Showing papers by "Duncan Thomas published in 2003"

Prospective Study of Air Pollution and Bronchitic Symptoms in Children with Asthma

Abstract: The relationship of bronchitic symptoms to ambient particulate matter and to particulate elemental and organic carbon (OC), nitrogen dioxide (NO2), and other gaseous pollutants was examined in a cohort of children with asthma in 12 Southern California communities. Symptoms, assessed yearly by questionnaire from 1996 to 1999, were associated with the yearly variability of particulate matter with aerodynamic diameter less than 2.5 microg (odds ratio [OR] 1.09/microg/m3; 95% confidence interval [CI] 1.01-1.17), OC (OR 1.41/microg/m3; 95% CI 1.12-1.78), NO2 (OR 1.07/ppb; 95% CI 1.02-1.13), and ozone (OR 1.06/ppb; 95% CI 1.00-1.12). The ORs associated with yearly within-community variability in air pollution were larger than the effect of the between-community 4-year average concentrations. In two pollutant models, the effects of yearly variation in OC and NO2 were only modestly reduced by adjusting for other pollutants, except in a model containing both OC and NO2; the effects of all other pollutants were reduced after adjusting for OC or NO2. We conclude that OC and NO2 deserve greater attention as potential causes of the chronic symptoms of bronchitis in children with asthma and that previous cross-sectional studies may have underestimated the risks associated with air pollution.

Economic Shocks, Wealth, and Welfare

Abstract: The immediate effects of the Asian crisis on the well-being of Indonesians are examined using the Indonesia Family Life Survey, an on-going longitudinal household survey. There is tremendous diversity in the effect of the shock: for some households, it was devastating; for others it brought new opportunities. A wide array of mechanisms were adopted in response to the crisis. Households combined to more fully exploit benefits of scale economies in consumption. Labor supply increased even as real wages collapsed. Households reduced spending on semi-durables while maintaining expenditures on foods. Rural households used wealth, particularly gold, to smooth consumption.

Remembrances of things past: test–retest reliability of retrospective migration histories

Abstract: Author(s): Smith, James P.; Thomas, Duncan | Abstract: Matched retrospective life history data collected from the same individuals in two waves of the Malaysian Family Life Survey provide a unique opportunity to evaluate the quality of long term recall data in a rapidly changing developing country. Recall quality, measured by consistency of incidence and dating of moves reported twelve years apart, is higher among the better educated. Respondents better remember more salient moves, those linked with other important life events such as marriage, childbirth or a job change and moves that lasted a long time. Migrations that dim in memory as time passes are typically shorter duration or local moves, often made while the respondent was young. Dating of moves is also significantly improved when linked with other salient events. Our findings suggest concrete and practical steps that can be followed to improve the quality of retrospective life histories collected in field surveys.

Iron deficiency and the well-being of older adults: Early results from a randomized nutrition intervention

Abstract: Iron deficiency is widespread throughout the developing world. We provide new evidence on the effect of iron deficiency on economic and social prosperity of older adults drawing on data from a random assignment treatment-control design intervention. The Work and Iron Status Evaluation is an on-going study following over 17,000 individuals in Central Java, Indonesia. Half the respondents receive a treatment of 120 mg of iron every week for a year; the controls receive a placebo. Compliance is monitored carefully. Results from the first six months of the intervention are presented for adults age 30 through 70 years. Males who were iron deficient prior to the intervention and who are assigned to the treatment are better off in terms of physical health, psycho-social health and economic success. These men are more likely to be working, sleep less, lose less work time to illness, are more energetic, more able to conduct physically arduous activities and their psycho-social health is better. There is evidence that economic productivity of these males also increased. Among iron-deficient males assigned to the treatment who were also self-employed prior to the baseline, hourly earnings rose substantially and so they earned more on a monthly basis. Benefits for women are in the same direction but the effects are more muted. The results provide unambiguous evidence in support of the hypothesis that health has a causal effect on economic prosperity of males during middle and older ages.