest and savannah) in Ghana. Results: Among 16,200 individuals who responded to the survey, 54 % were insured. Out of the 1349 who sought health care, 64 % were insured and 65 % of them had basic education and 60 % were women. The results from the logistic regressions show health insurance status, education and gender to be the three main determinants of health care utilisation. Overall, a large proportion of the insured who reported ill, sought care from formal health care providers compared to those who had never insured in the scheme. Conclusion: The paper demonstrates that the NHIS presents a workable policy tool for increasing access to healthcare through an emphasis on social health protection. However, affordability is not the only barrier for access to health services. Geographical, social, cultural, informational, political, and other barriers also come into play

Using remotely sensed night-time light as a proxy for poverty in Africa

BACKGROUND: Population health is linked closely to poverty. To assess the effectiveness of health interventions it is critical to monitor the spatial and temporal changes in the health indicators of populations and outcomes across varying levels of poverty. Existing measures of poverty based on income, consumption or assets are difficult to compare across geographic settings and are expensive to construct. Remotely sensed data on artificial night time lights (NTL) have been shown to correlate with gross domestic product in developed countries. METHODS: Using national household survey data, principal component analysis was used to compute asset-based poverty indices from aggregated household asset variables at the Administrative 1 level (n = 338) in 37 countries in Africa. Using geographical information systems, mean brightness of and distance to NTL pixels and proportion of area covered by NTL were computed for each Administrative1 polygon. Correlations and agreement of asset-based indices and the three NTL metrics were then examined in both continuous and ordinal forms. RESULTS: At the Administrative 1 level all the NTL metrics distinguished between the most poor and least poor quintiles with greater precision compared to intermediate quintiles. The mean brightness of NTL, however, had the highest correlation coefficient with the asset-based wealth index in continuous (Pearson correlation = 0.64, p < 0.01) and ordinal (Spearman correlation = 0.79, p < 0.01; Kappa = 0.64) forms. CONCLUSION: Metrics of the brightness of NTL data offer a robust and inexpensive alternative to asset-based poverty indices derived from survey data at the Administrative 1 level in Africa. These could be used to explore economic inequity in health outcomes and access to health interventions at sub-national levels where household assets data are not available at the required resolution