Changes in buprenorphine waivered provider supply after Virginia Medicaid implements the addiction and recovery treatment services program and Medicaid expansion

BACKGROUND

Shortages of providers authorized to prescribe buprenorphine may limit access to buprenorphine, which studies have shown to be effective in the treatment of opioid use disorder (OUD).

OBJECTIVE

To examine whether two state Medicaid policies in Virginia-the Addiction and Recovery Treatment Services (ARTS) program in 2017, and Medicaid expansion in 2019-increased the number of buprenorphine waivered providers (BWP) in Virginia, compared to other southern states in the United States that did not expand Medicaid.

METHODS

The study population includes providers authorized to prescribe buprenorphine. We compute the number of BWP per 100,000 people for the study states, overall and for different waiver limits (30, 100 or 275). Using difference-in-difference regression models, we examine changes in BWP rates for Virginia relative to nonexpansion states in the US South between 2015 and 2020.

RESULTS

The rate of increase in BWP was higher in Virginia after implementation of ARTS and Medicaid expansion (148 %), compared to southern nonexpansion states over the same time period (115 %). Relative to nonexpansion states in the South, BWP with patient limits of 100 or 275 increased by 7 % in Virginia after ARTS implementation in 2017, and by an additional 22 % after Medicaid expansion in 2019 (p < 0.05 each).

CONCLUSIONS

The findings suggest that public policies that expand access to OUD treatment services-including buprenorphine treatment-may also increase the supply of providers authorized to prescribe buprenorphine, helping to alleviate shortages of BWP providers and further increasing access to care.

Postpartum medication for opioid use disorder outcomes associated with prenatal treatment and neighborhood-level social determinants

BACKGROUND

Opioid use disorder is a leading cause of death through the year postpartum.

OBJECTIVE

This study aimed to identify the association of neighborhood-level social determinants of health and prenatal opioid use disorder treatment receipt with the outcomes of medication treatment for opioid use disorder through the year postpartum among a cohort of birthing people.

STUDY DESIGN

This was a population-based retrospective cohort study that used state Medicaid claims and enrollment data for the 1690 individuals who delivered a live infant between July 1, 2016 and December 31, 2020 and received medication for opioid use disorder at delivery. The primary exposure was the state Health Opportunity Index, a composite measure of social determinants of health linked at the census-tract level. Secondary exposures included comprehensiveness of opioid use disorder treatment and duration of medication treatment for opioid use disorder received prenatally. Outcomes included the duration and continuity of postpartum medication treatment for opioid use disorder, operationalized as the time from delivery to the discontinuation of medication treatment for opioid use disorder, and percentage of days covered by medication treatment for opioid use disorder within the 12 months after delivery, respectively.

RESULTS

Within the study sample, 711 deliveries were to birthing people in the lowest state Health Opportunity Index tercile (indicating high burden of negative social determinants of health), 647 in the middle state Health Opportunity Index tercile, and 332 in the highest state Health Opportunity Index tercile. Using stepwise multivariable regression (Cox proportional hazards and negative binomial models) guided by a socioecological framework, prenatal receipt of more comprehensive opioid use disorder treatment and/or longer duration of prenatal medication treatment for opioid use disorder was associated with improved 1-year postpartum opioid use disorder treatment outcomes (duration and continuity of medication treatment for opioid use disorder). When the state Health Opportunity Index was added to the models, these significant associations remained stable, with the state Health Opportunity Index not demonstrating an association with the outcomes (duration hazard ratio, 1.39; 95% confidence interval, 0.551-3.512; continuity relative risk, 1.024; 95% confidence interval, 0.323-3.247).

CONCLUSION

Targeted efforts at expanding access to and quality of evidence-based opioid use disorder treatments for reproductive-age people across the life course should be prioritized within the spectrum of work aimed at eradicating disparities in pregnancy-related mortality.

Changes in lung epithelial cell volatile metabolite profile induced by pro-fibrotic stimulation with TGF-β1

Volatile organic compounds (VOCs) have shown promise as potential biomarkers in idiopathic pulmonary fibrosis. Measuring VOCs in the headspace ofin vitromodels of lung fibrosis may offer a method of determining the origin of those detected in exhaled breath. The aim of this study was to determine the VOCs associated with two lung cell lines (A549 and MRC-5 cells) and changes associated with stimulation of cells with the pro-fibrotic cytokine, transforming growth factor (TGF)-β1. A dynamic headspace sampling method was used to sample the headspace of A549 cells and MRC-5 cells. These were compared to media control samples and to each other to identify VOCs which discriminated between cell lines. Cells were then stimulated with the TGF-β1 and samples were compared between stimulated and unstimulated cells. Samples were analysed using thermal desorption-gas chromatography-mass spectrometry and supervised analysis was performed using sparse partial least squares-discriminant analysis (sPLS-DA). Supervised analysis revealed differential VOC profiles unique to each of the cell lines and from the media control samples. Significant changes in VOC profiles were induced by stimulation of cell lines with TGF-β1. In particular, several terpenoids (isopinocarveol, sativene and 3-carene) were increased in stimulated cells compared to unstimulated cells. VOC profiles differ between lung cell lines and alter in response to pro-fibrotic stimulation. Increased abundance of terpenoids in the headspace of stimulated cells may reflect TGF-β1 cell signalling activity and metabolic reprogramming. This may offer a potential biomarker target in exhaled breath in IPF.

Absence of Staphylococcus aureus in Wild Populations of Fish Supports a Spillover Hypothesis

Staphylococcus aureus is a human commensal and opportunistic pathogen that also infects other animals. In humans and livestock, where S. aureus is most studied, strains are specialized for different host species. Recent studies have also found S. aureus in diverse wild animals. However, it remains unclear whether these isolates are also specialized for their hosts or whether their presence is due to repeated spillovers from source populations. This study focuses on S. aureus in fish, testing the spillover hypothesis in two ways. First, we examined 12 S. aureus isolates obtained from the internal and external organs of a farmed fish. While all isolates were from clonal complex 45, genomic diversity indicates repeated acquisition. The presence of a φSa3 prophage containing human immune evasion genes suggests that the source was originally human. Second, we tested for S. aureus in wild fish that were isolated from likely sources. In particular, we sampled 123 brown trout and their environment at 16 sites in the remote Scottish Highlands with variable levels of exposure to humans, birds, and livestock. This screen found no S. aureus infection in any of the wild populations or their environment. Together, these results support that the presence of S. aureus in fish and aquaculture is due to spillover from humans rather than specialization. Given the trends of increasing fish consumption, a better understanding of the dynamics of S. aureus spillover in aquaculture will mitigate future risks to fish and human health. IMPORTANCE Staphylococcus aureus is a human and livestock commensal but also an important pathogen responsible for high human mortality rates and economic losses in farming. Recent studies show that S. aureus is common in wild animals, including fish. However, we do not know whether these animals are part of the normal host range of S. aureus or whether infection is due to repeated spillover events from true S. aureus hosts. Answering this question has implications for public health and conservation. We find support for the spillover hypothesis by combining genome sequencing of S. aureus isolates from farmed fish and screens for S. aureus in isolated wild populations. The results imply that fish are unlikely to be a source of novel emergent S. aureus strains but highlight the prominence of the spillover of antibiotic-resistant bacteria from humans and livestock. This may affect both future fish disease potential and the risk of human food poisoning.

Use of residential opioid use disorder treatment among Medicaid enrollees in nine states

INTRODUCTION

Residential treatment is a key component of the opioid use disorder care continuum, but research has not measured well the differences in its use across states at the enrollee level.

METHODS

This cross-sectional observational study used Medicaid claims data from nine states to document the prevalence of residential treatment for opioid use disorder and to describe the characteristics of patients receiving care. For each patient characteristic, chi-square and t-tests tested for differences in the distribution between individuals who did and did not receive residential care.

RESULTS

Among 491,071 Medicaid enrollees with opioid use disorder, 7.5 % were treated in residential facilities in 2019, though this number ranged widely (0.3-14.6 %) across states. Residential patients were more likely to be younger, non-Hispanic White, male, and living in an urban area. Although residential patients were less likely than those without residential care to be eligible for Medicaid through disability, diagnoses for comorbid conditions were more frequently observed among residential patients.

CONCLUSIONS

Results from this large, multi-state study add context to the ongoing national conversation around opioid use disorder treatment and policy, providing a baseline for future work.

Use of Home and Community-Based Services After Implementation of Medicaid Managed Long Term Services and Supports in Virginia

Many state Medicaid programs contract with managed care organizations to deliver long-term services and supports (LTSS) to seniors and persons with disabilities. Managed LTSS (MLTSS) programs are often intended to increase access to and utilization of home- and community-based services (HCBS), yet there are few empirical studies of their effects. In this retrospective observational study, we used administrative data from Virginia Medicaid to compare HCBS waiver enrollment and service utilization pre- and post-implementation of MLTSS. Compared to the prior fee-for-service system, Medicaid beneficiaries with long-term care needs who were enrolled in Virginia's MLTSS program were more likely to be enrolled in Virginia's 1915(c) waivers for home and community-based services. Further, the likelihood of using personal care increased by nearly 5%, and the likelihood of using respite care increased by about 10%. These findings are pertinent to ongoing policy changes that use private managed care organizations to deliver long-term services and supports to seniors and persons with disabilities. Policymakers in states and the federal government should note these initial increases in service use under Medicaid MLTSS, while supporting evaluations of the long-term impacts of MLTSS on HCBS use and beneficiary health and satisfaction.

Outpatient follow-up and use of medications for opioid use disorder after residential treatment among Medicaid enrollees in 10 states

BACKGROUND

Follow-up after residential treatment is considered best practice in supporting patients with opioid use disorder (OUD) in their recovery. Yet, little is known about rates of follow-up after discharge. The objective of this analysis was to measure rates of follow-up and use of medications for OUD (MOUD) after residential treatment among Medicaid enrollees in 10 states, and to understand the enrollee and episode characteristics that are associated with both outcomes.

METHODS

Using a distributed research network to analyze Medicaid claims data, we estimated the likelihood of 4 outcomes occurring within 7 and 30 days post-discharge from residential treatment for OUD using multinomial logit regression: no follow-up or MOUD, follow-up visit only, MOUD only, or both follow-up and MOUD. We used meta-analysis techniques to pool state-specific estimates into global estimates.

RESULTS

We identified 90,639 episodes of residential treatment for OUD for 69,017 enrollees from 2018 to 2019. We found that 62.5% and 46.9% of episodes did not receive any follow-up or MOUD at 7 days and 30 days, respectively. In adjusted analyses, co-occurring mental health conditions, longer lengths of stay, prior receipt of MOUD or behavioral health counseling, and a recent ED visit for OUD were associated with a greater likelihood of receiving follow-up treatment including MOUD after discharge.

CONCLUSIONS

Forty-seven percent of residential treatment episodes for Medicaid enrollees are not followed by an outpatient visit or MOUD, and thus are not following best practices.

Health plan switching and satisfaction in a Medicaid MLTSS program

OBJECTIVES

This paper examines (1) the rate of plan switching among beneficiaries enrolled in a Medicaid managed long-term services and supports (MLTSS) program in Virginia, (2) barriers that prevent beneficiaries from changing plans, and (3) the extent to which a change in plans is associated with greater satisfaction with the current health plan.

STUDY DESIGN

Survey data from a representative sample of 1048 members enrolled in Commonwealth Coordinated Care Plus, a Virginia Medicaid MLTSS program.

METHODS

The survey ascertained whether beneficiaries changed plans at the previous open enrollment period, whether they wanted to change plans but did not, and reasons for not following through with a plan change. Logistic regression analysis examined the association between the intention to change plans and satisfaction with the current health plan.

RESULTS

Seven percent of respondents changed plans during the previous open enrollment. However, twice as many respondents (15%) wanted to change plans but did not. The main reason for not changing plans was uncertainty about whether the new plan would meet their needs better than their current plan. Logistic regression analysis shows that an intention to change plans (realized or not) was associated with higher odds (3.5 times higher) of being dissatisfied with the current health plan compared with beneficiaries who had no intention to change plans.

CONCLUSIONS

Greater dissatisfaction after a recent plan change may indicate that these members have specific needs beyond the scope of services offered by managed care organizations.

Duration of medication treatment for opioid-use disorder and risk of overdose among Medicaid enrollees in 11 states: a retrospective cohort study

BACKGROUND AND AIMS

Medication for opioid use disorder (MOUD) reduces harms associated with opioid use disorder (OUD), including risk of overdose. Understanding how variation in MOUD duration influences overdose risk is important as health-care payers increasingly remove barriers to treatment continuation (e.g. prior authorization). This study measured the association between MOUD continuation, relative to discontinuation, and opioid-related overdose among Medicaid beneficiaries.

DESIGN

Retrospective cohort study using landmark survival analysis. We estimated the association between treatment continuation and overdose risk at 5 points after the index, or first, MOUD claim. Censoring events included death and disenrollment.

SETTING AND PARTICIPANTS

Medicaid programs in 11 US states: Delaware, Kentucky, Maryland, Maine, Michigan, North Carolina, Ohio, Pennsylvania, Virginia, West Virginia and Wisconsin. A total of 293 180 Medicaid beneficiaries aged 18-64 years with a diagnosis of OUD and had a first MOUD claim between 2016 and 2017.

MEASUREMENTS

MOUD formulations included methadone, buprenorphine and naltrexone. We measured medically treated opioid-related overdose within claims within 12 months of the index MOUD claim.

FINDINGS

Results were consistent across states. In pooled results, 5.1% of beneficiaries had an overdose, and 67% discontinued MOUD before an overdose or censoring event within 12 months. Beneficiaries who continued MOUD beyond 60 days had a lower relative overdose hazard ratio (HR) compared with those who discontinued by day 60 [HR = 0.39; 95% confidence interval (CI) = 0.36-0.42; P < 0.0001]. MOUD continuation was associated with lower overdose risk at 120 days (HR = 0.34; 95% CI = 0.31-0.37; P < 0.0001), 180 days (HR = 0.31; 95% CI = 0.29-0.34; P < 0.0001), 240 days (HR = 0.29; 95% CI = 0.26-0.31; P < 0.0001) and 300 days (HR = 0.28; 95% CI = 0.24-0.32; P < 0.0001). The hazard of overdose was 10% lower with each additional 60 days of MOUD (95% CI = 0.88-0.92; P < 0.0001).

CONCLUSIONS

Continuation of medication for opioid use disorder (MOUD) in US Medicaid beneficiaries was associated with a substantial reduction in overdose risk up to 12 months after the first claim for MOUD.

Follow-up after ED visits for opioid use disorder: Do they reduce future overdoses?

INTRODUCTION

Follow-up visits within 7 days of an emergency department (ED) visit related to opioid use disorder (OUD) is a key measure of treatment quality, but we know little about its protective effect on future opioid-related overdoses. The objective this paper is to examine the rate of 7-day follow-up after an OUD-related ED visit and the association with future overdoses.

METHODS

Retrospective analysis of Medicaid enrollees in 11 states that had an OUD-related ED visit from 2016 through 2018. Each state used Cox proportional hazard models to estimate the association between having a follow-up visit within 7 days of an OUD-related ED visit, and an overdose within 6 months of the ED visit. State analyses were pooled to generate global estimates using random effects meta-analysis.

RESULTS

Among 114,945 Medicaid enrollees with an OUD-related ED visit, 15.7% had a follow-up visit within 7 days. State-specific rates varied from 7.2% to 22.4% across the 11 states. Compared to those with no follow-up visit, enrollees with a follow-up visit were more likely to be female, non-Hispanic White, less likely to have had an overdose or other substance use disorder at the time of the ED visit, and much more likely to have been receiving MOUD treatment prior to the ED visit. Global estimates based on multivariate analysis showed that having a 7-day follow-up visit was associated with a lower likelihood of overdose within 6 months of the index ED visit (HR = 0.91, CI = 0.84, 0.99). However, states had considerable heterogeneity in this association, with only two states having statistically significant results.

CONCLUSIONS

Among Medicaid enrollees with OUD, having a follow-up visit 7 days after an ED visit is protective against fatal or nonfatal overdose within 6 months, although the association varies considerably across states. Although the association with future overdoses was relatively modest, both practitioners and policymakers should seek to increase the number of Medicaid enrollees with OUD who receive follow-up care within 7 days after an ED visit.

Circadian clock function does not require the histone methyltransferase MLL3

The circadian clock controls the physiological function of tissues through the regulation of thousands of genes in a cell-type-specific manner. The core cellular circadian clock is a transcription-translation negative feedback loop, which can recruit epigenetic regulators to facilitate temporal control of gene expression. Histone methyltransferase, mixed lineage leukemia gene 3 (MLL3) was reported to be required for the maintenance of circadian oscillations in cultured cells. Here, we test the role of MLL3 in circadian organization in whole animals. Using mice expressing catalytically inactive MLL3, we show that MLL3 methyltransferase activity is in fact not required for circadian oscillations in vitro in a range of tissues, nor for the maintenance of circadian behavioral rhythms in vivo. In contrast to a previous report, loss of MLL3-dependent methylation did not affect the global levels of H3K4 methylation in liver, indicating substantial compensation from other methyltransferases. Furthermore, we found little evidence of genomic repositioning of H3K4me3 marks. We did, however, observe repositioning of H3K4me1 from intronic regions to intergenic regions and gene promoters; however, there were no changes in H3K4me1 mark abundance around core circadian clock genes. Output functions of the circadian clock, such as control of inflammation, were largely intact in MLL3-methyltransferase-deficient mice, although some gene-specific changes were observed, with sexually dimorphic loss of circadian regulation of specific cytokines. Taken together, these observations indicate that MLL3-directed histone methylation is not essential for core circadian clock function; however, it may influence the inflammatory response.

The Distressed State of Primary Care in Virginia Pre-Medicaid Expansion and Pre-Pandemic

BACKGROUND

Primary care is crucial to the health of individuals and communities, but it faces numerous structural and systemic challenges. Our study assessed the state of primary care in Virginia to prepare for Medicaid expansion. It also provides insight into the frontline of health care prior to an unprecedented global COVID-19 pandemic.

METHODS

We surveyed 1622 primary care practices to understand organizational characteristics, scope of care, capacity, and organizational stress.

RESULTS

Practices (484) varied in type, ownership, location, and care for medically underserved and diverse patient populations. Most practices accepted uninsured and Medicaid patients. Practices reported a broad scope of care, including offering behavioral health and medication-assisted therapy for opioid addiction. Over half addressed social needs like transportation and unstable housing. One in three practices experienced a significant stress in 2019, prepandemic, and only 18.8% of practices anticipated a stress in 2020.

CONCLUSIONS

Primary care serves as the foundation of our health care system and is an essential service, but it is severely stressed, under-resourced, and overburdened in the best of times. Primary care needs strategic workforce planning, adequate access to resources, and financial investment to sustain its value and innovation.

Use of Medications for Treatment of Opioid Use Disorder Among US Medicaid Enrollees in 11 States, 2014-2018

Importance

There is limited information about trends in the treatment of opioid use disorder (OUD) among Medicaid enrollees.

Objective

To examine the use of medications for OUD and potential indicators of quality of care in multiple states.

Design, Setting, and Participants

Exploratory serial cross-sectional study of 1 024 301 Medicaid enrollees in 11 states aged 12 through 64 years (not eligible for Medicare) with International Classification of Diseases, Ninth Revision (ICD-9 or ICD-10) codes for OUD from 2014 through 2018. Each state used generalized estimating equations to estimate associations between enrollee characteristics and outcome measure prevalence, subsequently pooled to generate global estimates using random effects meta-analyses.

Exposures

Calendar year, demographic characteristics, eligibility groups, and comorbidities.

Main Outcomes and Measures

Use of medications for OUD (buprenorphine, methadone, or naltrexone); potential indicators of good quality (OUD medication continuity for 180 days, behavioral health counseling, urine drug tests); potential indicators of poor quality (prescribing of opioid analgesics and benzodiazepines).

Results

In 2018, 41.7% of Medicaid enrollees with OUD were aged 21 through 34 years, 51.2% were female, 76.1% were non-Hispanic White, 50.7% were eligible through Medicaid expansion, and 50.6% had other substance use disorders. Prevalence of OUD increased in these 11 states from 3.3% (290 628 of 8 737 082) in 2014 to 5.0% (527 983 of 10 585 790) in 2018. The pooled prevalence of enrollees with OUD receiving medication treatment increased from 47.8% in 2014 (range across states, 35.3% to 74.5%) to 57.1% in 2018 (range, 45.7% to 71.7%). The overall prevalence of enrollees receiving 180 days of continuous medications for OUD did not significantly change from the 2014-2015 to 2017-2018 periods (-0.01 prevalence difference, 95% CI, -0.03 to 0.02) with state variability in trend (90% prediction interval, -0.08 to 0.06). Non-Hispanic Black enrollees had lower OUD medication use than White enrollees (prevalence ratio [PR], 0.72; 95% CI, 0.64 to 0.81; P < .001; 90% prediction interval, 0.52 to 1.00). Pregnant women had higher use of OUD medications (PR, 1.18; 95% CI, 1.11-1.25; P < .001; 90% prediction interval, 1.01-1.38) and medication continuity (PR, 1.14; 95% CI, 1.10-1.17, P < .001; 90% prediction interval, 1.06-1.22) than did other eligibility groups.

Conclusions and Relevance

Among US Medicaid enrollees in 11 states, the prevalence of medication use for treatment of opioid use disorder increased from 2014 through 2018. The pattern in other states requires further research.

Medicaid participation among practitioners authorized to prescribe buprenorphine

INTRODUCTION

This study examines Medicaid participation among buprenorphine waivered providers in Virginia in 2019, with a particular focus on the prescribing differences between different physician specialties, nurse practitioners and physicians assistants (NP and PA).

METHODS

Secondary data sources include the 2019 DEA list of buprenorphine waivered prescribers, Virginia Medicaid claims for buprenorphine, physician characteristics from the Virginia Department of Health Professions, SAMHSA Behavioral Treatment Services Locator, and area level characteristics. This cross-sectional study is based on a linkage of Medicaid claims data to a list of Virginia practitioners authorized to prescribe buprenorphine in 2019. Using a two-part logistic regression, we assess prescriber license type and local area factors that are associated with: (1) the probability of prescribing buprenorphine to any Medicaid patients in 2019; (2) the number of Medicaid patients treated by each prescriber in 2019.

RESULTS

Adjusted odds ratios show that nurse practitioners with buprenorphine waivers are more likely to treat any Medicaid patients compared to physicians (odds ratio (OR), 2.016; p = 0.000). Among prescribers who treated any Medicaid patients, the probability of treating a large number of Medicaid patients was higher among nurse practitioners relative to physicians (OR, 2.869, p = 0.002). Medicaid participation was much higher among prescribers with patient limits of 100 and 275 compared to prescribers with patient limits of 30 (OR, 6.66, p = 0.000 and 29.40, p = 0.000, respectively).

CONCLUSIONS

State Medicaid programs have been at the forefront of addressing their state's opioid epidemic, including expanding access to buprenorphine treatment. This study provides evidence that targeted outreach efforts should include NP license types as well as physicians, and is consistent with prior studies showing that NP are especially important in filling treatment gaps for underserved areas and populations.

A longitudinal assessment of nicotine dependence, mental health, and attempts to quit Smoking: Evidence from waves 1-4 of the Population Assessment of Tobacco and Health (PATH) study

BACKGROUND

Adult smokers with symptoms of any mental illness (AMI) are highly dependent on nicotine and may face additional difficulty quitting smoking. While there is evidence that adult smokers with AMI have high dependence, there is insufficient evidence regarding the unique role that AMI may play in moderating the relationship between dependence and cessation outcomes over time.

METHODS

7290 current established adult smokers at Wave 1 (2013-2014) of the PATH Study also participated in data collection in Waves 2-4 (2014-2018). Linear probability models with individual-level random effects were fit to the data, modeling associations between AMI, nicotine dependence, and the 1) likelihood of achieving cessation during the study period, 2) making a cessation attempt within the previous 12 months, and 3) log of past 30-day total consumption of cigarettes.

RESULTS

Adults who experienced both AMI symptoms and high dependence were 4.7 percentage points (PP) less likely to achieve cessation at any point during the study period (p < 0.01) and smoked more cigarettes per month (β = 0.214, p < 0.05) than adults with AMI who were not highly dependent, despite being as likely to attempt to quit. Adults with AMI who were not highly dependent were 4.6 PP more likely to report a quit attempt and 1.6 PP more likely to achieve cessation than those with neither AMI nor high dependence.

CONCLUSIONS

Adults with AMI are particularly affected by the burden of tobacco use, in part because of the likely interaction between nicotine dependence and AMI. Tobacco control efforts that focus on this interplay may provide an opportunity to better target interventions for this vulnerable population.

Genome-wide effect of pulmonary airway epithelial cell-specific Bmal1 deletion

Pulmonary airway epithelial cells (AECs) form a critical interface between host and environment. We investigated the role of the circadian clock using mice bearing targeted deletion of the circadian gene brain and muscle ARNT-like 1 (Bmal1) in AECs. Pulmonary neutrophil infiltration, biomechanical function, and responses to influenza infection were all disrupted. A circadian time-series RNA sequencing study of laser-captured AECs revealed widespread disruption in genes of the core circadian clock and output pathways regulating cell metabolism (lipids and xenobiotics), extracellular matrix, and chemokine signaling, but strikingly also the gain of a novel rhythmic transcriptome in Bmal1-targeted cells. Many of the rhythmic components were replicated in primary AECs cultured in air-liquid interface, indicating significant cell autonomy for control of pulmonary circadian physiology. Finally, we found that metabolic cues dictate phasing of the pulmonary clock and circadian responses to immunologic challenges. Thus, the local circadian clock in AECs is vital in lung health by coordinating major cell processes such as metabolism and immunity.-Zhang, Z. Hunter, L., Wu, G., Maidstone, R., Mizoro, Y., Vonslow, R., Fife, M., Hopwood, T., Begley, N., Saer, B., Wang, P., Cunningham, P., Baxter, M., Durrington, H., Blaikley, J. F., Hussell, T., Rattray, M., Hogenesch, J. B., Gibbs, J., Ray, D. W., Loudon, A. S. I. Genome-wide effect of pulmonary airway epithelial cell-specific Bmal1 deletion.

A diagnostic evaluation of a molecular assay used for testing and treating anorectal chlamydia and gonorrhoea infections at the point-of-care in Papua New Guinea

OBJECTIVES

Papua New Guinea has among the highest prevalences of sexually transmissible infections (STIs) globally with no services able to accurately test for anorectal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections. Here we prospectively evaluated the diagnostic performance of a molecular CT/NG assay used at the point-of-care (POC) with the aim of enhancing anorectal STI screening and same-day treatment.

METHODS

Men who have sex with men, transgender women and female sex workers taking part in Papua New Guinea's first large-scale biobehavioural study were enrolled and asked to provide a self-collected anorectal swab for POC GeneXpert CT/NG testing. Same-day treatment was offered if positive. A convenience sample of 396 unique and randomly selected samples were transported to Australia for comparison using the Cobas 4800 CT/NG test (Roche Molecular Diagnostics, Pleasanton, CA, USA).

RESULTS

A total of 326 samples provided valid results by Cobas whereas 70 samples provided invalid results suggesting inhibition. The positive, negative and overall percentage agreements of GeneXpert CT/NG for the detection of C. trachomatis were 96.7% (95% CI 92.3%-98.9%), 95.5% (95% CI 91.3%-98.0%) and 96.0% (95% CI 93.3%-97.8%), and for N. gonorrhoeae were 93.0% (95% CI 86.1%-97.1%), 100.0% (95% CI 98.3%-100.0%) and 97.8% (95% CI 95.6%-99.1%), respectively.

CONCLUSIONS

The overall rate of agreement between the GeneXpert and Cobas CT/NG assays was high with 96.0% for C. trachomatis and 97.8% for N. gonorrhoeae. Results from this study data suggest that the GeneXpert CT/NG assay is suitable for testing self-collected anorectal specimens at the POC and that same-day treatment was feasible.

Structural barriers to South African volunteer home-based caregivers providing quality care: the need for a policy for caregivers not affiliated to primary healthcare clinics

Community home-based care (CHBC) is a critical component of non-formal care in communities in Africa that have a high prevalence of HIV and tuberculosis (TB). Community carers consisting primarily of volunteers are critical role players in African healthcare systems and particularly in South Africa's strategy to fight HIV and AIDS. This paper explores the structural barriers volunteer caregivers need to overcome to provide quality CHBC. The researchers used two focus group discussions with key informants (each with four participants), and semi-structured interviews with six key informants to collect data relating to the meaning of quality CHBC. The data were coded using Tesch's data analysis technique. A major theme that emerged from the results was "Addressing structural challenges to improve the quality of CHBC". Subthemes underpinning this theme were: 1) lack of standardised training of volunteer caregivers; 2) the need for a scope of practice, parameters and legal boundaries; 3) lack of monitoring and evaluation (M&E) of CHBC; and 4) the importance of mentoring and supervision in CHBC. CHBC policy should address the need for standardised training programmes for caregivers, so that they are equipped with multiple skills. Furthermore CHBC policy must emphasise mentoring as well as M&E to encourage quality care. Finally, the policy should provide a clear scope of practice for caregivers to regulate their competencies and boundaries.

Impact of health reform on young adult prescription medication utilization

OBJECTIVES

To assess the impact of the Affordable Care Act dependent coverage provision on outpatient prescription expenditures among young adults and to characterize medication types that are prescribed for young adults.

STUDY DESIGN

Quasi-experimental.

METHODS

Using data from the Medical Expenditure Panel Survey from 2007 to 2009 and 2011 to 2013, difference-in-differences (DID) analyses estimated the provision's impact among young adults aged 19 to 25 years versus those aged 26 to 34 years. Five outcomes related to prescription medication access and utilization were evaluated, including whether young adults were unable to get necessary medications in the past year due to cost and whether there were changes in total, out-of-pocket (OOP), and private expenditures and the share of total expenditures paid OOP. DID analyses were also carried out for medication expenditures by class.

RESULTS

There were a total of 19,165 young adults aged 19 to 25 years and 23,892 aged 26 to 34 years. After adjusting for demographic and socioeconomic factors, provision implementation (DID coefficient P ≤.05) was associated with an increase in total expenditures (by 3.8 percentage points), including those paid by private insurance (7.6 percentage points), and decreases in OOP expenditures and the share of total expenditures paid OOP (4.4 and 1.2 percentage points, respectively). Commonly used medications were anti-infectives, central nervous system agents, and hormones. Expenditures significantly increased for anti-infectives and decreased for hormones and psychotherapeutics.

CONCLUSIONS

The dependent coverage provision was associated with an increase in prescription medication expenditures, especially for anti-infectives, among young adults. The amount of expenditures paid by private insurers increased, whereas they decreased for OOP spending.

Multi-centre field evaluation of the performance of the Trinity Biotech Uni-Gold HIV 1/2 rapid test as a first-line screening assay for gay and bisexual men compared with 4th generation laboratory immunoassays

BACKGROUND

The Trinity Biotech Uni-Gold HIV test (Uni-Gold) is often used as a supplementary rapid test in testing algorithms.

OBJECTIVE

To evaluate the operational performance of the Uni-Gold as a first-line screening test among gay and bisexual men (GBM) in a setting where 4th generation HIV laboratory assays are routinely used.

STUDY DESIGN

We compared the performance of Uni-Gold with conventional HIV serology conducted in parallel among GBM attending 22 testing sites. Sensitivity was calculated separately for acute and established infection, defined using 4th generation screening Ag/Ab immunoassay (EIA) and Western blot results. Previous HIV testing history and results of supplementary 3rd generation HIV Ab EIA, and p24 antigen EIA were used to further characterise cases of acute infection.

RESULTS

Of 10,793 specimens tested with Uni-Gold and conventional serology, 94 (0.90%, 95%CI:0.70-1.07) were confirmed as HIV-positive by conventional serology, and 37 (39.4%) were classified as acute infection. Uni-Gold sensitivity was 81.9% overall (77/94, 95%CI:72.6-89.1); 56.8% for acute infection (21/37, 95%CI:39.5-72.9) and 98.2% for established infection (56/57, 95%CI:90.6-100.0). Of 17 false non-reactive Uni-Gold results, 16 were acute infections, and of these seven were p24 antigen reactive but antibody negative. Uni-Gold specificity was 99.9% (10,692/10,699, 95%CI:99.9-100.0), PPV was 91.7% (95%CI:83.6-96.6) and NPV was 99.8% (95%CI:99.7-99.9), respectively.

CONCLUSIONS

In this population, Uni-Gold had good specificity and sensitivity was high for established infections when compared to 4th generation laboratory assays, however sensitivity was lower in acute infections. Where rapid tests are used in populations with a high proportion of acute infections, additional testing strategies are needed to detect acute infections.

Trends in Hospital Inpatient Admissions Following Early Medicaid Expansion in California

The Affordable Care Act is expected to profoundly affect inpatient hospital utilization, both as a result of expansions in insurance coverage as well as payment and delivery system reforms. The objective of this study is to examine changes in inpatient utilization between 2010 and 2013 in California, following a Medicaid expansion and implementation of the Delivery System Reform Incentive Payment program. Findings show that between 2010 and 2013: (a) the overall number of inpatient admissions increased, mainly because an increase in Medicaid admissions exceeded the decrease in uninsured admissions; (b) the number of preventable admissions did not change; (c) preventable admissions decreased at safety net hospitals that received Delivery System Reform Incentive Payment funds relative to other safety net hospitals. The results suggest that delivery system reforms may help offset the upward pressures on utilization and costs due to coverage expansions.

Home-based Reach-to-Grasp training for people after stroke is feasible: a pilot randomised controlled trial

Objective:

To determine feasibility of a randomised controlled trial (RCT) of home-based Reach-to-Grasp training after stroke.

Design:

single-blind parallel group RCT.

Participants:

Residual arm deficit less than 12 months post-stroke.

Interventions:

Reach-to-Grasp training in 14 one-hour therapist’s visits over 6 weeks, plus one hour self-practice per day (total 56 hours). Control: Usual care.

Main Measures:

Action Research Arm Test (ARAT), Wolf Motor Function Test (WMFT), pre-randomisation, 7, 12, 24 weeks post-randomisation.

Results:

Forty-seven participants (Reach-to-Grasp=24, usual care=23) were randomised over 17 months. Reach-to-Grasp participants received a median (IQR) 14 (13,14) visits, and performed 157 (96,211) repetitions per visit; plus 30 minutes (22,45) self-practice per day. Usual care participants received 10.5 (5,14) therapist visits, comprising 38.6 (30,45) minutes of arm therapy with 16 (6,24) repetitions of functional tasks per visit. Median ARAT scores in the reach-to-grasp group were 8.5 (3.0,24.0) at baseline and 14.5 (3.5,26.0) at 24 weeks compared to median of 4 at both time points (IQR: baseline (3.0,14.0), 24 weeks (3.0,30.0)) in the usual-care group. Median WMFT tasks completed at baseline and 24 weeks were 6 (3.0,11.5) and 8.5 (4.5,13.5) respectively in the reach-to-grasp group and 4 (3.0,10.0), 6 (3.0,14.0) in the usual care group. Incidence of arm pain was similar between groups. The study was stopped before 11 patients reached the 24 weeks assessment.

Conclusions:

An RCT of home-based Reach-to-Grasp training after stroke is feasible and safe. With ARAT being our preferred measure it is estimated that 240 participants will be needed for a future two armed trial.

Patient perceptions of clinician self-management support for chronic conditions

OBJECTIVES

This study investigates the extent to which patients with chronic conditions perceive that they are receiving clinician self-management support for their conditions, and whether this perceived support is associated with self-management behaviors, such as exercise and taking medications for chronic conditions.

STUDY DESIGN

A survey of a representative sample of current and retired autoworkers and their spouses, all younger than 65 years, who are or were employed by the 3 major US automobile manufacturing companies.

METHODS

An index of self-management support was constructed from 3 survey questions that asked respondents with chronic conditions about their perceived level of self-management support from clinicians. Multivariate regression analysis examined: a) the extent to which perceived self-management support was influenced by patient engagement and other patient factors, and b) whether self-management support and patient engagement were associated with self-management behaviors, including exercise, use of certain preventive care services, and taking medications for specific chronic conditions.

RESULTS

Most patients with chronic conditions reported that their clinicians provide some degree of self-management support of their chronic conditions. The extent to which a patient is engaged with their medical care-such as taking notes or bringing along friends or relatives to ask questions-is strongly associated with perceptions that they receive self-management support from their clinicians. Receiving clinician self-management support was modestly associated with most self-management behaviors.

CONCLUSIONS

Receiving self-management support from clinicians can positively influence patient self-management of chronic conditions, but patient engagement with their own healthcare is crucial to whether patients perceive they are receiving such support. Moreover, while patient engagement may influence whether self-management support is given, the study results suggest that self-management support may be just as effective with patients who are less engaged with their healthcare.

Effect of testing experience and profession on provider acceptability of rapid HIV testing after implementation in public sexual health clinics in Sydney

OBJECTIVES

Rapid HIV testing (RHT) is well established in many countries, but it is new in Australia since a policy change in 2011. We assessed service provider acceptability of RHT before and after its implementation in four Sydney public sexual health clinics.

METHODS

Service providers were surveyed immediately after training in RHT and again 6-12 months later. Differences in mean scores between survey rounds were assessed via t-tests, with stratification by profession and the number of tests performed.

RESULTS

RHT was rated as highly acceptable among staff at baseline and acceptability scores improved between survey rounds. Belief in being sufficiently skilled and experienced to perform RHT (P = 0.004) and confidence in the delivery of nonreactive results increased (P = 0.007), while the belief that RHT was disruptive declined (P = 0.001). Acceptability was higher for staff who had performed a greater number of tests regarding comfort with their role in RHT (P = 0.004) and belief that patients were satisfied with RHT (P = 0.007). Compared with nurses, doctors had a stronger preference for a faster rapid test (P = 0.027) and were more likely to agree that RHT interfered with consultations (P = 0.014).

CONCLUSIONS

Differences in responses between professions may reflect differences in staff roles, the type of patients seen by staff and the model of testing used, all of which may affect the number of tests performed by staff. These findings may inform planning for how best to implement RHT in clinical services.

Patient engagement during medical visits and smoking cessation counseling

IMPORTANCE

Increased patient engagement with health and health care is considered crucial to increasing the quality of health care and patient self-management of health.

OBJECTIVE

To examine whether patients with high levels of engagement during medical encounters are more likely to receive advice and counseling about smoking compared with less engaged patients.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional survey using multivariate regression analysis of 8656 current and retired autoworkers and their spouses younger than 65 years who are or were employed by the 3 major US auto companies.

MAIN OUTCOMES AND MEASURES

Clinician advice and counseling about smoking; patients who tried to quit smoking.

RESULTS

Among 1904 current smokers, 58.5% of those who were more highly engaged during medical encounters were counseled by clinicians about specific strategies and methods to stop smoking, compared with 45.4% of patients who were less engaged. Patient engagement and being advised by clinicians to stop smoking had independent effects on smoking cessation efforts by patients. Accounting for differences in other patient characteristics, patients with high engagement levels were more likely to try to stop smoking compared with patients with lower engagement (odds ratio, 1.62; P < .01). Patients who were both highly engaged and had received counseling from clinicians were the most likely to try to stop smoking (74.6%) while patients with low engagement who did not receive counseling were the least likely (46.0%). Nevertheless, counseling is still effective among even less engaged patients; 60.4% of smokers with low engagement who received counseling tried to quit smoking in the past year compared with 46.0% who did not receive counseling.

CONCLUSIONS AND RELEVANCE

The study results provide evidence that clinicians respond differently to patients who are highly engaged during medical encounters than they do to less engaged patients in terms of smoking cessation advice. Clinicians should not assume that low patient engagement and greater passivity during medical encounters is evidence of unwillingness to quit. The results show that smoking cessation counseling is associated with a higher likelihood of quit attempts even for patients who are less engaged during medical encounters.

Arachidonic acid metabolism in the human placenta: identification of a putative lipoxygenase

Arachidonic acid (ARA) metabolites maintain pregnancy and control parturition. We generated a network of 77 proteins involved in placental ARA metabolism to identify novel proteins in this pathway. We identified a long pathway within this network which showed that secretory and cytosolic phospholipase A2 proteins act in concert. The functions of all network proteins expressed in the placental decidua were determined by database searches. Thus ARA metabolism was linked to carbohydrate metabolism. One protein, transmembrane protein 62 (TMEM62), expressed in decidua was previously uncharacterized, and was identified as a putative lipoxygenase. TMEM62 may play a role in pregnancy and/or parturition.

Trends in the financial burden of medical care for nonelderly adults with diabetes, 2001 to 2009

OBJECTIVES

To examine trends in out-of-pocket spending and the financial burden of care for persons with diabetes between 2001 and 2009, and to examine whether these trends are consistent with trends in access to prescription drugs and utilization of hospital services.

STUDY DESIGN AND METHODS

Data are from the 2001 to 2009 Medical Expenditure Panel Survey (MEPS). The sample includes persons aged 18 to 64 years with diagnosed diabetes. The primary outcome variable is the percent of people with out-of-pocket spending on insurance premiums and services that exceed 10% of family income. Secondary outcome measures include the percent with diabetes-related prescription drug use, perceived access to prescription drugs, hospital inpatient stays, and emergency department use in the past 12 months. Multiple regression analysis is used to control for changes in comorbid chronic conditions and other characteristics of persons with diabetes.

RESULTS

Both out-of-pocket spending and the percent with high financial burden decreased markedly for persons with diabetes between 2001 to 2003 and 2007 to 2009. The decrease in spending was driven primarily by a decrease in spending on prescription drugs, including diabetes-related prescriptions. The shift from brand name drugs to generics accounts for much of this decline, although decreases in out-of-pocket spending for both brand name and generic drugs also contributed. During the same period, utilization of and access to diabetes-related prescriptions increased, and hospital use decreased.

CONCLUSIONS

Although the prevalence of diagnosed diabetes continues to increase, treatment is becoming more affordable, especially prescription drugs. This may offset some of the costs to the healthcare system of higher prevalence by reducing complications of uncontrolled diabetes that result in more costly hospital use.

Organ donation following the circulatory determination of death (DCD): an audit of donation and outcomes following renal transplantation

Organ Donation following the Circulatory determination of Death was introduced in Beaumont Hospital during 2011. The Intensive Care Society of Ireland formally endorsed a national DCD clinical practice guideline in 2012. This retrospective audit covers a 2-year period during which eleven patients were considered suitable for DCD and where consent was obtained. Nine patients died within the ninety-minute period following the withdrawal of life sustaining therapies and subsequently donated organs (82%). Eighteen kidneys were recovered and seventeen patients received renal transplants--one patient received a nephron-dosing dual renal transplant. Lungs were recovered on two occasions and one patient received a lung transplant. Heart valves were recovered on one occasion. To date sixteen of seventeen recipient patients have functioning renal transplants (94%). In conclusion, this model of deceased donation has proven acceptable to families, nursing and medical staff and the outcomes reported are consistent with international best practice.

Medical cost burdens among nonelderly adults with asthma

OBJECTIVES

We used the 2003-2009 Medical Expenditure Panel Survey to evaluate average annual total and out-of-pocket expenditures by nonelderly adults with asthma.

STUDY DESIGN

We divided patients diagnosed with asthma into 4 groups, based on whether or not they had had an asthma attack in the previous year (a crude marker for disease severity) and whether or not they reported using treatment for their asthma.

METHODS

For each group we calculated total and out-of-pocket average annual spending for hospital inpatient, hospital outpatient, emergency department, and physician office care, as well as for prescription drugs. These averages were adjusted to account for differences in respondents' overall health (presence of other co-morbidities, self-reported health status, and self-reported activity limitations), sociodemographic characteristics (age, sex, race/ethnicity, income), and insurance status.

RESULTS

We found that among the 4 groups, those who were receiving treatment but continued to experience asthma attacks had the highest total and out-of-pocket expenditures in all categories, consistent with their likely higher illness severity. However, patients who reported receiving treatment and did not experience attacks also reported relatively high adjusted total and out-of-pocket expenditures-most notably $536 per year out of pocket for prescription medications and $231 per year out of pocket for physician office visits. After adjustment, about the same proportion of patients in these 2 groups (13.5% who did not get treated and had attacks, and 13.8% who did get treated and avoided attacks) reported high financial burden.

CONCLUSIONS

Patients may experience financial challenges to appropriate self-management of asthma, even when they are able to avoid exacerbations.

Retrospective case note review of patients brought to Ipswich emergency department under mental health emergency examination orders: does intoxication alter outcome?

OBJECTIVE

To alter staff perceptions, and to examine alternative management processes for intoxicated patients brought to Ipswich ED under mental health emergency examination orders by comparing disposition outcomes with non-intoxicated patients.

METHODS

Consultation-Liaison mental health nursing staff completed surveys on all patients assessed under emergency examination orders over a 6 month period in 2008. Patients were classified as intoxicated if they recorded alcometer readings of greater than 0.05%, or self-reported drug use during the events leading to their transport to the ED. Outcomes were retrospectively collated with entries in Clinical Liaison nursing logbooks. Outcome measures recorded were rates of admission, outpatient referrals to the Integrated Mental Health Service, follow up by other community services or no follow up. Differences in outcomes for intoxicated and non-intoxicated patient groups were tested for significance using χ(2) or Fisher's exact test.

RESULTS

One hundred and sixty-eight cases were included in the audit. No cases were excluded. Sixty patients were identified as intoxicated. The age and sex distributions were similar between intoxicated and non-intoxicated patients. There were no significant differences in admission or referral rates. The average length of assessment time in the ED was longer in the intoxicated group.

DISCUSSION

This audit showed similar outcomes for both patient groups contrary to the perceptions expressed by ED staff in informal surveys. The admission and referral rate for both groups indicate they are an at-risk population. The admission rate of 16% has led to this department negotiating alternative accommodation for patients while they sober up.

Safety-net providers in some US communities have increasingly embraced coordinated care models

Safety-net organizations, which provide health services to uninsured and low-income people, increasingly are looking for ways to coordinate services among providers to improve access to and quality of care and to reduce costs. In this analysis, a part of the Community Tracking Study, we examined trends in safety-net coordination activities from 2000 to 2010 within twelve communities in the United States and found a notable increase in such activities. Six of the twelve communities had made formal efforts to link uninsured people to medical homes and coordinate care with specialists in 2010, compared to only two communities in 2000. We also identified key attributes of safety-net coordinated care systems, such as reliance on a medical home for meeting patients' primary care needs, and lingering challenges to safety-net integration, such as competition among hospitals and community health centers for Medicaid patients.

Ghrelin and cancer

Ghrelin is a peptide hormone that was originally isolated from the stomach as the endogenous ligand for the growth hormone secretagogue receptor (GHSR). Ghrelin has many functions, including the regulation of appetite and gut motility, growth hormone release from the anterior pituitary and roles in the cardiovascular and immune systems. Ghrelin and its receptor are expressed in a number of cancers and cancer cell lines and may play a role in processes associated with cancer progression, including cell proliferation, apoptosis, and cell invasion and migration.

Ghrelin axis genes, peptides and receptors: recent findings and future challenges

The ghrelin axis consists of the gene products of the ghrelin gene (GHRL), and their receptors, including the classical ghrelin receptor GHSR. While it is well-known that the ghrelin gene encodes the 28 amino acid ghrelin peptide hormone, it is now also clear that the locus encodes a range of other bioactive molecules, including novel peptides and non-coding RNAs. For many of these molecules, the physiological functions and cognate receptor(s) remain to be determined. Emerging research techniques, including proteogenomics, are likely to reveal further ghrelin axis-derived molecules. Studies of the role of ghrelin axis genes, peptides and receptors, therefore, promises to be a fruitful area of basic and clinical research in years to come.

Semiorganics: A New Class of Nlo Materials

Recent results indicate that certain organic molecules whose electronic structures are characterized by extended pi-molecular orbitals can exhibit significant second and third order nonlinear optical (NLO) effects [1]. Unfortunately, this same arrangement which leads to the NLO effects, can also result in essentially one-dimensional bonding coordination. This in turn means that crystals grown from these materials do not readily form good three-dimensional optical-quality crystals, but rather tend to form needles. In addition, pure organic crystals are usually bonded by weak van der Waals forces, often resulting in poor mechanical properties. Indeed, organic impurities are frequently incorporated into these systems during crystallization resulting in poor crystallinity, spurious absorptions, and low damage thresholds. This is particularly true in the case of polymeric NLO materials, where impurities result from the polymerization steps and/or starting materials.

Potential organ donor audit in Ireland

As increasing demand for organs is a challenge for transplant services worldwide it is essential to audit the process of organ donation. To address this, a national audit of potential organ donors was undertaken across hospitals with Intensive Care Units (N = 36). Questionnaires were returned on all patients (n = 2073) who died in these units from 1/9/07-31/8/08; 200 (10%) of these patients were considered for Brain Stem Testing (BST), 158 patients (79%) were diagnosed Brain Stem Dead (BSD) and 138 patients (87%) became potential donors. Consent for donation was given by 92 (69%) next of kin and 90 potential donors (65%) became organ donors. There was no evidence of a large number of potential organ donors being missed. Recommendations included completion of BSTs on all appropriate patients, development of support on BST, referral of all BSD patients to the Organ Procurement Service; enhanced co-ordination within hospitals and sustained information/education campaigns.

Differences in sexual dimorphism among four gazelle taxa (Gazella spp.) in the Middle East

Abstract

Sexual selection can lead to sexual dimorphism, where elaborated traits used in mate attraction or weaponry are more expressed in the male sex. The degree of sexual dimorphism, however, is known to vary even among closely related taxa. Here we examined sexual dimorphism in horn length and three measures related to body size (body weight, shoulder height, and neck circumference) in four gazelle taxa, representing at least three species, i.e. Dorcas gazelle (G. dorcas), Sand gazelle (G. subgutturosa marica) and Mountain gazelle (G. gazella). The latter is represented by two distinctive phenotypes maintained and bred at the King Khalid Wildlife Research Centre in Saudi Arabia. We describe marked differences in sexual dimorphism among taxa. For example, the difference in sexually dimorphic horn development was driven primarily by females exhibiting pronounced differences in horn development. We discuss how divergent mating systems, and group sizes affect these differences among the examined taxa, with more competition in larger groups probably promoting the evolution of larger horns in females, thereby leading to less sexual dimorphism.