[Minimizing losses and maximizing efficiency in the detection of acute severe malnutrition]. / Minimizando perdas e maximizando eficiência na detecção de casos de desnutrição aguda severa.

OBJECTIVE: One of the many challenges faced by epidemiologists is to adequately plan and optimize subject selection procedures in terms of effectiveness and efficiency. In the context of a case-control study involving severe acute malnutrition, a two-step subject selection procedure is used. The aim of the article is to establish an appropriate cut-off point for the screening phase and to achieve a common ground for standards, efficiency in detecting severe malnutrition and the two-step procedure. METHODS: The study includes 154 children under the age of 2 from two different hospitals. To determine the ideal cut-off point of weight-for-age (WFA), the following estimators are of interest: the proportion of false negatives (PFN), false positives (PFP) and the percentage of total gain by time (ptg). Weight-for-height (WFH) (cut-off point at -2 SDs) is used as reference for establishing severe acute malnutrition. RESULTS: The magnitude of false negatives declines steadily until the 3rd WFA percentile (P3) and reaches zero close to P9. At this point, the PFP is around 0.4. The ptg decreases sharply up to P4, declining smoothly towards P10 thereafter (54.5%). CONCLUSIONS: The WFA P10 can be recommended for the screening phase. At this cut-off point, there is still efficiency whereas losses of true cases of severe acute malnutrition are minimized.

[Semantic equivalence of the Portuguese version of the Abuse Assessment Screen tool used for the screening of violence against pregnant women]. / Equivalência semântica da versão em português do instrumento Abuse Assessment Screen para rastrear a violência contra a mulher grávida.

INTRODUCTION: Research programs and actions regarding family violence have been growing steadily. Therefore, there's a need to develop data collection tools. In Brazil, further problems come up since tools that have been developed elsewhere need to be adapted and translated. This study focuses on the Abuse Assessment Screening (AAS) used to detect violence against pregnant women. The objective is to evaluate the semantic equivalence between the original tool in English and two Portuguese versions, and propose a synthetic version to be used in the field. METHODS: The evaluation of semantic equivalence was carried out in 4 steps: (1) translation, (2) back translation, (3) formal appreciation of equivalence and (4) a final critical assessment by family violence experts. RESULTS: Translation, back translation and the steps 3 and 4 assessment are presented for each item of the tool, along with the original in English. The text covers each discussion that led to the final version. Both versions were quite similar in 14 out of 15 items. Nevertheless, the second version showed to be slightly more adequate although for some items the decision was to combine both versions or, in one case, use an item from version 1. CONCLUSION: The procedure undertaken in this study is discussed in the light of Herdman et al.'s proposal (1998) regarding transcultural equivalence. The study also stresses the importance of using more than one version in the process and the appropriateness of including an additional step about the assessment of the target population's understanding of the tool.

[Measurement reliability in a study on family violence and severe acute malnutrition]. / Confiabilidade das aferições de estudo sobre violência familiar e desnutrição severa na infância.

INTRODUCTION: This study is nested within a research program related to family violence and severe childhood malnutrition. Its aim is to evaluate the reliability of the data collection process in a case-control study. Four components of the main instrument are addressed: (a) CTS (Conflict Tactics Scales) used to measure violence at the family level; (b) CAGE (Cut-down; Annoyed; Guilty & Eye-opener) questionnaire used to gauge suspicion of drinking problems; NSDUQ (Non-student Drugs Use Questionnaire) used to indicate illicit drug consumption; and (d) height/length measurements. METHOD: Stability (intra-observer or test-retest reliability) and equivalence (inter-observer reliability) were evaluated for the cited components (a), (b) and (c). Information was replicated among the first 50 subjects selected for the underlying case-control study. The Kappa index (k) was used in the analysis. A pseudo-Bayes adjustment was carried out in order to handle estimation problems. Regarding (d), only equivalence was evaluated (n = 73), using the Intraclass Correlation Coefficient as the estimator. RESULTS: By and large, all components showed acceptable stability and equivalence. Regarding stability, the estimates of k were around 0.70, 0.78 and 0.85, for CTS, CAGE e NSDUQ, respectively. With respect to equivalence, k was 1.0 for CTS and NSDUQ and 0.75 for CAGE. Equivalence for height/length estimated through the ICC was 0.99. Nevertheless, some deviant situations were detected and are further discussed. The results point to an adequate standardization of observers and reflect the good quality of the data collection procedure concerning the main study, encouraging the research team to press forward with greater assurance.