THE USE OF ARM CIRCUMFERENCE FOR SIMPLIFIED SCREENING FOR MALNUTRITION BY MINIMALLY TRAINED HEALTH WORKERS

Because of its simplicity and low cost, arm circumference (AC) is being used increasingly in screening for protein energy malnutrition among pre-school children in many parts of the developing world, especially where minimally trained health workers are employed. The objectives of this study were as follows: (1) To determine the relationship of the AC measure with weight for age and weight for height in the detection of malnutrition among pre-school children in a Guatemalan Indian village. (2) To determine the performance of minimally trained promoters under field conditions in measuring AC, weight and height. (3) To describe the practical aspects of taking AC measures versus weight, age and height.^ The study was conducted in San Pablo La Laguna, one of four villages situated on the shores of Lake Atitlan, Guatemala, in which a program of simplified medical care was implemented by the Institute for Nutrition for Central America and Panama (INCAP). Weight, height, AC and age data were collected for 144 chronically malnourished children. The measurements obtained by the trained investigator under the controlled conditions of the health post were correlated against one another and AC was found to have a correlation with weight for age of 0.7127 and with weight for height of 0.7911, both well within the 0.65 to 0.80 range reported in the literature. False positive and false negative analysis showed that AC was more sensitive when compared with weight for height than with weight for age. This was fortunate since, especially in areas with widespread chronic malnutrition, weight for height detects those acute cases in immediate danger of complicating illness or death. Moreover, most of the cases identified as malnourished by AC, but not by weight for height (false positives), were either young or very stunted which made their selection by AC better than weight for height. The large number of cases detected by weight for age, but not by AC (false negative rate--40%) were, however, mostly beyond the critical age period and had normal weight for heights.^ The performance of AC, weight for height and weight for age under field conditions in the hands of minimally trained health workers was also analyzed by correlating these measurements against the same criterion measurements taken under ideally controlled conditions of the health post. AC had the highest correlation with itself indicating that it deteriorated the least in the move to the field. Moreover, there was a high correlation between AC in the field and criterion weight for height (0.7509); this correlation was almost as high as that for field weight for height versus the same measure in the health post (0.7588). The implication is that field errors are so great for the compounded weight for height variable that, in the field, AC is about as good a predictor of the ideal weight for height measure.^ Minimally trained health workers made more errors than the investigator as exemplified by their lower intra-observer correlation coefficients. They consistently measured larger than the investigator for all measures. Also there was a great deal of variability between these minimally trained workers indicating that careful training and followup is necessary for the success of the AC measure.^ AC has many practical advantages compared to the other anthropometric tools. It does not require age data, which are often unreliable in these settings, and does not require sophisticated subtraction and two dimensional table-handling skills that weight for age and weight for height require. The measure is also more easily applied with less disturbance to the child and the community. The AC tape is cheap and not easily damaged or jarred out of calibration while being transported in rugged settings, as is often the case with weight scales. Moreover, it can be kept in a health worker's pocket at all times for continual use in a widespread range of settings. ^

Chamber evaluation of a personal organic vapor dosimeter at ppb concentrations of VOCs, varying temperatures and humidities with 24 -hour exposures

An exposure system was constructed to evaluate the performance of a personal organic vapor dosimeter (3520 OVM) at ppb concentrations of nine selected target volatile organic compounds (VOCs). These concentration levels are generally encountered in community air environments, both indoor and outdoor. It was demonstrated that the chamber system could provide closely-controlled conditions of VOC concentrations, temperature and relative humidity (RH) required for the experiments. The target experimental conditions included combinations of three VOC concentrations (10, 20 and 200 $\rm\mu g/m\sp3),$ three temperatures (10, 25 and 40$\sp\circ$C) and three RHs (12, 50 and 90% RH), leading to a total of 27 exposure conditions. No backgrounds of target VOCs were found in the exposure chamber system. In the exposure chamber, the variation of the temperature was controlled within $\pm$1$\sp\circ$C, and the variation of RH was controlled within $\pm$1.5% at 12% RH, $\pm$2% at 50% RH and $\pm$3% at 90% RH. High-emission permeation tubes were utilized to generate the target VOCs. Various patterns of the permeation rates were observed over time. The lifetimes and permeation rates of the tubes differed by compound, length of the tube and manufacturer. By carefully selecting the source and length of the tubes, and closely monitoring tube weight loss over time, the permeation tubes can be used for delivering low and stable concentrations of VOCs during multiple days.^ The results of this study indicate that the performance of the 3520 OVM is compound-specific and depends on concentration, temperature and humidity. With the exception of 1,3-butadiene under most conditions, and styrene and methylene chloride at very high relative humidities, recoveries were generally within $\pm$25% of theory, indicating that the 3520 OVM can be effectively used over the range of concentrations and environmental conditions tested with a 24-hour sampling period. Increasing humidities resulted in increasing negative bias from full recovery. Reverse diffusion conducted at 200 $\rm\mu g/m\sp3$ and five temperature/humidity combinations indicated severe diffusion losses only for 1,3-butadiene, methylene chloride and styrene under increased humidity. Overall, the results of this study do not support the need to employ diffusion samplers with backup sections for the exposure conditions tested. ^

Comparison of accuracy captured by different controlled languages in oral pathology diagnoses.

This project was comparing the accuracy of capturing the oral pathology diagnoses among different coding systems. 55 diagnoses were selected for comparison among 5 coding systems. The results of accuracy in capturing oral diagnoses are: AFIP (96.4%), followed by Read 99 (85.5%), SNOMED 98 (74.5%), ICD-9 (43.6%), and CDT-3 (14.5%). It shows that the currently used coding systems, ICD-9 and CDT-3, were inadequate, whereas the AFIP coding system captured the majority of oral diagnoses. In conclusion, the most commonly used medical and dental coding systems lack terms for the diagnosis of oral and dental conditions.