Infant Behaviors, Prenatal Cocaine Exposure, and Adult Intelligence

Importance

Linking prenatal drug exposures to both infant behavior and adult cognitive outcomes may improve early interventions.

Objective

To assess whether neonatal physical, neurobehavioral, and infant cognitive measures mediate the association between prenatal cocaine exposure (PCE) and adult perceptual reasoning IQ.

Design, Setting, and Participants

This study used data from a longitudinal, prospective birth cohort study with follow-up from 1994 to 2018 until offspring were 21 years post partum. A total of 384 (196 PCE and 188 not exposed to cocaine [NCE]) infants and mothers were screened for cocaine or polydrug use. Structural equation modeling was performed from June to November 2023.

Exposures

Prenatal exposures to cocaine, alcohol, marijuana, and tobacco assessed through urine and meconium analyses and maternal self-report.

Main Outcomes and Measures

Head circumference, neurobehavioral assessment, Bayley Scales of Infant Development, Fagan Test of Infant Intelligence score, Wechsler Perceptual Reasoning IQ, Home Observation for Measurement of the Environment (HOME) score, and blood lead level.

Results

Among the 384 mothers in the study, the mean (SD) age at delivery was 27.7 (5.3) years (range, 18-41 years), 375 of 383 received public assistance (97.9%) and 336 were unmarried (87.5%). Birth head circumference (standardized estimate for specific path association, -0.05, SE = 0.02; P = .02) and 1-year Bayley Mental Development Index (MDI) (standardized estimate for total of the specific path association, -0.05, SE = 0.02; P = .03) mediated the association of PCE with Wechsler Perceptual Reasoning IQ, controlling for HOME score and other substance exposures. Abnormal results on the neurobehavioral assessment were associated with birth head circumference (β = -0.20, SE = 0.08; P = .01). Bayley Psychomotor Index (β = 0.39, SE = 0.05; P < .001) and Fagan Test of Infant Intelligence score (β = 0.16, SE = 0.06; P = .01) at 6.5 months correlated with MDI at 12 months.

Conclusions and Relevance

In this cohort study, a negative association of PCE with adult perceptual reasoning IQ was mediated by early physical and behavioral differences, after controlling for other drug and environmental factors. Development of infant behavioral assessments to identify sequelae of prenatal teratogens early in life may improve long-term outcomes and public health awareness.

Barriers to dental utilization among Medicaid-enrolled young children from primary care practices in Northeast Ohio

OBJECTIVES

To evaluate the individual and community factors that contribute to dental utilization among young children on Medicaid utilizing the Anderson Model and the Socio-Ecological Framework.

METHODS

This observational cross-sectional study was conducted using baseline data (socio-demographics, clinical dental need) from a cluster-randomized hybrid effectiveness-implementation trial among 1021 child-parent dyads recruited from primary care practices across northeast Ohio. The baseline data were then linked to dental Medicaid claims data (categorized as any dental visit, volume, and type in the past 12 months) and ICD-10 codes from the child's EHR data (individual-level) together with Dental Health Provider Shortage Area (HPSA) status and Area Deprivation Index (ADI) which were obtained at the neighbourhood-level using home address of each dyad (community-level). Multivariable analyses using generalized estimating equations (GEE) accounted for clustering by practice, and models included individual-level alone, and individual + community-level factors to evaluate their effects on dental utilization.

RESULTS

Medicaid claims data indicated that among the 1021 children (mean age: 4.3 ± 1.1 years; 54.4% males; 43.8% Black, Non-Hispanic), a majority of children were seeing the dentist at least once a year by the age of 4 (56.1%). The mean ADI of their neighbourhoods was 109.22 (20.2) and 27.5% lived in a HPSA area. The GEE analyses revealed that individual factors such as older children, parents being married, and continuous Medicaid enrollment were associated with significantly higher dental utilization. Among community factors, being in a HPSA had an OR = 1.53 (CI: 1.03, 2.27) associated with higher dental utilization.

CONCLUSIONS

Being in a HPSA was associated with higher dental utilization possibly due to dentists or safety net dental clinics in these areas accepting Medicaid-eligible children.

Treatment Patterns and Survival Outcomes in Patients With Breast Cancer on Medicaid, Pre- and Post-Expansion

BACKGROUND

The objective of this study was to evaluate the impact of Medicaid expansion on breast cancer treatment and survival among Medicaid-insured women in Ohio, accounting for the timing of enrollment in Medicaid relative to their cancer diagnosis and post-expansion heterogeneous Medicaid eligibility criteria, thus addressing important limitations in previous studies.

METHODS

Using 2011-2017 Ohio Cancer Incidence Surveillance System data linked with Medicaid claims data, we identified women aged 18 to 64 years diagnosed with local-stage or regional-stage breast cancer (n=876 and n=1,957 pre-expansion and post-expansion, respectively). We accounted for women's timing of enrollment in Medicaid relative to their cancer diagnosis, and flagged women post-expansion as Affordable Care Act (ACA) versus non-ACA, based on their income eligibility threshold. Study outcomes included standard treatment based on cancer stage and receipt of lumpectomy, mastectomy, chemotherapy, radiation, hormonal treatment, and/or treatment for HER2-positive tumors; time to treatment initiation (TTI); and overall survival. We conducted multivariable robust Poisson and Cox proportional hazards regression analysis to evaluate the independent associations between Medicaid expansion and our outcomes of interest, adjusting for patient-level and area-level characteristics.

RESULTS

Receipt of standard treatment increased from 52.6% pre-expansion to 61.0% post-expansion (63.0% and 59.9% post-expansion in the ACA and non-ACA groups, respectively). Adjusting for potential confounders, including timing of enrollment in Medicaid, being diagnosed in the post-expansion period was associated with a higher probability of receiving standard treatment (adjusted risk ratio, 1.14 [95% CI, 1.06-1.22]) and shorter TTI (adjusted hazard ratio, 1.14 [95% CI, 1.04-1.24]), but not with survival benefits (adjusted hazard ratio, 1.00 [0.80-1.26]).

CONCLUSIONS

Medicaid expansion in Ohio was associated with improvements in receipt of standard treatment of breast cancer and shorter TTI but not with improved survival outcomes. Future studies should elucidate the mechanisms at play.

Prenatal cocaine exposure and self-reported behavioral adjustments from ages 12 to 21: environmental pathways

BACKGROUND

In a birth-cohort study, we followed offspring with prenatal cocaine exposure (PCE) to investigate longitudinal associations of PCE with self-reported behavioral adjustment from early adolescence to emerging adulthood (EA). Environmental pathways (family functioning, non-kinship care, maltreatment) were specified as potential mediators of PCE.

METHODS

Participants were 372 (190 PCE; 47% male), primarily Black, low socioeconomic status, enrolled at birth. Internalizing and externalizing behaviors were assessed using Youth Self-Report at ages 12 and 15 and Adult Self-Report at age 21. Extended random-intercept cross-lagged panel modeling was used to account for potential bidirectional relationships between internalizing and externalizing behaviors over time, examining potential mediators.

RESULTS

Adjusting for covariates, significant indirect effects were found for each mediator at different ages. For family functioning, these were both internalizing (β = 0.83, p = 0.04) and externalizing behaviors (β = 1.58, p = 0.02) at age 12 and externalizing behaviors at age 15 (β = 0.51, p = 0.03); for non-kinship care, externalizing behaviors at ages 12 (β = 0.63, p = 0.02) and 15 (β = 0.20, p = 0.03); and for maltreatment, both internalizing and externalizing behaviors at ages 15 (β = 0.64, p = 0.02 for internalizing; β = 0.50, p = 0.03 for externalizing) and 21 (β = 1.39, p = 0.01 for internalizing; β = 1.11, p = 0.01 for externalizing). Direct associations of PCE with internalizing and externalizing behaviors were not observed, nor cross-lagged relationships between internalizing and externalizing behaviors.

CONCLUSIONS

Negative associations of PCE with behavioral adjustment persist into EA via environmental pathways, specifying intervention points to disrupt adverse pathways toward healthy development.

Chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusion

Earth's radiation belts consist of high-energy charged particles trapped by Earth's magnetic field. Strong pitch angle diffusion of electrons caused by wave-particle interaction in Earth's radiation belts has primarily been considered as a loss process, as trapped electrons are rapidly diffused into the loss cone and lost to the atmosphere. However, the wave power necessary to produce strong diffusion should also produce rapid energy diffusion, and has not been considered in this context. Here we provide evidence of strong diffusion using satellite data. We use two-dimensional Fokker-Planck simulations of electron diffusion in pitch angle and energy to show that scaling up chorus wave power to the strong diffusion limit produces rapid acceleration of electrons, sufficient to outweigh the losses due to strong diffusion. The rate of losses saturates at the strong diffusion limit, whilst the rate of acceleration does not. This leads to the surprising result of an increase, not a decrease in the trapped electron population during strong diffusion due to chorus waves as expected when treating strong diffusion as a loss process. Our results suggest there is a tipping point in chorus wave power between net loss and net acceleration that global radiation belt models need to capture to better forecast hazardous radiation levels that damage satellites.

Accounting for Medicaid expansion and regional policy and programs to advance equity in cancer prevention in the United States

BACKGROUND

Many studies compare state-level outcomes to estimate changes attributable to Medicaid expansion. However, it is imperative to conduct more granular, demographic-level analyses to inform current efforts on cancer prevention among low-income adults. Therefore, the authors compared the volume of patients with cancer and disease stage at diagnosis in Ohio, which expanded its Medicaid coverage in 2014, with those in Georgia, a nonexpansion state, by cancer site and health insurance status.

METHODS

The authors used state cancer registries from 2010 to 2017 to identify adults younger than 64 years who had incident female breast cancer, cervical cancer, or colorectal cancer. Multivariable Poisson regression was conducted by cancer type, health insurance, and state to examine the risk of late-stage disease, adjusting for individual-level and area-level covariates. A difference-in-differences framework was then used to estimate the differences in risks of late-stage diagnosis in Ohio versus Georgia.

RESULTS

In Ohio, the largest increase in all three cancer types was observed in the Medicaid group after Medicaid expansion. In addition, significantly reduced risks of late-stage disease were observed among patients with breast cancer on Medicaid in Ohio by approximately 7% and among patients with colorectal cancer on Medicaid in Ohio and Georgia after expansion by approximately 6%. Notably, the authors observed significantly reduced risks of late-stage diagnosis among all patients with colorectal cancer in Georgia after expansion.

CONCLUSIONS

More early stage cancers in the Medicaid-insured and/or uninsured groups after expansion suggest that the reduced cancer burden in these vulnerable population subgroups may be attributed to Medicaid expansion. Heterogeneous risks of late-stage disease by cancer type highlight the need for comprehensive evaluation frameworks, including local cancer prevention efforts and federal health policy reforms.

PLAIN LANGUAGE SUMMARY

This study looked at how Medicaid expansion affected cancer diagnosis and treatment in two states, Ohio and Georgia. The researchers found that, after Ohio expanded their Medicaid program, there were more patients with cancer among low-income adults on Medicaid. The study also found that, among people on Medicaid, there were lower rates of advanced cancer at the time of diagnosis for breast cancer and colon cancer in Ohio and for colon cancer in Georgia. These findings suggest that Medicaid expansion may be effective in reducing the cancer burden among low-income adults.

Community Members as Reviewers of Medical Journal Manuscripts: a Randomized Controlled Trial

BACKGROUND

Community members may provide useful perspectives on manuscripts submitted to medical journals.

OBJECTIVE

To determine the impact of community members reviewing medical journal manuscripts.

DESIGN

Randomized controlled trial involving 578 original research manuscripts submitted to two medical journals from June 2018 to November 2021.

PARTICIPANTS

Twenty-eight community members who were trained, supervised, and compensated.

INTERVENTIONS

A total of 289 randomly selected control manuscripts were reviewed by scientific reviewers only. And 289 randomly selected intervention manuscripts were reviewed by scientific reviewers and one community member. Journal editorial teams used all reviews to make decisions about acceptance, revision, or rejection of manuscripts.

MAIN MEASURES

Usefulness of reviews to editors, content of community reviews, and changes made to published articles in response to community reviewer comments.

KEY RESULTS

Editor ratings of community and scientific reviews averaged 3.1 and 3.3, respectively (difference 0.2, 95% confidence interval [CI] 0.1 to 0.3), on a 5-point scale where a higher score indicates a more useful review. Qualitative analysis of the content of community reviews identified two taxonomies of themes: study attributes and viewpoints. Study attributes are the sections, topics, and components of manuscripts commented on by reviewers. Viewpoints are reviewer perceptions and perspectives on the research described in manuscripts and consisted of four major themes: (1) diversity of study participants, (2) relevance to patients and communities, (3) cultural considerations and social context, and (4) implementation of research by patients and communities. A total of 186 community reviewer comments were integrated into 64 published intervention group articles. Viewpoint themes were present more often in 66 published intervention articles compared to 54 published control articles (2.8 vs. 1.7 themes/article, difference 1.1, 95% CI 0.4 to 1.8).

CONCLUSIONS

With training, supervision, and compensation, community members are able to review manuscripts submitted to medical journals. Their comments are useful to editors, address topics relevant to patients and communities, and are reflected in published articles.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03432143.

Increased Hazard Risk of First Malignancy in Adults with Undetectable Serum IgE: a Retrospective Cohort Study

PURPOSE

The clinical relevance of IgE-deficiency is not established. Previous studies have postulated a relationship between absent serum IgE and the incidence of specific malignancies. We sought to examine the relationship between undetectable total serum IgE (< 3 IU/mL) and first malignancy, considering both general all-cause malignancy risk and risk of specific malignancy subtypes in adult subjects.

METHODS

Retrospective cohort study at a single center of 39,965 adults aged 18 or older (median age 51, 65.1% female) with at least one serum total IgE measurement from 1998 to 2020. Analytics included chi² table and logistic regression modeling of the main outcome measures, which include diagnosis of first malignancy and first diagnosis of specific malignancy subtype.

RESULTS

Of the entire cohort, 2584 subjects (6.5%) developed a first malignancy and 2516 (6.3%) had an undetectable IgE. Of those with undetectable IgE levels, 8.9% developed a first malignancy versus 6.3% with detectable IgE measurements. After adjusting for risk factors, there was a significant association between undetectable IgE and risk/hazard of first malignancy (relative risk 1.49, 95% confidence interval (CI) 1.27-1.75) (hazard ratio 1.28, 95% CI 1.08-1.52). Results were similar in multiple sensitivity analyses. For type of malignancy developed, undetectable IgE was associated with increased risk of hematologic malignancy (relative risk 2.07, 95% CI 1.29-3.30) and skin malignancy (relative risk 1.52, 95% CI 1.13-2.05).

CONCLUSION

Compared to individuals with detectable IgE levels, patients with undetectable total serum IgE had increased risk and hazard of first malignancy in general, and increased risk of hematologic malignancy in particular.

Dental Caries in Medicaid-Insured Preschool Children With or Without Special Health Care Needs in Northeast Ohio

IMPORTANCE

Children with special health care needs (CSHCN) are recognized to be at increased risk of developing dental caries (decay). Evidence is mixed regarding the association of preventive oral health care delivered by pediatric primary care clinicians with caries experience among CSHCN.

OBJECTIVE

To investigate caries experience, including untreated decay, among Medicaid-enrolled preschoolers with or without special health care needs.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used baseline data from the Pediatric Providers Against Cavities in Children's Teeth study, a cluster-randomized hybrid effectiveness-implementation trial conducted among 1022 Medicaid-enrolled preschoolers aged 3 to 6 years attending well-child visits at 18 participating community pediatric primary care practices in northeast Ohio. Baseline data were collected from November 1, 2017, to August 31, 2019, with statistical analyses conducted from April to August 2022.

EXPOSURES

Presence of special health care needs, as assessed by applying the Pediatric Medical Complexity Algorithm to International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes, was abstracted from electronic medical records. CSHCN were defined as having either noncomplex chronic disease (presence of only 1 nonprogressive chronic condition, or multiple nonprogressive chronic conditions in a single body system) or complex chronic disease (presence of any progressive chronic condition, malignant neoplasm, or significant chronic conditions involving multiple body systems).

MAIN OUTCOMES AND MEASURES

Untreated dental decay and caries experience as assessed through clinical dental examinations using International Caries Detection and Assessment System criteria.

RESULTS

A total of 1022 children aged 3 to 6 years from 18 practices were enrolled in the study. The mean (SD) age of the study population was 4.3 (1.1) years, 554 (54.2%) were boys, and of 988 with data on race and ethnicity, 451 (45.6%) were Black. Of these, 301 of 1019 (29.5%) had a likely special health care need (225 with noncomplex chronic conditions and 76 with complex chronic conditions). The most frequent chronic conditions included asthma (n = 209) and mental or behavioral health disorders (n = 146), including attention-deficit/hyperactivity disorder, autism, and developmental delays. Overall, 296 children (29.0%) had untreated decay, and 378 (37.0%) had caries experience (decayed and filled teeth). Accounting for sociodemographic characteristics, CSHCN had 34% reduced odds of untreated decay (adjusted odds ratio [AOR], 0.66 [95% CI, 0.48-0.92]) compared with those with without chronic disease. In addition, caries experience was lower among CSHCN (AOR, 0.79 [95% CI, 0.60-1.04]).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study of Medicaid-enrolled children who attended well-child visits as preschoolers, untreated dental decay was lower among CSHCN compared with those without chronic conditions. This study suggests that CSHCN may have had better access to the various types of dental care facilitated in medical settings.

Post-Affordable Care Act Improvements in Cancer Stage Among Ohio Medicaid Beneficiaries Resulted From an Increase in Stable Coverage

BACKGROUND

The mechanisms underlying improvements in early-stage cancer at diagnosis following Medicaid expansion remain unknown. We hypothesized that Medicaid expansion allowed for low-income adults to enroll in Medicaid before cancer diagnosis, thus increasing the number of stably-enrolled relative to those who enroll in Medicaid only after diagnosis (emergently-enrolled).

METHODS

Using data from the 2011-2017 Ohio Cancer Incidence Surveillance System and Medicaid enrollment files, we identified individuals diagnosed with incident invasive breast (n=4850), cervical (n=1023), and colorectal (n=3363) cancer. We conducted causal mediation analysis to estimate the direct effect of pre- (vs. post-) expansion on being diagnosed with early-stage (-vs. regional-stage and distant-stage) disease, and indirect (mediation) effect through being in the stably- (vs. emergently-) enrolled group, controlling for individual-level and area-level characteristics.

RESULTS

The percentage of stably-enrolled patients increased from 63.3% to 73.9% post-expansion, while that of the emergently-enrolled decreased from 36.7% to 26.1%. The percentage of patients with early-stage diagnosis remained 1.3-2.9 times higher among the stably-than the emergently-enrolled group, both pre-expansion and post-expansion. Results from the causal mediation analysis showed that there was an indirect effect of Medicaid expansion through being in the stably- (vs. emergently-) enrolled group [risk ratios with 95% confidence interval: 1.018 (1.010-1.027) for breast cancer, 1.115 (1.064-1.167) for cervical cancer, and 1.090 (1.062-1.118) for colorectal cancer.

CONCLUSION

We provide the first evidence that post-expansion improvements in cancer stage were caused by an increased reliance on Medicaid as a source of stable insurance coverage.

Mass drug administration of ivermectin, diethylcarbamazine, plus albendazole compared with diethylcarbamazine plus albendazole for reduction of lymphatic filariasis endemicity in Papua New Guinea: a cluster-randomised trial

Background

Methods

Findings

Interpretation

Funding

Downregulation of Dihydrotestosterone and Estradiol Levels by HEXIM1

We have previously reported that hexamethylene bis-acetamide inducible protein 1 (HEXIM1) inhibits the activity of ligand-bound estrogen receptor α (ERα) and the androgen receptor (AR) by disrupting the interaction between these receptors and positive transcriptional elongation factor b (P-TEFb) and attenuating RNA polymerase II (RNAPII) phosphorylation at serine 2. Functional consequences of the inhibition of transcriptional activity of ERα and AR by HEXIM1 include the inhibition of ERα- and AR-dependent gene expression, respectively, and the resulting attenuation of breast cancer (BCa) and prostate cancer (PCa) cell proliferation and growth. In our present study, we determined that HEXIM1 inhibited AKR1C3 expression in BCa and PCa cells. AKR1C3, also known as 17β-hydroxysteroid dehydrogenase (17β-HSD) type 5, is a key enzyme involved in the synthesis of 17β-estradiol (E2) and 5-dihydrotestosterone (DHT). Downregulation of AKR1C3 by HEXIM1 influenced E2 and DHT production, estrogen- and androgen-dependent gene expression, and cell proliferation. Our studies indicate that HEXIM1 has the unique ability to inhibit both the transcriptional activity of the ER and AR and the synthesis of the endogenous ligands of these receptors.

Prenatal Substance Exposure and Developmental Trajectories of Internalizing Symptoms: Toddlerhood to Preadolescence

BACKGROUND

Little is known about how prenatal exposure to substances (alcohol, tobacco, marijuana, and cocaine) may contribute to heterogeneous childhood trajectories of internalizing symptoms (i.e., depression, withdrawal, anxiety). The present study aimed to identify developmental trajectories of internalizing symptoms in children using gender-separate analyses and to examine whether trajectories differ by prenatal substance exposure (PSE) and other environmental and biological correlates.

METHODS

Data from two large community-based birth cohorts with PSE were integrated (N = 1,651, 848 boys, 803 girls): the Cleveland cohort and the Maternal Lifestyle Study (MLS). Internalizing symptoms were assessed with the Child Behavior Checklist at ages 2, 4, 6, 9, 10, 11, and 12 in the Cleveland study and at ages 3, 5, 7, 9, 11, and 13 in the MLS.

RESULTS

Gender-separate group-based trajectory modeling yielded five distinctive developmental trajectories of internalizing symptoms from ages 2 to 13 in both boys and girls: low-risk group (14.4% girls, 28.8% boys); normative-decreasing group (35.3% girls, 33.1% boys); increasing risk group (14.4% girls, 13.0% boys); early-high group (22.3% girls, 17.9% boys); and chronic group (13.8% girls, 7.2% boys). Prenatal tobacco exposure, maternal psychological distress, and postnatal maternal alcohol use differentiated the longitudinal courses of internalizing symptoms. Boys were more likely to follow the low-risk trajectory, whereas girls were more likely to follow the chronic trajectory.

CONCLUSIONS

Prenatal tobacco exposure was associated with suboptimal developmental trajectories of internalizing symptoms in the context of prenatal poly-drug exposure, highlighting a need for continued and increased effort toward prevention of prenatal tobacco use.

Comparative Effectiveness of Two Nonsurgical Treatments to Reduce Oral Health Disparities From Untreated Tooth Decay in Older Adults: Protocol for a Cluster Randomized Trial

BACKGROUND

The majority of dental caries lesions in older adults are at the gumline, at the edges of failed fillings and crowns, and in the surfaces of roots after gum recession. These lesions are difficult to restore with conventional surgical treatments using a dental drill and restorations often fail. Clinical guidelines are general and apply treatments that were designed for younger individuals in the dental care of older adults.

OBJECTIVE

This study will compare the effectiveness of 2 evidence-based nonsurgical strategies to manage dental caries lesions in adults aged 62 or older: (1) biannual topical application of silver diamine fluoride versus (2) atraumatic restorative treatment + biannual fluoride varnish.

METHODS

A cluster randomized clinical trial is being conducted in 22 publicly subsidized and other low-income housing facilities/sites (Arm 1: 11 sites, 275 participants; Arm 2: 11 sites, 275 participants). At baseline, participants will be screened for caries lesions. Those with nonurgent lesions will be treated according to the treatment arm to which the housing site was randomly assigned. The primary outcomes are caries lesion arrest, tooth sensitivity, and tooth pain at 52 weeks after treatment. Analytic methods for the primary aim include a generalized estimating equation approach to determine noninferiority of silver diamine fluoride relative to atraumatic restorative treatment + fluoride varnish treatment.

RESULTS

The trial was funded in April 2019. Enrollment began in September 2019 and results are expected in June 2023.

CONCLUSIONS

This study will inform the standard of care for treating caries lesions in older adults. If effective, either of these interventions has broad applicability in clinical and community-based settings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03916926; https://clinicaltrials.gov/ct2/show/NCT03916926.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/17840.

Bayesian Causal Mediation Analysis with Multiple Ordered Mediators

Causal mediation analysis provides investigators insight into how a treatment or exposure can affect an outcome of interest through one or more mediators on causal pathway. When multiple mediators on the pathway are causally ordered, identification of mediation effects on certain causal pathways requires a sensitivity parameter to be specified. A mixed model-based approach was proposed in the Bayesian framework to connect potential outcomes at different treatment levels, and identify mediation effects independent of a sensitivity parameter, for the natural direct and indirect effects on all causal pathways. The proposed method is illustrated in a linear setting for mediators and outcome, with mediator-treatment interactions. Sensitivity analysis was performed for the prior choices in the Bayesian models. The proposed Bayesian method was applied to an adolescent dental health study, to see how social economic status can affect dental caries through a sequence of causally ordered mediators in dental visit and oral hygiene index.

Continuous-time causal mediation analysis

While causal mediation analysis has seen considerable recent development for a single measured mediator (M) and final outcome (Y), less attention has been given to repeatedly measured M and Y. Previous methods have typically involved discrete-time models that limit inference to the particular measurement times used and do not recognize the continuous nature of the mediation process over time. To overcome such limitations, we present a new continuous-time approach to causal mediation analysis that uses a differential equations model in a potential outcomes framework to describe the causal relationships among model variables over time. A connection between the differential equation models and standard repeated measures models is made to provide convenient model formulation and fitting. A continuous-time extension of the sequential ignorability assumption allows for identifiable natural direct and indirect effects as functions of time, with estimation based on a two-step approach to model fitting in conjunction with a continuous-time mediation formula. Novel features include a measure of an overall mediation effect based on the "area between the curves," and an approach for predicting the effects of new interventions. Simulation studies show good properties of estimators and the new methodology is applied to data from a cohort study to investigate sugary drink consumption as a mediator of the effect of socioeconomic status on dental caries in children.

Continuous Time Nonstationary Correlation Models for Sparse Longitudinal Data

In this paper, we present a new continuous time model for nonstationary correlation structures for longitudinal data. This model, which provides a continuous time analogue to the antedependence model and is thus referred to as the continuous antedependence (CAD) model, is intended to provide more refined correlation models for longitudinal data and to better accommodate sparse (or highly unbalanced) data. A key component of this model is the 'nonstationarity function' which describes nonstationarity as a unidimensional function of time and has an interesting time expansion/contraction interpretation. Focusing on a Markovian version of the model, we develop a novel nonlinear regression model providing nonlinear least square estimators of model parameters. Both unstructured (for nonparametric estimation) and structured versions of the model are presented. We apply the proposed approach to data from the Multicenter AIDS Clinical Study (MACS), with a focus on inference for the nonstationarity function. In simulation studies, we show good properties (low finite sample bias, and high convergence rates and efficiency) of the proposed unstructured model estimator, which compare favorably to those of an alternative maximum likelihood estimator, particularly in sparse data situations.

Generalized causal mediation and path analysis: Extensions and practical considerations

Causal mediation analysis seeks to decompose the effect of a treatment or exposure among multiple possible paths and provide casually interpretable path-specific effect estimates. Recent advances have extended causal mediation analysis to situations with a sequence of mediators or multiple contemporaneous mediators. However, available methods still have limitations, and computational and other challenges remain. The present paper provides an extended causal mediation and path analysis methodology. The new method, implemented in the new R package, gmediation (described in a companion paper), accommodates both a sequence (two stages) of mediators and multiple mediators at each stage, and allows for multiple types of outcomes following generalized linear models. The methodology can also handle unsaturated models and clustered data. Addressing other practical issues, we provide new guidelines for the choice of a decomposition, and for the choice of a reference group multiplier for the reduction of Monte Carlo error in mediation formula computations. The new method is applied to data from a cohort study to illuminate the contribution of alternative biological and behavioral paths in the effect of socioeconomic status on dental caries in adolescence.

The psychometric properties of a new oral health illness perception measure for adults aged 62 years and older

BACKGROUND

Based on the Common-Sense Model of Self-Regulation (CSM), a new integrated Illness Perception Questionnaire Revised for Dental Use in Older/Elder Adults (IPQ-RDE) was developed for single and multiple dental conditions. This study describes psychometric properties of the IPQ-RDE for adults 62 years and older.

METHODS

Participants (n = 198) living in 16 subsidized housing facilities completed the IPQ-RDE and a questionnaire assessing their socio-demographics, frequency of dental visits, perceived condition of teeth/gums, depression, social support, and oral health quality of life (OHQOL). Participants received dental screening for presence/absence of teeth, coronal and root caries, and periodontitis. The 43-item IPQ-RDE was tested for internal (construct, discriminant) and external validity (concurrent, construct, discriminant, predictive) and reliability (internal consistency).

RESULTS

Confirmatory factor analysis demonstrated that a ten-factor model in accordance with the CSM framework (identity, consequences, control, timeline, illness coherence, treatment burden, prioritization, causal relationship, activity restriction, emotional representations) had good construct validity based on significant factor loadings and acceptable model fit (RMSEA = 0.065, CFI = 0.902). Edentulous participants had significantly higher mean factor scores (inaccurate perception) for overall IPQ-RDE and four constructs indicating concurrent validity. Discriminant validity was suggested by non-relationship with external measures (education, dental visit frequency). Predictive validity was indicated by the negative correlation of most constructs with OHQOL suggesting that inaccurate perception was related to lower quality of life. Internal consistency of eight IPQ-RDE constructs was excellent (Cronbach's alpha > 0.73).

CONCLUSIONS

The IPQ-RDE is a valid and reliable new measure for assessing older adult's perception of dental conditions. It can be an important tool for oral health behavioral research to restructure older adult's perception of dental conditions, and subsequently prevent tooth loss and improve oral health quality of life.

Randomized Trial Based on the Common-Sense Model of Self-regulation to Increase Child Dental Visits

INTRODUCTION

School screening and the note home (pinned to a backpack) informing parents/caregivers that their child needs to see a dentist have not been effective.

OBJECTIVES

The Family Access to a Dentist Study (FADS) evaluated the effectiveness of school interventions based on the common-sense model of self-regulation (CSM) among K-4 children needing restorative treatment.

METHODS

FADS was a multisite double-blind randomized controlled trial with 5 arms. FADS tested a CSM-driven referral letter and dental information guide (DIG) to move caregivers from inaccurate to accurate perceptions of dental caries. Six school districts from Ohio and Washington (14 schools) participated in school years 2015 to 2016 and 2016 to 2017. A total of 611 caregivers were randomized, and 86% (n = 597 children) completed the exit examination. The primary outcome was receipt of care based on a change in oral health status determined clinically within 1 school year.

RESULTS

In accordance with our primary aims, 5 arms were collapsed into 3: CSM letter and reduced CSM letter (combined), CSM letter + DIG and reduced CSM letter + reduced DIG (combined), and standard letter. Among all sites, 39.7% received restorative care (237 of 597). Combined analysis of sites revealed that the CSM referral letter (with and without the DIG) did not increase dental visits when compared with the standard letter. However, for combined sites (East Cleveland, Ohio; Washington), the CSM + DIG increased dental visits when compared with standard letter in univariate analysis (51.3% vs. 40.9%), indicating 1.6-times increased odds of a dental visit (95% CI, 0.97 to 2.58) after imputation and adjustment for covariates. The CSM + DIG group had 1.9-times increased odds (95% CI, 1.21 to 3.08) of care when compared the CSM letter alone.

CONCLUSION

A CSM-driven approach to informing caregivers of the chronic nature of caries with resources in an illustrative manner can increase the benefit of school oral health screening (ClinicalTrials.gov NCT02395120).

KNOWLEDGE TRANSFER STATEMENT

A school dental referral (note home) that tells a parent that the child has cavities has not been effective. In this trial, a referral based on the common-sense model of self-regulation increased follow-up care for children with restorative needs.

Comparing web-based video interventions to enhance university student willingness to donate organs: A randomized controlled trial

BACKGROUND

The efficacy of video interventions to increase organ donation willingness remains unclear.

METHODS

Three-arm web-based randomized controlled trial involving 2261 students at 3 northeastern Ohio universities. Intervention students watched a live-action (n = 755) or animated (n = 753) donation video. Control students (n = 753) viewed wellness information from the Centers for Disease Control and Prevention (CDC). The primary outcome was proportion of students who visited their state electronic donor registry to consent. The secondary outcome was intervention quality. Logistic regression assessed the effects of interventions on visiting the state registry to provide donation consent while controlling for baseline variables.

RESULTS

Students in the live-action video arm visited their state registry more frequently than students in the CDC arm (OR = 1.86, 95% CI = 1.20-2.88). There was no difference between students in the animated video and CDC arms (OR = 1.10, 95% CI = 0.69-1.76). The quality of the live-action video was rated lower than the animated video and the CDC text (75% ± 18, 84% ± 16, 80% ± 16, respectively; P < 0.001).

CONCLUSION

Students who watched the live-action video were more willing to visit their electronic donor registry to register as organ donors, but rated it lower in satisfaction. Future work should identify the most potent components of organ donation interventions.

Early Origins of Later Life Psychological Well-Being? A Novel Application of Causal Mediation Analysis to Life Course Research

Objectives

This study employs a novel approach to mediation analysis to clarify the influence of interrelated indicators of life course socioeconomic status (SES) on later life psychological well-being in India. Contrary to traditional approaches (i.e., use of product and difference-in-coefficients), we recognize the role of confounders in the estimation of total, direct, and indirect effects of parental education on respondents' psychological well-being.

Method

Drawing from the first wave (2007-2010) of the Study on Global Ageing and Adult Health (SAGE) and adopting a counterfactual approach, we estimate both natural direct and indirect effects of parental education through individual educational attainment (secondarily, through household assets as an additional mediator) on respondents' life-satisfaction and quality of life (QOL).

Results

Findings document a statistically not significant positive total effect of parental education on life satisfaction and QOL. While lower for women, significant indirect effects suggest that the positive influence of parental education operates primarily through the individual's education. Notably, we found negative direct effect of parental education on psychological well-being outcomes.

Discussion

Contrary to prior literature, we found no positive direct influence of parental education on later life psychological well-being, but established its influence through socioeconomic positioning over the life course.

Quantifying the Time Used for Renal Dietitian's Responsibilities: A Pilot Study

OBJECTIVE

The purpose of this study was to quantify how dialysis dietitians spend their time and whether the activities that were most frequent varied based on the ratio of patient to full-time equivalent (FTE) dietitian.

METHODS

This study is a cross-sectional, observational, time-and-motion study carried out using the Work Activity Measurement by Activity Timing software/method for time recording. This study was carried out in 14 dialysis centers in and around Cleveland, Ohio. Fourteen registered dietitian nutritionists participated in this study. The mean time/experience of these nutritionists in dietetics was 26.6 ± 8.5 years. Percent of time in direct care (e.g., patient interaction) versus indirect care (e.g., documentation and plans of care, professional communication) versus other responsibilities (e.g., administrative work, education of self or others).

RESULTS

The mean number of tasks recorded per 3-hour observation session was 38.3 ± 14.0, including 18.5 ± 7.7 indirect care tasks, 7.7 ± 6.2 direct care tasks, and 9.7 ± 5.4 other tasks. The mean number of unique patients seen per observation session was 6.9 ± 5.4; the mean direct care time per patient encounter was 6.95 ± 4.05 minutes. Indirect care took the highest proportion of observed time, 56.0 ± 22.2%, followed by direct care, 24.9 ± 18.8%. Increasing the ratio of patient to FTE had a moderate negative correlation with the percent of time spent in direct patient care (r = -0.35, P = .21), but there was no relationship between the ratio of patient to FTE and direct care time per patient (r = 0.02, P = .94).

CONCLUSION

About 25% of dietitians' time was available for direct patient care. This is much less than that reported in previous studies and may not be sufficient to improve the nutritional status. Limitations of our study include a small sample size from a single region. Further work is needed to understand the balance of responsibilities among renal dietitians and their impact on patient outcomes.

Gendered "Long Arm" of Parental Education? Life Course Influences on Later Life Functional Limitations in India

Objective: We adopt a novel approach to mediation analysis to account for interrelated life course social processes that constitute later life health disparities. We examine gender-specific direct effect of parental education on functional limitations in later life. Method: Based on the first wave (2007-2010; n = 7,150) of the Study on Global Ageing and Adult Health (SAGE), we estimate both (natural) direct and indirect effects of parental education on functional limitations in later life. Results: We observed a significant indirect and positive effect of parental education on functional health. Contrary to prior literature, we documented adverse direct effect of parental education on later life functional health. The direct effect is statistically significant only for father's education, and is greater, though not statistically significantly so, for women than men. Discussion: The intersection of gender status and interrelated social stratification documented by this study highlights the need for gender-sensitive life course research. Such research can enhance our understanding of the ways patriarchal social systems produce heterogeneous effects of interrelated structural factors on later life health for men and women.

Impact of Navigators on First Visit to a Transplant Center, Waitlisting, and Kidney Transplantation: A Randomized, Controlled Trial

BACKGROUND AND OBJECTIVES

Many patients with ESKD face barriers in completing the steps required to obtain a transplant. These eight sequential steps are medical suitability, interest in transplant, referral to a transplant center, first visit to center, transplant workup, successful candidate, waiting list or identify living donor, and receive transplant. This study sought to determine the effect of navigators on helping patients complete these steps.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our study was a cluster randomized, controlled trial involving 40 hemodialysis facilities and four transplant centers in Ohio, Kentucky, and Indiana from January 1, 2014 to December 31, 2016. Four trained kidney transplant recipients met regularly with patients on hemodialysis at 20 intervention facilities, determined their step in the transplant process, and provided tailored information and assistance in completing that step and subsequent steps. Patients at 20 control facilities continued to receive usual care. Primary study outcomes were waiting list placement and receipt of a deceased or living donor transplant. An exploratory outcome was first visit to a transplant center.

RESULTS

Before the trial, intervention (1041 patients) and control (836 patients) groups were similar in the proportions of patients who made a first visit to a transplant center, were placed on a waiting list, and received a deceased or living donor transplant. At the end of the trial, intervention and control groups were also similar in first visit (16.1% versus 13.8%; difference, 2.3%; 95% confidence interval, -0.8% to 5.5%), waitlisting (16.3% versus 13.8%; difference, 2.5%; 95% confidence interval, -1.2% to 6.1%), deceased donor transplantation (2.8% versus 2.2%; difference, 0.6%; 95% confidence interval, -0.8% to 2.1%), and living donor transplantation (1.2% versus 1.0%; difference, 0.1%; 95% confidence interval, -0.9% to 1.1%).

CONCLUSIONS

Use of trained kidney transplant recipients as navigators did not increase first visits to a transplant center, waiting list placement, and receipt of deceased or living donor transplants.

Structural Equation Modeling to Explore Patient to Staff Ratios as an Explanatory Factor for Variation in Dialysis Facility Outcomes

OBJECTIVE

Patient to staff ratios vary based on facility characteristics, and therefore have been proposed as an explanatory factor for the variation in dialysis facility outcomes. This analysis tested that hypothesis.

DESIGN AND METHODS

Observational study using Dialysis Facility Report data. Reported staff numbers from the Annual Facility Survey were converted to full time equivalents (FTE). Subsequently, ratios were created for patients per FTE registered dietitian (RD), social worker, nurse, and patient care technician. Bivariate associations and structural equation modeling (SEM) were used to explore relationships between these ratios and patient outcomes: standardized mortality ratio and standardized hospitalization rate, when also considering the impact of non-modifiable facility characteristics (region, chain, profit status). Our focus was on RD staffing; therefore we also included serum phosphorus and normalized protein catabolic ratio in the model, and also conducted a sub-analysis of the 198 facilities that exceeded the KDOQI maximum of 150 patients:FTE RD.

SUBJECTS

Dialysis centers in the US with at least 30 adult patients and no pediatric patients. 4035 facilities had complete data for the proposed variables.

MAIN OUTCOME MEASURE

Standardized mortality ratio and standardized hospitalization rate were the primary outcomes.

RESULTS

The mean and standard deviation for patients per FTE staff were 90.0 ± 34.0, 88.7 ± 32.8, 17.1 ± 20.5 and 11.9 ± 7.0 for RDs, social workers, nurses, and technicians, respectively. Facility characteristics impacted staffing in bivariate analyses and SEM. The only significant paths from staffing ratio to outcomes were for patient:FTE social worker to SMR (standardized beta = -0.09, 95% CI -0.13, -0.04) and Patients:FTE RD to SHR Days (standardized beta = 0.04, 95% CI 0.001, 0.09). In the sub-analysis, there were no significant paths from staffing to outcomes.

CONCLUSIONS

This study did not provide evidence that patient per staff ratios explain variation in dialysis facility outcomes. While there are some important bivariate relationships, these disappear in more complex models. Future research should investigate the impacts of staffing ratios on individual patients, to overcome the possible ecological fallacy.

Failure mode and effects analysis: A community practice perspective

PURPOSE

To report our early experiences with failure mode and effects analysis (FMEA) in a community practice setting.

METHODS

The FMEA facilitator received extensive training at the AAPM Summer School. Early efforts focused on department education and emphasized the need for process evaluation in the context of high profile radiation therapy accidents. A multidisciplinary team was assembled with representation from each of the major department disciplines. Stereotactic radiosurgery (SRS) was identified as the most appropriate treatment technique for the first FMEA evaluation, as it is largely self-contained and has the potential to produce high impact failure modes. Process mapping was completed using breakout sessions, and then compiled into a simple electronic format. Weekly sessions were used to complete the FMEA evaluation. Risk priority number (RPN) values > 100 or severity scores of 9 or 10 were considered high risk. The overall time commitment was also tracked.

RESULTS

The final SRS process map contained 15 major process steps and 183 subprocess steps. Splitting the process map into individual assignments was a successful strategy for our group. The process map was designed to contain enough detail such that another radiation oncology team would be able to perform our procedures. Continuous facilitator involvement helped maintain consistent scoring during FMEA. Practice changes were made responding to the highest RPN scores, and new resulting RPN scores were below our high-risk threshold. The estimated person-hour equivalent for project completion was 258 hr.

CONCLUSIONS

This report provides important details on the initial steps we took to complete our first FMEA, providing guidance for community practices seeking to incorporate this process into their quality assurance (QA) program. Determining the feasibility of implementing complex QA processes into different practice settings will take on increasing significance as the field of radiation oncology transitions into the new TG-100 QA paradigm.

Outcomes of Deceased Donor Kidney Offers to Patients at the Top of the Waiting List

BACKGROUND AND OBJECTIVES

Transplant centers may accept or refuse deceased-donor kidneys that are offered to their patients at the top of the waiting list. We sought to determine the outcomes of deceased-donor kidney offers and their association with characteristics of waitlisted patients and organ donors.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined all 7 million deceased-donor adult kidney offers in the United States from 2007 to 2012 that led to eventual transplantation. Data were obtained from the national organ allocation system through the United Network of Organ Sharing. The study cohort consisted of 178,625 patients waitlisted for a deceased-donor kidney transplant and 31,230 deceased donors. We evaluated offers made to waitlisted patients and their outcomes (transplantation or specific reason for refusal).

RESULTS

Deceased-donor kidneys were offered a median of seven times before being accepted for transplantation. The most common reasons for refusal of an offer were donor-related factors, e.g., age or organ quality (3.2 million offers, 45.0%), and transplant center bypass, e.g., minimal acceptance criteria not met (3.2 million offers, 44.0%). After adjustment for characteristics of waitlisted patients, organ donors, and transplant centers, male (odds ratio [OR], 0.93; 95% confidence interval [95% CI], 0.91 to 0.95) and Hispanic (OR, 0.96; 95% CI, 0.93 to 0.99) waitlisted patients were less likely to have an offer accepted than female and white patients, respectively. The likelihood of offer acceptance varied greatly across transplant centers (interquartile ratio, 2.28).

CONCLUSIONS

Transplant centers frequently refuse deceased-donor kidneys. Such refusals differ by patient and donor characteristics, may contribute to disparities in access to transplantation, and vary greatly across transplant centers.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2017_07_27_Huml.mp3.

Do baby teeth really matter? Changing parental perception and increasing dental care utilization for young children

INTRODUCTION

Parent/caregivers' inability to recognize the importance of baby teeth has been associated with inadequate self-management of children's oral health (i.e. lower likelihood of preventive dental visits) which may result in dental caries and the need for more expensive caries-related restorative treatment under general anesthesia. Health behavior theories aid researchers in understanding the impact and effectiveness of interventions on changing health behaviors and health outcomes. One example is the Common-Sense Model of Self-Regulation (CSM) which focuses on understanding an individual's illness perception (i.e. illness and treatment representations), and subsequently has been used to develop behavioral interventions to change inaccurate perceptions and describe the processes involved in behavior change.

METHODS

We present two examples of randomized clinical trials that are currently testing oral health behavioral interventions to change parental illness perception and increase dental utilization for young children disproportionately impacted by dental caries in elementary schools and pediatric primary care settings. Additionally, we compared empiric data regarding parent/caregiver perception of the chronic nature of dental caries (captured by the illness perception questionnaire revised for dental: IPQ-RD constructs: identity, consequences, control, timeline, illness coherence, emotional representations) between parent/caregivers who did and did not believe baby teeth were important.

RESULTS

Caregivers who believed that baby teeth don't matter had significantly (P<0.05) less accurate perception in the majority of the IPQ-RD constructs (except timeline construct) compared to caregivers who believed baby teeth do matter.

CONCLUSION

These findings support our CSM-based behavioral interventions to modify caregiver caries perception, and improve dental utilization for young children.

Causal Mediation Analysis for the Cox Proportional Hazards Model with a Smooth Baseline Hazard Estimator

An important problem within the social, behavioral, and health sciences is how to partition an exposure effect (e.g. treatment or risk factor) among specific pathway effects and to quantify the importance of each pathway. Mediation analysis based on the potential outcomes framework is an important tool to address this problem and we consider the estimation of mediation effects for the proportional hazards model in this paper. We give precise definitions of the total effect, natural indirect effect, and natural direct effect in terms of the survival probability, hazard function, and restricted mean survival time within the standard two-stage mediation framework. To estimate the mediation effects on different scales, we propose a mediation formula approach in which simple parametric models (fractional polynomials or restricted cubic splines) are utilized to approximate the baseline log cumulative hazard function. Simulation study results demonstrate low bias of the mediation effect estimators and close-to-nominal coverage probability of the confidence intervals for a wide range of complex hazard shapes. We apply this method to the Jackson Heart Study data and conduct sensitivity analysis to assess the impact on the mediation effects inference when the no unmeasured mediator-outcome confounding assumption is violated.

Effects of a Video on Organ Donation Consent Among Primary Care Patients: A Randomized Controlled Trial

BACKGROUND

Low organ donation rates remain a major barrier to organ transplantation.

OBJECTIVE

We aimed to determine the effect of a video and patient cueing on organ donation consent among patients meeting with their primary care provider.

DESIGN

This was a randomized controlled trial between February 2013 and May 2014.

SETTING

The waiting rooms of 18 primary care clinics of a medical system in Cuyahoga County, Ohio.

PATIENTS

The study included 915 patients over 15.5 years of age who had not previously consented to organ donation.

INTERVENTIONS

Just prior to their clinical encounter, intervention patients (n = 456) watched a 5-minute organ donation video on iPads and then choose a question regarding organ donation to ask their provider. Control patients (n = 459) visited their provider per usual routine.

MAIN MEASURES

The primary outcome was the proportion of patients who consented for organ donation. Secondary outcomes included the proportion of patients who discussed organ donation with their provider and the proportion who were satisfied with the time spent with their provider during the clinical encounter.

KEY RESULTS

Intervention patients were more likely than control patients to consent to donate organs (22 % vs. 15 %, OR 1.50, 95%CI 1.10-2.13). Intervention patients were also more likely to have donation discussions with their provider (77 % vs. 18 %, OR 15.1, 95%CI 11.1-20.6). Intervention and control patients were similarly satisfied with the time they spent with their provider (83 % vs. 86 %, OR 0.87, 95%CI 0.61-1.25).

LIMITATION

How the observed increases in organ donation consent might translate into a greater organ supply is unclear.

CONCLUSION

Watching a brief video regarding organ donation and being cued to ask a primary care provider a question about donation resulted in more organ donation discussions and an increase in organ donation consent. Satisfaction with the time spent during the clinical encounter was not affected.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01697137.

Pathways to adolescent sexual risk behaviors: Effects of prenatal cocaine exposure

BACKGROUND

To assess the impact of prenatal cocaine exposure (PCE) on adolescent sexual risk behaviors. Externalizing behavior, teen substance use, and early sexual intercourse were examined as pathways mediating the effects of PCE on sexual risk behaviors.

METHODS

Adolescents (N=364; 185 PCE, 179 non-cocaine exposure (NCE); 205 girls, 159 boys), primarily African-American and of low socioeconomic status, were prospectively enrolled in a longitudinal study at birth. Risky sexual behaviors were assessed at ages 15 and 17. Externalizing behavior at 12 years was assessed with the Youth Self-Report. Substance use, via self-report and biologic assays, and early (before age 15) sexual intercourse were assessed at age 15. Path analyses with the weighted least squares estimator with mean and variance adjustments were performed.

RESULTS

The final structural equation model-based path model, χ(2)=31.97 (df=27), p=.23, CFI=.99, TLI=.99, RMSEA=.021, WRMR=.695, indicated a direct effect of PCE on sexual risk behavior (β=.16, p=.02). Although PCE was related to greater externalizing behavior (β=.14, p=.009), which in turn, predicted early sexual intercourse (β=.16, p=.03), leading to sexual risk behavior (β=.44, p<.001), bootstrapping indicated a non-significant indirect effect (β=.01, p>.10). Substance use was correlated with early sexual intercourse (r=.60, p<.001) and predicted sexual risk behavior by age 17 (β=.31, p=.01).

CONCLUSIONS

Prenatal cocaine exposure was related to more engagement in sexual risk behaviors, suggesting the importance of reducing substance use among pregnant women as a means of prevention of offspring substance use and sexual risk behavior.

Family Access to a Dentist Study (FADS): A multi-center randomized controlled trial

INTRODUCTION

Many low-income parent/caregivers do not understand the importance of cavity-free primary (baby) teeth and the chronic nature of dental caries (tooth decay). As a consequence, dental preventive and treatment utilization is low even when children are screened in schools and referred for care. This study aims to test a referral letter and Dental Information Guide (DIG) designed using the Common-Sense Model of Self-Regulation (CSM) framework to improve caregivers' illness perception of dental caries and increase utilization of care by children with restorative dental needs.

METHODS

A multi-site randomized controlled trial with caregivers of Kindergarten to 4th grade children in urban Ohio and rural Washington State will compare five arms: (1) CSM referral letter alone; (2) CSM referral letter+DIG; (3) reduced CSM referral letter alone; (4) reduced CSM referral letter+DIG; and (5) standard (control) referral. At baseline, children will be screened at school to determine restorative dental needs. If in need of treatment, caregivers will be randomized to study arms and an intervention packet will be sent home. The primary outcome will be dental care based on a change in oral health status by clinical examination 7 months post-screening (ICDAS sealant codes 1 and 2; restoration codes 3-8; extraction). Enrollment commenced summer 2015 with results in summer 2016.

CONCLUSION

This study uses the CSM framework to develop and test behavioral interventions to increase dental utilization among low-income caregivers. If effective this simple intervention has broad applicability in clinical and community-based settings.

Causal mediation analysis with a latent mediator

Health researchers are often interested in assessing the direct effect of a treatment or exposure on an outcome variable, as well as its indirect (or mediation) effect through an intermediate variable (or mediator). For an outcome following a nonlinear model, the mediation formula may be used to estimate causally interpretable mediation effects. This method, like others, assumes that the mediator is observed. However, as is common in structural equations modeling, we may wish to consider a latent (unobserved) mediator. We follow a potential outcomes framework and assume a generalized structural equations model (GSEM). We provide maximum-likelihood estimation of GSEM parameters using an approximate Monte Carlo EM algorithm, coupled with a mediation formula approach to estimate natural direct and indirect effects. The method relies on an untestable sequential ignorability assumption; we assess robustness to this assumption by adapting a recently proposed method for sensitivity analysis. Simulation studies show good properties of the proposed estimators in plausible scenarios. Our method is applied to a study of the effect of mother education on occurrence of adolescent dental caries, in which we examine possible mediation through latent oral health behavior.

Sensitivity analyses for parametric causal mediation effect estimation

Causal mediation analysis uses a potential outcomes framework to estimate the direct effect of an exposure on an outcome and its indirect effect through an intermediate variable (or mediator). Causal interpretations of these effects typically rely on sequential ignorability. Because this assumption is not empirically testable, it is important to conduct sensitivity analyses. Sensitivity analyses so far offered for this situation have either focused on the case where the outcome follows a linear model or involve nonparametric or semiparametric models. We propose alternative approaches that are suitable for responses following generalized linear models. The first approach uses a Gaussian copula model involving latent versions of the mediator and the final outcome. The second approach uses a so-called hybrid causal-observational model that extends the association model for the final outcome, providing a novel sensitivity parameter. These models, while still assuming a randomized exposure, allow for unobserved (as well as observed) mediator-outcome confounders that are not affected by exposure. The methods are applied to data from a study of the effect of mother education on dental caries in adolescence.

Sero-prevalence of herpes simplex type 2 virus (HSV-2) and HIV infection in Kampala, Uganda

BACKGROUND

Prevalence of herpes simplex type 2 virus (HSV-2) is high worldwide. Previous studies in Uganda were rural or in women. We estimated age and sex-specific sero-prevalence of HSV-2 in Kampala, Uganda.

METHODS

Using two-stage random sampling stratified on population density, a survey of persons 15-65 years was conducted. Type-specific serological tests for HSV-2, HSV-1(HerpeSelect2 and 1 ELISA), HIV (Rapid tests and ELISA), syphilis (RPR and TPHA) were done. Additional prevalence analysis included post-stratification weighting on the Uganda 2002 Census gender distribution.

RESULTS

Among 1124 persons, HSV-2 prevalence was 58% (95% CI: 55, 60), HSV-1; 98% (95% CI: 97.6, 99.1), HIV; 17.7% (95% CI: 14.8, 19.2) and syphilis; 1.7% (95% CI: 1.4, 1.9). Weighted HSV-2 prevalence was 53.8% (Women; 63.8%, men; 43.2%), similar to unweighted data. Weighted HIV prevalence was 20.7% in women, 8.6% in men. Of 165 HIV infected persons, 85.4% had HSV-2. Risk factors for HSV-2 were being a woman (OR 2.0; 95% CI: 1.42, 2.78), age (OR 3.3; 95% CI: 2.43, 4.53), education (OR 1.70; 95% CI: 1.34, 2.34) and HIV (OR 4.5; 95% CI: 2.70, 7.50).

CONCLUSION

Prevalence of HSV-2 and HIV was high especially in women. Syphilis was rare. Awareness of herpes was low. Interventions in young people are needed.

Establishing high-quality prostate brachytherapy using a phantom simulator training program

PURPOSE

To design and implement a unique training program that uses a phantom-based simulator to teach the process of prostate brachytherapy (PB) quality assurance and improve the quality of education.

METHODS AND MATERIALS

Trainees in our simulator program were practicing radiation oncologists, radiation oncology residents, and fellows of the American Brachytherapy Society. The program emphasized 6 core areas of quality assurance: patient selection, simulation, treatment planning, implant technique, treatment evaluation, and outcome assessment. Using the Iodine 125 ((125)I) preoperative treatment planning technique, trainees implanted their ultrasound phantoms with dummy seeds (ie, seeds with no activity). Pre- and postimplant dosimetric parameters were compared and correlated using regression analysis.

RESULTS

Thirty-one trainees successfully completed the simulator program during the period under study. The mean phantom prostate size, number of seeds used, and total activity were generally consistent between trainees. All trainees met the V100 >95% objective both before and after implantation. Regardless of the initial volume of the prostate phantom, trainees' ability to cover the target volume with at least 100% of the dose (V100) was not compromised (R=0.99 pre- and postimplant). However, the V150 had lower concordance (R=0.37) and may better reflect heterogeneity control of the implant process.

CONCLUSIONS

Analysis of implants from this phantom-based simulator shows a high degree of consistency between trainees and uniformly high-quality implants with respect to parameters used in clinical practice. This training program provides a valuable educational opportunity that improves the quality of PB training and likely accelerates the learning curve inherent in PB. Prostate phantom implantation can be a valuable first step in the acquisition of the required skills to safely perform PB.

Estimation of causal mediation effects for a dichotomous outcome in multiple-mediator models using the mediation formula

Mediators are intermediate variables in the causal pathway between an exposure and an outcome. Mediation analysis investigates the extent to which exposure effects occur through these variables, thus revealing causal mechanisms. In this paper, we consider the estimation of the mediation effect when the outcome is binary and multiple mediators of different types exist. We give a precise definition of the total mediation effect as well as decomposed mediation effects through individual or sets of mediators using the potential outcomes framework. We formulate a model of joint distribution (probit-normal) using continuous latent variables for any binary mediators to account for correlations among multiple mediators. A mediation formula approach is proposed to estimate the total mediation effect and decomposed mediation effects based on this parametric model. Estimation of mediation effects through individual or subsets of mediators requires an assumption involving the joint distribution of multiple counterfactuals. We conduct a simulation study that demonstrates low bias of mediation effect estimators for two-mediator models with various combinations of mediator types. The results also show that the power to detect a nonzero total mediation effect increases as the correlation coefficient between two mediators increases, whereas power for individual mediation effects reaches a maximum when the mediators are uncorrelated. We illustrate our approach by applying it to a retrospective cohort study of dental caries in adolescents with low and high socioeconomic status. Sensitivity analysis is performed to assess the robustness of conclusions regarding mediation effects when the assumption of no unmeasured mediator-outcome confounders is violated.

Defining incident cases of epilepsy in administrative data

PURPOSE

To determine the minimum enrollment duration for identifying incident cases of epilepsy in administrative data.

METHODS

We performed a retrospective dynamic cohort study using Ohio Medicaid data from 1992 to 2006 to identify a total of 5037 incident epilepsy cases who had at least 1 year of follow-up prior to epilepsy diagnosis (epilepsy-free interval). The incidence for epilepsy-free intervals from 1 to 8 years, overall and stratified by pre-existing disability status, was examined. The graphical approach between the slopes of incidence estimates and the epilepsy-free intervals was used to identify the minimum epilepsy-free interval that minimized misclassification of prevalent as incident epilepsy cases.

RESULTS

As the length of epilepsy-free interval increased, the incidence rates decreased. A graphical plot showed that the decline in incidence of epilepsy became nearly flat beyond the third epilepsy-free interval.

CONCLUSION

The minimum of 3-year epilepsy-free interval is needed to differentiate incident from prevalent cases in administrative data. Shorter or longer epilepsy-free intervals could result in over- or under-estimation of epilepsy incidence.

Increased enamel hypoplasia and very low birthweight infants

Birth cohort studies of developmental defects of enamel (DDE) and early childhood caries (ECC) in very low birthweight (VLBW) and normal birthweight (NBW) infants are rare. In this birth cohort of 234 VLBW and 234 NBW infants, we report the incidence of ECC and DDE at 8 and 18-20 mos of corrected age. Infant medical and maternal socio-demographic data were abstracted from medical records at birth. Dental assessments for ECC and DDE (enamel hypoplasia, demarcated and diffuse opacities) were completed at 8 and 18-20 mos. The incidence of hypoplasia was significantly higher in VLBW compared with NBW infants (8 mos, 19% vs. 2%; 18 mos, 31% vs. 8%). The incidence of ECC (International Caries Detection and Assessment System: ICDAS ≥ 2) was 1.4% (8 mos) and 12% (18-20 mos) and was similar between the VLBW and NBW groups. At both ages, using a beta-binomial regression model to control for potential confounders (maternal and infant characteristics), we found increased risk for enamel hypoplasia among the VLBW infants compared with the NBW infants. African Americans had a lower risk for enamel hypoplasia at 18-20 mos. The VLBW infants should be monitored for ECC due to the presence of enamel hypoplasia.

Estimation of mediation effects for zero-inflated regression models

The goal of mediation analysis is to identify and explicate the mechanism that underlies a relationship between a risk factor and an outcome via an intermediate variable (mediator). In this paper, we consider the estimation of mediation effects in zero-inflated (ZI) models intended to accommodate 'extra' zeros in count data. Focusing on the ZI negative binomial models, we provide a mediation formula approach to estimate the (overall) mediation effect in the standard two-stage mediation framework under a key sequential ignorability assumption. We also consider a novel decomposition of the overall mediation effect for the ZI context using a three-stage mediation model. Estimation of the components of the overall mediation effect requires an assumption involving the joint distribution of two counterfactuals. Simulation study results demonstrate low bias of mediation effect estimators and close-to-nominal coverage probability of confidence intervals. We also modify the mediation formula method by replacing 'exact' integration with a Monte Carlo integration method. The method is applied to a cohort study of dental caries in very low birth weight adolescents. For overall mediation effect estimation, sensitivity analysis was conducted to quantify the degree to which key assumption must be violated to reverse the original conclusion.

Distribution-free mediation analysis for nonlinear models with confounding

Recently, researchers have used a potential-outcome framework to estimate causally interpretable direct and indirect effects of an intervention or exposure on an outcome. One approach to causal-mediation analysis uses the so-called mediation formula to estimate the natural direct and indirect effects. This approach generalizes the classical mediation estimators and allows for arbitrary distributions for the outcome variable and mediator. A limitation of the standard (parametric) mediation formula approach is that it requires a specified mediator regression model and distribution; such a model may be difficult to construct and may not be of primary interest. To address this limitation, we propose a new method for causal-mediation analysis that uses the empirical distribution function, thereby avoiding parametric distribution assumptions for the mediator. To adjust for confounders of the exposure-mediator and exposure-outcome relationships, inverse-probability weighting is incorporated based on a supplementary model of the probability of exposure. This method, which yields the estimates of the natural direct and indirect effects for a specified reference group, is applied to data from a cohort study of dental caries in very-low-birth-weight adolescents to investigate the oral-hygiene index as a possible mediator. Simulation studies show low bias in the estimation of direct and indirect effects in a variety of distribution scenarios, whereas the standard mediation formula approach can be considerably biased when the distribution of the mediator is incorrectly specified.

Quality indicators in radiation oncology

Oncologic specialty societies and multidisciplinary collaborative groups have dedicated considerable effort to developing evidence-based quality indicators (QIs) to facilitate quality improvement, accreditation, benchmarking, reimbursement, maintenance of certification, and regulatory reporting. In particular, the field of radiation oncology has a long history of organized quality assessment efforts and continues to work toward developing consensus quality standards in the face of continually evolving technologies and standards of care. This report provides a comprehensive review of the current state of quality assessment in radiation oncology. Specifically, this report highlights implications of the healthcare quality movement for radiation oncology and reviews existing efforts to define and measure quality in the field, with focus on dimensions of quality specific to radiation oncology within the "big picture" of oncologic quality assessment efforts.

Effectiveness of radiation for prevention of mastectomy in older breast cancer patients treated with conservative surgery

BACKGROUND

A recent clinical trial concluded that radiation therapy (RT) does not lower the risk of mastectomy and, thus, may be omitted in older women with stage I, estrogen receptor (ER)-positive breast cancer who undergo conservative surgery (CS). However, it is not known whether this finding applies to patients outside of clinical trials. Accordingly, we used the Surveillance, Epidemiology, and End Results-Medicare observational cohort to determine the effect of RT on the risk of mastectomy among older women with stage I, ER-positive breast cancer.

METHODS

The authors identified 7403 women ages 70 to 79 years who underwent CS between 1992 and 2002. Claims were used to determine RT status and to identify women who underwent mastectomy subsequent to initial treatment. The Kaplan-Meier method was used to estimate the risk of subsequent mastectomy, and Cox regression analysis was used to determine the effect of RT adjusted for clinical-pathologic covariates.

RESULTS

At a median follow-up of 7.3 years, the risk of subsequent mastectomy within 10 years of diagnosis was 3.2% for patients who received RT versus 6.3% for patients who did not receive RT (P < .001). In adjusted analyses, RT was associated with a lower risk of mastectomy (hazard ratio, 0.33; 95% confidence interval, 0.22-0.48; P < .001). RT provided no benefit for patients ages 75 to 79 years without high-grade tumors who had a pathologic lymph node assessment (P = .80); however, for all other subgroups, RT was associated with an absolute reduction in risk of mastectomy that ranged from 4.3% to 9.8% at 10 years.

CONCLUSIONS

Outside of a clinical trial, the receipt of RT after CS was associated with a greater likelihood of ultimate breast preservation for most older women with early breast cancer.

Nomogram to predict the benefit of radiation for older patients with breast cancer treated with conservative surgery

PURPOSE

The role of radiation therapy (RT) after conservative surgery (CS) remains controversial for older patients with breast cancer. Guidelines based on recent clinical trials have suggested that RT may be omitted in selected patients with favorable disease. However, it is not known whether this recommendation should extend to other older women. Accordingly, we developed a nomogram to predict the likelihood of long-term breast preservation with and without RT.

METHODS

We used Surveillance, Epidemiology, and End Results-Medicare data to identify 16,092 women age 66 to 79 years treated with CS between 1992 and 2002, using claims to identify receipt of RT and subsequent mastectomy. Time to mastectomy was estimated using the Kaplan-Meier method. Cox proportional hazards models determined the effect of covariates on mastectomy-free survival (MFS). A nomogram was developed to predict 5- and 10-year MFS, given associated risk factors, and bootstrap validation was performed.

RESULTS

With a median follow-up of 7.2 years, the overall 5- and 10-year MFS rates were 98.1% (95% CI, 97.8% to 98.3%) and 95.4% (95% CI, 94.9% to 95.8%), respectively. In multivariate analysis, age, race, tumor size, estrogen receptor status, and receipt of RT were predictive of time to mastectomy and were incorporated into the nomogram. Nodal status was also included given a significant interaction with RT. The resulting nomogram demonstrated good accuracy in predicting MFS, with a bootstrap-corrected concordance index of 0.66.

CONCLUSION

This clinically useful tool predicts 5- and 10-year MFS among older women with early breast cancer using readily available clinicopathologic factors and can aid individualized clinical decision making by estimating predicted benefit from RT.

Early maternal psychosocial factors are predictors for adolescent caries

Few studies have investigated the role of early maternal enabling and psychosocial factors on subsequent adolescent caries experience. In this retrospective cohort study of 224 adolescents, we hypothesized that the causal pathway between early maternal enabling factors (education, cognitive abilities, psychological distress) and adolescent caries experience (DMFT) at age 14 yrs is mediated by maternal psychosocial factors (stress, coping, social support) and adolescent dental behavior/access. Maternal data on socio-demographic, medical, and psychosocial variables were measured when the child was 3, 8, and 14 yrs old. A structural equations model (SEM) evaluated the causal pathway, with latent variables for maternal enabling factors (MEF), stress, coping, and social support. Poor MEF was associated with increased stress and poorer coping when the child was 3 yrs old, which in turn affected adolescent dental visits and behavior. Greater social support at child's age 3 was directly associated with lower mean DMFT in adolescence. Maternal psychosocial factors measured when children are young are important mediators for adolescent mean DMFT, but these factors measured when children are adolescents are not. Better early and concurrent MEF, however, was associated directly/indirectly (through dental visits and insurance) with adolescent DMFT. Early maternal factors are important predictors for adolescent caries.

Impact of navigators on completion of steps in the kidney transplant process: a randomized, controlled trial

BACKGROUND AND OBJECTIVES

Many patients with ESRD, particularly minorities and women, face barriers in completing the steps required to obtain a transplant. These eight sequential steps are as follows: medical suitability, interest in transplant, referral to a transplant center, first visit to center, transplant workup, successful candidate, waiting list or identify living donor, and receive transplant. This study sought to determine the effect of navigators on completion of steps.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Cluster randomized, controlled trial at 23 Ohio hemodialysis facilities. One hundred sixty-seven patients were recruited between January 2009 and August 2009 and were followed for up to 24 months or until study end in February 2011. Trained kidney transplant recipients met monthly with intervention participants (n=92), determined their step in the transplant process, and provided tailored information and assistance in completing the step. Control participants (n=75) continued to receive usual care. The primary outcome was the number of transplant process steps completed.

RESULTS

Starting step did not significantly differ between the two groups. By the end of the trial, intervention participants completed more than twice as many steps as control participants (3.5 versus 1.6 steps; difference, 1.9 steps; 95% confidence interval, 1.3-2.5 steps). The effect of the intervention on step completion was similar across race and sex subgroups.

CONCLUSIONS

Use of trained transplant recipients as navigators resulted in increased completion of transplant process steps.

Effects on postoperative salivary cortisol of relaxation/music and patient teaching about pain management

The physiological and psychological stress of surgery and postoperative pain can leave patients more susceptible to infection and complications. The present study was designed to determine whether two interventions, patient teaching (PT) for pain management and relaxation/music (RM), reduced cortisol levels, an indicator of stress, following abdominal surgery. Patients (18-75 years) were randomly assigned to receive PT, RM, a combination of the two, or usual care; the 205 patients with both pre- and posttest cortisol values were analyzed. A 2 × 2 factorial design was used to compare groups for PT effects and RM effects. Stress was measured by salivary cortisol before and after 20-min tests of the interventions in the morning and afternoon of postoperative Day 2. Saliva was stimulated with lemon juice and analyzed with high-sensitivity salivary cortisol enzyme immunoassay. Comparisons using analysis of covariance (ANCOVA), controlling for baseline levels, showed no PT effect or RM effect on cortisol in the morning or afternoon. Post hoc ANCOVA showed no significant effects when intervention groups were compared to the control group. Although in previous studies, RM reduced pain and music reduced cortisol on Day 1, in the present study the cortisol response to surgery was not attenuated by PT or RM on Day 2. The RM intervention can be used for pain but needs to be further tested for effects on plasma cortisol in abdominal surgery patients on their first postoperative day.