Interpreting results of cluster surveys in emergency settings: is the LQAS test the best option?

Cluster surveys are commonly used in humanitarian emergencies to measure health and nutrition indicators. Deitchler et al. have proposed to use Lot Quality Assurance Sampling (LQAS) hypothesis testing in cluster surveys to classify the prevalence of global acute malnutrition as exceeding or not exceeding the pre-established thresholds. Field practitioners and decision-makers must clearly understand the meaning and implications of using this test in interpreting survey results to make programmatic decisions. We demonstrate that the LQAS test–as proposed by Deitchler et al. – is prone to producing false-positive results and thus is likely to suggest interventions in situations where interventions may not be needed. As an alternative, to provide more useful information for decision-making, we suggest reporting the probability of an indicator's exceeding the threshold as a direct measure of "risk". Such probability can be easily determined in field settings by using a simple spreadsheet calculator. The "risk" of exceeding the threshold can then be considered in the context of other aggravating and protective factors to make informed programmatic decisions

Comparison of anthropometric data quality in children aged 6-23 and 24-59 months: lessons from population-representative surveys from humanitarian settings

BACKGROUND: Ensuring the quality of anthropometry data is paramount for getting accurate estimates of malnutrition prevalence among children aged 6-59 months in humanitarian and refugee settings. Previous reports based on data from Demographic and Health Surveys suggested systematic differences in anthropometric data quality between the younger and older groups of preschool children. METHODS: We analyzed 712 anthropometric population-representative field surveys from humanitarian and refugee settings conducted during 2011-2018. We examined and compared the quality of five anthropometric indicators in children aged 6-23 months and children aged 24-59 months: weight for height, weight for age, height for age, body mass index for age and mid-upper arm circumference (MUAC) for age. Using the z-score distribution of each indicator, we calculated the following parameters: standard deviation (SD), percentage of outliers, and measures of distribution normality. We also examined and compared the quality of height, weight, MUAC and age measurements using missing data and rounding criteria. RESULTS: Both SD and percentage of flags were significantly smaller on average in older than in younger age group for all five anthropometric indicators. Differences in SD between age groups did not change meaningfully depending on overall survey quality or on the quality of age ascertainment. Over 50% of surveys overall did not deviate significantly from normality. The percentage of non-normal surveys was higher in older than in the younger age groups. Digit preference score for weight, height and MUAC was slightly higher in younger age group, and for age slightly higher in the older age group. Children with reported exact date of birth (DOB) had much lower digit preference for age than those without exact DOB. SD, percentage flags and digit preference scores were positively correlated between the two age groups at the survey level, such as those surveys showing higher anthropometry data quality in younger age group also tended to show higher quality in older age group. CONCLUSIONS: There should be an emphasis on increased rigor of training survey measurers in taking anthropometric measurements in the youngest children. Standardization test, a mandatory component of the pre-survey measurer training and evaluation, of 10 children should include at least 4-5 children below 2 years of age

РОЛЬ ЕНДОТЕЛІАЛЬНОЇ ДИСФУНКЦІЇ В РОЗВИТКУ АРТЕРІАЛЬНОЇ ГІПЕРТЕНЗІЇ У ХВОРИХ НА АНКІЛОЗИВНИЙ СПОНДИЛОАРТРИТ

Purpose: to establish the role of endothelial dysfunction in the development of arterial hypertension in patients with ankylosing spondylarthritis.Materials and Methods. A total of 110 patients with AS were examined with evaluation endothelium-dependent vasodilation (EDVD). All patients received antihypertensive therapy which did not change throughout all study.Results. It was found that every third patient  suffered from hypertension, endothelial function disorders were detected in 71.8 % of patients. A large cohort of patients showed low levels of HDL and elevated levels of LDL.At the same time, significant differences in disease activity and functional status were found in the group with hypertension.Conclusions. We must assume that endothelial dysfunction, which occurs on the background of systemic inflammatory syndrome, is probably the main reason for the development of hypertension in patients with AS.Мета: встановити роль ендотеліальної дисфункції в розвитку артеріальної гіпертензії у хворих на анкілозивний спондилоартрит.Матеріали і методи. Обстежено 110 пацієнтів з анкілозивним спондилоартритом, яким проводили оцінку стану ендотелію. До моменту включення в дослідження всі пацієнти отримували базисну антигіпертензивну терапію, котра не змінювалась під час обстеження.Результати. Встановлено, що практично кожен третій пацієнт хворів на артеріальну гіпертензію, порушення функції ендотелію виявлено у 71,8 % хворих. Достатньо велика когорта обстежених демонструвала знижений рівень ЛПВЩ і підвищений рівень ЛПНЩ. Поряд із тим, виявлено суттєві відмінності за показниками активності за­хворювання (СРБ, ШОЕ, BASDAI) та функціонального статусу (BASFI) у пацієнтів з артеріальною гіпертензією та без.Висновки. Можна припустити, що саме дисфункція ендотелію, котра виникає на фоні системного запального синдрому, ймовірно, є основною причиною розвитку артеріальної гіпертензії у пацієнтів з анкілозивним спондилоартритом, адже відмінностей за іншими класичними факторами ССР, окрім дисліпідемій, виявлено не було

A Decade Later, How Much of Rwanda's Musculoskeletal Impairment Is Caused by the War in 1994 and by Related Violence?

BACKGROUND: In 1994 there was a horrific genocide in Rwanda following years of tension, resulting in the murder of at least 800,000 people. Although many people were injured in addition to those killed, no attempt has been made to assess the lasting burden of physical injuries related to these events. The aim of this study was to estimate the current burden of musculoskeletal impairment (MSI) attributable to the 1994 war and related violence. METHODOLOGY/PRINCIPAL FINDINGS: A national cross-sectional survey of MSI was conducted in Rwanda. 105 clusters of 80 people were selected through probability proportionate to size sampling. Households within clusters were selected through compact segment sampling. Enumerated people answered a seven-question screening test to assess whether they might have an MSI. Those who were classed as potential cases in the screening test were examined and interviewed by a physiotherapist, using a standard protocol that recorded the site, nature, cause, and severity of the MSI. People with MSI due to trauma were asked whether this trauma occurred during the 1990-1994 war or during the episodes that preceded or followed this war. Out of 8,368 people enumerated, 6,757 were available for screening and examination (80.8%). 352 people were diagnosed with an MSI (prevalence=5.2%, 95% CI=4.5-5.9%). 106 cases of MSI (30.6%) were classified as resulting from trauma, based on self-report and the physiotherapist's assessment. Of these, 14 people (13.2%) reported that their trauma-related MSI occurred during the 1990-1994 war, and a further 7 (6.6%) that their trauma-related MSI occurred during the violent episodes that preceded and followed the war, giving an overall prevalence of trauma-related MSI related to the 1990-1994 war of 0.3% (95% CI=0.2-0.4%). CONCLUSIONS/SIGNIFICANCE: A decade on, the overall prevalence of MSI was relatively high in Rwanda but few cases appeared to be the result of the 1994 war or related violence

Old and new cluster designs in emergency field surveys: in search of a one-fits-all solution

<p>Abstract</p> <p>Introduction</p> <p>Cluster surveys are frequently used to measure key nutrition and health indicators in humanitarian emergencies. The survey design of 30 clusters of 7 children (30 × 7) was initially proposed by the World Health Organization for measuring vaccination coverage, and later a design of 30 clusters of 30 children (30 × 30) was introduced to measure acute malnutrition in emergency settings. Recently, designs of 33 clusters of 6 children (33 × 6) and 67 clusters of 3 children (67 × 3) have been proposed as alternatives that enable measurement of several key indicators with sufficient precision, while offering substantial savings in time. This paper explores expected effects of using 67 × 3, 33 × 6, or 30 × 7 designs instead of a "standard" 30 × 30 design on precision and accuracy of estimates, and on time required to complete the survey.</p> <p>Analysis</p> <p>The 67 × 3, 33 × 6, and 30 × 7 designs are expected to be more statistically efficient for measuring outcomes having high design effects (e.g., vaccination coverage, vitamin A distribution coverage, or access to safe water sources), and less efficient for measuring outcomes with more within-cluster variability, such as global acute malnutrition or anemia. Because of small sample sizes, these designs may not provide sufficient levels of precision to measure crude mortality rates. Given the small number (3 to 7) of survey subjects per cluster, it may be hard to select representative samples of subjects within clusters.</p> <p>The smaller sample size in these designs will likely result in substantial time savings. The magnitude of the savings will depend on several factors, including the average travel time between clusters. The 67 × 3 design will provide the least time savings. The 33 × 6 and 30 × 7 designs perform similarly to each other, both in terms of statistical efficiency and in terms of time required to complete the survey.</p> <p>Conclusion</p> <p>Cluster designs discussed in this paper may offer substantial time and cost savings compared to the traditional 30 × 30 design, and may provide acceptable levels of precision when measuring outcomes that have high intracluster homogeneity. Further investigation is required to determine whether these designs can consistently provide accurate point estimates for key outcomes of interest. Organizations conducting cluster surveys in emergency settings need to build their technical capacity in survey design to be able to calculate context-specific sample sizes individually for each planned survey.</p

Interventions to prevent youth violence in Latin America: a systematic review

Objectives: This review aims to summarise evidence on the effectiveness of interventions to prevent youth violence in Latin America. Methods: A systematic search on 13 academic databases was conducted to locate studies evaluating a primary or secondary prevention intervention in Latin America. Studies could use any type of quantitative design to assess outcomes related to youth violence. A search of websites, references and citation searching was also carried out. The quality of each study was assessed. Results: Nine studies were identified. Most documented positive effects of the interventions on the perception of youth violence present in the community/school. Evidence was found of a reduction in homicides and juvenile crimes in three studies, two of which evaluated a community-based intervention. There were mixed results for the self-report of participation on violent acts. The majority of the studies lacked of a rigorous design. Conclusions: Most of the interventions had some promising results, including the reduction of homicides within communities. Community-based programmes were the most consistent regarding an effectiveness to prevent violence. However, the evidence for Latin America is still scarce and relies on non-rigorously designed studies