Anthropometric Measurement - Coursework Example

Part Sampling Criteria Anthropometric measurement means establishing human physical variation by measuring physical features of the individual. It is a modern method of establishing the nutritional well being of an individual by establishing the ratio of height to body weight and middle-upper arm circumference (Muac) among other methods to establish the level of malnutrition that the individual has undergone. The Nakivale refugee camp in Uganda was set up to accommodate refugees from neighboring countries fleeing war and famine. However, the situation has escalated greatly forcing individual refugees to receive half rations of food. This is due to rapid increase in refugee numbers and interference with relief supply routes. This has resulted in malnutrition in the camp that is threatening to reach critical levels. Obviously the methods mentioned above are best applied to children below the age of 12. It is quite ambitious to target the entire population with anthropometric measurements but this is not the best approach. First of all, the method is quite disruptive and is akin to bring all the activities in the camp to a halt as the entire population is targeted. Taking samples of the children will live adults especially en, to go on with their lives as best they can. Secondly, children are a good indicator of the levels of malnutrition since they are usually the worst affected exhibiting symptoms that are not very manifest in adults as they have not fully developed immunity to basic health problems. For instance, adults have stores of body protein in the labile amino acid pool which is primarily used as energy when the individual is starving. Such storage is very minimal or nonexistent in children (Rowett, 2010). Methods of Measurement It is inevitable that anthropometric methods will need to be employed to determine how acute the situation is for government interventions. Given the situation, the most effective measurement that can be used is the Middle-Upper Arm Circumference [Muac] to establish the level of malnutrition in the camp (Mother Child Nutrition, 2010). Using other methods such as the Body Mass Index (BMI); which estimate nutritional health by calculating the body weight of an individual divided by the square of his height; is not reliable in this case since it is limited to adults. The method is not directly applied to children since they are still growing and have thus not attained their full height. As indicated earlier, children are usually the most affected by malnutrition in any given population hence this method would leave them out (Rowett, 2010). The Muac method has several advantages. First, it is both simple and cheap. It is applicable by service providers at different locations of contact without giving them a very heavy workload . It is highly effective for case finding even by community based persons with little health training. Moreover, Muac has been proven to be a better indicator of malnutrition associated mortality risk than the Height/Weight among other methods. It can accurately identify children most in need of treatment (Mother Child Nutrition, 2010). In addition, comparative studies carried out show that Muac is less prone to mistakes than other methods since fewer errors occur in the process of gathering data. It is also easier to understand since the color coding of results is easily mastered by all users (Myatt et al, 2006). The color indicators are as follows: MUAC below 110mm [11.0cm], RED COLOUR, indicates Severe Acute Malnutrition [SAM]. In such a case the child must immediately be referred for treatment. Between 110mm [11.0cm] and 125mm [12.5cm], RED COLOUR on the 3-colour Tape or ORANGE COLOUR on the 4-colour Tape means Moderate Acute Malnutrition [MAM]. The child therefore needs immediate food supplementation. A measure of 125mm [12.5cm] and 135mm [13.5cm], YELLOW COLOUR, means the child risks acute malnutrition and needs counseling and follow-up for Growth Promotion and Monitoring [GPM]. Over 135mm [13.5cm], GREEN COLOUR, indicates a well nourished child (Mother Child Nutrition, 2010). Muac is therefore an accurate measure for determining cases of Severe Acute Malnutrition [SAM] . Since it is relatively easy to use and brings out results that are easily interpreted, it is among the preferred methods for gauging Global Acute Malnutrition [GAM] (Mother Child Nutrition, 2010). Analysis of the Two Step Screening Procedure The two step screening procedure involving Muac followed by the height to weight method is quite useful in many situations. However in the refugee camp this is a lengthier and costlier process. The government of Uganda is naturally interested in a simple, straight forward process that will cost as little as possible to carry out in terms of time and money. So Muac is the most applicable. Where it is accurate the weight to height measure is quite useful. However the Muac tends to be more accurate because of its simplicity which involves little in terms of complicated calculations. Moreover there are other reasons for discrepancies in weight for height measures. One of the glaring reasons the muac is relatively more accurate than the weight for height method is that the latter does not take into consideration the age of the child. Naturally some children grow faster than others. This growth however reflects body elongation rather than full development. Consequently, these children will tend to be lighter than children of the same height who are older. Their weight for height ratio is thus lower resulting in inconsistent findings. Comparatively, the muac method therefore gives consistent results even in such cases (Berkley J et al, 2005, 592). Sampling Methods The two types of sampling methods for consideration here are the traditional two-stage 30 x30 cluster technique and the Lot Quality Assurance Sampling (LQAS). Given the prevailing situation the Uganda Government will naturally need to find out which of the two methods is the better in terms of effectiveness and cost. Originally designed for estimation of the coverage of vaccination within a given area, the 30 x 30 cluster method is frequently used to provide rapid estimates during emergencies such as in refugee camp. The method is applied by taking people in 30 clusters of 30 households (30 x 30). The selected samples are surveyed by being recalled over a 30 days to six months period. The main advantage of the method is that it is flexible enough to be used in a variety of situations including informal settings like refugee camps. The use of this method is widespread due to its relative simplicity (Bilukha, 2008, 7). The lot Quality Assurance Sampling (LQAS) on the other hand is a method of sampling used to gather information in a small geographic or administrative area using a small sample. It is useful in detecting extremes of performance (Deitchler et al, 2007, 860). This means that it can show the highest and lowest levels but it is not easy to tell what the figures are in between. In other words it is not a useful measure for showing degrees of variation. It can only show the uppermost and lowest thresholds. The study is therefore by its very nature descriptive and cross sectional (Morris S., 2007, 864). Another important consideration for this method is the sample size. This is determined by the level of precision necessary for the success of the survey. The sample size is chosen considering the maximum allowable defective units. This means that to achieve a level of accuracy of 80% in a sample of 13 there can only be 4 defective units. The defective units refer to samples that do not exhibit the expected quality in any degree. If people who are malnourished are expected for instance, then those who are well fed cannot be more than 4 in a sample of 13 (Olives et al, 2009, 498). Of the two methods the first one is the most useful in the Ugandan situation because it tends to give more accurate figures than the second since it will reveal not only the number of children with malnutrition but also the degree of malnutrition in the camp. As stated earlier, the second method only reveals the extremes, those who are malnourished and those who are not (Bilukha, 2008, 7). The Group to be Targeted Though it seems simple to only target the most severely malnourished children in the camp, this is not the proper solution. The government of Uganda must endeavor to treat all the children with varying degrees of malnutrition (Yip R, Scanlon K., 1994, 2043s). Moreover, it is not just the children facing malnutrition but the survey carried out on them is a reflection of the general situation in the camp facing the adults as well. Proper interventions must therefore be made to tackle the malnutrition problem across the board since tackling it in bits will turn out to be counterproductive in the end (de Onis, 2000, 1272). References Berkerky J, Mwangi I, Griffiths K, Ahmed I, Mithwani S, English M, Newton C, Maitland K, 2005, Assessment of severe malnutrition among hospitalized children in rural Kenya: comparison of weight for height and mid upper arm circumference. JAMA. 3;294(5):591-7.  Bilukha OO, 2008 July,” Old and new cluster designs in emergency field surveys: in search of a one-fits-all solution”. Emerg Themes Epidemiol, 8;5(1): p 7.  Deitchler M, Valadez JJ, Egge K, Fernandez S, Hennigan M., 2007 May 21, “A field test of three LQAS designs to assess the prevalence of acute malnutrition”, Int J Epidemiol. 36(4): pp 860. Epub Mother Child Nutrition.org 2010, “Early Malnutrition Detection”, Retrieved on 20/11/2010 from de Onis M, 2000, “Measuring nutritional status in relation to mortality” Bull World Health Organ., 78(10):p 1272.  Morris S., 2007 Jun 27, “Commentary: learning to love lot quality assurance sampling”, Int J Epidemiol, 36(4):p 864. Epub. Myatt, M.A. et al, 2006, Community Based Therapeutic Care, CTC Field Manual, retrieved on 19/11/2010 from < www.fantaproject.org/downloads/pdfs/CTC_l_Manual_v1_Oct06-2.pdf> Olives C, Pagano M, Deitchler M, Hedt BL, Egge K, Valadez JJ., 2009 April, “ Cluster designs to assess the prevalence of acute malnutrition by lot quality assurance sampling: a validation study by computer simulation”, J R Stat Soc Ser A Stat Soc.; 172(2):pp 498.  Rowett Research Institute, 2010, “Improving Food Quality and Preventign Disease, NJ: Rowett (PDF). Yip R, Scanlon K., 1994 October, “ The burden of malnutrition: a population perspective”. J Nutr. 124(10 Suppl):2043S.  Part 2 Body Weight Assessment The two component model of body composition refers to the Fat Free Mass (FFM) and the Fat Mass (FM). The fat mass refers to the functional parts of the body including water, bone, protein and muscle. The fat mass consists of the fats accumulated and stored in the body (Gibson, 2005, 14). Under Water Weighing (UWW) or hydrostatic weighing is a method of determining the two components of body. It operates on the principle of Archimedes displacement. It is based on the concept that the density of fat mass and free fat mass is constant. Consequently, a person is weighed on land before being reweighed under water. Since body fat is less dense than water while bone and tissue is denser than water, a person with more fat will weigh much less in water than a person with a lean athletic muscular body, even if they weigh the same on land (Gibson, 2005, 17). Dual Energy X-ray Absorptiometry (Dexa) refers to a method of measuring bone density, lean soft tissue (LST) and body cell mass (BCM) using an x-ray scan. The amount of fat in the body can them be accurately calculated by subtracting all these measurements from the total body mass. In this way the two component system of the body can be analysed since the fat content, which x-rays cannot measure, is accurately calculated in this way (Lee & Nieman, 2010, 21). Impedance refers to any opposition to the flow of alternating electrical current. Any amount of opposition that the current encounters, especially from poor of electricity is called impedance (Lee & Nieman, 2010, 31). Water has a lower impedance than skeletal muscle. This is because it is a fluid with freely moving electrons. This enables electric charge to flow freely using the electrons. Bone on the other hand does not exhibit the same free electrons and is generally a poor conductor of electricity (Gibson, 2005, 37). The factors that affect impudence are resistance and reactance of the tissue. While resistance refers to the ability of the material to oppose the flow of current, such that current chooses the path of least resistance, reactance is the ability of material to hold current for some time before releasing it, like a capacitor. This means that when bone resists current, it will flow down the blood vessel as the path of least resistance. Body tissue on the other hand will store some current before releasing it (Lee & Nieman, 2010, 38). Materials of high resistance will stop the flow of current while those with high reactance will hold before releasing it (Lee & Nieman, 2010, 38). Bioelectric Impedance Analysis is a method of estimating composition using the differences in conductivity of different body tissues. BIA is conducted under controlled conditions. These conditions include the amount of current applied. A low current may be stopped by materials with high reactance while a higher current will flow through. In this way a lower current can pass through fluid only while a higher one will pass through fluid and tissue (Lee & Nieman, 2010, 39). X-ray computed tomography (CT) is a technique of medical imaging using graphics developed though a computer scan. The image can accurately in three dimensions show the internal composition of the body. A good ct scan is a high definition image of bones, body tissue and fat that can clearly be seen (Lee & Nieman, 2010, 45). Another variety of this method known as Digital Tomosynthesis is a combination of both digital capturing of the image and processing with simple tube/detector motion. It is similar to that used in regular radiographic tomography. Although quite similar to CT, it is a different technique. In CT, the detector makes a 360° rotation around the subject thus recording a complete set of data which helps in reconstructing the complete image (Lee & Nieman, 2010, 45). In digital tomosynthesis on the other hand, a smaller rotation angle like 40° with less discrete exposures are used. Though incomplete, this data set is digitally processed to compute images similar to CT, but with a limited field depth. Nevertheless, since the image is digitally processed, slices at different depths, with different thicknesses are reconstructed from the same source. In this way less time and radiation exposure are used (Lee & Nieman, 2010, 45). Magnetic resonance imaging (MRI) is another scanning device that uses a powerful magnetic device to align atoms in the body. It also uses radio frequencies to alter this alignment causing the nuclei to emit a rotating magnetic field detected by the scanner and used to create images. It is a highly precise method of imaging internal body organs and tissues (Lee & Nieman, 2010, 45). MRI is applied in clinical uses to distinguish pathologic tissue such as cancer and tumor, from ordinary tissue. One major advantage of an MRI scan is that it has no known side effects on the patient. This is because it employs the use of strong magnetic fields and non-ionizing radiation within the required range of radio frequency. Thisis as opposed to CT scans and x-rays which use ionizing radiation. Such radioation is of course potentially harmful to body tissue (Lee & Nieman, 2010, 45). The second method, MRI, is the most applicable in estimating the composition of the bodies of young overweight women. The main reason for this is that it does not employ the use of radiology in x-rays which can seriously affect people if improperly used (Lee & Nieman, 2010, 45). While CT has the distinct advantage of good spatial radiation, which refers to the ability to clearly distinguish between two separate structures an extremely small distance from each other; MRI gives far better contrast resolution, which is the ability to highlight the differences between two similar but non-identical tissues. This ability is based on the complex collection of pulse sequences included in the contemporary MRI scanner. Each of the pulse sequences is optimized to give image contrast due to the chemical sensitivity of MRI (Lee & Nieman, 2010, 45). Radiology in general is especially discouraged where there is a possibility that there could be an unborn baby. Radiology is proven to affect them. MRI on the other hand has no known side effects and is therefore used even to scan expectant women (Lee & Nieman, 2010, 45). References Gibson RS, 2005, Principles of Nutritional Assessment, Oxford University Press, pp 14-37. Lee RD & Nieman DC, 2010, “Nutritional Assessment. 5th Edition”, Boston: McGraw-Hill, pp 21-45. Read More