Delayed entry into prenatal care among women with pre-pregnancy health conditions, National Birth Defects Prevention Study, 1997-2011.

First trimester entry into prenatal care is recommended for all women, and especially women with pre-pregnancy conditions. Our objective was to determine whether women with pre-pregnancy conditions were at lower risk of entry after the first trimester (delayed entry) into prenatal care than women without a pre-pregnancy health condition. We used data from 10,890 participants in the National Birth Defects Prevention Study who delivered liveborn infants without birth defects. Women reported pre-pregnancy conditions and timing of entry into prenatal care during a computer-assisted telephone interview. Multivariable logistic regression analyses were conducted to evaluate whether having a pre-pregnancy condition was associated with delayed entry into prenatal care compared to women without pre-pregnancy conditions. Approximately 13% of women reported delayed entry into prenatal care, and 18% of women reported a pre-pregnancy condition. Delayed entry into prenatal care was not associated with pre-pregnancy cardiometabolic or neurologic conditions. Women with thyroid conditions were less likely to report delayed entry into prenatal care (prevalence odds ratio (OR), 95% confidence interval (CI): 0.55 [0.32, 0.94]), but women with hematologic and respiratory conditions were more likely to report delayed entry into prenatal care (OR: 1.95 [1.00, 3.82] and 1.27 [0.95, 1.72], respectively), compared to those without any chronic conditions. Future research investigating the success of early prenatal care among women with thyroid conditions could identify ways to reduce delayed prenatal care among women with other pre-pregnancy conditions.

Associations Between Maternal Exposure to Child Abuse, Preterm Birth, and Very Preterm Birth in Young, Nulliparous Women.

Objectives Preterm birth (PTB) is a leading cause of infant morbidity and mortality. One goal of Healthy People 2020 is to understand the role of preconception lifecourse exposures in relation to pregnancy outcomes, including PTB. The objective of this study was to examine the relationship between maternal exposure to multiple forms of childhood abuse and PTB and very preterm birth (vPTB), utilizing a national, population-based sample. MethodsThis study utilized retrospective self-reported maternal exposure to parent/adult caregiver perpetrated emotional, physical, and sexual abuse; non-parental/adult caregiver perpetrated sexual abuse; and history of PTB and vPTB in the National Longitudinal Study of Adolescent to Adult Health. The cross-sectional analytic study population consisted of first deliveries to 4181 nulliparous women (mean age at time of delivery = 21.7 years). Results With one exception, we did not observe associations between experiences of child abuse and the likelihood of PTB or vPTB. Only sexual abuse, accompanied by physical force and perpetrated by a non-parent/adult caregiver, was associated with an increased odds of vPTB (aOR = 1.94 (95% CI 1.10, 3.44)), particularly in women for whom abuse began after age 9 (aOR = 2.32 (95% CI 1.25, 4.28)).Conclusions for Practice The relationship between maternal exposure to child abuse and PTB may be limited to specific abuse and PTB subtypes, namely non-parent/caregiver perpetrated sexual abuse by force and vPTB. Future studies should also examine possible effect modifiers, such as maternal age and resilience, which may have the potential to inform interventions that can mitigate effects of maternal early life adversity.

Estimating the Effect of School Water, Sanitation, and Hygiene Improvements on Pupil Health Outcomes.

BACKGROUND: We conducted a cluster-randomized water, sanitation, and hygiene trial in 185 schools in Nyanza province, Kenya. The trial, however, had imperfect school-level adherence at many schools. The primary goal of this study was to estimate the causal effects of school-level adherence to interventions on pupil diarrhea and soil-transmitted helminth infection. METHODS: Schools were divided into water availability groups, which were then randomized separately into either water, sanitation, and hygiene intervention arms or a control arm. School-level adherence to the intervention was defined by the number of intervention components-water, latrines, soap-that had been adequately implemented. The outcomes of interest were pupil diarrhea and soil-transmitted helminth infection. We used a weighted generalized structural nested model to calculate prevalence ratio. RESULTS: In the water-scarce group, there was evidence of a reduced prevalence of diarrhea among pupils attending schools that adhered to two or to three intervention components (prevalence ratio = 0.28, 95% confidence interval: 0.10, 0.75), compared with what the prevalence would have been had the same schools instead adhered to zero components or one. In the water-available group, there was no evidence of reduced diarrhea with better adherence. For the soil-transmitted helminth infection and intensity outcomes, we often observed point estimates in the preventive direction with increasing intervention adherence, but primarily among girls, and the confidence intervals were often very wide. CONCLUSIONS: Our instrumental variable point estimates sometimes suggested protective effects with increased water, sanitation, and hygiene intervention adherence, although many of the estimates were imprecise.

Test-retest reliability of retrospective self-reported maternal exposure to childhood abuse and neglect.

Retrospective reports of exposure to childhood trauma indicate it is common. There is growing interest in relationships between maternal exposure to childhood adversity, perinatal mental health, and pregnancy outcomes. The goal of this study was to describe the self-reported prevalence and test-retest reliability of exposure to childhood maltreatment using the Childhood Trauma Questionnaire among adult women around the time of pregnancy. A substantial proportion of women reported exposure to maltreatment and reliability was generally at least moderate, indicating consistent reporting.

Karyotype versus microarray testing for genetic abnormalities after stillbirth.

BACKGROUND: Genetic abnormalities have been associated with 6 to 13% of stillbirths, but the true prevalence may be higher. Unlike karyotype analysis, microarray analysis does not require live cells, and it detects small deletions and duplications called copy-number variants. METHODS: The Stillbirth Collaborative Research Network conducted a population-based study of stillbirth in five geographic catchment areas. Standardized postmortem examinations and karyotype analyses were performed. A single-nucleotide polymorphism array was used to detect copy-number variants of at least 500 kb in placental or fetal tissue. Variants that were not identified in any of three databases of apparently unaffected persons were then classified into three groups: probably benign, clinical significance unknown, or pathogenic. We compared the results of karyotype and microarray analyses of samples obtained after delivery. RESULTS: In our analysis of samples from 532 stillbirths, microarray analysis yielded results more often than did karyotype analysis (87.4% vs. 70.5%, P<0.001) and provided better detection of genetic abnormalities (aneuploidy or pathogenic copy-number variants, 8.3% vs. 5.8%; P=0.007). Microarray analysis also identified more genetic abnormalities among 443 antepartum stillbirths (8.8% vs. 6.5%, P=0.02) and 67 stillbirths with congenital anomalies (29.9% vs. 19.4%, P=0.008). As compared with karyotype analysis, microarray analysis provided a relative increase in the diagnosis of genetic abnormalities of 41.9% in all stillbirths, 34.5% in antepartum stillbirths, and 53.8% in stillbirths with anomalies. CONCLUSIONS: Microarray analysis is more likely than karyotype analysis to provide a genetic diagnosis, primarily because of its success with nonviable tissue, and is especially valuable in analyses of stillbirths with congenital anomalies or in cases in which karyotype results cannot be obtained. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development.).

New models for large prospective studies: is there a risk of throwing out the baby with the bathwater?

Manolio et al. (Am J Epidemiol. 2012;175:859-866) proposed that large cohort studies adopt novel models using "temporary assessment centers" to enroll up to a million participants to answer research questions about rare diseases and "harmonize" clinical endpoints collected from administrative records. Extreme selection bias, we are told, will not harm internal validity, and "process expertise to maximize efficiency of high-throughput operations is as important as scientific rigor" (p. 861). In this article, we describe serious deficiencies in this model as applied to the United States. Key points include: 1) the need for more, not less, specification of disease endpoints; 2) the limited utility of data collected from existing administrative and clinical databases; and 3) the value of university-based centers in providing scientific expertise and achieving high recruitment and retention rates through community and healthcare provider engagement. Careful definition of sampling frames and high response rates are crucial to avoid bias and ensure inclusion of important subpopulations, especially the medically underserved. Prospective hypotheses are essential to refine study design, determine sample size, develop pertinent data collection protocols, and achieve alliances with participants and communities. It is premature to reject the strengths of large national cohort studies in favor of a new model for which evidence of efficiency is insufficient.

Parenting stress in the infant aphakia treatment study.

OBJECTIVE: To evaluate parenting stress following infants' cataract extraction surgery, and to determine if levels of stress differ between 2 treatments for unilateral congenital cataract in a randomized clinical trial. METHODS: At surgery, an intraocular lens (IOL) was implanted or children were left aphakic, treated with contact lens (CL). Stress measures were administered 3 months after surgery and at the first visit after the visual acuity (VA) assessment done at 12 months of age. RESULTS: Caregivers in the IOL group reported higher levels of stress than those in the CL group 3 months after surgery, but there were no group differences in stress scores at the post-VA assessment. Stress scores did not change differentially for participants assigned to IOL versus CL treatments. CONCLUSIONS: Treatment assignment did not have a significant impact on caregiver stress during infancy or on the change in stress during the child's first 2 years of life.

Outcomes of secondary intraocular lens implantation in the Infant Aphakia Treatment Study.

PURPOSE: To report outcomes of secondary intraocular lens (IOL) implantation in the Infant Aphakia Treatment Study (IATS). SETTING: Multicenter clinical practice. DESIGN: Secondary analysis of patients enrolled in a randomized clinical trial. METHODS: Details regarding all secondary IOL surgeries conducted in children enrolled in the IATS were compiled. Visual outcomes, refractive outcomes, and adverse events at the age of 10½ years were evaluated. Comparisons were made with eyes that remained aphakic and with eyes randomized to primary IOL placement. RESULTS: The study included 114 infants, 57 in the aphakic group and 57 in the primary IOL group; 55 of 57 patients randomized to aphakia with contact lens correction were seen for the 10½-year study visit; 24 (44%) of 55 eyes had secondary IOL surgery. Median age at IOL surgery was 5.4 years (range 1.7 to 10.3 years). Mean absolute prediction error was 1.00 ± 0.70 diopters (D). At age 10½ years, the median logarithm of the minimum angle of resolution visual acuity (VA) was 0.9 (range 0.2 to 1.7), similar to VA in the 31 eyes still aphakic (0.8, range 0.1 to 2.9); the number of eyes with stable or improved VA scores between the 4½-year and 10½-year study visits was also similar (78% secondary IOL eyes; 84% aphakic eyes). For eyes undergoing IOL implantation after the 4½-year study visit (n = 22), the mean refraction at age 10½ years was -3.20 ± 2.70 D (range -9.90 to 1.10 D), compared with -5.50 ± 6.60 D (n = 53, range -26.50 to 3.00 D) in eyes with primary IOL (P = .03). CONCLUSIONS: Delayed IOL implantation allows a more predictable refractive outcome at age 10½ years, although the range of refractive error is still large.

Glaucoma-Related Adverse Events at 10 Years in the Infant Aphakia Treatment Study: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Glaucoma-related adverse events constitute serious complications of cataract removal in infancy, yet long-term data on incidence and visual outcome remain lacking. Objective: To identify and characterize incident cases of glaucoma and glaucoma-related adverse events (glaucoma + glaucoma suspect) among children in the Infant Aphakia Treatment Study (IATS) by the age of 10.5 years and to determine whether these diagnoses are associated with optic nerve head (ONH) and peripapillary retinal nerve fiber layer (RNFL) assessment. Design, Setting, and Participants: Analysis of a multicenter randomized clinical trial of 114 infants with unilateral congenital cataract who were aged 1 to 6 months at surgery. Data on long-term glaucoma-related status and outcomes were collected when children were 10.5 years old (July 14, 2015, to July 12, 2019) and analyzed from March 30, 2019, to August 6, 2019. Interventions: Participants were randomized at cataract surgery to either primary intraocular lens (IOL), or aphakia (contact lens [CL]). Standardized definitions of glaucoma and glaucoma suspect were created for IATS and applied for surveillance and diagnosis. Main Outcomes and Measures: Development of glaucoma and glaucoma + glaucoma suspect in operated-on eyes up to age 10.5 years, plus intraocular pressure, axial length, RNFL (by optical coherence tomography), and ONH photographs. Results: In Kaplan-Meier analysis, for all study eyes combined (n = 114), risk of glaucoma after cataract removal rose from 9% (95% CI, 5%-16%) at 1 year, to 17% (95% CI, 11%-25%) at 5 years, to 22% (95% CI, 16%-31%) at 10 years. The risk of glaucoma plus glaucoma suspect diagnosis after cataract removal rose from 12% (95% CI, 7%-20%) at 1 year, to 31% (95% CI, 24%-41%) at 5 years, to 40% (95% CI, 32%-50%) at 10 years. Risk of glaucoma and glaucoma plus glaucoma suspect diagnosis at 10 years was not significantly different between treatment groups. Eyes with glaucoma (compared with eyes with glaucoma suspect or neither) had longer axial length but relatively preserved RNFL and similar ONH appearance and visual acuity at age 10 years. Conclusions and Relevance: Risk of glaucoma-related adverse events continues to increase with longer follow-up of children following unilateral cataract removal in infancy and is not associated with primary IOL implantation. Development of glaucoma (or glaucoma suspect) after removal of unilateral congenital cataract was not associated with worse visual acuity outcomes at 10 years. Trial Registration: ClinicalTrials.gov Identifier: NCT00212134.

Do measures matter? Comparing surface-density-derived and census-tract-derived measures of racial residential segregation.

BACKGROUND: Racial residential segregation is hypothesized to affect population health by systematically patterning health-relevant exposures and opportunities according to individuals' race or income. Growing interest into the association between residential segregation and health disparities demands more rigorous appraisal of commonly used measures of segregation. Most current studies rely on census tracts as approximations of the local residential environment when calculating segregation indices of either neighborhoods or metropolitan areas. Because census tracts are arbitrary in size and shape, reliance on this geographic scale limits understanding of place-health associations. More flexible, explicitly spatial derivations of traditional segregation indices have been proposed but have not been compared with tract-derived measures in the context of health disparities studies common to social epidemiology, health demography, or medical geography. We compared segregation measured with tract-derived as well as GIS surface-density-derived indices. Measures were compared by region and population size, and segregation measures were linked to birth record to estimate the difference in association between segregation and very preterm birth. Separate analyses focus on metropolitan segregation and on neighborhood segregation. RESULTS: Across 231 metropolitan areas, tract-derived and surface-density-derived segregation measures are highly correlated. However overall correlation obscures important differences by region and metropolitan size. In general the discrepancy between measure types is greatest for small metropolitan areas, declining with increasing population size. Discrepancies in measures are greatest in the South, and smallest in Western metropolitan areas. Choice of segregation index changed the magnitude of the measured association between segregation and very preterm birth. For example among black women, the risk ratio for very preterm birth in metropolitan areas changed from 2.12 to 1.68 for the effect of high versus low segregation when using surface-density-derived versus tract-derived segregation indices. Variation in effect size was smaller but still present in analyses of neighborhood racial composition and very preterm birth in Atlanta neighborhoods. CONCLUSION: Census tract-derived measures of segregation are highly correlated with recently introduced spatial segregation measures, but the residual differences among measures are not uniform for all areas. Use of surface-density-derived measures provides researchers with tools to further explore the spatial relationships between segregation and health disparities.

Rate of ocular trauma in children operated on for unilateral cataract in infancy-data from the Infant Aphakia Treatment Study.

To determine whether the fellow eye of children who have undergone unilateral cataract extraction in the first year of life are at increased risk of injury and vision loss, the 10.5-year data on 109 of 114 children enrolled in the Infant Aphakia Treatment Study were examined. Based on this limited data, it was estimated that the fellow eye is at greater risk of injury than the operated eye. Our data do not support the risk being higher in children with the worst vision in the treated eye.

Management of optic neuritis and impact of clinical trials: an international survey.

OBJECTIVE: 1) To evaluate the management of acute isolated optic neuritis (ON) by ophthalmologists and neurologists; 2) to evaluate the impact of clinical trials; 3) to compare these practices among 7 countries. METHODS: A survey on diagnosis and treatment of acute isolated ON was sent to 5,443 neurologists and 6,099 ophthalmologists in the southeast-USA, Canada, Australia/New Zealand, Denmark, France, and Thailand. USA data were compared to those of other countries. RESULTS: We collected 3,142 surveys (1,449 neurologists/1,693 ophthalmologists) (29.8% response rate). In all countries, ON patients more frequently presented to ophthalmologists, and were subsequently referred to neurologists or subspecialists. Evaluation and management of ON varied among countries, mostly because of variations in healthcare systems, imaging access, and local guidelines. A brain MRI was obtained for 70-80% of ON patients; lumbar punctures were obtained mostly in Europe and Thailand. Although most patients received acute treatment with intravenous steroids, between 14% and 65% of neurologists and ophthalmologists still recommended oral prednisone (1 mg/kg/day) for the treatment of acute isolated ON. In all countries, steroids were often prescribed to improve visual outcome or to decrease the long-term risk of multiple sclerosis. INTERPRETATION: Although recent clinical trials have changed the management of acute ON around the world, many neurologists and ophthalmologists do not evaluate and treat acute ON patients according to the best evidence from clinical research. This confirms that evaluation of the impact of major clinical trials ("translational T2 clinical research") is essential when assessing the effects of interventions designed to improve quality of care.

Impact of an American board of pediatrics maintenance of certification (MOC) on weight-related counseling at well-child check-ups.

OBJECTIVE: The Healthy Weight Counseling Maintenance of Certification (MOC) program integrates pediatrician training and clinic changes to promote use of evidence-based, diet and physical activity (PA) health messages and counseling strategies. This interrupted time series study assessed the impact of this MOC program on provision of weight-related counseling. METHODS: We randomly selected 10-15 well-child visit charts at three time points before and three time points after 102 Georgia pediatricians began the MOC in 2012-2015. Linear binomial regression compared the frequency of behavior-change goal setting and health messaging documentation (fruit/vegetable consumption, sugar-sweetened beverage consumption, out-of-home food consumption, PA, and screen time) before and after MOC participation. RESULTS: At baseline, pediatricians documented behavior-change goals with 44% of patients, with an additional 49% of patients having documented goals after their pediatrician started the MOC (99.5% confidence interval [CI]: 21-77%). Similarly, absolute increases in the proportion of patients with documentation for sugar-sweetened beverage consumption (adjusted prevalence difference [aPD]: 37%; 99.5% CI: 13-62%) and out-of-home eating were observed (aPD: 38%; 99.5% CI: 12-64%). CONCLUSION: The Healthy Weight Counseling MOC is associated with increased and sustained use of evidence-based health messages and counseling strategies. PRACTICE IMPLICATIONS: Continuing education and facilitation of system changes help improve physicians' weight-related counseling.

Elementary school physical activity opportunities and physical fitness of students: A statewide cross-sectional study of schools.

BACKGROUND: Using a cross-sectional design, we assessed the relationship between the time schools provide for physical activity and the proportion of students achieving a healthy aerobic capacity or body mass index. METHODS: In 2013-2014, physical education and grade-level teachers from 905 of 1,244 Georgia elementary schools provided survey data about the frequency and duration of physical activity opportunities offered before, during, and after school. Log-binomial models related the weekly physical activity minutes provided by schools to the proportion of children in the FitnessGram healthy fitness zone for aerobic capacity or body mass index while adjusting for school characteristics and demographics. RESULTS: During-school physical activity time was not associated with student fitness, but schools with before-school physical activity programs had a moderately higher prevalence of healthy aerobic capacity (prevalence ratio among girls: 1.06; 99% confidence interval: 1.00-1.13; prevalence ratio among boys: 1.03; 99% confidence interval: 0.99-1.08). Each additional 30 minutes of recess per week was associated with no more than a 3%-higher proportion of students with healthy body mass indexes (prevalence ratio among girls: 1.01; 99% confidence interval: 1.00-1.03; prevalence ratio among boys: 1.01; 99% confidence interval: 0.99-1.03). CONCLUSIONS: The amount of physical activity time provided by schools is not strongly associated with school-aggregated student fitness. Future studies should be designed to assess the importance of school-based physical activity time on student fitness, relative to physical activity type and quality.

Management of optic neuritis in Canada: survey of ophthalmologists and neurologists.

BACKGROUND: Acute isolated optic neuritis is often the first manifestation of multiple sclerosis (MS), and its management remains controversial. Over the past decade, with the advent of new disease-modifying agents, management of isolated optic neuritis has become more complicated. OBJECTIVES: To evaluate the current practice patterns of Canadian ophthalmologists and neurologists in the management of acute optic neuritis, and to evaluate the impact of recently published randomized clinical trials. DESIGN: Mail survey. METHODS: All practicing ophthalmologists and neurologists in Canada were mailed a survey evaluating the management of isolated acute optic neuritis and familiarity with recent clinical trials. Surveys for 1158 were mailed, and completed surveys were collected anonymously through a datafax system. Second and third mailings were sent to non-respondents 6 and 12 weeks later. RESULTS: The final response rate was 34.5%. Although many acute optic neuritis patients initially present to ophthalmologists, neurologists are the physicians primarily managing these patients. Ordering magnetic resonance imaging, and treating with high dose intravenous steroids has become the standard of care. However, 15% of physicians (14% of ophthalmologists and 16% of neurologists) continue to prescribe low dose oral steroids, and steroids are being given for reasons other than to shorten the duration of visual symptoms by 73% of ophthalmologists and 50% of neurologists. More neurologists than ophthalmologists are familiar with recent clinical trials involving disease-modifying agents. CONCLUSION: Although the management of acute optic neuritis has been evaluated in large clinical trials that were published in major international journals, some ophthalmologists and neurologists are not following evidence-based recommendations.

An exploratory study of whether pregnancy outcomes influence maternal self-reported history of child maltreatment.

Childhood maltreatment is common and has been increasingly studied in relation to perinatal outcomes. While retrospective self-report is convenient to use in studies assessing the impact of maltreatment on perinatal outcomes, it may be vulnerable to bias. We assessed bias in reporting of maltreatment with respect to women's experiences of adverse perinatal outcomes in a cohort of 230 women enrolled in studies of maternal mental illness. Each woman provided a self-reported history of childhood maltreatment via the Childhood Trauma Questionnaire at two time points: 1) the preconception or prenatal period and 2) the postpartum period. While most women's reports of maltreatment agreed, there was less agreement for physical neglect among women experiencing adverse perinatal outcomes. Further, among women who discrepantly reported maltreatment, those experiencing adverse pregnancy outcomes tended to report physical neglect after delivery but not before, and associations between physical neglect measured after delivery and adverse pregnancy outcomes were larger than associations that assessed physical neglect before delivery. There were larger associations between post-delivery measured maltreatment and perinatal outcomes among women who had not previously been pregnant and in those with higher postpartum depressive symptoms. Although additional larger studies in the general population are necessary to replicate these findings, they suggest retrospective reporting of childhood maltreatment, namely physical neglect, may be prone to systematic differential recall bias with respect to perinatal outcomes. Measures of childhood maltreatment reported before delivery may be needed to validly estimate associations between maternal exposure to childhood physical neglect and perinatal outcomes.

Ascaris lumbricoides Infection Following School-Based Deworming in Western Kenya: Assessing the Role of Pupils' School and Home Water, Sanitation, and Hygiene Exposures.

Water, sanitation, and hygiene (WaSH) technologies and behaviors can prevent infection by soil-transmitted helminth species independently, but may also interact in complex ways. However, these interactions are poorly understood. The purpose of this study was to characterize how school and home WaSH exposures were associated with Ascaris lumbricoides infection and to identify relevant interactions between separate WaSH technologies and behaviors. A study was conducted among 4,404 children attending 51 primary schools in western Kenya. We used multivariable mixed effects logistic regression to characterize how various WaSH exposures were associated with A. lumbricoides infection after annual school-based deworming. Few WaSH behaviors and technologies were independently associated with A. lumbricoides infection. However, by considering relevant interdependencies between variables, important associations were elucidated. The association between handwashing and A. lumbricoides depended largely upon the pupils' access to an improved water source. Among pupils who had access to improved water sources, A. lumbricoides prevalence was lower for those who handwashed both at school and home compared with neither place (odds ratio: 0.38, 95% confidence interval: 0.18-0.83; P = 0.01). This study contributes to a further understanding of the impact of WaSH on A. lumbricoides infection and shows the importance of accounting for interactions between WaSH technologies and behaviors.

Voluntary alteration of full-field electroretinogram.

PURPOSE: To evaluate whether a normal subject can deliberately produce abnormal electroretinogram (ERG) results that simulate disorders of the retina. DESIGN: Prospective study. METHODS: Five normal subjects were evaluated twice with full-field ERGs. The subjects were randomly assigned to be compliant or noncompliant (i.e., to deliberately attempt to alter the test results) at each visit. Results from compliant eyes were compared with those of noncompliant eyes. RESULTS: While the amplitudes of all parameters were decreased in the noncompliant group, the difference was not statistically significant, and the results were usually within the normal limits of our laboratory. No subject was able to alter the results to mimic a retinal disease or to reproduce a specific pattern of changes. CONCLUSIONS: Although ERG results can be altered by noncompliant subjects, the results are usually only "borderline abnormal" and do not correspond to any pattern of retinal disease. These results confirm that abnormal full-field ERGs indicate true retinal disease.

Factors associated with pupil toilet use in kenyan primary schools.

The purpose of this study was to quantify how school sanitation conditions are associated with pupils' use of sanitation facilities. We conducted a longitudinal assessment in 60 primary schools in Nyanza Province, Kenya, using structured observations to measure facility conditions and pupils' use at specific facilities. We used multivariable mixed regression models to characterize how pupil to toilet ratio was associated with toilet use at the school-level and also how facility conditions were associated with pupils' use at specific facilities. We found a piecewise linear relationship between decreasing pupil to toilet ratio and increasing pupil toilet use (p < 0.01). Our data also revealed significant associations between toilet use and newer facility age (p < 0.01), facility type (p < 0.01), and the number of toilets in a facility (p < 0.01). We found some evidence suggesting facility dirtiness may deter girls from use (p = 0.06), but not boys (p = 0.98). Our study is the first to rigorously quantify many of these relationships, and provides insight into the complexity of factors affecting pupil toilet use patterns, potentially leading to a better allocation of resources for school sanitation, and to improved health and educational outcomes for children.