Management and Clinical Outcomes of Neonatal Hypothermia in the Newborn Nursery.

OBJECTIVES: Neonatal hypothermia has been shown to be commonly detected among late preterm and term infants. In preterm and very low birth weight infants, hypothermia is associated with increased morbidity and mortality. Little is known about the clinical interventions and outcomes in hypothermic late preterm and term infants. This study fills this gap in the evidence. METHODS: Single-center retrospective cohort study using electronic health record data on infants ≥35 weeks' gestation admitted to a newborn nursery from 2015 to 2021. Hypothermia was categorized by severity: none, mild (single episode, 36.0-36.4°C), and moderate or recurrent (<36.0°C and/or 2+ episodes lasting at least 2 hours). Bivariable and multivariable logistic regression examined associations between hypothermia and interventions or outcomes. Stratified analyses by effect modifiers were conducted when appropriate. RESULTS: Among 24 009 infants, 1111 had moderate or recurrent hypothermia. These hypothermic infants had higher odds of NICU transfer (adjusted odds ratio [aOR] 2.10, 95% confidence interval [CI] 1.68-2.60), sepsis evaluation (aOR 2.23, 95% CI 1.73-2.84), and antibiotic use (aOR 1.73, 95% CI 1.15-2.50) than infants without hypothermia. No infants with hypothermia had culture-positive sepsis, and receipt of antibiotics ≥72 hours (surrogate for culture-negative sepsis and/or higher severity of illness) was not more common in hypothermic infants. Hypothermic infants also had higher odds of blood glucose measurement and hypoglycemia, slightly higher percent weight loss, and longer lengths of stay. CONCLUSIONS: Late preterm and term infants with hypothermia in the nursery have potentially unnecessary increased resource utilization. Evidence-based and value-driven approaches to hypothermia in this population are needed.

Mucocutaneous toxicities from MEK inhibitors: a scoping review of the literature.

BACKGROUND: MEK inhibitors cause a wide spectrum of mucocutaneous toxicities which can delay or interrupt life-saving therapy. PURPOSE: To summarize the morphology, incidence, and clinical presentation of mucocutaneous toxicities from MEK inhibitors via a scoping review of the literature. METHODS: We conducted a scoping review of the published literature, including clinical trials, retrospective and prospective studies, reviews, and case reports and series. All included literature was analyzed by a panel of pediatric and adult oncodermatologists. RESULTS: Of 1626 initial citations, 227 articles met final inclusion criteria. Our review identified follicular reactions, ocular toxicities, xerosis, eczematous dermatitis, edema, and paronychia as the most common mucocutaneous side effects from MEK inhibitor therapy. Grade 1 and 2 reactions were the most prevalent and were typically managed while continuing treatment; however, grade 3 toxicities requiring dose reductions or treatment interruptions were also reported. CONCLUSION: Mucocutaneous toxicities to MEK inhibitor therapy are common and most often mild in severity. Early recognition and treatment can mitigate disruptions in oncologic therapy.

Structure Elucidation of Pharmaceutically Relevant Compounds within Pyrene-based Frameworks.

Single crystal X-ray diffraction (SCXRD) is the preferred and most accurate technique for determining molecular structures. However, it can present challenges when dealing with specific small molecules and active pharmaceutical ingredients (APIs), as many do not form quality crystals without coformers or can be unstable. In this study, we introduce tetrakis(guanidinium) pyrenetetrasulfonate (G4PYR), a robust guanidinium-organosulfonate (GS) framework that efficiently encapsulates small molecules and APIs rich in functional groups. The hydrogen bonding frameworks formed by G4PYR display well-ordered structures with predictable pyrene-pyrene distances, making them ideally suited for targeting arene-based APIs with pendant groups. Successful encapsulation of various guests, including benzaldehyde, benzamide, and arenes containing multiple hydrogen bond donors and acceptors like uracil and thymine, was achieved. Furthermore, we successfully encapsulated important pharmaceutical and biologically relevant compounds, such as lidocaine, ropinirole, adenosine, thymidine, and others. Notably, we present a workflow for investigating host-guest complex formation using powder X-ray diffraction and high throughput experimentation.

Telemedicine Use Before and During the COVID-19 Pandemic in People with Alzheimer's Disease, Multiple Sclerosis, or Parkinson's Disease: A Cross-Sectional Study Using US Commercial Claims Data.

Background: During the COVID-19 pandemic, use of telemedicine (TM) increased dramatically, but it is unclear how use varies by characteristics of people with Alzheimer's disease (AD), multiple sclerosis (MS), or Parkinson's disease (PD). Methods: This cross-sectional study used US PharMetrics Plus commercial claims data from January 1, 2019, to December 31, 2021. TM use (≥1 Current Procedural Terminology code) was assessed in each study year (2019, 2020, and 2021) among people with ≥1 inpatient or ≥2 outpatient diagnosis codes ≥30 days apart for AD, MS, or PD. Any TM use and disease-related visits (AD, MS, or PD diagnosis code within TM claim) were summarized, and characteristics of TM users versus nonusers during the pandemic (2020 and 2021) were described. Results: Among people with AD, MS, or PD, 0.9% used TM in 2019 versus 58.0% in 2020 and 42.5% in 2021. Among TM users in 2020 and 2021, the majority had TM visits related to their neurological disorder (73.2% and 64.6%, respectively). During the pandemic, approximately 25% of total TM visits (n = 296,434) were provided by a neurologist. Mean (SD) age of TM users was similar to nonusers (60.5 [15.1] and 61.5 [15.3] years), but TM users were more likely to be female (62% vs 60%), enrolled in Medicare (33% vs 30%), and reside in western (64.2% vs 35.8%) or eastern (61.0% vs 39.0%) regions versus nonusers. Conclusions: Although results indicate expanded use of and access to TM among people with AD, MS, or PD, differences in patient and health care provider characteristics for TM use were notable.

Development and validation of a claims-based algorithm to identify patients with Neuromyelitis Optica Spectrum disorder.

INTRODUCTION: No validated algorithm exists to identify patients with neuromyelitis optica spectrum disorder (NMOSD) in healthcare claims data. We developed and tested the performance of a healthcare claims-based algorithm to identify patients with NMOSD. METHODS: Using medical record data of 101 adults with NMOSD, multiple sclerosis (MS), or myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), we tested the sensitivity and specificity of claims-based algorithms developed through interviews with neurologists. We tested the best-performing algorithm's face validity using 2016-2019 data from IBM MarketScan Commercial and Medicare Supplemental databases. Demographics and clinical characteristics were reported. RESULTS: Algorithm inclusion criteria were age ≥ 18 years and (≥1 NMO diagnosis [or ≥ 1 transverse myelitis (TM) and ≥ 1 optic neuritis (ON) diagnosis] and ≥ 1 NMOSD drug) or (≥2 NMO diagnoses ≥90 days apart). Exclusion criteria were MS diagnosis or use of MS-specific drug after last NMO diagnosis or NMOSD drug; sarcoidosis diagnosis after last NMO diagnosis; or use of ≥1 immune checkpoint inhibitor. In medical record billing data of 50 patients with NMOSD, 30 with MS, and 21 with MOGAD, the algorithm had 82.0% sensitivity and 70.6% specificity. When applied to healthcare claims data, demographic and clinical features of the identified cohort were similar to known demographics of NMOSD. CONCLUSIONS: This clinically derived algorithm performed well in medical records. When tested in healthcare claims, demographics and clinical characteristics were consistent with previous clinical findings. This algorithm will enable a more accurate estimation of NMOSD disease burden using insurance claims datasets.

Outcome risk model development for heterogeneity of treatment effect analyses: a comparison of non-parametric machine learning methods and semi-parametric statistical methods.

BACKGROUND: In randomized clinical trials, treatment effects may vary, and this possibility is referred to as heterogeneity of treatment effect (HTE). One way to quantify HTE is to partition participants into subgroups based on individual's risk of experiencing an outcome, then measuring treatment effect by subgroup. Given the limited availability of externally validated outcome risk prediction models, internal models (created using the same dataset in which heterogeneity of treatment analyses also will be performed) are commonly developed for subgroup identification. We aim to compare different methods for generating internally developed outcome risk prediction models for subject partitioning in HTE analysis. METHODS: Three approaches were selected for generating subgroups for the 2,441 participants from the United States enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) randomized controlled trial. An extant proportional hazards-based outcomes predictive risk model developed on the overall ASPREE cohort of 19,114 participants was identified and was used to partition United States' participants by risk of experiencing a composite outcome of death, dementia, or persistent physical disability. Next, two supervised non-parametric machine learning outcome classifiers, decision trees and random forests, were used to develop multivariable risk prediction models and partition participants into subgroups with varied risks of experiencing the composite outcome. Then, we assessed how the partitioning from the proportional hazard model compared to those generated by the machine learning models in an HTE analysis of the 5-year absolute risk reduction (ARR) and hazard ratio for aspirin vs. placebo in each subgroup. Cochran's Q test was used to detect if ARR varied significantly by subgroup. RESULTS: The proportional hazard model was used to generate 5 subgroups using the quintiles of the estimated risk scores; the decision tree model was used to generate 6 subgroups (6 automatically determined tree leaves); and the random forest model was used to generate 5 subgroups using the quintiles of the prediction probability as risk scores. Using the semi-parametric proportional hazards model, the ARR at 5 years was 15.1% (95% CI 4.0-26.3%) for participants with the highest 20% of predicted risk. Using the random forest model, the ARR at 5 years was 13.7% (95% CI 3.1-24.4%) for participants with the highest 20% of predicted risk. The highest outcome risk group in the decision tree model also exhibited a risk reduction, but the confidence interval was wider (5-year ARR = 17.0%, 95% CI= -5.4-39.4%). Cochran's Q test indicated ARR varied significantly only by subgroups created using the proportional hazards model. The hazard ratio for aspirin vs. placebo therapy did not significantly vary by subgroup in any of the models. The highest risk groups for the proportional hazards model and random forest model contained 230 participants each, while the highest risk group in the decision tree model contained 41 participants. CONCLUSIONS: The choice of technique for internally developed models for outcome risk subgroups influences HTE analyses. The rationale for the use of a particular subgroup determination model in HTE analyses needs to be explicitly defined based on desired levels of explainability (with features importance), uncertainty of prediction, chances of overfitting, and assumptions regarding the underlying data structure. Replication of these analyses using data from other mid-size clinical trials may help to establish guidance for selecting an outcomes risk prediction modelling technique for HTE analyses.

The Benefits and Challenges of Providing School Meals during the First Year of California's Universal School Meal Policy as Reported by School Foodservice Professionals.

States in the U.S. are newly implementing universal school meal (USM) policies, yet little is known about the facilitators of their success and the challenges they confront. This study evaluated the challenges and facilitators faced by school food authorities (SFAs) implementing California's universal school meal (USM) policy during its inaugural year (2022-2023) using an online survey. In March 2023, 430 SFAs reported many benefits, including increased meal participation (64.2% of SFAs) and revenues (65.7%), reduced meal debt (41.8%) and stigma (30.9%), and improved meal quality (44.3%) and staff salaries (36.9%). Reported challenges include product/ingredient availability (80.9%), staffing shortages (77.0%), vendor/distributor logistics issues (75.9%), and administrative burden (74.9%). Top facilitators included state funding (78.2%) and increased federal reimbursement (77.2%). SFAs with fewer students eligible for free or reduced-price meals (as opposed to SFAs with more) reported greater increases in meal participation and reductions in stigma but also more administrative burdens. Larger SFAs reported greater increases in revenues, staff salaries, and improvements in meal quality than smaller SFAs but also more challenges. Overall, California's USM policy has enhanced student access to healthy meals while mitigating social and financial barriers. Understanding California's experience can inform other jurisdictions considering or implementing similar policies.

Parent perceptions of school meals and how perceptions differ by race and ethnicity.

Parental perceptions of school meals can affect student participation and overall support for school meal policies. Little is known about parental school meal perceptions under universal free school meals (UFSM) policies. We assessed California parents' perceptions of school meals during the COVID-19 emergency response with federally funded UFSM and whether perceptions differed by race/ethnicity. Among 1110 California parents of K-12 students, most reported school meals benefit their families, saving them money (81.6%), time (79.2%), and stress (75.0%). Few reported that their child would be embarrassed to eat school meals (11.7%), but more parents of White students than Hispanic students reported this. Many parents reported that their child likes to eat lunch to be with friends (64.7%); about half felt their child has enough time to eat (54.2%). Fewer parents perceived school lunches to be of good quality (36.9%), tasty (39.6%), or healthy (44.0%). Parents of Hispanic and Asian students had less favorable perceptions of school meal quality, taste, and healthfulness than parents of White students. Parents report that school meals benefit their families, but policy efforts are needed to ensure schools have the resources needed to address cultural appropriateness. Schools should address parental perceptions of meals to optimize participation, nutrition security, and health.

Corrigendum: Lithium-ion battery second life: pathways, challenges and outlook.

[This corrects the article DOI: 10.3389/fchem.2024.1358417.].

Universal School Meals During the Pandemic: A Mixed Methods Analysis of Parent Perceptions From California and Maine.

BACKGROUND: In response to the COVID-19 pandemic, the US Congress authorized the US Department of Agriculture to waive a variety of school meal regulations and funded school meals daily for all students at no charge regardless of family income. Because federal Universal Free School Meals (UFSM) ended with the 2021-2022 school year, several states, including California and Maine, adopted state-level UFSM policies. OBJECTIVE: This study aimed to understand parent perceptions of school meals and the federal and new state UFSM policies in California and Maine, including potential challenges and benefits to students and households. DESIGN: A mixed methods study design was used. A quantitative cross-sectional survey was administered, and semi-structured interviews were conducted in English and Spanish during the 2021-2022 school year. PARTICIPANTS/SETTING: The quantitative survey was administered to parents of students in elementary, middle, and high schools in rural, suburban, and urban communities in California (n = 1110) and Maine (n = 80). Qualitative interviews were then conducted with a subset of these parents in California (n = 46) and Maine (n = 20) using Zoom (Zoom Video Communications). Most survey participants (708 of 1190 [59.5%]) and interviewees (40 of 66 [60.6%]) were parents of students who were eligible for free or reduced-price meals. MAIN OUTCOME MEASURES: Parents' perceptions of UFSM, school meal quality, and experiences applying for free or reduced-price meals were examined. ANALYSES PERFORMED: Tests of proportions were used to analyze survey data. Using grounded theory, interview transcripts were analyzed qualitatively by 2 trained research assistants, applying principles of content analysis to identify themes and domains. Inter-rater reliability was conducted. RESULTS: Parents perceived that school meals and UFSM saved families money and time, as parents had fewer meals to purchase and prepare for their children. In addition, UFSM reduced parents' stress and reduced stigma for children and for parents, who described feelings of embarrassment when they previously filled out paperwork for free or reduced-price meals. Although parent perceptions of school meal quality and healthfulness were mixed, most parents reported feeling grateful for school meals. CONCLUSIONS: Parents had mixed opinions on the quality and healthfulness of school meals, but believed UFSM saved them money and time and reduced their stress. Parents also felt UFSM reduced stigma for families.

Defining D-irAEs: consensus-based disease definitions for the diagnosis of dermatologic adverse events from immune checkpoint inhibitor therapy.

With an increasing number of patients eligible for immune checkpoint inhibitors, the incidence of immune-related adverse events (irAEs) is on the rise. Dermatologic immune-related adverse events (D-irAEs) are the most common and earliest to manifest, often with important downstream consequences for the patient. Current guidelines lack clarity in terms of diagnostic criteria for D-irAEs. The goal of this project is to better define D-irAE for the purposes of identification, diagnosis, and future study of this important group of diseases.The objectives of this project were to develop consensus guidance for an approach to D-irAEs including disease definitions and severity grading. Knowing that consensus among oncologists, dermatologists, and irAE subspecialists would be critical for usability, we formed a Dermatologic irAE Disease Definition Panel. The panel was composed of 34 experts, including oncologists, dermatologists, a rheumatologist, and an allergist/immunologist from 22 institutions across the USA and internationally. A modified Delphi consensus process was used, with two rounds of anonymous ratings by panelists and two virtual meetings to discuss areas of controversy. Panelists rated content for usability, appropriateness, and accuracy on 9-point scales in electronic surveys and provided free text comments. A working group aggregated survey responses and incorporated them into revised definitions. Consensus was based on numeric ratings using the RAND/UCLA Appropriateness Method with prespecified definitions.Following revisions based on panelist feedback, all items received consensus in the second round of ratings. Consensus definitions were achieved for 10 core D-irAE diagnoses: ICI-vitiligo, ICI-lichen planus, ICI-psoriasis, ICI-exanthem, ICI-bullous pemphigoid, ICI-Grover's, ICI-eczematous, ICI-eruptive atypical squamous proliferation, ICI-pruritus without rash, and ICI-erosive mucocutaneous. A standard evaluation for D-irAE was also found to reach consensus, with disease-specific exceptions detailed when necessary. Each disorder's description includes further details on disease subtypes, symptoms, supportive exam findings, and three levels of diagnostic certainty (definite, probable, and possible).These consensus-driven disease definitions standardize D-irAE classification in a useable framework for multiple disciplines and will be the foundation for future work. Given consensus on their accuracy and usability from a representative panel group, we anticipate that they can be used broadly across clinical and research settings.

Lithium-ion battery second life: pathways, challenges and outlook.

Net zero targets have resulted in a drive to decarbonise the transport sector worldwide through electrification. This has, in turn, led to an exponentially growing battery market and, conversely, increasing attention on how we can reduce the environmental impact of batteries and promote a more efficient circular economy to achieve real net zero. As these batteries reach the end of their first life, challenges arise as to how to collect and process them, in order to maximise their economical use before finally being recycled. Despite the growing body of work around this topic, the decision-making process on which pathways batteries could take is not yet well understood, and clear policies and standards to support implementation of processes and infrastructure are still lacking. Requirements and challenges behind recycling and second life applications are complex and continue being defined in industry and academia. Both pathways rely on cell collection, selection and processing, and are confronted with the complexities of pack disassembly, as well as a diversity of cell chemistries, state-of-health, size, and form factor. There are several opportunities to address these barriers, such as standardisation of battery design and reviewing the criteria for a battery's end-of-life. These revisions could potentially improve the overall sustainability of batteries, but may require policies to drive such transformation across the industry. The influence of policies in triggering a pattern of behaviour that favours one pathway over another are examined and suggestions are made for policy amendments that could support a second life pipeline, while encouraging the development of an efficient recycling industry. This review explains the different pathways that end-of-life EV batteries could follow, either immediate recycling or service in one of a variety of second life applications, before eventual recycling. The challenges and barriers to each pathway are discussed, taking into account their relative environmental and economic feasibility and competing advantages and disadvantages of each. The review identifies key areas where processes need to be simplified and decision criteria clearly defined, so that optimal pathways can be rapidly determined for each end-of-life battery.

Parent Perceptions of School Meals Influence Student Participation in School Meal Programs.

OBJECTIVE: To evaluate if parent perceptions of school meals influence student participation. DESIGN: In May 2022, an online survey was used to evaluate parents' perceptions of school meals and their children's participation. PARTICIPANTS: A total of 1,110 California parents of kindergarten through 12th-grade students. MAIN OUTCOME MEASURES: Student participation in school lunch and breakfast. ANALYSIS: Principal component analysis and Poisson regression models. RESULTS: Three groups of parental perceptions were identified: (1) positive perceptions (eg, liking school meals and thinking that they are tasty and healthy), (2) perceived benefits to families (eg, school meals save families money, time, and stress), and (3) negative (eg, concerns about the amount of sugar in school meals and stigma). More positive parental perceptions about school meals and their benefits to families were associated with greater student meal participation. In contrast, more negative parental perceptions were associated with reduced student participation in school meals (P < 0.05). CONCLUSION AND IMPLICATIONS: Parent perceptions of school meals may affect student participation in school meal programs. Working to ensure parents are familiar with the healthfulness and quality of school meals and the efforts schools are making to provide high-quality, appealing meals may be critical for increasing school meal participation rates.

Forensic neuropsychological assessment.

With its firm establishment as a neuropsychology subspecialty, forensic neuropsychological assessment is integral to many criminal and civil forensic evaluations. In addition to evaluating cognitive deficits, forensic neuropsychologists can provide reliable information regarding symptom magnification, malingering, and other neurocognitive and psychological issues that may impact the outcome of a particular legal case. This article is an overview and introduction to neuropsychological assessment in the forensic mental health context. Major issues impacting the current practice of forensic neuropsychology are summarized, and several examples from case law are highlighted.

Cutaneous toxicities of mitogen-activated protein kinase inhibitors in children and young adults with neurofibromatosis-1.

PURPOSE: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder which commonly causes neoplasms leading to disfigurement or dysfunction. Mitogen-activated protein kinase inhibitors (MEKi) are generally well-tolerated treatments which target neural tumor progression in patients with NF1. However, cutaneous adverse events (CAEs) are common and may hinder patients' abilities to remain on treatment, particularly in children. We aim to characterize CAEs secondary to MEKi treatment in pediatric and young adult patients with NF1. METHODS: We reviewed institutional medical records of patients under 30 years with a diagnosis of "NF1," "NF2," or "other neurofibromatoses" on MEKi therapy between January 1, 2019 and June 1, 2022. We recorded the time-to-onset, type, and distribution of CAEs, non-cutaneous adverse events (AEs), AE management, and tumor response. RESULTS: Our cohort consisted of 40 patients with NF1 (median age, 14 years). Tumor types included low-grade gliomas (51%) and plexiform neurofibromas (38%). MEKi used included selumetinib (69%), trametinib (25%), and mirdametinib (6%). A total of 74 CAEs occurred, with 28 cases of acneiform rash (38%). Other common CAEs were paronychia, seborrheic dermatitis, eczema, xerosis, and oral mucositis. The most common treatments included oral antibiotics and topical corticosteroids. Most patients had clinical (stable or improved) tumor response (71%) while 29% had tumor progression while on a MEKi. There was no significant association between CAE presence and tumor response (p = 0.39). CONCLUSIONS: Improvement in characterization of MEKi toxicities and their management is important to develop treatment guidelines for pediatric and young adult patients with NF1 on MEKi therapy.

Clinicopathologic correlation of dermatologic diseases in patients with darker pigmentation.

OBJECTIVES: Cutaneous diseases that disproportionately affect patients with darker pigmentation and their histologic features are historically understudied and undertreated. This review article aims to highlight the key clinical features, histopathology, and diagnostic pearls of several cutaneous diseases that commonly present in patients with darker pigmentation. METHODS: A literature search was conducted, and a list of cutaneous diseases that frequently affect patients with darker pigmentation was compiled. A group of experts expounded upon those that were most common or misdiagnosed according to scientific evidence and clinical practice. RESULTS: The diseases were divided into hypopigmented disorders, hyperpigmented disorders, scarring disorders, and alopecic disorders. Within each category, the etiology, clinical features, histopathology, and key histologic differential diagnoses are described and discussed. CONCLUSIONS: As many clinicians are taught that there are no effective treatment options or that these diseases are considered "cosmetic" in nature, patients often do not get a thorough medical workup or skin biopsy. This article aims to decrease the knowledge gap and serve as a resource for anyone involved in the care of patients with these cutaneous conditions.

Resolution of painful trichodysplasia spinulosa with topical cidofovir: case report.

Purpose: Trichodysplasia spinulosa (TS) is a rare, disfiguring skin condition which presents with widespread asymptomatic or pruritic, skin-colored papules with white protruding keratin spiculations in immunocompromised individuals. Due to its rarity, there is little data to guide treatment decisions. The purpose of this article is to report a case of TS that completely resolved after treatment with topical cidofovir.Materials and methods: A 19-year-old immunosuppressed female presented with widespread painful, itchy bumps on the nose and face. Upon examination, there were erythematous papules with hyperkeratinized spicules affecting the central face. Biopsy of the lesions was consistent with TS which was confirmed via PCR analysis. The tenderness of this patient's eruption was highly atypical for TS. Once daily topical application of compounded 1% cidofovir cream was prescribed.Results: The patient's symptoms resolved completely after 4 weeks of therapy with topical cidofovir 1% cream, without reduction of immunosuppression.Conclusions: Topical cidofovir 1% cream may be a valuable treatment for this rare disease.

Paris classification of colonic polyps using CT colonography: prospective cohort study of interobserver variation.

BACKGROUND: The Paris classification categorises colorectal polyp morphology. Interobserver agreement for Paris classification has been assessed at optical colonoscopy (OC) but not CT colonography (CTC). We aimed to determine the following: (1) interobserver agreement for the Paris classification using CTC between radiologists; (2) if radiologist experience influenced classification, gross polyp morphology, or polyp size; and (3) the extent to which radiologist classifications agreed with (a) colonoscopy and (b) a combined reference standard. METHODS: Following ethical approval for this non-randomised prospective cohort study, seven radiologists from three hospitals classified 52 colonic polyps using the Paris system. We calculated interobserver agreement using Fleiss kappa and mean pairwise agreement (MPA). Absolute agreement was calculated between radiologists; between CTC and OC; and between CTC and a combined reference standard using all available imaging, colonoscopic, and histopathological data. RESULTS: Overall interobserver agreement between the seven readers was fair (Fleiss kappa 0.33; 95% CI 0.30-0.37; MPA 49.7%). Readers with < 1500 CTC experience had higher interobserver agreement (0.42 (95% CI 0.35-0.48) vs. 0.33 (95% CI 0.25-0.42)) and MPA (69.2% vs 50.6%) than readers with ≥ 1500 experience. There was substantial overall agreement for flat vs protuberant polyps (0.62 (95% CI 0.56-0.68)) with a MPA of 87.9%. Agreement between CTC and OC classifications was only 44%, and CTC agreement with the combined reference standard was 56%. CONCLUSION: Radiologist agreement when using the Paris classification at CT colonography is low, and radiologist classification agrees poorly with colonoscopy. Using the full Paris classification in routine CTC reporting is of questionable value. CLINICAL RELEVANCE STATEMENT: Interobserver agreement for radiologists using the Paris classification to categorise colorectal polyp morphology is only fair; routine use of the full Paris classification at CT colonography is questionable. KEY POINTS: • Overall interobserver agreement for the Paris classification at CT colonography (CTC) was only fair, and lower than for colonoscopy. • Agreement was higher for radiologists with < 1500 CTC experience and for larger polyps. There was substantial agreement when classifying polyps as protuberant vs flat. • Agreement between CTC and colonoscopic polyp classification was low (44%).