Combination interventions for Hepatitis C and Cirrhosis reduction among people who inject drugs: An agent-based, networked population simulation experiment

Hepatitis C virus (HCV) infection is endemic in people who inject drugs (PWID), with prevalence estimates above 60% for PWID in the United States. Previous modeling studies suggest that direct acting antiviral (DAA) treatment can lower overall prevalence in this population, but treatment is often delayed until the onset of advanced liver disease (fibrosis stage 3 or later) due to cost. Lower cost interventions featuring syringe access (SA) and medically assisted treatment (MAT) have shown mixed results in lowering HCV rates below current levels. However. little is known about the potential cumulative effects of combining DAA and MAT treatment. While simulation experiments can reveal likely long-term effects, most prior simulations have been performed on closed populations of model agents—a scenario quite different from the open, mobile populations known to most health agencies. This paper uses data from the Centers for Disease Control’s National HIV Behavioral Surveillance project, IDU round 3, collected in New York City in 2012 to parameterize simulations of open populations. To test the effect of combining DAA treatment with SA/MAT participation, multiple, scaled implementations of the two intervention strategies were simulated. Our results show that, in an open population, SA/MAT by itself has only small effects on HCV prevalence, while DAA treatment by itself can lower both HCV and HCV-related advanced liver disease prevalence. More importantly, the simulation experiments suggest that combinations of the two strategies can, when implemented together and at sufficient levels, dramatically reduce HCV incidence. We conclude that adopting SA/MAT implementations alongside DAA interventions can play a critical role in reducing the long-term consequences of ongoing HCV infection.

Unstable Inflation Causing Injury. Insight from Prone Position and Paired Computed Tomography Scans

RATIONALE

It remains unclear how prone positioning improves survival in acute respiratory distress syndrome. Using serial computed tomography (CT), we previously reported that "unstable" inflation (i.e., partial aeration with large tidal density swings, indicating increased local strain) is associated with injury progression.

OBJECTIVES

We prospectively tested whether prone position contains the early propagation of experimental lung injury by stabilizing inflation.

METHODS

Injury was induced by tracheal hydrochloric acid in rats; after randomization to supine or prone position, injurious ventilation was commenced using high tidal volume and low positive end-expiratory pressure. Paired end-inspiratory (EI) and end-expiratory (EE) CT scans were acquired at baseline and hourly up to 3 hours. Each sequential pair (EI, EE) of CT images was superimposed in parametric response maps to analyze inflation. Unstable inflation was then measured in each voxel in both dependent and nondependent lung. In addition, five pigs were imaged (EI and EE) prone versus supine, before and (1 hour) after hydrochloric acid aspiration.

MEASUREMENTS AND MAIN RESULTS

In rats, prone position limited lung injury propagation and increased survival (11/12 vs. 7/12 supine; P = 0.01). EI-EE densities, respiratory mechanics, and blood gases deteriorated more in supine versus prone rats. At baseline, more voxels with unstable inflation occurred in dependent versus nondependent regions when supine (41 ± 6% vs. 18 ± 7%; P < 0.01) but not when prone. In supine pigs, unstable inflation predominated in dorsal regions and was attenuated by prone positioning.

CONCLUSIONS

Prone position limits the radiologic progression of early lung injury. Minimizing unstable inflation in this setting may alleviate the burden of acute respiratory distress syndrome.

Clemastine effects in rat models of a myelination disorder

BackgroundPelizaeus Merzbacher disease (PMD) is a dysmyelinating disorder of the central nervous system caused by impaired differentiation of oligodendrocytes. This study was prompted by findings that antimuscarinic compounds enhance oligodendrocyte differentiation and remyelination in vitro. One of these compounds, clemastine fumarate, is licensed for treatment of allergic conditions. We tested whether clemastine fumarate can promote myelination in two rodent PMD models, the myelin-deficient and the PLP transgenic rat.MethodsPups were treated with daily injections of clemastine (10-30 mg/kg/day) on postnatal days 1-21. Neurologic phenotypes and myelination patterns in the brain, optic nerves, and spinal cords were assessed using histological techniques.ResultsNo changes in neurological phenotype or survival were observed even at the highest dose of clemastine. Postmortem staining with Luxol fast blue and myelin basic protein immunohistochemistry revealed no evidence for improved myelination in the CNS of treated rats compared to vehicle-treated littermates. Populations of mature oligodendrocytes were unaffected by the treatment.ConclusionThese results demonstrate lack of therapeutic effect of clemastine in two rat PMD models. Both models have rapid disease progression consistent with the connatal form of the disease. Further studies are necessary to determine whether clemastine bears a therapeutic potential in milder forms of PMD.

Lung Metabolism and Inflammation during Mechanical Ventilation; An Imaging Approach

Acute respiratory distress syndrome (ARDS) is a major cause of mortality in critically ill patients. Patients are currently managed by protective ventilation and alveolar recruitment using positive-end expiratory pressure (PEEP). However, the PEEP's effect on both pulmonary metabolism and regional inflammation is poorly understood. Here, we demonstrate the effect of PEEP on pulmonary anaerobic metabolism in mechanically ventilated injured rats, using hyperpolarized carbon-13 imaging. Pulmonary lactate-to-pyruvate ratio was measured in 21 rats; 14 rats received intratracheal instillation of hydrochloric-acid, while 7 rats received sham saline. 1 hour after acid/saline instillation, PEEP was lowered to 0 cmH2O in 7 injured rats (ZEEP group) and in all sham rats; PEEP was continued in the remaining 7 injured rats (PEEP group). Pulmonary compliance, oxygen saturation, histological injury scores, ICAM-1 expression and myeloperoxidase expression were measured. Lactate-to-pyruvate ratio progressively increased in the dependent lung during mechanical ventilation at ZEEP (p < 0.001), but remained unchanged in PEEP and sham rats. Lactate-to-pyruvate ratio was correlated with hyaline membrane deposition (r = 0.612), edema severity (r = 0.663), ICAM-1 (r = 0.782) and myeloperoxidase expressions (r = 0.817). Anaerobic pulmonary metabolism increases during lung injury progression and is contained by PEEP. Pulmonary lactate-to-pyruvate ratio may indicate in-vivo neutrophil activity due to atelectasis.

Injection-related hepatitis C serosorting behaviors among people who inject drugs: An urban/rural comparison

Although previous research has focused on injection drug use behaviors in both urban and rural settings, few have drawn direct comparisons between adjacent rural and urban areas. Using data from the National HIV Behavioral Surveillance study as well as original data collected in a similar fashion, we compare the risk behaviors of people who inject drugs (PWID) in San Juan, Puerto Rico, with those of PWID in nearby rural areas. Specifically, we examine whether one's own hepatitis C (HCV) infection status can be used to predict whether one asked their most recent co-injection partner about their HCV status. Acquiring such information allows injectors to seek out co-injection partners of concordant status as a way to minimize the risk of viral transmission. Results indicate that urban PWID with a known HCV+ status were more likely to know their last co-injector partner's HCV status than were their peers with a negative or unknown HCV status. However, this relationship was not present in the rural data. These findings suggest that there are different risk norms in rural and urban PWID communities and that interventions successful in one type of community may not be so in others.

Needle acquisition patterns, network risk and social capital among rural PWID in Puerto Rico

BACKGROUND

People who inject drugs (PWID) take on significant risks of contracting blood-borne infection, including injecting with a large number of partners and acquiring needles from unsafe sources. When combined, risk of infection can be magnified.

METHODS

Using a sample of PWID in rural Puerto Rico, we model the relationship between a subject's number of injection partners and the likelihood of having used an unsafe source of injection syringes. Data collection with 315 current injectors identified six sources of needles.

RESULTS

Of the six possible sources, only acquisition from a seller (paid or free), or using syringes found on the street, was significantly related to number of partners.

CONCLUSIONS

These results suggest that sources of syringes do serve to multiply risk of infection caused by multi-partner injection concurrency. They also suggest that prior research on distinct forms of social capital among PWID may need to be rethought.

Hyperpolarized gas diffusion MRI of biphasic lung inflation in short- and long-term emphysema models

During lung inflation, airspace dimensions are affected nonlinearly by both alveolar expansion and recruitment, potentially confounding the identification of emphysematous lung by hyperpolarized helium-3 diffusion magnetic resonance imaging (HP MRI). This study aimed to characterize lung inflation over a broad range of inflation volume and pressure values in two different models of emphysema, as well as in normal lungs. Elastase-treated rats (n = 7) and healthy controls (n = 7) were imaged with HP MRI. Gradual inflation was achieved by incremental changes to both inflation volume and airway pressure. The apparent diffusion coefficient (ADC) was measured at each level of inflation and fitted to the corresponding airway pressures as the second-order response equation, with minimizing residue (χ² < 0.001). A biphasic ADC response was detected, with an initial ADC increase followed by a decrease at airway pressures >18 cmH₂O. Discrimination between treated and control rats was optimal when airway pressure was intermediate (between 10 and 11 cmH₂O). Similar findings were confirmed in mice following long-term exposure to cigarette smoke, where optimal discrimination between treated and healthy mice occurred at a similar airway pressure as in the rats. We subsequently explored the evolution of ADC measured at the intermediate inflation level in mice after prolonged smoke exposure and found a significant increase (P < 0.01) in ADC over time. Our results demonstrate that measuring ADC at intermediate inflation enhances the distinction between healthy and diseased lungs, thereby establishing a model that may improve the diagnostic accuracy of future HP gas diffusion studies.

Hepatitis C serosorting among people who inject drugs in rural Puerto Rico

Due to the high cost of treatment, preventative measures to limit Hepatitis C (HCV) transmission among people who inject drugs (PWID) are encouraged by many public health officials. A key one of these is serosorting, where PWID select risk partners based on concordant HCV status. Research on the general U.S. population by Smith et al. (2013) found that knowledge of one's own HCV status facilitated serosorting behaviors among PWID, such that respondents with knowledge of their own status were more likely to ask potential partners about their status prior to sharing risk. Our objective was to see if this held true in rural Puerto Rico. We replicate this study using a sample of PWID in rural Puerto Rico to draw comparisons. We used respondent driven sampling to survey 315 participants, and have a final analytic sample of 154. The survey was heavily modeled after the National HIV Behavioral Survey, which was the dataset used by the previous researchers. We found that among PWID in rural Puerto Rico, unlike in the general population, knowledge of one's own HCV status had no significant effect on the selection of one's most recent injection partner, based on his/her HCV status. We conclude that PWID in rural Puerto Rico differ from the general U.S. population when it comes to serosorting behaviors, and that these differences should be taken into account in future outreaches and intervention strategies.

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Recent study finds PWID ask potential partners about infections once own status known.

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We replicate this using similar measures with a sample in rural Puerto Rico.

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Find no evidence this happens in rural Puerto Rico, though women more likely to ask.

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Null finding may be due to small sample size, but pattern still appears unique.

Quantifying reaction kinetics of the non-enzymatic decarboxylation of pyruvate and production of peroxymonocarbonate with hyperpolarized13C-NMR

Hyperpolarized¹³C-NMR is used to study the reaction mechanism and kinetics for non-enzymatic decarboxylation of pyruvate and formation of peroxymonocarbonate.

Use of a Publicly Available Database to Determine the Impact of Diabetes on Length of Hospital Stay for Elective Orthopedic Procedures in California

In California, 1 in 3 hospital beds are occupied by adults with diabetes. The aim of this study was to examine whether diabetes impacts length of stay (LOS) following common elective orthopedic procedures compared to nondiabetic individuals, and also the performance of hospitals across California for these procedures. Using the Public Use California Patient Discharge Data Files for 2010-2012, the authors examined LOS for elective discharges for hip, spine, or knee surgery (n = 318,861) from the total population of all discharges (n = 11,476,073) for 309 hospitals across California. In all, 16% of discharges had a codiagnosis of diabetes. Unadjusted average LOS was 3.11 days without and 3.40 days with diabetes (mean difference 0.29 [95% confidence interval (0.27, 0.31) days, P < 0.01]). After adjusting for covariates, diabetes no longer resulted in a significant difference in LOS. However, the presence of common comorbidities did significantly impact LOS. Average LOS for patients with diabetes also varied widely by hospital, ranging between -50% and +100% of the mean LOS for all hospitals. Diabetes does not prolong LOS after orthopedic procedures unless comorbidities are present. Nevertheless, across California there is significant variation in LOS between individual hospitals, which may inform the decision-making process for prospective patients and payers.

Walgreens connected care: impact of managed therapy on adherence to medications used to treat multiple sclerosis and related comorbid conditions

BACKGROUND

The Walgreens Connected Care Multiple Sclerosis (CCMS) treatment management program provides enhanced levels of monitoring, oversight, and care for patients taking MS disease-modifying agents. This study compared rates of adherence to MS medications for patients participating in the CCMS program for at least 6 months with those for patients participating for less than 6 months. For a subsample of patients, we also examined the relationship between adherence and the presence of fatigue or depression.

METHODS

This was a retrospective study of patients new to the CCMS program and followed up for 1 year of participation. Adherence to MS medications was measured as the proportion of days covered, with propensity scores used to match the CCMS intervention group to the less-managed comparison group. The impact of program participation on the relationship between depression or fatigue and adherence over time was a separate analysis.

RESULTS

Mean proportion of days covered rates improved significantly in the group managed for at least 6 months compared with those who were less managed. Positive screenings for fatigue and depression reduced adherence in the less-managed group but not in patients with longer participation in the program.

CONCLUSIONS

Overall, the CCMS program significantly increased adherence to MS medications. This improved adherence was not negatively impacted by positive screenings for fatigue and depression.

Impact of HIV-specialized pharmacies on adherence to medications for comorbid conditions

OBJECTIVE

To determine if patients using human immunodeficiency virus (HIV)-specialized pharmacies have greater adherence to drugs used to treat comorbid conditions and HIV compared with patients who use traditional pharmacies.

DESIGN

Retrospective cohort study, with patients' propensity matched based on pharmacy use: HIV-specialized versus traditional.

SETTING

Nationwide pharmacy chain.

PARTICIPANTS

Adult patients who filled at least two prescriptions for an antiretroviral therapy (ART). Patients also needed to have at least two prescriptions for an angiotensin-converting enzyme (ACE) inhibitor/angiotensin receptor blocker (ARB) or a statin for analyses examining comorbid conditions.

MAIN OUTCOME MEASURE

Proportion of days covered (PDC).

RESULTS

The adherence analyses for ART, ACE inhibitors/ARBs, and statins included 14,278, 1,484, and 1,372 pairs, respectively. The mean PDC for ART patients using HIV-specialized pharmacies was higher than that for patients using traditional pharmacies (86.20% vs. 81.87%; P <0.0001). Patients taking ACE inhibitors/ARBs in the specialized group also had a higher mean PDC compared with patients in the traditional group (82.61 vs. 79.66; P = 0.0002), as did specialized pharmacy users in the statin group (83.77 vs. 81.29; P = 0.0009).

CONCLUSION

HIV patients managed by an HIV-specialized pharmacy have significantly higher adherence to medication for comorbid conditions compared with patients using traditional pharmacies. Patients of HIV-specialized pharmacies also have significantly higher adherence to ART compared with peers using traditional pharmacies.

Worksite primary care clinics: a systematic review

Despite levels of health spending that are higher per capita and as share of gross domestic product than any country worldwide, the US health care system is fragmented, technology and administration heavy, and primary care deficient. Studies of regional variations in US health care show similar "disconnects" between higher spending and better health outcomes. Faced with rising health benefit costs and suboptimal workforce health amid economic downturn, concerned US employers have implemented innovative payment and health care delivery strategies such as consumer-driven health plans and targeted prevention programs. The former may impose undue cost shifting, prohibitive out-of-pocket expenses, and health literacy challenges, while the latter have shown inconsistent near-term economic returns and long-term clinical efficacy. Employers have begun exploring more comprehensive health delivery platforms such as integrated worksite primary care clinics that have potential to cost-effectively address several pressing problems with current US health care: the growing primary care physician shortage, poor access to routine care, lack of coordinated and patient-centered treatment models, low rates of childhood immunizations, and "quality-blind" fee-for-service payment mechanisms. Such on-site medical clinics exploit one of the rare comparative strengths of the US health care system-its plentiful supply of highly skilled registered nurses-to offer workers and their dependents convenient, high-quality, affordable care. A relatively recent health care paradigm, worksite clinics must yet develop consistent reporting strategies and credible demonstration of outcomes. This review explores available evidence regarding worksite primary care clinics, including current rationale, historical trends, prevalence and projected growth, expected health and financial benefits, challenges, and future research directions.

The impact of a worksite weight management program on obesity: a retrospective analysis

The objective of this study was to examine the efficacy of a worksite weight management program on the reduction of weight and lipid levels in employees and their dependents. This retrospective study examined the impact of a one-on-one worksite weight management program. Patients with a body mass index (BMI)>30, or a BMI>25 and 2 or more risk factors were eligible for inclusion. Laboratory and biometric readings at study end were compared to those at baseline. In addition, the percentage change of patients reaching recommended guideline levels was reported. Of the 310 employees enrolled, 157 completed the program (50.6%) with an average weight loss of 5.6%. Improvement was realized for pre-post weight (-6.0 lbs.; P≤.0001), BMI (-0.9; P≤.0001), blood pressure (systolic: -2.6; P≤.0001; diastolic: -1.9; P≤.0001), total cholesterol (-5.9; P=.0485), low-density lipoprotein cholesterol (LDL; -4.7; P=.0004), and triglycerides (-7.6; P=.0060). The proportion moving to within guideline levels increased for the following metrics: normal BMI category (2.6%; P=.0060),<30 BMI (10%; P≤.0001), systolic and diastolic blood pressure readings (7.7%; P=.0011 and 6.1; P=.0056, respectively), total cholesterol (6.5%; P=.0020), LDL (3.9%; P=.0396), and triglycerides (4.8; P=.0137). Retention in the worksite program was almost twice that seen in some commercial weight loss programs and significant improvements in laboratory and biometric readings were achieved. This study suggests that employer worksite-based programs may have an important role in improving the health of an employee population, which is of particular interest given the high prevalence of obesity and its attendant costs.