Tag: statistics

Retina. 2021 Dec 17. doi: 10.1097/IAE.0000000000003385. Online ahead of print.

ABSTRACT

PURPOSE: To investigate the correlation of volumetric measurements of intraretinal (IRF) and subretinal fluid (SRF) obtained by deep learning and central retinal subfield thickness (CSFT) based on optical coherence tomography (OCT) in retinal vein occlusion (RVO), diabetic macular edema (DME) and neovascular age-related macular degeneration (nAMD).

METHODS: A previously validated deep learning-based approach was used for automated segmentation of IRF and SRF in spectral domain-OCT images. OCT volumes of 2.433 patients obtained from multicenter studies were analyzed. Fluid volumes were measured at baseline and under anti-vascular endothelial growth factor (VEGF) therapy in the central 1, 3, and 6 mm.

RESULTS: Patients with nAMD demonstrated generally the weakest association between CSFT and fluid volumes measurements in the central 1mm (0.107 to 0.569). In patients with DME, IRF correlated moderately with CSFT (0.668 to 0.797). In patients with RVO, IRF volumes showed a moderate correlation with CSFT (0.603 to 0.704).

CONCLUSION: The correlation of CSFT and fluid volumes depends on the underlying pathology. Although the amount of central IRF seems to partly drive CSFT in DME and RVO, it has only a limited impact on patients with nAMD. Our findings do not support the use of CSFT as primary or secondary outcome measure for quantification of exudative activity or treatment guidance.

PMID:34934034 | DOI:10.1097/IAE.0000000000003385

Proc Natl Acad Sci U S A. 2021 Dec 28;118(52):e2106178118. doi: 10.1073/pnas.2106178118.

ABSTRACT

While the social sciences have made impressive progress in adopting transparent research practices that facilitate verification, replication, and reuse of materials, the problem of publication bias persists. Bias on the part of peer reviewers and journal editors, as well as the use of outdated research practices by authors, continues to skew literature toward statistically significant effects, many of which may be false positives. To mitigate this bias, we propose a framework to enable authors to report all results efficiently (RARE), with an initial focus on experimental and other prospective empirical social science research that utilizes public study registries. This framework depicts an integrated system that leverages the capacities of existing infrastructure in the form of public registries, institutional review boards, journals, and granting agencies, as well as investigators themselves, to efficiently incentivize full reporting and thereby, improve confidence in social science findings. In addition to increasing access to the results of scientific endeavors, a well-coordinated research ecosystem can prevent scholars from wasting time investigating the same questions in ways that have not worked in the past and reduce wasted funds on the part of granting agencies.

PMID:34933997 | DOI:10.1073/pnas.2106178118

Proc Natl Acad Sci U S A. 2021 Dec 28;118(52):e2107019118. doi: 10.1073/pnas.2107019118.

ABSTRACT

The learning of first object names is deemed a hard problem due to the uncertainty inherent in mapping a heard name to the intended referent in a cluttered and variable world. However, human infants readily solve this problem. Despite considerable theoretical discussion, relatively little is known about the uncertainty infants face in the real world. We used head-mounted eye tracking during parent-infant toy play and quantified the uncertainty by measuring the distribution of infant attention to the potential referents when a parent named both familiar and unfamiliar toy objects. The results show that infant gaze upon hearing an object name is often directed to a single referent which is equally likely to be a wrong competitor or the intended target. This bimodal gaze distribution clarifies and redefines the uncertainty problem and constrains possible solutions.

PMID:34933998 | DOI:10.1073/pnas.2107019118

Glob Health Sci Pract. 2021 Dec 21;9(4):818-831. doi: 10.9745/GHSP-D-20-00349. Print 2021 Dec 31.

ABSTRACT

BACKGROUND: Over 43% of children living in low- and middle-income countries are at risk for developmental delays; however, access to protective interventions in these settings is limited. We evaluated the effect of maternal participation in Chamas for Change (Chamas)-a community-based women’s health education program during pregnancy and postpartum-and risk of developmental delay among their children in rural Kenya.

METHODS: We analyzed developmental screening questionnaire (DSQ) data from a cluster randomized controlled trial in Trans Nzoia County, Kenya (ClinicalTrials.gov, NCT03187873). Intervention clusters (Chamas) participated in community health volunteer-led, group-based health lessons twice a month during pregnancy and postpartum; controls had monthly home visits (standard of care). We screened all children born during the trial who were alive at 1-year follow-up. We labeled children with any positive item on the DSQ as “at-risk development.” We analyzed data using descriptive statistics and multilevel regression models (α=.05); analyses were intention-to-treat using individual-level data.

RESULTS: Between November 2017 and March 2018, we enrolled 1,920 pregnant women to participate in the parent trial. At 1-year follow-up, we screened 1,273 (689 intervention, 584 control) children born during the trial with the DSQ. Intervention mothers had lower education levels and higher poverty likelihood scores than controls (P<.001 and P=.007, respectively). The overall rate of at-risk development was 3.5%. Children in Chamas clusters demonstrated significantly lower rates of at-risk development than controls (2.5% vs. 4.8%, P=.025). Adjusted analyses revealed lower odds for at-risk development in the intervention arm (OR=0.50; 95% confidence interval=0.27, 0.94).

CONCLUSIONS: Maternal participation in a community-based women’s health education program was associated with lower rates of at-risk development compared to the standard of care. Overall, rates of at-risk development were lower than expected for this population, warranting further investigation. Chamas may help protect children from developmental delay in rural Kenya and other resource-limited settings.

PMID:34933978 | DOI:10.9745/GHSP-D-20-00349

Glob Health Sci Pract. 2021 Dec 21;9(4):881-889. doi: 10.9745/GHSP-D-20-00450. Print 2021 Dec 31.

ABSTRACT

BACKGROUND: In countries with a high prevalence of undernutrition, timely, accurate screening at the community level is essential to identify children with wasting. The World Health Organization recommends using either weight-for-height z-scores (WHZ) and mid-upper arm circumference (MUAC) or both measures and signs of edema to be used to identify children with severe acute malnutrition for treatment. We compared WHZ and MUAC cutoffs to identify wasting among children aged 6-59 months in Nepal, using WHZ as the reference standard.

METHODS: We used cross-sectional anthropometric data for 3,169 children aged 6-59 months from a 2017 cross-sectional dataset, representative of 42 of Nepal’s 77 districts. We used descriptive statistics, receiver operating characteristic (ROC) curves, and kappa statistics to compare the use of MUAC and WHZ to identify wasting. The Youden index was calculated to determine the optimum MUAC cutoffs.

RESULTS: The prevalence of wasting was 3.1% and 10.5% using MUAC and WHZ, respectively. We found 13.6% sensitivity for severe acute malnutrition (SAM) (MUAC <115 mm) and 21.0% sensitivity for moderate acute malnutrition (MAM) (MUAC ≥115 to <125 mm), with specificity of 99.7% and 91.2%, respectively. The sensitivity of MUAC for children aged 6-23 months was higher than for children aged 24-59 months. The total area of the ROC curve was 0.53 for the MUAC cutoff for SAM and 0.56 for MAM. The optimum MUAC cutoffs for SAM and MAM were 125 mm and 132 mm, respectively.

CONCLUSIONS: Although MUAC can be used as a rapid screening tool to detect wasting in children aged 6-59 months, using the recommended MUAC cutoffs captures only a small proportion of the total number of wasted children. The poor sensitivity and specificity of MUAC compared to WHZ suggests a need to refine admission and discharge criteria for acute malnutrition management programs to ensure that wasting among infants and children in Nepal is consistently and accurately diagnosed and treated.

PMID:34933983 | DOI:10.9745/GHSP-D-20-00450

Cancer Epidemiol Biomarkers Prev. 2021 Dec 21:cebp.0765.2021. doi: 10.1158/1055-9965.EPI-21-0765. Online ahead of print.

ABSTRACT

BACKGROUND: A high healthy lifestyle index (HLI), a composite score based on good diet quality, low alcohol consumption, no smoking, moderate to high physical activity, and waist circumference <80cm, has been consistently associated with a reduced risk of breast cancer (BC). Recently, high levels of body fat were found to be associated with an elevated risk of BC in postmenopausal women with a normal body mass index (BMI) (18.5-<25 kg/m2). Whether the HLI is associated with BC risk in women with normal BMI is unknown.

METHODS: We studied 102,572 women aged 40-69 years with a normal BMI at enrollment into the UK Biobank cohort study. The HLI was created by assigning to each component higher scores for healthier behaviors and then summing the scores. The HLI was categorized by tertiles and age- and multivariable-adjusted hazard ratios (HRs) for the association of the HLI with BC risk by menopausal status were estimated using Cox proportional hazards models.

RESULTS: In postmenopausal women, compared to a low HLI, higher scores were associated with a reduced risk of BC (HRHLI-3rd tertile 0.76; 95% CI, 0.64-0.91). Findings were similar for premenopausal women, although they did not reach statistical significance, except when smoking status was excluded from the HLI score (HLIwithout smoking: HR3rd tertile, 0.71; 95% CI, 0.56-0.90).

CONCLUSIONS: In normal BMI postmenopausal women, a high HLI score was associated with a reduced risk of BC.

IMPACT: Following a healthy lifestyle may reduce the risk of BC among normal weight postmenopausal women.

PMID:34933955 | DOI:10.1158/1055-9965.EPI-21-0765

Open Heart. 2021 Dec;8(2):e001850. doi: 10.1136/openhrt-2021-001850.

ABSTRACT

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a well-established risk factor for cardiovascular disease, with ethnic and regional differences noted. With the recent surge of research within this field, we re-examine the evidence associating NAFLD with subclinical atherosclerosis, and investigate potential regional differences.

METHODS: This is a systematic review and meta-analysis. PubMed and EMBASE were systematically searched for publications from January 1967 to July 2020 using standardised criteria. Original, observational studies investigating the association between NAFLD and either carotid intima-media thickness (CIMT) and/or coronary artery calcification (CAC) were included. Key outcomes included differences in mean CIMT, the presence of increased CIMT, the presence of CAC and the development/progression of CAC. Pooled ORs and pooled standard differences in means were calculated using random-effects models. Between-study heterogeneity was quantified using the Q statistic and I². Subgroup analyses stratified by region of study (Asian vs Western) were also conducted.

RESULTS: 64 studies involving a total of 172 385 participants (67 404 with NAFLD) were included. 44 studies assessed the effect of NAFLD on CIMT, with the presence of NAFLD associated with increased CIMT (OR 2.00, 95% CI 1.56 to 2.56). 22 studies assessed the effects of NAFLD on CAC score, with the presence of NAFLD associated with the presence of any coronary calcification (OR 1.21, 95% CI 1.12 to 1.32), and the development/progression of CAC (OR 1.26, 95% CI 1.04 to 1.52). When stratified by region, these associations remained consistent across both Asian and Western populations (p>0.05). The majority (n=39) of studies were classified as ‘high quality’, with the remaining 25 of ‘moderate quality’.

CONCLUSIONS: There is a significant positive association between various measures of subclinical atherosclerosis and NAFLD, seen across both Western and Asian populations. These results re-emphasise the importance of early risk evaluation and prophylactic intervention measures to preclude progression to clinical cardiovascular disease in patients with NAFLD.

PMID:34933963 | DOI:10.1136/openhrt-2021-001850

Clin Med Res. 2021 Dec;19(4):161-168. doi: 10.3121/cmr.2021.1654.

ABSTRACT

Objective: Characterization of COVID-19 in the Latinx community is necessary for guiding public health initiatives, health system policy, clinical management practices, and improving outcomes. Our aim was to describe the socioeconomic background and clinical profile of patients with COVID-19 at a large public hospital in Los Angeles to improve health disparities leading to poor outcomes during the pandemic.Design, Setting and Participants: A single center retrospective cross-sectional study of all patients with a positive polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who presented to Los Angeles County (LAC)+University of Southern California (USC) Medical Center between March 15, 2020 and April 30, 2020.Methods: We describe patient characteristics, socioeconomic factors, laboratory findings, and outcomes of the first 278 patients to present to LAC+USC Medical Center with COVID-19.Results: Patients self-identified as Hispanic (82.4%) or non-Hispanic (17.6%). Hispanic patients presented later from symptom onset (6 days vs 3 days, P = 0.027) and had higher post-intubation mortality (40.9% vs. 33.3%, P = 1), intensive care unit (ICU) mortality (31.1% vs. 22.2%, P = 0.87), and overall mortality (11.1% vs 10.2%, P = 1). However, the difference in admission rates, mechanical ventilation rates, and overall mortality rates were not statistically significant. A majority of patients, 275/278 (98.9%), reported residency ZIP codes in areas of higher population density, higher percentage of Latinx, born outside the United States, lower median income, and lower high school graduation rate when compared to the rest of Los Angeles County. Regression analysis within the Hispanic cohort found that age, history of hypertension, history of diabetes, lactate dehydrogenase (LDH), and C-reactive protein (CRP) were predictors of mechanical ventilation and mortality.Conclusion: We show the Latinx community has been disproportionally affected by the pandemic in Los Angeles and we identified multiple socioeconomic and clinical characteristics that predispose this population to COVID-19 infection. This study highlights the need for change in local and national strategies to protect vulnerable communities during public health outbreaks.

PMID:34933948 | DOI:10.3121/cmr.2021.1654

BMJ Evid Based Med. 2021 Dec 21:bmjebm-2021-111836. doi: 10.1136/bmjebm-2021-111836. Online ahead of print.

ABSTRACT

Registration of health and medical research is an effective way of improving the transparency and credibility of evidence. Registration involves pre-specifying the research objectives, design, methods and analytic plan on a publicly accessible repository before conducting the study. Registration can reduce bias and improve the transparency and credibility of research findings. Registration is mandated for clinical trials, but it is also relevant to systematic reviews, observational and preclinical experimental research. This paper describes how researchers can register their research and outlines possible barriers and challenges in doing so. Widespread adoption of research registration can reduce research waste and improve evidence-informed clinical and policy decision making.

PMID:34933926 | DOI:10.1136/bmjebm-2021-111836

BMJ Evid Based Med. 2021 Dec 21:bmjebm-2021-111746. doi: 10.1136/bmjebm-2021-111746. Online ahead of print.

ABSTRACT

The disproportionate focus on statistical significance in reporting and interpreting clinical research studies contributes to publication bias and encourages selective reporting. This highlights a need for alternative approaches that clearly communicate the uncertainty in the data, enabling researchers to provide a more nuanced interpretation of clinical research findings.Our purpose in this article is to introduce the density strip method as one potential approach that might act as a bridge between data visualisation for descriptive purposes and formal statistical inference. We build on existing theory, translating it to the applied research context to illustrate its utility to clinical researchers.We achieve this by considering an exemplar clinical trial, Multiple Sclerosis-Secondary Progressive Multi-Arm Randomisation Trial (MS-SMART). MS-SMART was a multiarm randomised placebo-controlled trial of three potentially neuroprotective drugs in secondary progressive MS. We illustrate through MS-SMART the potential of the density strip as an effective visualisation of the distribution of clinical trial outcomes and as a complementary approach to aid the interpretation of formal, inferential, statistical analysis.We conclude by summarising the advantages and disadvantages of the density strip methodology and provide suggestions for its potential extensions and possible further uses.

PMID:34933930 | DOI:10.1136/bmjebm-2021-111746