Open science practices need substantial improvement in prognostic model studies in oncology using machine learning.

OBJECTIVE: To describe the frequency of open science practices in a contemporary sample of studies developing prognostic models using machine learning methods in the field of oncology. STUDY DESIGN AND SETTING: We conducted a systematic review, searching the MEDLINE database between December 1, 2022, and December 31, 2022, for studies developing a multivariable prognostic model using machine learning methods (as defined by the authors) in oncology. Two authors independently screened records and extracted open science practices. RESULTS: We identified 46 publications describing the development of a multivariable prognostic model. The adoption of open science principles was poor. Only one study reported availability of a study protocol, and only one study was registered. Funding statements and conflicts of interest statements were common. Thirty-five studies (76%) provided data sharing statements, with 21 (46%) indicating data were available on request to the authors and seven declaring data sharing was not applicable. Two studies (4%) shared data. Only 12 studies (26%) provided code sharing statements, including 2 (4%) that indicated the code was available on request to the authors. Only 11 studies (24%) provided sufficient information to allow their model to be used in practice. The use of reporting guidelines was rare: eight studies (18%) mentioning using a reporting guideline, with 4 (10%) using the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis Or Diagnosis statement, 1 (2%) using Minimum Information About Clinical Artificial Intelligence Modeling and Consolidated Standards Of Reporting Trials-Artificial Intelligence, 1 (2%) using Strengthening The Reporting Of Observational Studies In Epidemiology, 1 (2%) using Standards for Reporting Diagnostic Accuracy Studies, and 1 (2%) using Transparent Reporting of Evaluations with Nonrandomized Designs. CONCLUSION: The adoption of open science principles in oncology studies developing prognostic models using machine learning methods is poor. Guidance and an increased awareness of benefits and best practices of open science are needed for prediction research in oncology.

Estimated fetal weight standards of the INTERGROWTH-21st project for the prediction of adverse outcomes: a systematic review with meta-analysis.

OBJECTIVE: To systematically review and assess the risk of bias in the literature evaluating the performance of INTERGROWTH-21st estimated fetal weight (EFW) standards to predict maternal, fetal and neonatal adverse outcomes. METHODS: Searches were performed in seven electronic databases (Scopus, Web of Science, Medline, Embase, Lilacs, Scielo and Google Scholar) using citation tools and keywords (intergrowth AND (standard OR reference OR formula OR model OR curve); all from 2014 to the last search on April 16th, 2021). We included full-text articles investigating the ability of INTERGROWTH-21st EFW standards to predict maternal, fetal or neonatal adverse outcomes in women with a singleton pregnancy who gave birth to infants with no congenital abnormalities. The study was registered on PROSPERO under the number CRD42020115462. Risk of bias was assessed with a customized instrument based on the CHARMS checklist and composed of 9 domains. Meta-analysis was performed using relative risk (RR [95%CI]) and summary ROC curves on outcomes reported by two or more methodologically homogeneous studies. RESULTS: Sixteen studies evaluating fifteen different outcomes were selected. The risk of bias was high (>50% of studies with high risk) for two domains: blindness of assessment (81.3%) and calibration assessment (93.8%). Considering all the outcomes investigated, for 95% of the results, the specificity was above 73.0%, but the sensitivity was below 64.1%. Pooled results demonstrated a higher RR of neonatal small for gestational age (6.71 [5.51-8.17]), Apgar <7 at 5 min (2.17 [1.48-3.18]), and neonatal intensive care unit admission (2.22 [1.76-2.79]) for fetuses classified <10th percentile when compared to those classified above this limit. The limitation of the study is the absence of heterogeneity exploration or publication bias investigation, whereas no outcomes were evaluated by more than five studies. CONCLUSIONS: The IG-21 EFW standard has low sensitivity and high specificity for adverse events of pregnancy. Classification <10th percentile identifies a high-risk group for developing maternal, fetal and neonatal adverse outcomes, especially neonatal small for gestational age, Apgar <7 at 5 min, and neonatal intensive care unit admission. Future studies should include blind assessment of outcomes, perform calibration analysis with continuous data, and evaluate alternative cutoff points.

Minimal reporting guideline for research involving eye tracking (2023 edition).

A guideline is proposed that comprises the minimum items to be reported in research studies involving an eye tracker and human or non-human primate participant(s). This guideline was developed over a 3-year period using a consensus-based process via an open invitation to the international eye tracking community. This guideline will be reviewed at maximum intervals of 4 years.

Reminding Peer Reviewers of Reporting Guideline Items to Improve Completeness in Published Articles: Primary Results of 2 Randomized Trials.

Importance: Numerous studies have shown that adherence to reporting guidelines is suboptimal. Objective: To evaluate whether asking peer reviewers to check if specific reporting guideline items were adequately reported would improve adherence to reporting guidelines in published articles. Design, Setting, and Participants: Two parallel-group, superiority randomized trials were performed using manuscripts submitted to 7 biomedical journals (5 from the BMJ Publishing Group and 2 from the Public Library of Science) as the unit of randomization, with peer reviewers allocated to the intervention or control group. Interventions: The first trial (CONSORT-PR) focused on manuscripts that presented randomized clinical trial (RCT) results and reported following the Consolidated Standards of Reporting Trials (CONSORT) guideline, and the second trial (SPIRIT-PR) focused on manuscripts that presented RCT protocols and reported following the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guideline. The CONSORT-PR trial included manuscripts that described RCT primary results (submitted July 2019 to July 2021). The SPIRIT-PR trial included manuscripts that contained RCT protocols (submitted June 2020 to May 2021). Manuscripts in both trials were randomized (1:1) to the intervention or control group; the control group received usual journal practice. In the intervention group of both trials, peer reviewers received an email from the journal that asked them to check whether the 10 most important and poorly reported CONSORT (for CONSORT-PR) or SPIRIT (for SPIRIT-PR) items were adequately reported in the manuscript. Peer reviewers and authors were not informed of the purpose of the study, and outcome assessors were blinded. Main Outcomes and Measures: The difference in the mean proportion of adequately reported 10 CONSORT or SPIRIT items between the intervention and control groups in published articles. Results: In the CONSORT-PR trial, 510 manuscripts were randomized. Of those, 243 were published (122 in the intervention group and 121 in the control group). A mean proportion of 69.3% (95% CI, 66.0%-72.7%) of the 10 CONSORT items were adequately reported in the intervention group and 66.6% (95% CI, 62.5%-70.7%) in the control group (mean difference, 2.7%; 95% CI, -2.6% to 8.0%). In the SPIRIT-PR trial, of the 244 randomized manuscripts, 178 were published (90 in the intervention group and 88 in the control group). A mean proportion of 46.1% (95% CI, 41.8%-50.4%) of the 10 SPIRIT items were adequately reported in the intervention group and 45.6% (95% CI, 41.7% to 49.4%) in the control group (mean difference, 0.5%; 95% CI, -5.2% to 6.3%). Conclusions and Relevance: These 2 randomized trials found that it was not useful to implement the tested intervention to increase reporting completeness in published articles. Other interventions should be assessed and considered in the future. Trial Registration: ClinicalTrials.gov Identifiers: NCT05820971 (CONSORT-PR) and NCT05820984 (SPIRIT-PR).

Reporting guidelines used varying methodology to develop recommendations.

BACKGROUND AND OBJECTIVES: We investigated the developing methods of reporting guidelines in the EQUATOR (Enhancing the QUAlity and Transparency Of health Research) Network's database. METHODS: In October 2018, we screened all records and excluded those not describing reporting guidelines from further investigation. Twelve researchers performed duplicate data extraction on bibliometrics, scope, development methods, presentation, and dissemination of all publications. Descriptive statistics were used to summarize the findings. RESULTS: Of the 405 screened records, 262 described a reporting guidelines development. The number of reporting guidelines increased over the past 3 decades, from 5 in the 1990s and 63 in the 2000s to 157 in the 2010s. Development groups included 2-151 people. Literature appraisal was performed during the development of 56% of the reporting guidelines; 33% used surveys to gather external opinion on items to report; and 42% piloted or sought external feedback on their recommendations. Examples of good reporting for all reporting items were presented in 30% of the reporting guidelines. Eighteen percent of the reviewed publications included some level of spin. CONCLUSION: Reporting guidelines have been developed with varying methodology. Reporting guideline developers should use existing guidance and take an evidence-based approach, rather than base their recommendations on expert opinion of limited groups of individuals.

Completeness of Reporting in Diet- and Nutrition-Related Randomized Controlled Trials and Systematic Reviews With Meta-Analysis: Protocol for 2 Independent Meta-Research Studies.

BACKGROUND: Journal articles describing randomized controlled trials (RCTs) and systematic reviews with meta-analysis of RCTs are not optimally reported and often miss crucial details. This poor reporting makes assessing these studies' risk of bias or reproducing their results difficult. However, the reporting quality of diet- and nutrition-related RCTs and meta-analyses has not been explored. OBJECTIVE: We aimed to assess the reporting completeness and identify the main reporting limitations of diet- and nutrition-related RCTs and meta-analyses of RCTs, estimate the frequency of reproducible research practices among these RCTs, and estimate the frequency of distorted presentation or spin among these meta-analyses. METHODS: Two independent meta-research studies will be conducted using articles published in PubMed-indexed journals. The first will include a sample of diet- and nutrition-related RCTs; the second will include a sample of systematic reviews with meta-analysis of diet- and nutrition-related RCTs. A validated search strategy will be used to identify RCTs of nutritional interventions and an adapted strategy to identify meta-analyses in PubMed. We will search for RCTs and meta-analyses indexed in 1 calendar year and randomly select 100 RCTs (June 2021 to June 2022) and 100 meta-analyses (July 2021 to July 2022). Two reviewers will independently screen the titles and abstracts of records yielded by the searches, then read the full texts to confirm their eligibility. The general features of these published RCTs and meta-analyses will be extracted into a research electronic data capture database (REDCap; Vanderbilt University). The completeness of reporting of each RCT will be assessed using the items in the CONSORT (Consolidated Standards of Reporting Trials), its extensions, and the TIDieR (Template for Intervention Description and Replication) statements. Information about practices that promote research transparency and reproducibility, such as the publication of protocols and statistical analysis plans will be collected. There will be an assessment of the completeness of reporting of each meta-analysis using the items in the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement and collection of information about spin in the abstracts and full-texts. The results will be presented as descriptive statistics in diagrams or tables. These 2 meta-research studies are registered in the Open Science Framework. RESULTS: The literature search for the first meta-research retrieved 20,030 records and 2182 were potentially eligible. The literature search for the second meta-research retrieved 10,918 records and 850 were potentially eligible. Among them, random samples of 100 RCTs and 100 meta-analyses were selected for data extraction. Data extraction is currently in progress, and completion is expected by the beginning of 2023. CONCLUSIONS: Our meta-research studies will summarize the main limitation on reporting completeness of nutrition- or diet-related RCTs and meta-analyses and provide comprehensive information regarding the particularities in the reporting of intervention studies in the nutrition field. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/43537.

Recruitment of low-income pregnant women into a dietary and dental care intervention: lessons from a feasibility trial.

BACKGROUND: There are difficulties in carrying out research in low-income urban communities, but the methodological challenges and suggestions on how to deal with them are often undocumented. The aims of this study are to describe the challenges of recruiting and enrolling low-income pregnant women with periodontitis to a clinical trial on vitamin D/calcium milk fortification and periodontal therapy and also to describe the patient-, study protocol- and setting-related factors related to women's ineligibility and refusal to participate in the study. METHODS: A mixed-method sequential exploratory design was applied. Qualitative and quantitative data on recruitment to a 2 × 2 factorial feasibility clinical trial were used. Eighteen women attending the health centre in a low-income area in Duque de Caxias (Rio de Janeiro, Brazil) took part in focus group discussions, and the data were thematically analysed. Quantitative data were analysed using appropriate descriptive statistics, including absolute and relative frequencies. RESULTS: Of all referrals (767), 548 (78.5%) did not meet the initial eligibility criteria. The main reason for exclusion (58%) was advanced gestational age (> 20 weeks) at first prenatal appointment. In the periodontal examination (dental screen), the main reason for exclusion was the presence of extensive caries (64 out of 127 exclusions). Non-participation of those eligible after the periodontal examination was approximately 24% (22 out 92 eligible women) and predominantly associated with patient-related barriers (e.g. transportation barriers, family obligations, patients being unresponsive to phone calls and disconnected telephones). The study recruited 70 women with periodontitis in 53 weeks and did not reach the benchmark of 120 women in 36 weeks (58.3% of the original target). Recruitment was severely hindered by health centre closures due to general strikes. The recruitment yields were 9.1% (70/767) of all women contacted at first prenatal visit and 76.1% (70/92) of those screened eligible and enrolled in the trial. Women did not report concerns regarding random allocation and considered fortified milk as a healthful and safe food for pregnant women. Some women reported that financial constraints (e.g. transportation costs) could hinder participation in the study. CONCLUSION: Engagement between the research team and health centre staff (e.g. nurses) facilitated referral and recruitment, yet some pregnant women failed to participate in the study largely due to significant patient-related sociodemographic barriers and setting-related factors. Our data illustrate the complexity of overcoming recruitment and enrolment challenges for clinical trials in resource-limited settings. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03148483. Registered on 11 May 2017.

Development and prospective external validation of a tool to predict poor recovery at 9 months after acute ankle sprain in UK emergency departments: the SPRAINED prognostic model.

OBJECTIVES: To develop and externally validate a prognostic model for poor recovery after ankle sprain. SETTING AND PARTICIPANTS: Model development used secondary data analysis of 584 participants from a UK multicentre randomised clinical trial. External validation used data from 682 participants recruited in 10 UK emergency departments for a prospective observational cohort. OUTCOME AND ANALYSIS: Poor recovery was defined as presence of pain, functional difficulty or lack of confidence in the ankle at 9 months after injury. Twenty-three baseline candidate predictors were included together in a multivariable logistic regression model to identify the best predictors of poor recovery. Relationships between continuous variables and the outcome were modelled using fractional polynomials. Regression parameters were combined over 50 imputed data sets using Rubin's rule. To minimise overfitting, regression coefficients were multiplied by a heuristic shrinkage factor and the intercept re-estimated. Incremental value of candidate predictors assessed at 4 weeks after injury was explored using decision curve analysis and the baseline model updated. The final models included predictors selected based on the Akaike information criterion (p<0.157). Model performance was assessed by calibration and discrimination. RESULTS: Outcome rate was lower in the development (6.7%) than in the external validation data set (19.9%). Mean age (29.9 and 33.6 years), body mass index (BMI; 26.3 and 27.1 kg/m2), pain when resting (37.8 and 38.5 points) or bearing weight on the ankle (75.4 and 71.3 points) were similar in both data sets. Age, BMI, pain when resting, pain bearing weight, ability to bear weight, days from injury until assessment and injury recurrence were the selected predictors. The baseline model had fair discriminatory ability (C-statistic 0.72; 95% CI 0.66 to 0.79) but poor calibration. The updated model presented better discrimination (C-statistic 0.78; 95% CI 0.72 to 0.84), but equivalent calibration. CONCLUSIONS: The models include predictors easy to assess clinically and show benefit when compared with not using any model. TRIAL REGISTRATION NUMBER: ISRCTN12726986; Results.

Prognostic models for identifying risk of poor outcome in people with acute ankle sprains: the SPRAINED development and external validation study.

BACKGROUND: Ankle sprains are very common injuries. Although recovery can occur within weeks, around one-third of patients have longer-term problems. OBJECTIVES: To develop and externally validate a prognostic model for identifying people at increased risk of poor outcome after an acute ankle sprain. DESIGN: Development of a prognostic model in a clinical trial cohort data set and external validation in a prospective cohort study. SETTING: Emergency departments (EDs) in the UK. PARTICIPANTS: Adults with an acute ankle sprain (within 7 days of injury). SAMPLE SIZE: There were 584 clinical trial participants in the development data set and 682 recruited for the external validation study. PREDICTORS: Candidate predictor variables were chosen based on availability in the clinical data set, clinical consensus, face validity, a systematic review of the literature, data quality and plausibility of predictiveness of the outcomes. MAIN OUTCOME MEASURES: Models were developed to predict two composite outcomes representing poor outcome. Outcome 1 was the presence of at least one of the following symptoms at 9 months after injury: persistent pain, functional difficulty or lack of confidence. Outcome 2 included the same symptoms as outcome 1, with the addition of recurrence of injury. Rates of poor outcome in the external data set were lower than in the development data set, 7% versus 20% for outcome 1 and 16% versus 24% for outcome 2. ANALYSIS: Multiple imputation was used to handle missing data. Logistic regression models, together with multivariable fractional polynomials, were used to select variables and identify transformations of continuous predictors that best predicted the outcome based on a nominal alpha of 0.157, chosen to minimise overfitting. Predictive accuracy was evaluated by assessing model discrimination (c-statistic) and calibration (flexible calibration plot). RESULTS: (1) Performance of the prognostic models in development data set - the combined c-statistic for the outcome 1 model across the 50 imputed data sets was 0.74 [95% confidence interval (CI) 0.70 to 0.79], with good model calibration across the imputed data sets. The combined c-statistic for the outcome 2 model across the 50 imputed data sets was 0.70 (95% CI 0.65 to 0.74), with good model calibration across the imputed data sets. Updating these models, which used baseline data collected at the ED, with an additional variable at 4 weeks post injury (pain when bearing weight on the ankle) improved the discriminatory ability (c-statistic 0.77, 95% CI 0.73 to 0.82, for outcome 1 and 0.75, 95% CI 0.71 to 0.80, for outcome 2) and calibration of both models. (2) Performance of the models in the external data set - the combined c-statistic for the outcome 1 model across the 50 imputed data sets was 0.73 (95% CI 0.66 to 0.79), with a calibration plot intercept of -0.91 (95% CI -0.98 to 0.44) and slope of 1.13 (95% CI 0.76 to 1.50). The combined c-statistic for the outcome 2 model across the 50 imputed data sets was 0.63 (95% CI 0.58 to 0.69), with a calibration plot intercept of -0.25 (95% CI -0.27 to 0.11) and slope of 1.03 (95% CI 0.65 to 1.42). The updated models with the additional pain variable at 4 weeks had improved discriminatory ability over the baseline models but not better calibration. CONCLUSIONS: The SPRAINED (Synthesising a clinical Prognostic Rule for Ankle Injuries in the Emergency Department) prognostic models performed reasonably well, and showed benefit compared with not using any model; therefore, the models may assist clinical decision-making when managing and advising ankle sprain patients in the ED setting. The models use predictors that are simple to obtain. LIMITATIONS: The data used were from a randomised controlled trial and so were not originally intended to fulfil the aim of developing prognostic models. However, the data set was the best available, including data on the symptoms and clinical events of interest. FUTURE WORK: Further model refinement, including recalibration or identifying additional predictors, may be required. The effect of implementing and using either model in clinical practice, in terms of acceptability and uptake by clinicians and on patient outcomes, should be investigated. TRIAL REGISTRATION: Current Controlled Trials ISRCTN12726986. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 64. See the NIHR Journals Library website for further project information. Funding was also recieved from the NIHR Collaboration for Leadership in Applied Health Research, Care Oxford at Oxford Health NHS Foundation Trust, NIHR Biomedical Research Centre, Oxford, and the NIHR Fellowship programme.

Platelet-rich plasma in Achilles tendon healing 2 (PATH-2) trial: statistical analysis plan for a multicentre, double-blinded, parallel-group, placebo-controlled randomised clinical trial.

BACKGROUND: There has been a recent steep growth in platelet-rich plasma (PRP) use for musculoskeletal conditions, but findings from high quality clinical trial data are lacking in the literature. Here, we describe the statistical analysis plan (SAP) for the Platelet-rich plasma in Achilles Tendon Healing 2 (PATH-2) trial. METHODS: PATH-2 is a pragmatic, parallel-group, multi-centre, double-blinded, randomised, placebo-controlled, superiority trial. The study aims to evaluate the clinical efficacy of PRP in acute Achilles tendon rupture in terms of muscle-tendon function. Patients are identified in the orthopaedic/trauma outpatient clinic. The primary outcome is muscle-tendon work capacity from the Heel Rise Endurance Test result, expressed as the Limb Symmetry Index (work, in joules), at 24 weeks post randomisation. Multivariate linear regression adjusting for the stratification factors (centre and age) and additional prognostic factors will be used to investigate the adjusted effect of the intervention. The analysis will be by modified intention-to-treat. Sensitivity analysis will assess the internal validity of the trial results by performing a per-protocol analysis. Safety will be summarised by treatment arm for all patients who started treatment. Secondary patient-reported outcome measures will be analysed using linear mixed effects models to allow all data collected at all follow-up points to be considered. Missing data will be summarised and reported by treatment arm. Missing data imputation will be performed, if appropriate. DISCUSSION: The PATH-2 trial will be reported in accordance with the CONSORT statement. This SAP publication will avoid bias arising from prior knowledge of the study results. Any changes or deviations from the current SAP will be described and justified in the final report. TRIAL REGISTRATION: ISRCTN registry: ISRCTN54992179 , assigned 12 January 2015. ClinicalTrials.gov: NCT02302664, received 18 November 2014. UK Clinical Research Network Study Portfolio Database: ID 17850.

Sleep duration of 24 h is associated with birth weight in nulli- but not multiparous women.

OBJECTIVES: This study aimed to evaluate the association between nightly, napping, and 24-h sleep duration throughout pregnancy and birth weight z-score among nulli- and multiparous women. METHODS: Nightly,napping, and 24-h sleep duration and birth weight z-score (calculated on thebasis of the International Fetal and Newborn Growth Consortium for the 21st century standards) were studied in a cohort of 176 pregnant women from Brazil. Linear mixed-effect analyses were performed to assess the longitudinal evolution of sleep duration and the best unbiased linear predictors of the random coefficients were estimated. The best unbiased linear predictor estimates of sleep duration intercept and slope were included in the linear regression models with birth weight z-score as the outcome. RESULTS: The mean hours of nightly sleep decreased during pregnancy in nulliparous women (ß = -0.55; 95% confidence interval [CI], -0.83 to -0.27) but the decrease was not statistically significant in multiparous women (ß = -0.19; 95% CI, -0.30 to 0.01). Twenty-four hour sleep duration decreased during pregnancy in both multiparous (ß = -0.50; 95% CI, -0.76 to -0.25) and nulliparous women (ß = 0.77; 95% CI, -1.06 to -0.48). Napping sleep duration did not change in either group. Among the nulliparous women, both first-trimester 24-h sleep duration and its change throughout pregnancy were inversely associated with birth weight (ß = -0.44; 95% CI, -0.68 to -0.21; ß = -1.75; 95% CI, -3.17 to -0.30, respectively). No associations were detected in multiparous women for nightly and napping sleep duration. CONCLUSIONS: Nulliparous women with greater decreases in sleep duration throughout their pregnancy gave birth to newborns with lower birth weight z-scores.

Blood pressure in healthy pregnancy and factors associated with no mid-trimester blood pressure drop: a prospective cohort study.

BACKGROUND: The well-known mid-trimester drop in blood pressure (BP) during normal pregnancy was recently questioned. OBJECTIVE: To describe longitudinal changes in BP during healthy pregnancies and to investigate factors associated with no mid-trimester drop in BP. METHODS: A prospective cohort with 158 healthy pregnant women was followed up in a public health care center in Rio de Janeiro, Brazil. We used linear mixed-effects models to estimate longitudinal changes in systolic BP (SBP) and diastolic BP (DBP) during pregnancy. Poisson regression models were performed to identify factors associated with no mid-trimester drop in BP. RESULTS: Significant mid-trimester increase in SBP (5.6 mm Hg; 95% confidence interval (CI) = 4.6-6.7) and DBP (4.4 mm Hg; 95% CI = 3.4-5.3) was observed in 44.3% and 39.9% of the sample, respectively. Women (37.1%) who had not a mid-trimester SBP drop still had a DBP drop. White skin color (incidence ratio (IR): 1.71; 95% CI = 1.22-2.39), family history of hypertension (IR: 1.93; 95% CI = 1.29-2.89), early pregnancy obesity (IR: 2.29; 95% CI = 1.27-4.11), outside temperature variation (IR: 1.45; 95% CI = 1.00-2.10), and gestational weight gain from the first to second trimester (IR: 1.71; 95% CI = 1.01-2.88 and IR: 2.32; 95% CI = 1.39-3.89 for second and third tertiles) were characteristics associated with no mid-trimester drop in SBP. The same characteristics were associated with no mid-trimester drop in DBP, except family history of hypertension and outside temperature variation. CONCLUSIONS: Some women without a mid-trimester SBP drop still present a DBP drop. The different patterns of mid-trimester change in BP seem to be determined by preexisting and pregnancy-related factors.

Total cholesterol and leptin concentrations are associated with prospective changes in systemic blood pressure in healthy pregnant women.

BACKGROUND: Lipids and leptin have been associated with high blood pressure (BP) levels during pregnancy. The aim was to evaluate the associations between serum lipids and leptin concentrations during the first trimester and longitudinal changes of SBP and DBP in healthy pregnancies. METHODS: Prospective cohort of pregnant women followed at a public healthcare center in Rio de Janeiro, Brazil. SBP and DBP were obtained at the ≤13th, 20-26th, and 30-36th weeks of gestation and were the dependent variables. Serum lipids and plasma leptin concentrations were collected at 13 weeks or less of gestation and were the main independent variables. Statistical analyses included longitudinal linear mixed-effects regression models, with (ß) coefficients and their 95% confidence intervals (CI). RESULTS: Mean BPs were 109.8/66.9, 107.8/64.3, and 111.2/66.9  mmHg, respectively in the 1st, 2nd, and 3rd trimester. Multiple longitudinal regressions revealed that leisure time physical activity before pregnancy (ß(SBP) = -3.003, 95% CI = -5.034 to -0.971; ß(DBP) = -2.620, 95% CI = -4.177 to -1.064), baseline BMI (ß(SBP) = 4.003, 95% CI = 1.924-6.081; ß(DBP) = 1.862, 95% CI = 0.252-3.412), parity (ß(SBP) = -2.778, 95% CI = -4.627 to -0.929; ß(DBP) = -1.780, 95% CI = -3.168 to -0.392), and Homeostasis model of assessment-Insulin Resistance (HOMA-IR; ß(SBP) = 2.554, 95% CI = 0.552-4.557; ß(DBP) = 2.962, 95% CI = 1.436-4.489) were the covariates independently associated with SBP and DBP changes. Monthly per-capita family income (ß(SBP) = -0.006, 95% CI = -0.010 to -0.001), total cholesterol (ß(SBP) = 2.094, 95% CI = 0.223-3.965), and leptin (ß(SBP) = 2.211, 95% CI = 0.159-4.263) were associated only with SBP changes. CONCLUSION: Serum total cholesterol and leptin concentrations, HOMA-IR, and BMI were positively associated with changes in BP during healthy pregnancies, whereas physical activity, parity, and family income were negatively associated.

C-reactive protein and later preeclampsia: systematic review and meta-analysis taking into account the weight status.

OBJECTIVES: This study aims to determine whether high C-reactive protein (CRP) concentration during pregnancy is associated with later preeclampsia and whether weight status (BMI) is a potential modifier of the relation between CRP and preeclampsia. METHODS: Twenty-three studies were included in a systematic literature review and a subset of 18 in a meta-analysis. Weighted mean difference (WMD) [with their 95% confidence intervals (CI)] of CRP in preeclampsia and control groups was the estimator. A quality assessment was carried out using a scale specifically developed for this study. Meta-regression with estimates for study characteristics and inter-arm differences and sensitivity and subgroup analysis was employed. Statistical heterogeneity was investigated using I(2) statistic. RESULTS: The pooled estimated CRP between 727 women, who developed preeclampsia and 3538 controls was 2.30 mg/l (95% CI: 1.27-3.34). The heterogeneity among studies was high (I(2) = 92.8). The WMD was found to be lower in studies comprising preeclampsia and control groups with similar BMI [WMD = 0.85 (95% CI: 0.10-1.61); I(2) = 25.3%] compared with studies among which BMI was significantly elevated in the preeclampsia group [2.01 (95% CI: 1.23-2.78); I(2) = 0.0%], which may explain the high heterogeneity of pooled data. Meta-regression results confirmed that difference in BMI between groups modifies the association of CRP and preeclampsia. High quality studies represented 30%. CONCLUSION: The pooled WMD suggest that women with higher levels of CRP may have an increased risk of developing preeclampsia. This association seems to be modified by confounders, such as BMI. Further studies of high methodological quality are needed.

Household food insecurity is not associated with BMI for age or weight for height among Brazilian children aged 0-60 months.

We examined the association between Household Food Insecurity (HFI), weight for height z-score (WHZ) and Body Mass Index for age z-score (BMI-Z) in a representative sample of children 0-60 months of age (n = 3,433) in five Brazilian geographical regions. Data were derived from the 2006-07 Brazilian Demographic and Health Survey. HFI was measured with the Brazilian Food Insecurity Scale. Associations were estimated using multiple linear regression models (ß coefficients and 95% CI) taking into account the complex sampling design. Interaction terms between HFI and geographical region and HFI and child sex and child age were assessed. The weighted prevalence of any level of HFI was 48.6%. Severe food insecurity was more prevalent among children from the North region (16.8%), born from mothers with <4 years of schooling (15.9%) and those from families with ≥3 children (18.8%). The interaction between HFI and geographical region was non-significant for BMI-Z (P = 0.119) and WHZ (P = 0.198). Unadjusted results indicated that HFI was negatively associated with BMI-Z (moderate to severe HFI: ß = -0.19, 95% CI: -0.35 - -0.03, P = 0.047), and WHZ (moderate to severe HFI: ß = -0.26, 95% CI: -0.42 - -0.09, P = 0.009). Estimates lost significance after adjustments for key confounders such as mothers' skin color, mothers' years of schooling, place of household, household income quartiles, mothers' smoking habit, mothers' marital status, number of children 0-60 months in the household, and birth order. HFI is unrelated to weight outcomes among Brazilian children 0-60 months.

Severe food insecurity is associated with obesity among Brazilian adolescent females.

OBJECTIVE: To determine whether household food insecurity (HFI) is associated with a higher prevalence of excessive weight (EW) in a large random sample of Brazilian female adolescents. DESIGN: Nationally representative cross-sectional study. EW was the outcome variable (BMI ≥ 85th percentile of WHO reference for adolescents aged 15-18 years and BMI ≥ 25 kg/m(2) for those aged 19 years). HFI was measured with the Brazilian Food Insecurity Scale. Associations were measured using crude and adjusted prevalence ratios (PR) with 95 % confidence intervals through Poisson regression models taking into account the complex sampling design. SETTING: Data were derived from the third wave of the Demographic and Health Survey conducted in 2006-2007, in Brazil. SUBJECTS: The sample included 1529 female adolescents aged 15-19 years. RESULTS: The prevalence of any level of HFI was 40.8 %, with 26.6 % of households experiencing mild, 9.4 % moderate and 4.8 % severe food insecurity. The overall prevalence of EW was 21.9 % (12.9 % were overweight and 9.0 % obese). EW prevalence among those living in severely, moderately and mildly food-insecure households was 36.8 %, 14.9 % and 16.5 %, respectively (P for the overall association = 0.036). Women living in severely food-insecure households had an increased prevalence of EW compared with their food-secure counterparts (PR = 1.96; 95 % CI 1.18, 3.27; P = 0.007), after adjusting for important confounders. CONCLUSIONS: The study suggests that severe but not mild or moderate HFI is independently associated with EW among adolescents residing in Brazil, a middle-income country undergoing the nutrition transition.

Mild but not light or severe food insecurity is associated with obesity among Brazilian women.

Our aim was to determine whether food insecurity was associated with a higher prevalence of obesity in a large random sample of Brazilian women of reproductive age. The data were derived from the 3rd edition of the Children's and Women's National Demographic and Health Survey conducted in 2006-07. This was a nationally representative cross-sectional study. Obesity (BMI ≥ 30 kg/m(2)) was the outcome variable. Associations were measured using crude and adjusted prevalence ratios (PR) with 95% CI through Poisson regression models taking into account the complex sampling design. The sample included 10,226 women from 18 to 45 y of age. The prevalence of any level of food insecurity measured by the Brazilian Food Insecurity Scale was 40.9%, with 25.5% light, 10.1% mild, and 5.3% severe food insecurities. The prevalence of obesity was 17.4%. We found a borderline effect of light food insecurity and increased prevalence of obesity in Brazil (PR = 1.16; 95% CI = 0.98-1.38; P = 0.08). Women with mild food insecurity had a higher risk of being obese than their food-secure counterparts (PR = 1.49; 95% CI = 1.17-1.90; P = 0.010) after adjustment for skin color/ethnicity, years of schooling, geographical region, income, age, and marital status. In conclusion, this study suggests that mild but not light or severe food insecurity was associated with obesity as assessed by BMI, even after adjusting for various confounding factors in this large cross-sectional survey performed in a middle-income country undergoing the nutrition transition.