Are confidence intervals better termed "uncertainty intervals"?

The effects of a 6-week sand- vs. Land-based jump training programme on frontal plane knee angle and jump performance in adolescent female football players

Our study investigated the effects of a six-week jump-training intervention (sand- vs land- based incorporated in a warmup), on frontal plane knee angle and jump performance of adolescent female football players. Fifty-six females were randomly allocated to either the SAND or LAND group. Thirty-nine females completed the programme twice weekly and were eligible for analysis. Two-dimensional frontal plane projection angle (FPPA), countermovement jump (CMJ) and reactive strength index (RSI) (10-5 repeated jump test) were measured 1-week pre- and post-intervention. Analysis of covariance was used to model post-intervention group differences. Compatibility curves were used to visualise parameter estimates alongside p- values, and surprisal (S) value transforms. Mean difference (X - ) and compatibility intervals (CI) (95|75%) for FPPA for SAND vs. LAND were X -  = 1.29° (-0.11 to 2.69°|0.49 to 2.10°) for the dominant limb, and X -  = 1.80° (0.56 to 3.04°|1.09 to 2.51°)| for the non-dominant limb. Interval estimates for jump performance were imprecise and unclear. The data indicates that including a sand surface within a jump training intervention could be beneficial when aiming to improve knee control in asymptomatic adolescent female football players, with no apparent detriment to jumping performance.Clinical trials registration: The trial was registered with clinicaltrials.gov prior to study recruitment (NCT04502615).

Strength Setbacks: The Impact of Youth Sport-Related Knee Joint Injuries on Thigh Muscle Strength. A 24-Month Prospective Cohort Study

OBJECTIVE: To compare injured and uninjured limb knee extensor and flexor peak torque between youth who experienced a sport-related, traumatic knee joint injury and comparable uninjured youth, at baseline (≤4 months of injury) and semiannually for 2 years. Differences by injury type and sex were also explored. DESIGN: Prospective cohort study. METHODS: Bilateral knee extensor and flexor concentric isokinetic peak torque at 90° per second was assessed semiannually in 186 youth (106 injured, 80 controls) for 2 years. Between-group differences in strength over time were estimated with generalized estimating equations (95% confidence interval [CI]). Confounding was controlled using inverse probability weighting. Strength differences between those with anterior cruciate ligament (ACL) tears and those with non-ACL tear injuries as well as between male and female participants were explored. RESULTS: Compared to uninjured controls, injured limb knee extensor strength was lowest at baseline (-37.1 Nm; 95% CI, -45.3 to -28.9) and 6-month follow-up (-13.3 Nm; 95% CI, -20.4 to -6.2), with minimal strength gain beyond the 12-month follow-up (1.7 Nm; 95% CI, -14.3 to 17.6). Knee flexor strength of the injured limb was lowest at baseline (-24.6 Nm; 95% CI, -31.5 to -17.8), and there was minimal strength gain beyond 6 months (2.3 Nm; 95% CI, -7.7 to 12.3). The average residual deficit was similar to the knee extensors (10% to 11%) at 24 months. Exploratory analysis suggested no difference based on injury type or sex. CONCLUSION: Injured limb knee extensor and flexor weakness was present after different youth sport-related knee joint injuries. Strength deficits peaked early after injury, improved over time, and plateaued after 12 months, with lingering deficits at 24 months. Thigh muscle strength trajectory was similar across injury types and sex. J Orthop Sports Phys Ther 2025;55(2):1-11. Epub 20 December 2024. doi:10.2519/jospt.2024.12663.

Transcriptomics profiling of Parkinson's disease progression subtypes reveals distinctive patterns of gene expression

Background

Parkinson's Disease (PD) varies widely among individuals, and Artificial Intelligence (AI) has recently helped to identify three disease progression subtypes. While their clinical features are already known, their gene expression profiles remain unexplored.

Objectives

The objectives of this study were (1) to describe the transcriptomics characteristics of three PD progression subtypes identified by AI, and (2) to evaluate if gene expression data can be used to predict disease subtype at baseline.

Design

This is a retrospective longitudinal cohort study utilizing the Parkinson's Progression Markers Initiative (PPMI) database.

Methods

Whole blood RNA-Sequencing data underwent differential gene expression analysis, followed by multiple pathway analyses. A Machine Learning (ML) classifier, namely XGBoost, was trained using data from multiple modalities, including gene expression values.

Results

Our study identified differentially expressed genes (DEGs) that were uniquely associated with Parkinson's disease (PD) progression subtypes. Importantly, these DEGs had not been previously linked to PD. Gene-pathway analysis revealed both distinct and shared characteristics between the subtypes. Notably, two subtypes displayed opposite expression patterns for pathways involved in immune response alterations. In contrast, the third subtype exhibited a more unique profile characterized by increased expression of genes related to detoxification processes. All three subtypes showed a significant modulation of pathways related to the regulation of gene expression, metabolism, and cell signaling. ML revealed that the progression subtype with the worst prognosis can be predicted at baseline with 0.877 AUROC, yet the contribution of gene expression was marginal for the prediction of the subtypes.

Conclusion

This study provides novel information regarding the transcriptomics profiles of PD progression subtypes, which may foster precision medicine with relevant indications for a finer-grained diagnosis and prognosis.

Interactions with alloparents are associated with the diversity of infant skin and fecal bacterial communities in Chicago, United States

INTRODUCTION

Social interactions shape the infant microbiome by providing opportunities for caregivers to spread bacteria through physical contact. With most research focused on the impact of maternal-infant contact on the infant gut microbiome, it is unclear how alloparents (i.e., caregivers other than the parents) influence the bacterial communities of infant body sites that are frequently contacted during bouts of caregiving, including the skin.

METHODS

To begin to understand how allocare may influence the diversity of the infant microbiome, detailed questionnaire data on infant-alloparent relationships and specific allocare behaviors were coupled with skin and fecal microbiome samples (four body sites) from 48 infants living in Chicago, United States.

RESULTS

Data from 16S rRNA gene amplicon sequencing indicated that infant skin and fecal bacterial diversity showed strong associations (positive and negative) to having female adult alloparents. Alloparental feeding and co-sleeping displayed stronger associations to infant bacterial diversity compared to playing or holding. The associations with allocare behaviors differed in magnitude and direction across infant body sites. Bacterial relative abundances varied by infant-alloparent relationship and breastfeeding status.

CONCLUSION

This study provides some of the first evidence of an association between allocare and infant skin and fecal bacterial diversity. The results suggest that infants' exposure to bacteria from the social environment may vary based on infant-alloparent relationships and allocare behaviors. Since the microbiome influences immune system development, variation in allocare that impacts the diversity of infant bacterial communities may be an underexplored dimension of the social determinants of health in early life.

Non-senescent species are not immortal: Stress and decline in two planaria species

Potential immortality is observed in several species (e.g. prickly pear cactus, hydra and flatworms) and is indicative of their negligible or even negative senescence rates. Unlike in senescent species, which experience reduced individual performance with age due to physiological degradation, species with negligible or negative senescence display mortality rates that remain constant or decline with age, respectively. These rates vary across taxa and are correlated with life history traits. Yet, the extent to which variable resource availability, a key driver of variation in life history traits, impacts species that show negligible or negative senescence is currently unknown. Here, we examine whether and how variation in the quantity, quality and feeding interval of resources impact population structure, population performance and life history trait trade-offs in two long-lived planaria that do not senesce: Schmidtea mediterranea and Dugesia tahitiensis. In a full factorial design, different combinations of resource quantity (reduced intake, standard intake and high intake) and quality (high and low quality) were provided in two different feeding intervals (7-day and 14-day intervals) for 19 weeks. We show that variability in resource availability, via decreases in quantity, quality and frequency of resources, does not diminish population viability in either species but does result in suboptimal conditions of stress in S. mediterranea. The high population viability we report can be attributed to two different mechanisms: increased reproduction or increased investment into maintenance at the expense of reproduction. Moreover, which mechanism was responsible for said high population viability was context-dependent and modulated by the specific life history strategy of the two planaria species. We show that suboptimal conditions can cause stress responses that have significant impacts on non-senescent species. The context-dependent response we observe suggests that species that do not senesce but are subject to suboptimal conditions of stress may ultimately exhibit declines in performance and ultimately die. A clearer understanding of the impact of suboptimal conditions of resource availability on non-senescent species is needed to determine the extent of stress experienced and ultimately whether a species can truly be immortal.

Racial Disparities in Surgical Treatment of Uterine Fibroids During the COVID-19 Pandemic

Objective: Analyze the association between race and surgery performed for uterine fibroids during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Retrospective exploratory cross-sectional study of patients with fibroids who underwent surgery during the COVID-19 pandemic. We compared the type of surgery performed (minimally invasive hysterectomy [MIH], uterine-sparing procedure [USP], or total abdominal hysterectomy [TAH]) by White versus non-White patients. Absolute percentage differences were estimated with multinomial logistic regression adjusting for age, body mass index (BMI), parity, comorbidities, and maximum fibroid diameter. Results: Of 350 subjects, the racial composition was 1.7% Asian, 23.4% Black, and 74.9% White. Non-White patients had greater fibroid burden by mean maximum fibroid diameter, mean uterine weight, and mean fibroid weight. Although MIH occurred more frequently among White patients (7.5% points higher [95% confidence interval (CI) = -3.1 to 18.2]), USP and TAH were more commonly conducted for non-White patients (3.4% points higher [95% CI = -10.4 to 3.6] and 4.2% points higher [95% CI = -13.2 to 4.8], respectively). The overall complication rate was 18.6%, which was 6% points lower (95% CI = -15.8 to 3.7) among White patients. Conclusion: During the COVID-19 pandemic at a single-site institution, non-White patients were more likely to undergo a uterine-sparing procedure for surgical treatment of uterine fibroids, abdominal procedures, including both hysterectomy and myomectomy, and experience surgery-related complications.

Durga: an R package for effect size estimation and visualization

Statistical analysis and data visualization are integral parts of science communication. One of the major issues in current data analysis practice is an overdependency on-and misuse of-p-values. Researchers have been advocating for the estimation and reporting of effect sizes for quantitative research to enhance the clarity and effectiveness of data analysis. Reporting effect sizes in scientific publications has until now been mainly limited to numeric tables, even though effect size plotting is a more effective means of communicating results. We have developed the Durga R package for estimating and plotting effect sizes for paired and unpaired group comparisons. Durga allows users to estimate unstandardized and standardized effect sizes and bootstrapped confidence intervals of the effect sizes. The central functionality of Durga is to combine effect size visualizations with traditional plotting methods. Durga is a powerful statistical and data visualization package that is easy to use, providing the flexibility to estimate effect sizes of paired and unpaired data using different statistical methods. Durga provides a plethora of options for plotting effect size, which allows users to plot data in the most informative and aesthetic way. Here, we introduce the package and its various functions. We further describe a workflow for estimating and plotting effect sizes using example data sets.

Comparison of Radial Versus Femoral Access for Neuroendovascular Procedures in Very High Body Mass Index Individuals

BACKGROUND

Femoral access (TFA) for neuroendovascular procedures may present a challenge in very high body mass index (BMI) individuals. Whether radial access (TRA) confers a comparative benefit in this specific population has not been studied.

METHODS

We retrospectively identified all patients undergoing neuroendovascular procedures at our center between 2017 and 2021 with BMI ≥35 kg/m2. A total of 335 patients met our inclusion criteria, with 224 undergoing femoral access and 111 undergoing radial access. Electronic medical records were reviewed for baseline clinical and angiographic characteristics and procedural outcomes.

RESULTS

The primary outcome of any bleeding complication occurred in 7% of the femoral group and 2% of the radial group (odds ratio 4.2, 95% confidence interval 1.0-18.6, P = 0.0421). Radial access was also associated with significantly shorter mean procedure times (median 43 minutes for radial, median 58 minutes for femoral, P = 0.0009) and mean fluoroscopy exposure times (median 15 minutes for radial, median 20 minutes for femoral, P = 0.0003). There were no significant differences in nonaccess site complications, procedural failure, length of stay, or deaths during hospitalization.

CONCLUSIONS

When compared to TRA, TFA was associated with a significantly greater rate of bleeding complications in very high BMI patients undergoing neuroendovascular procedures. Procedure time and fluoroscopy time were both significantly longer when using TFA compared to TRA in this patient population.

The effects of respiratory rate and tidal volume on pulse pressure variation in healthy lungs-a generalized additive model approach may help overcome limitations

Pulse pressure variation (PPV) is a well-established method for predicting fluid responsiveness in mechanically ventilated patients. The predictive accuracy is, however, disputed for ventilation with low tidal volume (VT) or low heart-rate-to-respiratory-rate ratio (HR/RR). We investigated the effects of VT and RR on PPV and on PPV's ability to predict fluid responsiveness. We included patients scheduled for open abdominal surgery. Prior to a 250 ml fluid bolus, we ventilated patients with combinations of VT from 4 to 10 ml kg-1 and RR from 10 to 31 min-1. For each of 10 RR-VT combinations, PPV was derived using both a classic approach and a generalized additive model (GAM) approach. The stroke volume (SV) response to fluid was evaluated using uncalibrated pulse contour analysis. An SV increase > 10% defined fluid responsiveness. Fifty of 52 included patients received a fluid bolus. Ten were fluid responders. For all ventilator settings, fluid responsiveness prediction with PPV was inconclusive with point estimates for the area under the receiver operating characteristics curve between 0.62 and 0.82. Both PPV measures were nearly proportional to VT. Higher RR was associated with lower PPV. Classically derived PPV was affected more by RR than GAM-derived PPV. Correcting PPV for VT could improve PPV's predictive utility. Low HR/RR has limited effect on GAM-derived PPV, indicating that the low HR/RR limitation is related to how PPV is calculated. We did not demonstrate any benefit of GAM-derived PPV in predicting fluid responsiveness.Trial registration: ClinicalTrials.gov, reg. March 6, 2020, NCT04298931.

Cost Effectiveness of Calorie Labeling at Large Fast-Food Chains Across the U.S

INTRODUCTION

Calorie labeling of standard menu items has been implemented at large restaurant chains across the U.S. since 2018. The objective of this study was to evaluate the cost effectiveness of calorie labeling at large U.S. fast-food chains.

METHODS

This study evaluated the national implementation of calorie labeling at large fast-food chains from a modified societal perspective and projected its cost effectiveness over a 10-year period (2018-2027) using the Childhood Obesity Intervention Cost-Effectiveness Study microsimulation model. Using evidence from over 67 million fast-food restaurant transactions between 2015 and 2019, the impact of calorie labeling on calorie consumption and obesity incidence was projected. Benefits were estimated across all racial, ethnic, and income groups. Analyses were performed in 2022.

RESULTS

Calorie labeling is estimated to be cost saving; prevent 550,000 cases of obesity in 2027 alone (95% uncertainty interval=518,000; 586,000), including 41,500 (95% uncertainty interval=33,700; 50,800) cases of childhood obesity; and save $22.60 in healthcare costs for every $1 spent by society in implementation costs. Calorie labeling is also projected to prevent cases of obesity across all racial and ethnic groups (range between 126 and 185 cases per 100,000 people) and all income groups (range between 152 and 186 cases per 100,000 people).

CONCLUSIONS

Calorie labeling at large fast-food chains is estimated to be a cost-saving intervention to improve long-term population health. Calorie labeling is a low-cost intervention that is already implemented across the U.S. in large chain restaurants.

Statistical significance and publication reporting bias in abstracts of reproductive medicine studies

STUDY QUESTION

What were the frequency and temporal trends of reporting P-values and effect measures in the abstracts of reproductive medicine studies in 1990-2022, how were reported P-values distributed, and what proportion of articles that present with statistical inference reported statistically significant results, i.e. 'positive' results?

SUMMARY ANSWER

Around one in six abstracts reported P-values alone without effect measures, while the prevalence of effect measures, whether reported alone or accompanied by P-values, has been increasing, especially in meta-analyses and randomized controlled trials (RCTs); the reported P-values were frequently observed around certain cut-off values, notably at 0.001, 0.01, or 0.05, and among abstracts present with statistical inference (i.e. P-value, CIs, or significant terms), a large majority (77%) reported at least one statistically significant finding.

WHAT IS KNOWN ALREADY

Publishing or reporting only results that show a 'positive' finding causes bias in evaluating interventions and risk factors and may incur adverse health outcomes for patients.

Despite efforts to minimize publication reporting bias in medical research, it remains unclear whether the magnitude and patterns of the bias have changed over time.

STUDY DESIGN, SIZE, DURATION

We studied abstracts of reproductive medicine studies from 1990 to 2022. The reproductive medicine studies were published in 23 first-quartile journals under the category of Obstetrics and Gynaecology and Reproductive Biology in Journal Citation Reports and 5 high-impact general medical journals (The Journal of the American Medical Association, The Lancet, The BMJ, The New England Journal of Medicine, and PLoS Medicine). Articles without abstracts, animal studies, and non-research articles, such as case reports or guidelines, were excluded.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Automated text-mining was used to extract three types of statistical significance reporting, including P-values, CIs, and text description. Meanwhile, abstracts were text-mined for the presence of effect size metrics and Bayes factors. Five hundred abstracts were randomly selected and manually checked for the accuracy of automatic text extraction. The extracted statistical significance information was then analysed for temporal trends and distribution in general as well as in subgroups of study designs and journals.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 24 907 eligible reproductive medicine articles were identified from 170 739 screened articles published in 28 journals. The proportion of abstracts not reporting any statistical significance inference halved from 81% (95% CI, 76-84%) in 1990 to 40% (95% CI, 38-44%) in 2021, while reporting P-values alone remained relatively stable, at 15% (95% CI, 12-18%) in 1990 and 19% (95% CI, 16-22%) in 2021. By contrast, the proportion of abstracts reporting effect measures alone increased considerably from 4.1% (95% CI, 2.6-6.3%) in 1990 to 26% (95% CI, 23-29%) in 2021. Similarly, the proportion of abstracts reporting effect measures together with P-values showed substantial growth from 0.8% (95% CI, 0.3-2.2%) to 14% (95% CI, 12-17%) during the same timeframe. Of 30 182 statistical significance inferences, 56% (n = 17 077) conveyed statistical inferences via P-values alone, 30% (n = 8945) via text description alone such as significant or non-significant, 9.3% (n = 2820) via CIs alone, and 4.7% (n = 1340) via both CI and P-values. The reported P-values (n = 18 417), including both a continuum of P-values and dichotomized P-values, were frequently observed around common cut-off values such as 0.001 (20%), 0.05 (16%), and 0.01 (10%). Of the 13 200 reproductive medicine abstracts containing at least one statistical inference, 77% of abstracts made at least one statistically significant statement. Among articles that reported statistical inference, a decline in the proportion of making at least one statistically significant inference was only seen in RCTs, dropping from 71% (95% CI, 48-88%) in 1990 to 59% (95% CI, 42-73%) in 2021, whereas the proportion in the rest of study types remained almost constant over the years. Of abstracts that reported P-value, 87% (95% CI, 86-88%) reported at least one statistically significant P-value; it was 92% (95% CI, 82-97%) in 1990 and reached its peak at 97% (95% CI, 93-99%) in 2001 before declining to 81% (95% CI, 76-85%) in 2021.

LIMITATIONS, REASONS FOR CAUTION

First, our analysis focused solely on reporting patterns in abstracts but not full-text papers; however, in principle, abstracts should include condensed impartial information and avoid selective reporting. Second, while we attempted to identify all types of statistical significance reporting, our text mining was not flawless. However, the manual assessment showed that inaccuracies were not frequent.

WIDER IMPLICATIONS OF THE FINDINGS

There is a welcome trend that effect measures are increasingly reported in the abstracts of reproductive medicine studies, specifically in RCTs and meta-analyses. Publication reporting bias remains a major concern. Inflated estimates of interventions and risk factors could harm decisions built upon biased evidence, including clinical recommendations and planning of future research.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for this study. B.W.M. is supported by an NHMRC Investigator grant (GNT1176437); B.W.M. reports research grants and travel support from Merck and consultancy from Merch and ObsEva. W.L. is supported by an NHMRC Investigator Grant (GNT2016729). Q.F. reports receiving a PhD scholarship from Merck. The other author has no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Investigating the effect of prophylactic claw trimming on the interval between calving and first observed elevated locomotion score in pasture-based dairy cows

AIMS

To evaluate, in a pasture-based dairy herd, the response to a three-time point hoof trimming regime on lameness incidence and time from calving to observation of an elevated locomotion score (LS).

METHODS

This study was conducted on a 940-cow spring-calving herd in New Zealand's North Island between May 2018 and May 2019. Cows (n = 250) were randomly allocated to the hoof trimming group, with the remainder assigned to the non-trim cohort. One trained professional hoof trimmer used the five-step Dutch method to trim the hind feet of the trimming group. Throughout the subsequent production season, the whole herd was locomotion-scored fortnightly using the 4-point (0-3) Dairy NZ lameness score. Kaplan-Meier survival curves were used to assess the univariable effect of trimming on the interval between calving and first LS of ≥ 2 and first LS ≥ 1. A multivariable Cox proportional hazards regression was used to further evaluate the effect of trimming on time to elevated LS.

RESULTS

Mean lameness (LS ≥ 2) prevalence was 2.6%, with 30% of cows having ≥ 4 observations during the study period when at least one LS was ≥ 2. For LS ≥ 1, mean prevalence was 40%, with 98.6% of cows having ≥ 4 observations during the study period when at least one LS was ≥ 1 during lactation. Hoof trimming had no apparent effect on the incidence of clinical lameness (LS ≥ 2) (trimmed vs. non-trimmed: 33.2% vs. 28.8%, respectively), but for LS ≥ 1, there was a small decrease in the incidence of LS ≥ 1 (trimmed vs. non-trimmed: 96.9% vs. 99.3%, respectively). The hazard of a cow having a first observed LS ≥ 2 in the control group was 0.87 (95% CI = 0.66-1.14) times that of the trimmed group; however, the hazard of a cow having a first LS ≥ 1 was 1.60 (95% CI = 1.37-1.88) times higher in the control than in the trimmed group.

CONCLUSION AND CLINICAL RELEVANCE

On this farm, prophylactic hoof trimming had no clinically relevant impact on the incidence of clinical lameness and was not associated with clinically beneficial reductions in time to first observed LS ≥ 2. This may be because claw horn imbalance was not pronounced on this farm, with 53% of cows needing no trim on either hind limb on the first trimming occasion. Further research on the response to prophylactic trimming in pasture-based dairy cattle is required.

Patterns of high-flying insect abundance are shaped by landscape type and abiotic conditions

Insects are of increasing conservation concern as a severe decline of both biomass and biodiversity have been reported. At the same time, data on where and when they occur in the airspace is still sparse, and we currently do not know whether their density is linked to the type of landscape above which they occur. Here, we combined data of high-flying insect abundance from six locations across Switzerland representing rural, urban and mountainous landscapes, which was recorded using vertical-looking radar devices. We analysed the abundance of high-flying insects in relation to meteorological factors, daytime, and type of landscape. Air pressure was positively related to insect abundance, wind speed showed an optimum, and temperature and wind direction did not show a clear relationship. Mountainous landscapes showed a higher insect abundance than the other two landscape types. Insect abundance increased in the morning, decreased in the afternoon, had a peak after sunset, and then declined again, though the extent of this general pattern slightly differed between landscape types. We conclude that the abundance of high-flying insects is not only related to abiotic parameters, but also to the type of landscapes and its characteristics, which, on a long-term, should be taken into account for when designing conservation measures for insects.

Evidence of Lack of Treatment Efficacy Derived From Statistically Nonsignificant Results of Randomized Clinical Trials

Importance

Many randomized clinical trials yield statistically nonsignificant results. Such results are difficult to interpret within the dominant statistical framework.

Objective

To estimate the strength of evidence in favor of the null hypothesis of no effect vs the prespecified effectiveness hypothesis among nonsignificant primary outcome results of randomized clinical trials by application of the likelihood ratio.

Design, Setting, and Participants

Cross-sectional study of statistically nonsignificant results for primary outcomes of randomized clinical trials published in 6 leading general medical journals in 2021.

Outcome measures

The likelihood ratio for the null hypothesis of no effect vs the effectiveness hypothesis stated in the trial protocol (alternate hypothesis). The likelihood ratio quantifies the support that the data provide to one hypothesis vs the other.

Results

In 130 articles that reported 169 statistically nonsignificant results for primary outcomes, 15 results (8.9%) favored the alternate hypothesis (likelihood ratio, <1), and 154 (91.1%) favored the null hypothesis of no effect (likelihood ratio, >1). For 117 (69.2%), the likelihood ratio exceeded 10; for 88 (52.1%), it exceeded 100; and for 50 (29.6%), it exceeded 1000. Likelihood ratios were only weakly correlated with P values (Spearman r, 0.16; P = .045).

Conclusions

A large proportion of statistically nonsignificant primary outcome results of randomized clinical trials provided strong support for the hypothesis of no effect vs the alternate hypothesis of clinical efficacy stated a priori. Reporting the likelihood ratio may improve the interpretation of clinical trials, particularly when observed differences in the primary outcome are statistically nonsignificant.

Inequity of antenatal influenza and pertussis vaccine coverage in Australia: the Links2HealthierBubs record linkage cohort study, 2012-2017

BACKGROUND

Pregnancy and early infancy are increased risk periods for severe adverse effects of respiratory infections. Aboriginal and/or Torres Strait Islander (respectfully referred to as First Nations) women and children in Australia bear a disproportionately higher burden of respiratory diseases compared to non-Indigenous women and infants. Influenza vaccines and whooping cough (pertussis) vaccines are recommended and free in every Australian pregnancy to combat these infections. We aimed to assess the equity of influenza and/or pertussis vaccination in pregnancy for three priority groups in Australia: First Nations women; women from culturally and linguistically diverse (CALD) backgrounds; and women living in remote areas or socio-economic disadvantage.

METHODS

We conducted individual record linkage of Perinatal Data Collections with immunisation registers/databases between 2012 and 2017. Analysis included generalised linear mixed model, log-binomial regression with a random intercept for the unique maternal identifier to account for clustering, presented as prevalence ratios (PR) and 95% compatibility intervals (95%CI).

RESULTS

There were 445,590 individual women in the final cohort. Compared with other Australian women (n = 322,848), First Nations women (n = 29,181) were less likely to have received both recommended antenatal vaccines (PR 0.69, 95% CI 0.67-0.71) whereas women from CALD backgrounds (n = 93,561) were more likely to have (PR 1.16, 95% CI 1.10-1.13). Women living in remote areas were less likely to have received both vaccines (PR 0.75, 95% CI 0.72-0.78), and women living in the highest areas of advantage were more likely to have received both vaccines (PR 1.44, 95% CI 1.40-1.48).

CONCLUSIONS

Compared to other groups, First Nations Australian families, those living in remote areas and/or families from lower socio-economic backgrounds did not receive recommended vaccinations during pregnancy that are the benchmark of equitable healthcare. Addressing these barriers must remain a core priority for Australian health care systems and vaccine providers. An extension of this cohort is necessary to reassess these study findings.

Prenatal household size and composition are associated with infant fecal bacterial diversity in Cebu, Philippines

OBJECTIVES

The gut microbiome (GM) connects physical and social environments to infant health. Since the infant GM affects immune system development, there is interest in understanding how infants acquire microbes from mothers and other household members.

MATERIALS AND METHODS

As a part of the Cebu Longitudinal Health and Nutrition Survey (CLHNS), we paired fecal samples (proxy for the GM) collected from infants living in Metro Cebu, Philippines at 2 weeks (N = 39) and 6 months (N = 36) with maternal interviews about prenatal household composition. We hypothesized that relationships between prenatal household size and composition and infant GM bacterial diversity (as measured in fecal samples) would vary by infant age, as well as by household member age and sex. We also hypothesized that infant GM bacterial abundances would differ by prenatal household size and composition.

RESULTS

Data from 16 S rRNA bacterial gene sequencing show that prenatal household size was the most precise estimator of infant GM bacterial diversity, and that the direction of the association between this variable and infant GM bacterial diversity changed between the two time points. The abundances of bacterial families in the infant GM varied by prenatal household variables.

CONCLUSIONS

Results highlight the contributions of various household sources to the bacterial diversity of the infant GM, and suggest that prenatal household size is a useful measure for estimating infant GM bacterial diversity in this cohort. Future research should measure the effect of specific sources of household bacterial exposures, including social interactions with caregivers, on the infant GM.

Evaluating the Effect of Preventative Trimming on Distance from the Sole Surface to the Distal Phalanx Using Ultrasonography for Lameness Prevention in Pasture-Based Dairy Cows

One common management strategy used to reduce the risk of lameness is prophylactic claw trimming. However, in pasture-based cattle, there is a concern that the immediate reduction in sole thickness resulting from sole trimming will lead to medium-to-long-term reductions in sole thickness, which may increase the risk of lameness. Nevertheless, there is a lack of data on sole thickness and trimming in pasture-based cows. Therefore, the aim of this study was to evaluate the effect of trimming on sole thickness over the medium-to-long term, as estimated using the ultrasound-measured distance from the external claw sole surface to the distal phalanx (DDP) and of DDP on the interval between calving and increased locomotion scores. A total of 38 cows were randomly selected from a 940-cow spring calving dairy farm in the North Island of New Zealand; 18 were allocated to the ultrasound hoof-trimming group and 20 were allocated to the ultrasound non-trimming group. Starting in May 2018, at the end of the 2017/18 lactation, ultrasound measurements of DDP of the right hind hoof were made on all 38 cows, and the hindlimbs of the trimming group cows were trimmed by an experienced professional hoof trimmer using the five-step Dutch method. This was repeated in October 2018 (early lactation) and May 2019 (late lactation). After calving, the cows were locomotion scored fortnightly until the end of lactation using the 4-point (0-3) scale DairyNZ system. The effect of DDP on the interval between calving and the first locomotion scores ≥1 and ≥2 was assessed using Cox proportional hazards models, and the association between trimming and DDP was explored using linear mixed models. The results suggest that DDP has no effect on the time to locomotion scores ≥1 or ≥2, although the wide confidence intervals of the latter suggest that more data are needed before any definitive conclusions can be drawn. The study failed to find any clinically important impact of prophylactic trimming on DDP. This is likely related to the finding that cows with the highest DDP at the first trimming were identified by the hoof trimmer as those needing the most trimming. The results of this study thus suggest that if the Dutch five-step method is properly applied, it is unlikely to affect sole thickness over the short-to-medium term in pasture-based cattle.

Parental occupational exposures prior to conception and offspring wheeze and eczema during first year of life

PURPOSE

Parental exposures prior to conception might influence asthma and allergy risk in offspring. As occupational exposures are established risk factors for asthma and allergies, we investigated if parental occupational exposures prior to conception cause wheeze and eczema in offspring during the first year of life.

METHODS

We analysed data of 436 families from an offspring cohort based on a follow-up study of German participants of the International Study of Asthma and Allergies in Childhood (ISAAC). Offspring cohort data was collected between 2009 and 2019. Occupational exposures were based on participants' work histories and measured by a Job-Exposure-Matrix. We used Bayesian logistic regression models for analysis. Inference and confounder selection were based on directed acyclic graphs.

RESULTS

In mothers, for both allergic and irritative occupational exposures prior to conception suggestive effects on offspring eczema during the first year of life were found (allergens: odds ratio (OR) 1.22, 95% compatibility interval (CI) 0.92-1.57; irritants: OR 1.36, 95% CI 0.99-1.77), while no relation with wheeze was suggested.

CONCLUSIONS

Our results suggest that reduction of asthma-related occupational exposures might not only reduce the burden of disease for occupationally induced or aggravated asthma and allergies in employees but also in their children.

Influence of dynamic stretching on ankle joint stiffness, vertical stiffness and running economy during treadmill running

The purpose of the present study was to investigate whether and how dynamic stretching of the plantarflexors may influence running economy. A crossover design with a minimum of 48 h between experimental (dynamic stretching) and control conditions was used. Twelve recreational runners performed a step-wise incremental protocol to the limit of tolerance on a motorised instrumented treadmill. The initial speed was 2.3 m/s, followed by increments of 0.2 m/s every 3 min. Dynamic joint stiffness, vertical stiffness and running kinematics during the initial stage of the protocol were calculated. Running economy was evaluated using online gas-analysis. For each participant, the minimum number of stages completed before peak O2 uptake (V̇O2peak) common to the two testing conditions was used to calculate the gradient of a linear regression line between V̇O2 (y-axis) and speed (x-axis). The number of stages, which ranged between 4 and 8, was used to construct individual subject regression equations. Non-clinical forms of magnitude-based decision method were used to assess outcomes. The dynamic stretching protocol resulted in a possible decrease in dynamic ankle joint stiffness (−10.7%; 90% confidence limits ±16.1%), a possible decrease in vertical stiffness (−2.3%, ±4.3%), a possibly beneficial effect on running economy (−4.0%, ±8.3%), and very likely decrease in gastrocnemius medialis muscle activation (−27.1%, ±39.2%). The results indicate that dynamic stretching improves running economy, possibly via decreases in dynamic joint and vertical stiffness and muscle activation. Together, these results imply that dynamic stretching should be recommended as part of the warm-up for running training in recreational athletes examined in this study.

Why and how we should join the shift from significance testing to estimation

A paradigm shift away from null hypothesis significance testing seems in progress. Based on simulations, we illustrate some of the underlying motivations. First, p-values vary strongly from study to study, hence dichotomous inference using significance thresholds is usually unjustified. Second, 'statistically significant' results have overestimated effect sizes, a bias declining with increasing statistical power. Third, 'statistically non-significant' results have underestimated effect sizes, and this bias gets stronger with higher statistical power. Fourth, the tested statistical hypotheses usually lack biological justification and are often uninformative. Despite these problems, a screen of 48 papers from the 2020 volume of the Journal of Evolutionary Biology exemplifies that significance testing is still used almost universally in evolutionary biology. All screened studies tested default null hypotheses of zero effect with the default significance threshold of p = 0.05, none presented a pre-specified alternative hypothesis, pre-study power calculation and the probability of 'false negatives' (beta error rate). The results sections of the papers presented 49 significance tests on average (median 23, range 0-390). Of 41 studies that contained verbal descriptions of a 'statistically non-significant' result, 26 (63%) falsely claimed the absence of an effect. We conclude that studies in ecology and evolutionary biology are mostly exploratory and descriptive. We should thus shift from claiming to 'test' specific hypotheses statistically to describing and discussing many hypotheses (possible true effect sizes) that are most compatible with our data, given our statistical model. We already have the means for doing so, because we routinely present compatibility ('confidence') intervals covering these hypotheses.

Benchmark dose modelling in regulatory ecotoxicology, a potential tool in pest management

For several authorities, benchmark dose (BMD) methodology has become the recommended approach by which to derive reference values for risk assessment. However, in practice, the BMD approach is not standard use in risk assessment for pesticides where the no observed adverse effect level, lowest observed adverse effect level and effective dose (ED₅₀ or ED_x ) prevail. Regression-based BMD and the benchmark dose lower confidence limit (BMDL) have several advantages, such as utilizing more information from the generated data and being less dependent on tested dose levels. However, the BMD approach requires some degree of expert knowledge for defining an appropriate risk level for estimating the BMD and using more sophisticated statistical methods to calculate BMD and BMDL. The BMD approach is one way to move away from p value-based binary decision-making towards putting the weight on effect sizes. We review the advantages and disadvantages of focusing on the BMD approach for risk assessment of pesticides. Further, we discuss potential applications in efficacy trials for pest management purposes. © 2021 Society of Chemical Industry.

Colorful Collar-Covers and Bells Reduce Wildlife Predation by Domestic Cats in a Continental European Setting

In many areas, domestic cats are the most abundant predators of small vertebrates. Due to the potential impact on prey populations by cats, there are calls to investigate the effectiveness of visual and acoustic cues as measures to reduce the cat’s hunting efficiency. In this study, we complement previous studies on the efficacy of Birdsbesafe collar-covers (BBScc) in a so far not investigated Continental European setting and explore the effectiveness in combination with a bell. We also evaluate the tolerability of these devices by the cat and the acceptance by their owners. With a randomized and comparative citizen science-based approach we collected data from 26 households with 31 study cats, which were wearing either a BBScc or both a BBScc and a bell. The BBScc reduced the number of birds brought home by 37% (probability of reduction of 88%). The number of mammals brought home was reduced by 54–62%, but only with the additional bell (probability of reduction of &gt;99%). About one fourth of the birds that could be dissected were found to have collided with a hard object prior to having been brought home by the cats. Our results are in line with previous findings from Australia, the United States, and the United Kingdom and highlight the great potential of visual and acoustic cues in reducing hunting success in domestic cats also in Continental Europe. On the other hand, our result show that the number of prey brought home by cats overestimates their hunting bag, if scavenging is not considered. The majority of cat owners reported that their cats habituated quickly to the BBScc. However, frequent scratching in some cats indicates that some individuals may not habituate. Most participating cat owners had a positive attitude toward the BBScc and said that they were willing to use it after the study. However, cat owners reported that their social environment (e.g., neighbors, family, friends) was relatively skeptical, which indicates a need for communication. To conclude, commercially available devices with visual and acoustic stimuli are straightforward and effective ways to mitigate the potentially harmful effect of domestic cats on wildlife.

The burden of low back pain, rheumatoid arthritis, osteoarthritis, and gout and their respective attributable risk factors in Brazil: results of the GBD 2017 study

INTRODUCTION

Musculoskeletal (MSK) disorders are a major cause of disability worldwide. Different modifiable risk factors are associated to these disorders. The objective of this study was to analyze the burden of low back pain (LBP), rheumatoid arthritis (RA), osteoarthritis (OA), and gout, attributable to risk factors, in 2017.

METHODS

The burden of LBP, RA, OA, and gout, and attributable risk factors were analyzed using data extracted from the Global Burden of Disease (GBD) Brasil-2017 study. Descriptive analysis was conducted to compare disability-adjusted life years (DALY) rates between sexes and age groups (15-49 and 50-69 years), in 2017.

RESULTS

The highest rates of DALY due to LBP were attributed to occupational ergonomic factors in the 15-49-year group, regardless of sex and males aged 50-69 years, whereas smoking was the major contributor in the 50-69-year female group. RA-related DALY rates were attributed to smoking and were higher among women aged 50-69 years. High body mass index (BMI) was the most relevant risk factor for the burden of OA, with higher rates detected in the 50-69-year group, and it was the most significant risk factor for DALY rate attributed to gout, regardless of sex or age group.

CONCLUSIONS

Occupational surveillance measures are indicated to prevent LBP. Actions to decrease smoking and overweight, and the surveillance of weight gain are warranted to decrease the burden of LBP, RA and OA, and gout, respectively. These actions will be more effective if age and sex differentials are considered in planning.

Mortality and years of life lost to death or disability by interpersonal violence against women in Brazil: Global Burden of Disease Study, 1990 and 2019

INTRODUCTION

Aggression against women is an important cause of morbidity and death. This study compares the variation of deaths and years of life lost to death or disability (DALY) caused by interpersonal violence against women in Brazil and its states.

METHODS

This descriptive study analyzed estimates from the Global Burden of Disease Study (GBD) referring to interpersonal violence against women, aged 15 to 49 years, examining the mortality and DALY rates for Brazil and its states, in 1990 and 2019.

RESULTS

In this study, 3,168 deaths of women between 15 and 49 years of age, caused by interpersonal violence, were estimated in 1990, and 4,262 in 2019, which represents an increase of 33.8%. Regardless of the Maria da Penha Law and the progress in policies for curbing violence against women, one can observe a stability in the mortality and DALY rates in most of the Brazilian states. Only Bahia had a significant increase in those rates, while Federal District, Rio de Janeiro, and São Paulo showed a significant decline.

CONCLUSIONS

The rates of female homicide have remained stable when comparing 1990 and 2019. Although there were improvements in terms of women's rights in the early 2000's, the chauvinist and conservative society of Brazil has not been able to protect women, and the country might not reach the targets established by the UN's 2030 Agenda.

Burden of Cardiovascular diseases attributable to risk factors in Brazil: data from the "Global Burden of Disease 2019" study

INTRODUCTION

To better understand trends in the main cause of death in Brazil, we sought to analyze the burden of cardiovascular risk factors (RF) and cardiovascular diseases (CVD) attributable to specific RFs in Brazil from 1990 to 2019, using the estimates from the GBD 2019 study.

METHODS

To estimate RF exposure, the Summary Exposure Value (SEV) was used, whereas for disease burden attributed to RF, mortality and disability-adjusted life-years (DALY) due to CVD were used. For comparisons over time and between states, we compared age-standardized rates. The sociodemographic index (SDI) was used as a marker of socioeconomic conditions.

RESULTS

In 2019, 83% of CVD mortality in Brazil was attributable to RF. For SEV, there was a reduction in smoking and environmental RF, but an increase in metabolic RF. High systolic blood pressure and dietary risks continue to be the main RF for CVD mortality and DALY. While there was a decline in age-standardized mortality rates attributable to the evaluated RF, there was also a stability or increase in crude mortality rates, with the exception of smoking. It is important to highlight the increase in the risk of death attributable to a high body mass index. Regarding the analysis per state, SEVs and mortality attributable to RF were higher in those states with lower SDIs.

CONCLUSIONS

Despite the reduction in CVD mortality and DALY rates attributable to RF, the stability or increase in crude rates attributable to metabolic RFs is worrisome, requiring investments and a renewal of health policies.

Road traffic injuries and deaths and the achievement of UN Sustainable Development Goals in Brazil: results from the Global Burden of Disease Study, 1990 to 2019

INTRODUCTION

Brazil ranks 5th in the number of deaths due to road injuries. This study aimed to analyze mortality and disabilities resulting from road injuries in Brazil, and to assess the Sustainable Development Goals (SDG) target of reducing deaths due to road injuries by 50% by 2030.

METHODS

This descriptive and exploratory study used the estimates from the Global Burden of Disease 2019: indicators of mortality, premature deaths, and disabilities according to sex, age group, and type of transport for 1990, 2015, and 2019. Time trends in mortality rates from 1990 to 2019 were assessed, and a projection for 2030 was calculated, applying a linear regression model.

RESULTS

Deaths due to road injuries were 44,236 in 1990, and 44,529 in 2019, representing a 43% reduction in mortality rates. The highest rates were in the North, Northeast, and Midwest regions of Brazil, in males and young adults. A 77% reduction was observed in mortality rates for pedestrians and an increase of 53% for motorcyclists and of 54% for cyclists during the period. In terms of motorcycle road injuries, the mortality rate for men increased from 7.3/100,000 (1990) to 11.7/100,000 inhabitants (2019). The rates of premature deaths and disabilities were also higher for men when compared to women. Amputations, fractures, spinal cord injuries, and head trauma were the main types of road injuries. The projections for 2030 show that Brazil might not reach the SDG target.

CONCLUSIONS

Despite the decline in mortality rates, the 2030 Agenda's target might not be achieved.

The increasing burden of pancreatic cancer in Brazil from 2000 to 2019: estimates from the Global Burden of Disease Study 2019

INTRODUCTION

Pancreatic cancer is increasing worldwide. The burden of pancreatic cancer in Brazil and its states was analyzed and compared with that from the USA and China.

METHODS

This is a descriptive study of the incidence and mortality estimates from the Global Burden of Disease 2019 study, from 2000 to 2019. The Brazilian states presenting the highest and lowest socio-demographic index (SDI) were selected from each of the five regions. The SDI consists of the per capita income, education, and fertility rate of each population.

RESULTS

A significant increase was found in age-standardized incidence and mortality of pancreatic cancer in all three countries, with differences in magnitude and annual increases. In Brazil, this incidence rose from 5.33 [95% Uncertainty Interval (UI): 5.06- 5.51] to 6.16 (95% UI: 5.68- 6.53) per 100,000 inhabitants. China and the Brazilian states with the lowest SDI, such as Pará and Maranhão, showed lower incidence and mortality rates, although presenting the highest annual increases. No difference was found between the sexes. A higher mortality rate was observed for those individuals of 70+ years, which was three to four times higher than those aged 50 to 69 years.

CONCLUSIONS

The increasing burden of pancreatic cancer in the studied countries, and the higher estimates for the elderly in a fast-aging country such as Brazil, indicates that more resources and health policies will be necessary. The greatest increase in the states with lower SDI reflects inequalities in the access to diagnosis and registries of this cancer.

Burden of disease attributable to Risk Factors in Brazil: an analysis of national and subnational estimates from the 2019 Global Burden of Disease study

INTRODUCTION:

Monitoring trends in risk factors (RFs) and the burden of diseases attributable to exposure to RFs is an important measure to identify public health advances and current inadequate efforts. Objective: Analyze the global burden of disease attributable to exposure RFs in Brazil, and its changes from 1990 to 2019, according to the sex and age group.

METHODS:

This study used data from the Global Burden of Disease study. The Summary Exposure Value, which represents weighted prevalence by risk, was used to estimate exposure to RFs. The mortality and DALYs (Disability Adjusted Life Years) measurements were used to estimate the burden of diseases. For comparisons by year and between Brazilian states, age-standardized rates were used.

RESULTS:

Arterial hypertension was the factor responsible for most deaths in both sexes. For DALYs, the most important RF was the high body mass index (BMI) for women and alcohol consumption for men. Smoking had a substantial reduction in the attributable burden of deaths in the period. An important reduction was identified in the exposure to RFs related to socioeconomic development, such as unsafe water, lack of sanitation, and child malnutrition. Metabolic RFs, such as high BMI, hypertension, and alcohol consumption showed an increase in the attributable burden.

CONCLUSIONS:

Our findings point to an increase in metabolic RFs, which are the main RFs for mortality and DALYs. These results can help to consolidate and strengthen public policies that promote healthy lifestyles, thus reducing disease and death.

Trend of the Burden of Larynx Cancer in Brazil, 1990 to 2019

INTRODUCTION:

Larynx cancer is one of the most common head and neck cancers, whose main risk factors are smoking and alcohol use, and its occurrence and prognosis depend on adequate and timely preventive measures. This study aimed to investigate the burden of larynx cancer in Brazil and its states.

METHODS:

Using estimates from the Global Burden of Disease Study 2019, this study analyzed the trends of incidence, mortality, and disability-adjusted life years (DALYs) for larynx cancer between 1990 and 2019, besides the mortality-to-incidence ratio and the socio demographic index.

RESULTS:

Incidence and mortality due to larynx cancer in Brazil, which are approximately eight-fold higher for men, showed a declining trend between 1990 and 2019 (APPC: -0.4% and -1.0%, respectively). The DALYs also showed negative variation between 1990 and 2019 for both sexes in Brazil, mainly due to the decrease in premature deaths, with the greatest reduction in the state of São Paulo. For the states of Brazil in 2019, the higher age-standardized incidence rate (Rio Grande do Sul, 3.83 cases per 100,000 inhabitants) is twice the lowest rate (Piauí, 1.56 cases per 100,000 inhabitants).

CONCLUSIONS:

A fall in the burden of larynx cancer was observed in Brazil over the past 30 years, which may be attributed to a reduction in smoking and to an improvement in treatment. However, the regional inequalities in the country remain evident, especially for males. This data can guide public policy priorities to control the disease in Brazil.

Optimizing cluster survey designs for estimating trachomatous inflammation-follicular within trachoma control programs

OBJECTIVES

The World Health Organization recommends mass drug administration (MDA) with azithromycin to eliminate trachoma as a public health problem. MDA decisions are based on prevalence estimates from two-stage cluster surveys. Work remains to mathematically evaluate current trachoma survey designs. We aimed to characterize the effects of the number of units sampled on the precision and cost of trachomatous inflammation-follicular (TF) estimates.

METHODS

We simulated a population of 30 districts to represent the breadth of possible TF distributions in Amhara, Ethiopia. Samples of varying numbers of clusters (14-34) and households (10-60) were selected. Sampling schemes were evaluated on precision, proportion of incorrect and low MDA decisions made, and estimated cost.

RESULTS

Number of clusters sampled had a greater impact on precision than number of households. The most efficient scheme depended on the underlying TF prevalence in a district. For lower prevalence areas (<10%) the most cost efficient (providing adequate precision while minimizing cost) design was 20 clusters of 20-30 households. For higher prevalence areas (>10%), the most efficient design was 15-20 clusters of 20-30 households.

CONCLUSIONS

For longer-running programs, using context-specific survey designs would allow for practical precision while reducing survey costs. Sampling 15 clusters of 20-30 households in suspected moderate to high prevalence districts and 20 clusters of 20-30 households in districts suspected to be near the 5% threshold appears to be a balanced approach.

Teaching: confidence, prediction and tolerance intervals in scientific practice: a tutorial on binary variables

BACKGROUND

One of the emerging themes in epidemiology is the use of interval estimates. Currently, three interval estimates for confidence (CI), prediction (PI), and tolerance (TI) are at a researcher's disposal and are accessible within the open access framework in R. These three types of statistical intervals serve different purposes. Confidence intervals are designed to describe a parameter with some uncertainty due to sampling errors. Prediction intervals aim to predict future observation(s), including some uncertainty present in the actual and future samples. Tolerance intervals are constructed to capture a specified proportion of a population with a defined confidence. It is well known that interval estimates support a greater knowledge gain than point estimates. Thus, a good understanding and the use of CI, PI, and TI underlie good statistical practice. While CIs are taught in introductory statistical classes, PIs and TIs are less familiar.

RESULTS

In this paper, we provide a concise tutorial on two-sided CI, PI and TI for binary variables. This hands-on tutorial is based on our teaching materials. It contains an overview of the meaning and applicability from both a classical and a Bayesian perspective. Based on a worked-out example from veterinary medicine, we provide guidance and code that can be directly applied in R.

CONCLUSIONS

This tutorial can be used by others for teaching, either in a class or for self-instruction of students and senior researchers.

Hatching phenology is lagging behind an advancing snowmelt pattern in a high-alpine bird

To track peaks in resource abundance, temperate-zone animals use predictive environmental cues to rear their offspring when conditions are most favourable. However, climate change threatens the reliability of such cues when an animal and its resource respond differently to a changing environment. This is especially problematic in alpine environments, where climate warming exceeds the Holarctic trend and may thus lead to rapid asynchrony between peaks in resource abundance and periods of increased resource requirements such as reproductive period of high-alpine specialists. We therefore investigated interannual variation and long-term trends in the breeding phenology of a high-alpine specialist, the white-winged snowfinch, Montifringilla nivalis, using a 20-year dataset from Switzerland. We found that two thirds of broods hatched during snowmelt. Hatching dates positively correlated with April and May precipitation, but changes in mean hatching dates did not coincide with earlier snowmelt in recent years. Our results offer a potential explanation for recently observed population declines already recognisable at lower elevations. We discuss non-adaptive phenotypic plasticity as a potential cause for the asynchrony between changes in snowmelt and hatching dates of snowfinches, but the underlying causes are subject to further research.

Impacts of an Urban Sanitation Intervention on Fecal Indicators and the Prevalence of Human Fecal Contamination in Mozambique

Fecal source tracking (FST) may be useful to assess pathways of fecal contamination in domestic environments and to estimate the impacts of water, sanitation, and hygiene (WASH) interventions in low-income settings. We measured two nonspecific and two human-associated fecal indicators in water, soil, and surfaces before and after a shared latrine intervention from low-income households in Maputo, Mozambique, participating in the Maputo Sanitation (MapSan) trial. Up to a quarter of households were impacted by human fecal contamination, but trends were unaffected by improvements to shared sanitation facilities. The intervention reduced Escherichia coli gene concentrations in soil but did not impact culturable E. coli or the prevalence of human FST markers in a difference-in-differences analysis. Using a novel Bayesian hierarchical modeling approach to account for human marker diagnostic sensitivity and specificity, we revealed a high amount of uncertainty associated with human FST measurements and intervention effect estimates. The field of microbial source tracking would benefit from adding measures of diagnostic accuracy to better interpret findings, particularly when FST analyses convey insufficient information for robust inference. With improved measures, FST could help identify dominant pathways of human and animal fecal contamination in communities and guide the implementation of effective interventions to safeguard health.

Using historical control data in bioassays for regulatory toxicology

Historical control data (HCD) consist of pooled control group responses from bioassays. These data must be collected and are often used or reported in regulatory toxicology studies for multiple purposes: as quality assurance for the test system, to help identify toxicological effects and their effect-size relevance and to address the statistical multiple comparison problem. The current manuscript reviews the various classical and potential new approaches for using HCD. Issues in current practice are identified and recommendations for improved use and discussion are provided. Furthermore, stakeholders are invited to discuss whether it is necessary to consider uncertainty when using HCD formally and statistically in toxicological discussions and whether binary inclusion/exclusion criteria for HCD should be revised to a tiered information contribution to assessments. Overall, the critical value of HCD in toxicological bioassays is highlighted when used in a weight-of-evidence assessment.

Predictors of gastrointestinal bleeding in adult ICU patients in the SUP-ICU trial

BACKGROUND

In previous studies of predictors of gastrointestinal (GI) bleeding in the intensive care unit (ICU), most patients received pharmacological stress ulcer prophylaxis (SUP). We aimed to assess associations between potential predictors of clinically important GI bleeding (CIB) and overt GI bleeding in adult ICU patients, while considering the effect and potential interaction with use of SUP.

METHODS

We included 3291 acutely admitted adult ICU patients with risk factors for GI bleeding randomized to SUP (pantoprazole) or placebo in the SUP-ICU trial. We used logistic regression models adjusted for allocation to SUP to estimate associations between 23 potential predictors and CIB (primary outcome) and overt GI bleeding (secondary outcome). Furthermore, we assessed associations between potential predictors and both outcomes in each allocation group and assessed potential interaction with allocation to SUP.

RESULTS

Increasing SAPS II and SOFA scores, use of circulatory support and renal replacement therapy were associated with increased risk of CIB and overt GI bleeding; chronic lung disease was associated with increased risk of overt GI bleeding. Results for the remaining potential predictors were compatible with both no difference or increased and decreased risks. We found no strong evidence for any interaction between treatment allocation and any potential predictors.

CONCLUSION

In adult ICU patients at risk of GI bleeding, severity of illness, use of circulatory support and renal replacement therapy were associated with higher odds of CIB, with no strong evidence of interaction with SUP.

Reflection on modern methods: Statistics education beyond 'significance': novel plain English interpretations to deepen understanding of statistics and to steer away from misinterpretations

Concerns have been expressed over standards of statistical interpretation. Results with P <0.05 are often referred to as 'significant' which, in plain English, implies important. This leads some people directly into the misconception that this provides proof that associations are clinically relevant. There are calls for statistics educators to respond to these concerns. This article provides novel plain English interpretations that are designed to deepen understanding. Experience teaching postgraduates at Imperial College is discussed. A key issue with focusing on 'significance' is the common inappropriate practice of implying no association exists, simply because P >0.05. Referring to strengths of association in 'study participants' gives them gravitas, which may help to avoid this. This contrasts with the common practice of focusing on imprecision, by referring to the 'sample' and to 'point estimates'. Unlike formal statistical definitions, interpretations developed and presented here are rooted in the application of statistics. They are based on one set of study participants (not many random samples). Precision of strengths of association are based on using strengths in study participants to estimate strengths of association in the population (from which participants were selected by probability random sampling). Reference to 'compatibility with study data, dependent on statistical modelling assumptions' reminds us of the importance of data quality and modelling assumptions. A straightforward graph shows the relationship between P-values and test statistics. This figure and associated interpretations were developed to illuminate the continuous nature of P-values. This is designed to discourage focus on whether P <0.05, and encourage interpretation of exact P-values.

Effects of whey protein on skeletal muscle microvascular and mitochondrial plasticity following 10 weeks of exercise training in men with type 2 diabetes

Skeletal muscle microvascular dysfunction and mitochondrial rarefaction feature in type 2 diabetes mellitus (T2DM) linked to low tissue glucose disposal rate (GDR). Exercise training and milk protein supplementation independently promote microvascular and metabolic plasticity in muscle associated with improved nutrient delivery, but combined effects are unknown. In a randomised-controlled trial, 24 men (55.6 y, SD 5.7) with T2DM ingested whey protein drinks (protein/carbohydrate/fat: 20/10/3 g; WHEY) or placebo (carbohydrate/fat: 30/3 g; CON) before/after 45 mixed-mode intense exercise sessions over 10 weeks, to study effects on insulin-stimulated (hyperinsulinemic clamp) skeletal-muscle microvascular blood flow (mBF) and perfusion (near-infrared spectroscopy), and histological, genetic, and biochemical markers (biopsy) of microvascular and mitochondrial plasticity. WHEY enhanced insulin-stimulated perfusion (WHEY-CON 5.6%; 90% CI -0.1, 11.3), while mBF was not altered (3.5%; -17.5, 24.5); perfusion, but not mBF, associated (regression) with increased GDR. Exercise training increased mitochondrial (range of means: 40%-90%) and lipid density (20%-30%), enzyme activity (20%-70%), capillary:fibre ratio (∼25%), and lowered systolic (∼4%) and diastolic (4%-5%) blood pressure, but without WHEY effects. WHEY dampened PGC1α -2.9% (90% compatibility interval: -5.7, -0.2) and NOS3 -6.4% (-1.4, -0.2) expression, but other messenger RNA (mRNA) were unclear. Skeletal muscle microvascular and mitochondrial exercise adaptations were not accentuated by whey protein ingestion in men with T2DM. ANZCTR Registration Number: ACTRN12614001197628. Novelty: Chronic whey ingestion in T2DM with exercise altered expression of several mitochondrial and angiogenic mRNA. Whey added no additional benefit to muscle microvascular or mitochondrial adaptations to exercise. Insulin-stimulated perfusion increased with whey but was without impact on glucose disposal.

Expanding the toxicologist's statistical toolbox: Using effect size estimation and dose-response modelling for holistic assessments instead of generic testing

It is tempting to base (eco-)toxicological assay evaluation solely on statistical significance tests. The approach is stringent, objective and facilitates binary decisions. However, tests according to null hypothesis statistical testing (NHST) are thought experiments that rely heavily on assumptions. The generic and unreflected application of statistical tests has been called "mindless" by Gigerenzer. While statistical tests have an appropriate application domain, the present work investigates how unreflected testing may affect toxicological assessments. Dunnett multiple-comparison and Williams trend testing and their compatibility intervals are compared with dose-response-modelling in case studies, where data do not follow textbook behavior, nor behave as expected from a toxicological point of view. In such cases, toxicological assessments based only on p-values may be biased and biological evaluations based on plausibility may be prioritized. If confidence in a negative assay outcome cannot be established, further data may be needed for a robust toxicological assessment.

Compounded conservatism in European re-entry worker risk assessment of pesticides

We review the risk parameters and drivers in the current European Union (EU) worker risk assessment for pesticides, for example considering crop maintenance, crop inspection or harvesting activities, and show that the current approach is very conservative due to multiple worst-case default assumptions. As a case study, we compare generic exposure model estimates with measured worker re-entry exposure values which shows that external cumulative exposure is overpredicted by about 50-fold on average. For this exercise, data from 16 good laboratory practice (GLP)-compliant worker exposure studies in 6 crops were evaluated with a total number of 184 workers. As generic overprediction does not allow efficient risk management or realistic risk communication, we investigate how external exposure can be better predicted within the generic model, and outline options for possible improvements in the current methodology. We show that simply using averages achieves more meaningful exposure estimates, while still being conservative, with an average exposure overprediction of about 9-fold. Overall, EU risk assessment includes several numerically unaccounted "hidden safety factors", which means that workers are well protected; but simultaneously risk assessments are biased towards failing due to compounded conservatism. This should be considered for further global or regional guidance developments and performing more exposure-relevant risk assessment.

Semantic and cognitive tools to aid statistical science: replace confidence and significance by compatibility and surprise

BACKGROUND

Researchers often misinterpret and misrepresent statistical outputs. This abuse has led to a large literature on modification or replacement of testing thresholds and P-values with confidence intervals, Bayes factors, and other devices. Because the core problems appear cognitive rather than statistical, we review some simple methods to aid researchers in interpreting statistical outputs. These methods emphasize logical and information concepts over probability, and thus may be more robust to common misinterpretations than are traditional descriptions.

METHODS

We use the Shannon transform of the P-value p, also known as the binary surprisal or S-value s = -log2(p), to provide a measure of the information supplied by the testing procedure, and to help calibrate intuitions against simple physical experiments like coin tossing. We also use tables or graphs of test statistics for alternative hypotheses, and interval estimates for different percentile levels, to thwart fallacies arising from arbitrary dichotomies. Finally, we reinterpret P-values and interval estimates in unconditional terms, which describe compatibility of data with the entire set of analysis assumptions. We illustrate these methods with a reanalysis of data from an existing record-based cohort study.

CONCLUSIONS

In line with other recent recommendations, we advise that teaching materials and research reports discuss P-values as measures of compatibility rather than significance, compute P-values for alternative hypotheses whenever they are computed for null hypotheses, and interpret interval estimates as showing values of high compatibility with data, rather than regions of confidence. Our recommendations emphasize cognitive devices for displaying the compatibility of the observed data with various hypotheses of interest, rather than focusing on single hypothesis tests or interval estimates. We believe these simple reforms are well worth the minor effort they require.

Assessing variability and uncertainty in orthopedic randomized controlled trials

Background and purpose - Low statistical power remains endemic in clinical medicine including orthopedics and manifests as high uncertainty and wide confidence intervals (CI). We evaluated the reporting and correspondence between power calculation and observed data on key parameters of variability and uncertainty in orthopedic randomized controlled trials (RCTs).Material and methods - RCTs with 1:1 allocation published in 8 major orthopedic journals between 2016 and 2017 with one continuous primary outcome were included in the review. The components of power calculation and observed standard deviation (SD), mean difference (MD), and confidence interval (CI) of MD between groups were assessed for primary outcome.Results - 160 RCTs were included, of which 93 (58%) and 138 (86%) studies reported the estimated SD and MD in the power calculation, respectively. The median ratio of the estimated SD and SDs observed in the data was 1.0 (IQR -0.76 to 1.32) for 69 (43%) studies. Only 31 of 138 studies reported the CI of MD in primary outcome. In 42% of the negative studies, the estimated MD was included in the CI of the observed MD.Interpretation - The key parameters of data variability, both in power analyses and in final study results, were poorly reported. Low power in orthopedics may result from too high an estimated effect size due to an overoptimistic estimate of MD between study groups. In almost half of the studies, overlap of the CI of the observed MD and estimated MD suggested that the reported results of these studies were inconclusive.

Potential sex-dependent effects of weather on apparent survival of a high-elevation specialist

Mountain ecosystems are inhabited by highly specialised and endemic species which are particularly susceptible to climatic changes. However, the mechanisms by which climate change affects species population dynamics are still largely unknown, particularly for mountain birds. We investigated how weather variables correlate with survival or movement of the white-winged snowfinch Montifringilla nivalis, a specialist of high-elevation habitat. We analysed a 15-year (2003-2017) mark-recapture data set of 671 individuals from the Apennines (Italy), using mark-recapture models. Mark-recapture data allow estimating, forgiven time intervals, the probability that individuals stay in the study area and survive, the so called apparent survival. We estimated annual apparent survival to be around 0.44-0.54 for males and around 0.51-0.64 for females. Variance among years was high (range: 0.2-0.8), particularly for females. Apparent survival was lower in winter compared to summer. Female annual apparent survival was negatively correlated with warm and dry summers, whereas in males these weather variables only weakly correlated with apparent survival. Remarkably, the average apparent survival measured in this study was lower than expected. We suggest that the low apparent survival may be due to recent changes in the environment caused by global warming. Possible, non-exclusive mechanisms that potentially also could explain sexual differential apparent survival act via differential breeding dispersal, hyperthermia, weather-dependent food availability, and weather-dependent trade-off between reproduction and self-maintenance. These results improve our current understanding of the mechanisms driving population dynamics in high-elevation specialist birds, which are particularly at risk due to climate change.