Tests for predicting complications of pre-eclampsia: A protocol for systematic reviews

Background Pre-eclampsia is associated with several complications. Early prediction of complications and timely management is needed for clinical care of these patients to avert fetal and maternal mortality and morbidity. There is a need to identify best testing strategies in pre eclampsia to identify the women at increased risk of complications. We aim to determine the accuracy of various tests to predict complications of pre-eclampsia by systematic quantitative reviews. Method We performed extensive search in MEDLINE (1951–2004), EMBASE (1974–2004) and also will also include manual searches of bibliographies of primary and review articles. An initial search has revealed 19500 citations. Two reviewers will independently select studies and extract data on study characteristics, quality and accuracy. Accuracy data will be used to construct 2 × 2 tables. Data synthesis will involve assessment for heterogeneity and appropriately pooling of results to produce summary Receiver Operating Characteristics (ROC) curve and summary likelihood ratios. Discussion This review will generate predictive information and integrate that with therapeutic effectiveness to determine the absolute benefit and harm of available therapy in reducing complications in women with pre-eclampsia

Synthesizing Short-Circuiting Validation of Data Structure Invariants

This paper presents incremental verification-validation, a novel approach for checking rich data structure invariants expressed as separation logic assertions. Incremental verification-validation combines static verification of separation properties with efficient, short-circuiting dynamic validation of arbitrarily rich data constraints. A data structure invariant checker is an inductive predicate in separation logic with an executable interpretation; a short-circuiting checker is an invariant checker that stops checking whenever it detects at run time that an assertion for some sub-structure has been fully proven statically. At a high level, our approach does two things: it statically proves the separation properties of data structure invariants using a static shape analysis in a standard way but then leverages this proof in a novel manner to synthesize short-circuiting dynamic validation of the data properties. As a consequence, we enable dynamic validation to make up for imprecision in sound static analysis while simultaneously leveraging the static verification to make the remaining dynamic validation efficient. We show empirically that short-circuiting can yield asymptotic improvements in dynamic validation, with low overhead over no validation, even in cases where static verification is incomplete

Systems validation: application to statistical programs

BACKGROUND: In 2003, the United States Food and Drug Administration (FDA) released a guidance document on the scope of "Part 11" enforcement. In this guidance document, the FDA indicates an expectation of a risk-based approach to determining which systems should undergo validation. Since statistical programs manage and manipulate raw data, their implementation should be critically reviewed to determine whether or not they should undergo validation. However, the concepts of validation are not often discussed in biostatistics curriculum. DISCUSSION: This paper summarizes a "Plan, Do, Say" approach to validation that can be incorporated into statistical training so that biostatisticians can understand and implement validation principles in their research. SUMMARY: Validation is a process that requires dedicated attention. The process of validation can be easily understood in the context of the scientific method

EN-BIRTH Data Collector Training - Handbook and Manual

The EN-BIRTH study aims to validate selected newborn and maternal indicators for routine facility-based tracking of coverage and quality of care for use at district, national and global levels. The item contains the EN-BIRTH_Trainer's Manual (14 June 2017) and EN-BIRTH_Training Handbook (23 May 2017)

Added predictive value of high-throughput molecular data to clinical data, and its validation

Hundreds of ''molecular signatures'' have been proposed in the literature to predict patient outcome in clinical settings from high-dimensional data, many of which eventually failed to get validated. Validation of such molecular research findings is thus becoming an increasingly important branch of clinical bioinformatics. Moreover, in practice well-known clinical predictors are often already available. From a statistical and bioinformatics point of view, poor attention has been given to the evaluation of the added predictive value of a molecular signature given that clinical predictors are available. This article reviews procedures that assess and validate the added predictive value of high-dimensional molecular data. It critically surveys various approaches for the construction of combined prediction models using both clinical and molecular data, for validating added predictive value based on independent data, and for assessing added predictive value using a single data set

Validation of Survey Data on Income and Employment: The ISMIE Experience

This report derives from the project "Improving survey measurement of income and employment (ISMIE)" which investigates measurement error in survey data on income and employment, using a UK sub-sample of the European Household Community Panel (ECHP). In this paper we describe the process of collecting validation data and the outcomes of the process. Validation data were obtained from two sources: employers' records and government benefit data from the Department for Work and Pensions (DWP). The former provided information on occupation and employment status, gross and net pay, membership of company pension schemes and industry sector. The latter provided histories of benefit receipt and tax credits, for example, child, disability, housing and unemployment benefits, pensions and income support. In the survey interview, respondents were asked for written permission both to obtain their DWP records and to contact their employer. They were also asked to provide information that would facilitate the process of obtaining the validation data: National Insurance number (NINO) and employer contact details. Subsequently, DWP records were extracted using a non-hierarchical matching strategy, based on different combinations of identifying variables obtained in the survey (NINO, sex, date of birth, name and postcode), and a survey of employers was carried out (mail, with telephone follow-up). The representativeness of the validation samples obtained depends on the co-operation of both survey respondents and providers of validation data, as well as errors in the matching process. We report permission rates, proportions providing matching items, match rates for the DWP data and response rates to the employer survey. We identify correlates of these measures of success at each stage of the validation process in terms of substantive characteristics of the survey respondents. Variation by subgroups is identified and implications for the representativeness of the validation sample are discussed.

A statistical method (cross-validation) for bone loss region detection after spaceflight.

Astronauts experience bone loss after the long spaceflight missions. Identifying specific regions that undergo the greatest losses (e.g. the proximal femur) could reveal information about the processes of bone loss in disuse and disease. Methods for detecting such regions, however, remains an open problem. This paper focuses on statistical methods to detect such regions. We perform statistical parametric mapping to get t-maps of changes in images, and propose a new cross-validation method to select an optimum suprathreshold for forming clusters of pixels. Once these candidate clusters are formed, we use permutation testing of longitudinal labels to derive significant changes

Validation of the Clinical COPD questionnaire in Italian language

BACKGROUND: The development and validation study of the Clinical Chronic Obstructive Disease (COPD) Questionnaire (CCQ) has recently been published in this journal. The CCQ is the first questionnaire that incorporates both clinician and patient guideline goals in the clinical control evaluation of patients with COPD in general clinical practice. The aim of this study is the validation of the CCQ questionnaire in Italian, in specific pulmonary disease clinical practice. METHODS: Validity was tested on a population of healthy subjects and patients with COPD, using the Italian validated version of the Short Form Health Survey (SF-36) and guideline recommended routine measurement in COPD patients (FEV(1), FVC, BMI and functional dyspnoea). Test-retest reliability was tested by re-administering the CCQ after 2 weeks. Responsiveness was tested by re-administering the CCQ after three weeks of hospital pulmonary rehabilitation. Distance walked and Borg breathlessness rating were measured at the end of the six-minute walking test (6 MWT), before and after rehabilitation. RESULTS: Cross-sectional data were collected from 175 subjects (55 healthy; 40 mild-moderate, 50 severe and 25 very severe COPD). Cronbach's alpha was high (0.89). The CCQ scores in patients were significantly worse than in healthy subjects. The CCQ total score in patients with COPD was significantly worse in those with BMI < = 21. Significant correlations were found between the CCQ total score and domains of the SF-36 (rho = -0.43 to rho = -0.72). The correlation between the CCQ and FEV1 % predicted was rho = -0.57. The correlation between the CCQ and MRC was rho = 0.63. Test-retest reliability was determined in 112 subjects over a period of two weeks (Intra Class Coefficient = 0.99). Forty-six patients with COPD showed significant improvement in CCQ scores, distance-walked and Borg breathlessness rating after 3 weeks of pulmonary rehabilitation, indicating CCQ responsiveness. CONCLUSIONS: The CCQ is self-administered and has been specially developed to measure clinical control in patients with COPD. Data support its validity, reliability and responsiveness in Italian and in specific pulmonary disease clinical practice