Retinal Dystrophies Associated With Peripherin-2: Genetic Spectrum and Novel Clinical Observations in 241 Patients.

Purpose: To describe the clinical, electrophysiological and genetic spectrum of inherited retinal diseases associated with variants in the PRPH2 gene. Methods: A total of 241 patients from 168 families across 15 sites in 9 countries with pathogenic or likely pathogenic variants in PRPH2 were included. Records were reviewed for age at symptom onset, visual acuity, full-field ERG, fundus colour photography, fundus autofluorescence (FAF), and SD-OCT. Images were graded into six phenotypes. Statistical analyses were performed to determine genotype-phenotype correlations. Results: The median age at symptom onset was 40 years (range, 4-78 years). FAF phenotypes included normal (5%), butterfly pattern dystrophy, or vitelliform macular dystrophy (11%), central areolar choroidal dystrophy (28%), pseudo-Stargardt pattern dystrophy (41%), and retinitis pigmentosa (25%). Symptom onset was earlier in retinitis pigmentosa as compared with pseudo-Stargardt pattern dystrophy (34 vs 44 years; P = 0.004). The median visual acuity was 0.18 logMAR (interquartile range, 0-0.54 logMAR) and 0.18 logMAR (interquartile range 0-0.42 logMAR) in the right and left eyes, respectively. ERG showed a significantly reduced amplitude across all components (P < 0.001) and a peak time delay in the light-adapted 30-Hz flicker and single-flash b-wave (P < 0.001). Twenty-two variants were novel. The central areolar choroidal dystrophy phenotype was associated with 13 missense variants. The remaining variants showed marked phenotypic variability. Conclusions: We described six distinct FAF phenotypes associated with variants in the PRPH2 gene. One FAF phenotype may have multiple ERG phenotypes, demonstrating a discordance between structure and function. Given the vast spectrum of PRPH2 disease our findings are useful for future clinical trials.

Rapid Variant Pathogenicity Analysis by CRISPR Activation of CRB1 Gene Expression in Patient-Derived Fibroblasts.

Inherited retinal diseases (IRDs) are a heterogeneous group of blinding genetic disorders caused by pathogenic variants in genes expressed in the retina. In this study, we sought to develop a method for rapid evaluation of IRD gene variant pathogenicity by inducing expression of retinal genes in patient-derived fibroblasts using CRISPR-activation (CRISPRa). We demonstrate CRISPRa of CRB1 expression in fibroblasts derived from patients with retinitis pigmentosa, enabling investigation of pathogenic mechanisms associated with specific variants. We show the CRB1 c.4005 + 1G>A variant caused exon 11 skipping in CRISPR-activated fibroblasts and retinal organoids (ROs) derived from the same RP12 patient. The c.652 + 5G>C variant was shown to enhance exon 2 skipping in CRISPR-activated fibroblasts and differentially affected CRB1 isoform expression in fibroblasts and ROs. Our study demonstrates an accessible platform for transcript screening of IRD gene variants in patient-derived fibroblasts, which can potentially be applied for rapid pathogenicity assessments of any gene variant.

Assessing efficacy in non-inferiority trials with non-adherence to interventions: Are intention-to-treat and per-protocol analyses fit for purpose?

BACKGROUND: Non-inferiority trials comparing different active drugs are often subject to treatment non-adherence. Intention-to-treat (ITT) and per-protocol (PP) analyses have been advocated in such studies but are not guaranteed to be unbiased in the presence of differential non-adherence. METHODS: The REMoxTB trial evaluated two 4-month experimental regimens compared with a 6-month control regimen for newly diagnosed drug-susceptible TB. The primary endpoint was a composite unfavorable outcome of treatment failure or recurrence within 18 months post-randomization. We conducted a simulation study based on REMoxTB to assess the performance of statistical methods for handling non-adherence in non-inferiority trials, including: ITT and PP analyses, adjustment for observed adherence, multiple imputation (MI) of outcomes, inverse-probability-of-treatment weighting (IPTW), and a doubly-robust (DR) estimator. RESULTS: When non-adherence differed between trial arms, ITT, and PP analyses often resulted in non-trivial bias in the estimated treatment effect, which consequently under- or over-inflated the type I error rate. Adjustment for observed adherence led to similar issues, whereas the MI, IPTW and DR approaches were able to correct bias under most non-adherence scenarios; they could not always eliminate bias entirely in the presence of unobserved confounding. The IPTW and DR methods were generally unbiased and maintained desired type I error rates and statistical power. CONCLUSIONS: When non-adherence differs between trial arms, ITT and PP analyses can produce biased estimates of efficacy, potentially leading to the acceptance of inferior treatments or efficacious regimens being missed. IPTW and the DR estimator are relatively straightforward methods to supplement ITT and PP approaches.

NADPH oxidase 1 promotes hepatic steatosis in obese mice and is abrogated by augmented skeletal muscle mass.

Exercise as a lifestyle modification is a frontline therapy for nonalcoholic fatty liver disease (NAFLD), but how components of exercise attenuate steatosis is unclear. To uncouple the effect of increased muscle mass from weight loss in obesity, myostatin knockout mice were bred on a lean and obese db/db background. Myostatin deletion increases gastrocnemius (Gastrocn.) mass and reduces hepatic steatosis and hepatic sterol regulatory element binding protein 1 (Srebp1) expression in obese mice, with no impact on adiposity or body weight. Interestingly, hypermuscularity reduces hepatic NADPH oxidase 1 (Nox1) expression but not NADPH oxidase 4 (Nox4) in db/db mice. To evaluate a deterministic function of Nox1 on steatosis, Nox1 knockout mice were bred on a lean and db/db background. NOX1 deletion significantly attenuates hepatic oxidant stress, steatosis, and Srebp1 programming in obese mice to parallel hypermuscularity, with no improvement in adiposity, glucose control, or hypertriglyceridemia to suggest off-target effects. Directly assessing the role of NOX1 on SREBP1, insulin (Ins)-mediated SREBP1 expression was significantly increased in either NOX1, NADPH oxidase organizer 1 (NOXO1), and NADPH oxidase activator 1 (NOXA1) or NOX5-transfected HepG2 cells versus ?-galactosidase control virus, indicating superoxide is the key mechanistic agent for the actions of NOX1 on SREBP1. Metabolic Nox1 regulators were evaluated using physiological, genetic, and diet-induced animal models that modulated upstream glucose and insulin signaling, identifying hyperinsulinemia as the key metabolic derangement explaining Nox1-induced steatosis in obesity. GEO data revealed that hepatic NOX1 predicts steatosis in obese humans with biopsy-proven NAFLD. Taken together, these data suggest that hypermuscularity attenuates Srebp1 expression in db/db mice through a NOX1-dependent mechanism.NEW & NOTEWORTHY This study documents a novel mechanism by which changes in body composition, notably increased muscle mass, protect against fatty liver disease. This mechanism involves NADPH oxidase 1 (NOX1), an enzyme that increases superoxide and increases insulin signaling, leading to increased fat accumulation in the liver. NOX1 may represent a new early target for preventing fatty liver to stave off later liver diseases such as cirrhosis or liver cancer.

Potentiation of Adipogenesis by Reactive Oxygen Species Is a Unifying Mechanism in the Proadipogenic Properties of Bisphenol A and Its New Structural Analogues.

Aims: Structural analogues of bisphenol A (BPA), including bisphenol S (BPS) and bisphenol F (BPF), are emerging environmental toxicants as their presence in the environment is rising since new regulatory restrictions were placed on BPA-containing infant products. The adipogenesis-enhancing effect of bisphenols may explain the link between human exposure and metabolic disease; however, underlying molecular pathways remain unresolved. Results: Exposure to BPS, BPF, BPA, or reactive oxygen species (ROS) generators enhanced lipid droplet formation and expression of adipogenic markers after induction of differentiation in adipose-derived progenitors isolated from mice. RNAseq analysis in BPS-exposed progenitors revealed modulation in pathways regulating adipogenesis and responses to oxidative stress. ROS were higher in bisphenol-exposed cells, while cotreatment with antioxidants attenuated adipogenesis and abolished the effect of BPS. There was a loss of mitochondrial membrane potential in BPS-exposed cells and mitochondria-derived ROS contributed to the potentiation of adipogenesis by BPS and its analogues. Male mice exposed to BPS during gestation had higher whole-body adiposity, as measured by time domain nuclear magnetic resonance, while postnatal exposure had no impact on adiposity in either sex. Innovation: These findings support existing evidence showing a role for ROS in regulating adipocyte differentiation and are the first to highlight ROS as a unifying mechanism that explains the proadipogenic properties of BPA and its structural analogues. Conclusion: ROS act as signaling molecules in the regulation of adipocyte differentiation and mediate bisphenol-induced potentiation of adipogenesis. Antioxid. Redox Signal. 40, 1-15.

Analysis of the Outer Retinal Bands in ABCA4 and PRPH2-Associated Retinopathy using OCT.

PURPOSE: To evaluate the outer retinal bands using OCT in ABCA4- and PRPH2-associated retinopathy and develop a novel imaging biomarker to differentiate between these 2 genotypes. DESIGN: Multicenter case-control study. PARTICIPANTS: Patients with a clinical and genetic diagnosis of ABCA4- or PRPH2-associated retinopathy and an age-matched control group. METHODS: Macular OCT was used to measure the thickness of the outer retinal bands 2 and 4 by 2 independent examiners at 4 retinal loci. MAIN OUTCOME MEASURES: Outcome measures included the thicknesses of band 2, band 4, and the band 2/band 4 ratio. Linear mixed modeling was used to make comparisons across the 3 groups. Receiver operating characteristic (ROC) analysis determined the optimal cutoff for the band 2/band 4 ratio to distinguish PRPH2- from ABCA4-associated retinopathy. RESULTS: We included 45 patients with ABCA4 variants, 45 patients with PRPH2 variants, and 45 healthy controls. Band 2 was significantly thicker in patients with PRPH2 compared with ABCA4 (21.4 vs. 15.9 µm, P < 0.001) variants, whereas band 4 was thicker in patients with ABCA4 variants than those with PRPH2 variants (27.5 vs. 21.7 µm, P < 0.001). Similarly, the band 2/band 4 ratio was significantly different (1.0 vs. 0.6 for PRPH2 vs. ABCA4, P < 0.001). The area under the ROC curve was 0.87 for either band 2 (> 18.58 µm) or band 4 (< 26.17 µm) alone and 0.99 (95% confidence interval: 0.97-0.99) for the band 2/band 4 ratio with a cutoff threshold of 0.79, providing 100% specificity. CONCLUSIONS: We report an altered outer retinal band profile whereby the band 2/band 4 ratio was able to discriminate between PRPH2- and ABCA4-associated retinopathy. This may have future clinic utility in predicting the genotype and provide further insight into the anatomic correlate of band 2. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Cluster randomized controlled trial analysis at the cluster level: The clan command.

In this article, we introduce a new command, clan, that conducts a cluster-level analysis of cluster randomized trials. The command simplifies adjusting for individual- and cluster-level covariates and can also account for a stratified design. It can be used to analyze a continuous, binary, or rate outcome.

High maternal adiposity during pregnancy programs an imbalance in the lipidome and predisposes to diet-induced hepatosteatosis in the offspring.

BACKGROUND: Exposure to high maternal adiposity in utero is a significant risk factor for the later-life development of metabolic syndrome (MetS), including non-alcoholic fatty liver disease (NAFLD). We have previously shown that high pre-pregnancy adiposity programs adipose tissue dysfunction in the offspring, leading to spillover of fatty acids into the circulation, a key pathogenic event in obesity-associated MetS. Herein, we hypothesized that programming of adipose tissue dysfunction in offspring born to overweight dams increases the risk for developing NAFLD. RESULTS: Females heterozygous for leptin receptor deficiency (Hetdb) were used as a model of high pre-pregnancy adiposity. Female wild-type (Wt) offspring born to Hetdb pregnancies gained significantly more body fat following high-fat/fructose diet (HFFD) compared with Wt offspring born to Wt dams. HFFD increased circulating free fatty acids (FFA) in male offspring of control dams, while FFA levels were similar in HFFD-fed offspring from Wt dams and CD or HFFD-fed Wt offspring from Hetdb dams. Despite female-specific protection from diet-induced FFA spillover, both male and female offspring from Hetdb dams were more susceptible to diet-induced hepatosteatosis. Lipidomic analysis revealed that CD-offspring of overweight dams had decreased hepatic polyunsaturated FA (PUFA) levels compared with control offspring. Changes to saturated FA (SFA) and the de novo lipogenic (DNL) index were diet driven; however, there was a significant effect of the intrauterine environment on FA elongation and Δ9 desaturase activity. CONCLUSION: High maternal adiposity during pregnancy programs a susceptibility to diet-induced hepatosteatosis.

Driving with retinitis pigmentosa.

BACKGROUND: To establish the proportion of patients with retinitis pigmentosa (RP) meeting the Australian fitness to drive (FTD) visual standards. METHODOLOGY: A prospective consecutive case series of patients with a clinical or genetic diagnosis of RP. Data on age at symptom onset, current driving status, inheritance pattern, better eye visual acuity (BEVA), binocular Esterman visual field (BEVF) parameters, genotype and ability to meet the driving standards based on BEVA and BEVF were collected. Outcome measures included the proportion of RP patients overall meeting the standards and clinical predictors for passing. A sub-analysis was performed on those RP patients who reported to drive. Change in BEVA and BEVF parameters across age in specific genotype groups was assessed. RESULTS: Overall, 228 patients with RP had a BEVF assessment. Only 39% (89/228) met the driving standards. Younger age at the time of testing was the only significant predictor (p < 0.01) for passing. Of the 55% of RP patients who reported to drive, 52% (65/125) met the standards, decreasing to 14% in the 56- to 65-year-old age group. RP patients harbouring mutations in HK1 or RHO genes may have slower rates of decline in their VF parameters. CONCLUSION: Nearly 40% of RP patients met the driving standards. However, almost 50% of RP drivers were unaware of their failure to meet the current standards. BEVF testing is essential in the assessment of RP patients who are still driving. Phenotype and genotype predictors for passing the standards warrant further investigation.Abbreviation: FTD, fitness to drive; IRD, inherited retinal disease; RP, retinitis pigmentosa; RHO, rhodopsin; HK1, hexokinase 1; PRPF31 pre-mRNA processing factor 31; RPGR, retinitis pigmentosa GTPase regulator; VF, visual field; BEVA, better eye visual acuity; BEVF, binocular Esterman visual field.

Maternal obesity and programming of metabolic syndrome in the offspring: searching for mechanisms in the adipocyte progenitor pool.

BACKGROUND: It is now understood that it is the quality rather than the absolute amount of adipose tissue that confers risk for obesity-associated disease. Adipose-derived stem cells give rise to adipocytes during the developmental establishment of adipose depots. In adult depots, a reservoir of progenitors serves to replace adipocytes that have reached their lifespan and for recruitment to increase lipid buffering capacity under conditions of positive energy balance. MAIN: The adipose tissue expandability hypothesis posits that a failure in de novo differentiation of adipocytes limits lipid storage capacity and leads to spillover of lipids into the circulation, precipitating the onset of obesity-associated disease. Since adipose progenitors are specified to their fate during late fetal life, perturbations in the intrauterine environment may influence the rapid expansion of adipose depots that occurs in childhood or progenitor function in established adult depots. Neonates born to mothers with obesity or diabetes during pregnancy tend to have excessive adiposity at birth and are at increased risk for childhood adiposity and cardiometabolic disease. CONCLUSION: In this narrative review, we synthesize current knowledge in the fields of obesity and developmental biology together with literature from the field of the developmental origins of health and disease (DOHaD) to put forth the hypothesis that the intrauterine milieu of pregnancies complicated by maternal metabolic disease disturbs adipogenesis in the fetus, thereby accelerating the trajectory of adipose expansion in early postnatal life and predisposing to impaired adipose plasticity.

Microperimetry and Adaptive Optics Imaging Reveal Localized Functional and Structural Changes in Asymptomatic RPGR Mutation Carriers.

Purpose: Female carriers of RPGR mutations demonstrate no significant retinal dysfunction or structural change despite a characteristic tapetal-like reflex. In this study, we examined localized changes of pointwise sensitivity (PWS) and cone density (CD) using microperimetry (MP) and adaptive optics (AO) imaging in female carriers of RPGR mutations. Methods: In this cross-sectional case-control study, MP (MAIA, 10-2 test grid) and AO imaging (rtx1) were performed in female carriers of RPGR mutations and unrelated age-matched healthy controls. PWS at 68 loci located 1 degree to 9 degrees away from the preferred retinal locus and CD at 12 loci located 1 degree to 3 degrees away from the foveal center were measured. Severity of defect was defined by standard deviation (SD) from age-matched healthy control means: normal (<1 SD from normal average), moderate defect (1-2 SD from normal average), and severe defect (>2 SD from normal average). Results: Twelve patients from seven unrelated families were enrolled. Seven patients were asymptomatic, 5 of whom had visual acuity 20/20 or better in both eyes. PWS and CD were available in 12 and 8 patients, respectively. Severe PWS and CD defect in at least 1 test location was observed in 10 of 12 patients and 7 of 8 patients, respectively. Among the five asymptomatic patients who had normal visual acuity, severe PWS and CD defects were observed in three of five and four of five patients, respectively. Conclusions: MP and AO imaging revealed early functional and structural changes in asymptomatic RPGR mutation carriers and should be considered in clinical assessment of these patients.

Forgiveness Is the Attribute of the Strong: Nonadherence and Regimen Shortening in Drug-sensitive Tuberculosis.

Rationale: "Forgiveness" charts the ability of a drug or regimen to withstand nonadherence without negative clinical consequences. Objectives: We aimed to determine the influence of regimen length, regimen drugs, and dosing, and when during treatment nonadherence occurs on the forgiveness of antituberculosis regimens. Methods: Using data from three randomized controlled trials comparing experimental 4-month regimens for drug-sensitive tuberculosis with the standard 6-month regimen, we used generalized linear models to examine how the risk of a negative composite outcome changed as dose-taking decreased. The percentage of doses taken and the absolute number of doses missed were calculated during the intensive and continuation phases of treatment, and overall. A mediation analysis was undertaken to determine how much the association between intensive phase dose-taking and the negative composite outcome was mediated through continuation phase dose-taking. Measurements and Main Results: Forgiveness of the 4- and 6-month regimens did not differ for any treatment period. Importantly, 4-month regimens were no less forgiving of small numbers of absolute missed doses than the 6-month regimen (e.g., for 3-7 missed doses vs. no missed doses [baseline], 6-month regimen adjusted risk ratio 1.65 [95% confidence interval, 0.80-3.41] and 4-month regimens 1.80 [1.33-2.45]). No 4-month regimen was conclusively more forgiving than another. We found evidence of mediation by continuation phase dose-taking on the intensive phase dose-taking and negative composite outcome relationship. Conclusions: With the current appetite for, and progress toward, shorter drug-sensitive tuberculosis regimens worldwide, we offer reassurance that shorter regimens are not necessarily less forgiving of nonadherence. Given the importance of continuation phase adherence, patient support during this period should not be neglected.

Longitudinal Analysis of Functional and Structural Outcome Measures in PRPH2-Associated Retinal Dystrophy.

PURPOSE: To establish disease progression rates in total lesion size (TLS), decreased autofluorescence (DAF) area, total macular volume (TMV), and mean macular sensitivity (MMS) in PRPH2-associated retinal dystrophy. DESIGN: Single-center, retrospective chart review. PARTICIPANTS: Patients with heterozygous pathogenic or likely pathogenic PRPH2 variants. METHODS: Patients who underwent serial ultrawide-field (UWF) fundus autofluorescence (FAF), OCT, and Macular Integrity Assessment microperimetry with at least 1 year of follow-up were included. Linear correlation was performed in eyes of all patients to determine the rate of change over time. MAIN OUTCOME MEASURES: Outcome measures included changes in TLS, DAF area, TMV, and MMS. RESULTS: Twelve patients (mean age, 55) from 10 unrelated families attended 100 clinic visits, which spanned over a mean (SD) of 4.7 (2.0) years. Mean (SD) TLS and DAF radius expansion were 0.14 (0.12) and 0.10 (0.08) mm/year, respectively. Mean (SD) TMV change was -0.071 (0.040) mm3/year with no interocular difference (P = 0.20) and strong interocular correlation (r2 = 0.88, P < 0.01). Mean (SD) MMS change was -0.10 (1.25) dB/year. Mean macular sensitivity declined in 4 and improved in 6 patients. Mean macular sensitivity was subnormal despite a TMV within the normal range. CONCLUSIONS: Serial measurements of UWF-FAF-derived TLS and DAF showed slow expansion. Total macular volume might be a more sensitive measure than MMS in detecting disease progression.

Characterising splicing defects of ABCA4 variants within exons 13-50 in patient-derived fibroblasts.

The ATP-binding cassette subfamily A member 4 gene (ABCA4)-associated retinopathy, Stargardt disease, is the most common monogenic inherited retinal disease. Given the pathogenicity of numerous ABCA4 variants is yet to be examined and a significant proportion (more than 15%) of ABCA4 variants are categorized as splice variants in silico, we therefore established a fibroblast-based splice assay to analyze ABCA4 variants in an Australian Stargardt disease cohort and characterize the pathogenic mechanisms of ABCA4 variants. A cohort of 67 patients clinically diagnosed with Stargardt disease was recruited. Genomic DNA was analysed using a commercial panel for ABCA4 variant detection and the consequences of ABCA4 variants were predicted in silico. Dermal fibroblasts were propagated from skin biopsies, total RNA was extracted and the ABCA4 transcript was amplified by RT-PCR. Our analysis identified a total of 67 unique alleles carrying 74 unique variants. The most prevalent splice-affecting complex allele c.[5461-10T>C; 5603A>T] was carried by 10% of patients in a compound heterozygous state. ABCA4 transcripts from exon 13 to exon 50 were readily detected in fibroblasts. In this region, aberrant splicing was evident in 10 out of 57 variant transcripts (18%), carried by 19 patients (28%). Patient-derived fibroblasts provide a feasible platform for identification of ABCA4 splice variants located within exons 13-50. Experimental evidence of aberrant splicing contributes to the pathogenic classification for ABCA4 variants. Moreover, identification of variants that affect splicing processes provides opportunities for intervention, in particular antisense oligonucleotide-mediated splice correction.

Prenatal exposure to a low dose of BPS causes sex-dependent alterations to vascular endothelial function in adult offspring.

Background: Bisphenol S (BPS) is among the most commonly used substitutes for Bisphenol A (BPA), an endocrine disrupting chemical used as a plasticizer in the manufacture of polycarbonate plastics and epoxy resins. Bisphenols interfere with estrogen receptor (ER) signaling, which modulates vascular function through stimulation of nitric oxide (NO) production via endothelial nitric oxide synthase (eNOS). BPS can cross into the placenta and accumulates in the fetal compartment to a greater extent than BPA, potentially interfering with key developmental events. Little is known regarding the developmental impact of exposure to BPA substitutes, particularly with respect to the vasculature. Objective: To determine if prenatal BPS exposure influences vascular health in adulthood. Methods: At the time of mating, female C57BL/6 dams were administered BPS (250 nM) or vehicle control in the drinking water, and exposure continued during lactation. At 12-week of age, mesenteric arteries were excised from male and female offspring and assessed for responses to an endothelium-dependent (acetylcholine, ACh) and endothelium-independent (sodium nitroprusside, SNP) vasodilator. Endothelium-dependent dilation was measured in the presence or absence of L-NAME, an eNOS inhibitor. To further explore the role of NO and ER signaling, wire myography was used to assess ACh responses in aortic rings after acute exposure to BPS in the presence or absence of L-NAME or an ER antagonist. Results: Increased ACh dilation and increased sensitivity to Phe were observed in microvessels from BPS-exposed females, while no changes were observed in male offspring. Differences in ACh-induced dilation between control or BPS-exposed females were eliminated with L-NAME. Increased dilatory responses to ACh after acute BPS exposure were observed in aortic rings from female mice only, and differences were eliminated with inhibition of eNOS or inhibition of ER. Conclusion: Prenatal BPS exposure leads to persistent changes in endothelium-dependent vascular function in a sex-specific manner that appears to be modulated by interaction of BPS with ER signaling.

"It reflects the society in which we live, except now everything is accentuated": youth, social inequities, and the COVID-19 pandemic.

OBJECTIVES: The COVID-19 pandemic has been an extraordinary moment of uncertainty and rapid transformation. The effects lockdowns had on youths' mental and physical health, as well as the challenges they posed for young peoples' learning, were of great concern. It quickly became clear that government responses to COVID-19, in particular regarding the social determinants of health, were not equally experienced across all social groups. This paper adopts an interdisciplinary lens at the intersection of health and education and uses Max Weber's lifestyle theory to analyze the inequitable experience of the COVID-19 pandemic. We examine most directly social inequities in education during the first wave of COVID-19 and explore long-term effects on youths' educational opportunities, health, and well-being. METHODS: We use focus group materials collected from our Spring 2020 study. This study explored how youth were differentially experiencing the pandemic. Participants included 18 youth between the ages of 13 and 18 (11 girls, 7 boys). Participants were stratified by private and public secondary schools and we ran focus groups in which experiences of the pandemic were discussed. RESULTS: Our results show (1) clear differences in early access to education for youth who attended public and private institutions in Quebec during the COVID-19 pandemic; (2) access to the internet and computers offset learning opportunities for students across Quebec throughout the COVID-19 pandemic; and (3) few of the differences experienced during the pandemic were based on youth's behaviours, or life choices, but rather stemmed from differences in material and structural opportunities, based largely, but not solely, on what type of school the youth attended (public or private). CONCLUSION: The way in which the COVID-19 pandemic was handled by the Quebec education system deepened existing social inequities in education between private and public school attendees. Given the importance of education as one of the main determinants of health, particularly during transition periods such as adolescence, we must ensure that future policies do not repeat past mistakes.

RéSUMé: OBJECTIFS: La pandémie de la COVID-19 a été un moment d'incertitude et de transformation rapide hors du commun, soulevant des questions inédites sur les effets du confinement sur la santé mentale et physique des jeunes ainsi que sur les défis engendrés en termes d'apprentissage chez les jeunes. Il s'est rapidement avéré que les réponses du gouvernement à la COVID-19, en particulier en ce qui concerne les déterminants sociaux de la santé, n'étaient pas vécues de la même manière dans tous les groupes sociaux. Cet article adopte une optique interdisciplinaire à l'intersection de la santé et de l'éducation et utilise la théorie du mode de vie de Max Weber pour analyser l'expérience inéquitable de la pandémie de COVID-19. Nous examinons plus directement les inégalités sociales dans l'éducation pendant la première vague de COVID-19 et explorons les effets à long terme sur la santé et le bien-être des jeunes. MéTHODES: Nous utilisons les données recueillies lors de notre étude du printemps 2020 qui a exploré comment les jeunes vivaient différemment la pandémie. Les participants sont 18 jeunes âgés de 13 à 18 ans (11 filles, 7 garçons). Les participants ont été stratifiés par écoles secondaires privées et publiques et nous avons organisé des groupes de discussion dans lesquels les expériences de la pandémie ont été discutées. RéSULTATS: Nos résultats montrent 1) de nouvelles et profondes inégalités sociales dans le système d'éducation qui ont été créées par les mesures de confinement gouvernementales au Québec et 2) un accès inéquitable aux ressources mobilisées pour s'adapter aux mesures gouvernementales. CONCLUSION: L'étude du cas des inégalités sociales en contexte d'éducation pendant la pandémie offre d'importants apprentissages sur les inégalités sociales en général. Nous concluons cette étude en réfléchissant à l'espace intersectoriel important entre l'éducation et la santé pour les jeunes.

Cluster randomised trials with a binary outcome and a small number of clusters: comparison of individual and cluster level analysis method.

BACKGROUND: Cluster randomised trials (CRTs) are often designed with a small number of clusters, but it is not clear which analysis methods are optimal when the outcome is binary. This simulation study aimed to determine (i) whether cluster-level analysis (CL), generalised linear mixed models (GLMM), and generalised estimating equations with sandwich variance (GEE) approaches maintain acceptable type-one error including the impact of non-normality of cluster effects and low prevalence, and if so (ii) which methods have the greatest power. We simulated CRTs with 8-30 clusters, altering the cluster-size, outcome prevalence, intracluster correlation coefficient, and cluster effect distribution. We analysed each dataset with weighted and unweighted CL; GLMM with adaptive quadrature and restricted pseudolikelihood; GEE with Kauermann-and-Carroll and Fay-and-Graubard sandwich variance using independent and exchangeable working correlation matrices. P-values were from a t-distribution with degrees of freedom (DoF) as clusters minus cluster-level parameters; GLMM pseudolikelihood also used Satterthwaite and Kenward-Roger DoF. RESULTS: Unweighted CL, GLMM pseudolikelihood, and Fay-and-Graubard GEE with independent or exchangeable working correlation matrix controlled type-one error in > 97% scenarios with clusters minus parameters DoF. Cluster-effect distribution and prevalence of outcome did not usually affect analysis method performance. GEE had the least power. With 20-30 clusters, GLMM had greater power than CL with varying cluster-size but similar power otherwise; with fewer clusters, GLMM had lower power with common cluster-size, similar power with medium variation, and greater power with large variation in cluster-size. CONCLUSION: We recommend that CRTs with ≤ 30 clusters and a binary outcome use an unweighted CL or restricted pseudolikelihood GLMM both with DoF clusters minus cluster-level parameters.

Measuring the unknown: An estimator and simulation study for assessing case reporting during epidemics.

The fraction of cases reported, known as 'reporting', is a key performance indicator in an outbreak response, and an essential factor to consider when modelling epidemics and assessing their impact on populations. Unfortunately, its estimation is inherently difficult, as it relates to the part of an epidemic which is, by definition, not observed. We introduce a simple statistical method for estimating reporting, initially developed for the response to Ebola in Eastern Democratic Republic of the Congo (DRC), 2018-2020. This approach uses transmission chain data typically gathered through case investigation and contact tracing, and uses the proportion of investigated cases with a known, reported infector as a proxy for reporting. Using simulated epidemics, we study how this method performs for different outbreak sizes and reporting levels. Results suggest that our method has low bias, reasonable precision, and despite sub-optimal coverage, usually provides estimates within close range (5-10%) of the true value. Being fast and simple, this method could be useful for estimating reporting in real-time in settings where person-to-person transmission is the main driver of the epidemic, and where case investigation is routinely performed as part of surveillance and contact tracing activities.

SIBLING CONCORDANCE IN SYMPTOM ONSET AND ATROPHY GROWTH RATES IN STARGARDT DISEASE USING ULTRA-WIDEFIELD FUNDUS AUTOFLUORESCENCE.

PURPOSE: To investigate concordance in symptom onset, area of dark autofluorescence (DAF), and growth rate (GR) between Stargardt disease siblings at an age-matched time point. METHODS: In this retrospective longitudinal study of sibling pairs with identical biallelic ABCA4 variants, age at symptom onset, best-corrected visual acuity, atrophy area, and effective radius of DAF on ultra-widefield fundus autofluorescence were recorded. Absolute intersibling differences for both eyes were compared with absolute interocular differences using the Mann-Whitney test. RESULTS: Overall 39 patients from 19 families were recruited. In 16 families, age-matched best-corrected visual acuity and DAF were compared between siblings. In 8 families, DAF GR was compared. The median (range) absolute difference in age at symptom onset between siblings was 3 (0-35) years. Absolute intersibling differences in age-matched best-corrected visual acuity were greater than interocular differences ( P = 0.01). Similarly, absolute intersibling differences in DAF area and radius were greater than interocular differences ( P = 0.04 for area and P = 0.001 for radius). Differences between absolute interocular and intersibling GR were not statistically significant ( P = 0.44 for area GR and P = 0.61 for radius GR). CONCLUSION: There was significant discordance in age-matched best-corrected visual acuity and DAF beyond the expected limits of interocular asymmetry. Lack of significant intersibling differences in GR warrants further investigation.