Effectiveness and cost-effectiveness of albendazole in improving nutritional status of pre-school children in urban slums.

OBJECTIVE: To study the clinical efficacy and the incremental cost-effectiveness of albendazole in improving the nutritional status of pre-school children. DESIGN: Single blind, placebo-controlled trial with child as the unit of randomization. SETTING: In the Anganwadi centers of the Integrated Child Development Services situated in the urban slums of Lucknow, North India. METHODS: Thirty-two Anganwadi centers were randomly selected for the trial. Included were registered resident children between 1.5 to 3.5 years of age with informed and written parental consent. The intervention group received 600 mg of albendazole powder every six months while the placebo group received same quantity of calcium powder. Enrolled children were contacted once in six months from January 1995 to 1997 and given treatment. The outcome measure were change in the proportion of underweight (weight for age <-2.00z), stunted (height for age <-2.00z) children and the cost per child prevented from becoming stunted. RESULTS: There were 610 and 451 children in the albendazole and placebo groups, respectively. Mean age at recruitment was 31.8 months (SD: 9.7). Follow-up and compliance in both the groups was >95%. During the 2 year follow-up, the proportion of stunted children increased by 11.44% and 2.06% in the placebo and albendazole groups, respectively, and the difference was 9.38% (95% CI 6.01% to 12.75%; p value <0.0001). Direct fecal smear was positive for the ova of ascaris in 41.2% and 55.3% children in the albendazole and placebo groups, respectively at the end of the study (p value <0.001). The annual family expenditure on illness in the recruited child was Rs. 743 (SD: 662) and Rs. 625 (SD: 609) in the albendazole and the placebo groups, respectively. The incremental cost-effectiveness ratio was Rs 543.00 for each case of stunting prevented with albendazole. There was no difference in the various morbidity or cognitive performance, as judged by the revised Denver prescreening questionnaire, in both the groups at enrollment as well as at the end of the study. CONCLUSIONS: Six monthly albendazole reduces the risk of stunting with a small increase in the expenditure on health care from the payer's perspective. Larger trials are needed to study the effect of albendazole on prevention of stunting, cognitive functions and all-cause childhood mortality.

Interpretation of diagnostic tests.

Clinicians can now base clinical decisions on the results of rigorous studies of the performance of diagnostic tests. In selecting the tests, clinicians should take into account their sensitivity (the proportion of patients with the disease who have a positive test result) and specificity (the proportion of patients without disease who have a negative test results). Sensitivity and specificity are affected by the "spectrum" of patients studied i.e. the severity of disease in those with disease and the clinical characteristics of those without disease. Test results are interpreted by predictive values--the proportion of patients with a positive (negative) test result who have (do not have) the disease. Predictive values depend on both test sensitivity and specificity and disease prevalence. The information content of a test is further increased by taking into account where the cut-off point between normal and abnormal is placed, the degree of abnormality of the result, and the results of the preceding tests (done either in parallel or in series). Describing test performance in terms of likelihood ratios facilitates this process. Readers should be able to critique published studies of diagnostic tests which are still far from perfect.

Ambient air pollution & respiratory symptoms complex in preschool children.

To study the association between ambient air pollutants (AAP) and respiratory symptoms complex (RSC) in preschool children, a cohort of 664 children between the ages of 1 month to 4.5 yr were randomly selected from 28 slums (anganwadi centres) of Lucknow, north India. They were followed up fortnightly for six months. The outcomes assessed were presence of RSC at the time of interview and days on which symptoms had occurred in the past week. Exposure to ambient air sulphur dioxide (SO2), oxides of nitrogen (NOx) and suspended particulate matter (SPM) on the day of the interview or in the week prior, was assessed by ambient air monitoring at 9 centres within the city. The cumulative incidence of RSC was 1.06 and the incidence density per 100 days of follow up was 1.63. All three pollutants were positively correlated with each other and negatively correlated with temperature. Ambient air SPM and SO2 and cooking and heating fuels like dung cakes, wood, coal and kerosene and remaining indoors while the food was cooked were associated with increased incidence of RSC, increased duration of symptoms, or both. We conclude that to improve the respiratory health of preschool children, ambient air SPM and SO2 levels should be kept as low as possible and mothers should be advised to keep children in another room while cooking.