Coding Intensity Through Health Risk Assessments and Chart Reviews in Medicare Advantage: Does It Explain Resource Use?

Medicare Advantage (MA) plans increase their risk-adjusted payments through intensive coding in health risk assessments (HRAs) and chart reviews. Whether the additional diagnoses from HRAs and chart reviews are associated with increased resource use is not known. Using national MA encounter data (2016-2019), we examine the relative contributions of three health risk scores to MA resource use: the base risk score that excludes diagnoses from HRAs and chart reviews; the incremental score added to the base score from diagnoses in HRAs; and the incremental score added from diagnoses in chart reviews. We find that the incremental risk scores explain 53.5% to 64.5% of resource use relative to the base risk score effect-that is, 35.5% to 46.5% of the incremental risk scores are not accompanied by increased resource use. While HRAs and chart reviews contribute to more complete coding of diagnoses, they are sources of intensive coding not accompanied by resource use.

A Digital Diabetes Storytelling Intervention for the Hmong Community: A Pilot Study

Hmong-Americans experience higher rates of diabetes and poorer diabetes-related health outcomes than their White peers. Traditional methods of diabetes education do not reach Hmong patients effectively due to known socioeconomic and literacy barriers. The purpose of this study is to examine the acceptability of a culturally informed diabetes self-management education video tool, using digital storytelling that was created using a community-engaged approach, administered in a single academic clinic that sees a large percentage of Hmong patients. The video tool was successful in the areas of acceptability, story transformation, and story identification; 96% of participants stated that the video felt like something from their community, 88% stated that they could identify with the story, 79% stated that they wanted to know what happened next, and 70% of participants reported that they were motivated to do something different after watching. New methods to improve diabetes education and improve health outcomes in Hmong communities are needed. Culturally informed digital storytelling is one tool, which may be used to improve diabetes health outcomes in this population.

Implementation of resource use measures in Medicare Advantage

OBJECTIVE

To complement the previously illustrated method to measure resource use in Medicare Advantage (MA) using Encounter data and provide technical details and SAS code to validate Encounter data and implement resource use measures in MA.

DATA SOURCES

2015-2018 MA Encounter, Medicare Provider Analysis and Review (MedPAR), Healthcare Effectiveness Data and Information System (HEDIS), and Traditional Medicare (TM) claims data.

STUDY DESIGN

Secondary data analysis.

DATA COLLECTION/EXTRACTION METHODS

We select MA contracts with high data completeness (≤10% missing hospital stays in Encounter data and ≤±10% difference in ambulatory and emergency department visits between Encounter and HEDIS data). We randomly sample TM beneficiaries with a similar geographic distribution as MA enrollees in the selected contracts. We develop standardized prices of services using TM payments, and we measure MA resource use for inpatient, outpatient, Part D, and hospice services.

PRINCIPAL FINDINGS

We report identifiers/names of contracts with high data completeness. We provide SAS code to manage Encounter data, develop standardized prices, and measure MA resource use.

CONCLUSIONS

Greater use and validation of Encounter data can help improve data quality. Our results can be used to inform studies using Encounter data to learn about MA performance.

Diabetes care quality: do large medical groups perform better?

OBJECTIVES

To compare primary care management processes (CMPs) and outcome measures for diabetes quality among large, medium, and small medical groups.

STUDY DESIGN

Observational comparison of differences in processes and outcomes over time among 329 primary care practices that agreed to participate and returned completed surveys in both 2017 and 2019.

METHODS

We used a standardized composite measure of diabetes quality along with its 5 components and a survey measure of the presence of systematic CMPs to compare the outcomes and processes of care among clinics that were in large (≥ 12 sites), medium (4-11 sites), and small (1-3 sites) medical groups.

RESULTS

Practices from large groups had better performance than those in medium and small groups on the composite measure of diabetes outcomes in 2017 (46.5 vs 40.6 and 34.4, respectively; P < .001), as well as on each of the 5 component measures. They also had more CMPs in place (74.2% vs 66.9% and 61.4%; P < .001), including the 10 CMPs that are associated with the highest level of performance (84.2% vs 77.9% and 72.2%; P < .001). However, repeated measures in 2019 showed that the smaller groups had gained on both quality and CMP measures. There was also substantial overlap on both CMPs and performance among practices in groups of different sizes.

CONCLUSIONS

On average, primary care practices that are part of large well-established medical groups outperformed smaller-sized groups in diabetes care quality, probably because they have the resources, leadership, and infrastructure to provide more consistent care through more organized CMPs.

Measuring resource use in Medicare Advantage using Encounter data

OBJECTIVE

To check the completeness of Medicare Advantage (MA) Encounter data and to illustrate a process to measure resource use among MA enrollees using Encounter data.

DATA SOURCES

2015 Preliminary MA Encounter, Medicare Provider Analysis and Review (MedPAR), Healthcare Effectiveness Data and Information System (HEDIS), and 2013 Traditional Medicare (TM) claims data.

STUDY DESIGN

Secondary data analysis.

DATA COLLECTION/EXTRACTION METHODS

We calculated the percentage of each contract's total hospitalizations in Encounter data after identifying total inpatient stays from Encounter and MedPAR data. We constructed each contract's ambulatory visits and emergency department (ED) visits per 1000 enrollees using Encounter data and compared those visit counts with the counts from HEDIS. We defined high data completeness as having less than 10% missing hospital stays and less than ±10% difference in ambulatory and ED visits between Encounter and HEDIS data. We used TM payments as standardized prices of services to examine resource use among MA enrollees with cancer in the contracts with high data completeness.

PRINCIPAL FINDINGS

We identified 83 of 380 MA contracts with high data completeness. Total resource use per enrollee with cancer in the 83 contracts was $14,715 in 2015. Service-specific resource use was $5342 for inpatient care, $5932 for professional services and $3441 for outpatient facility services. These represent what an MA enrollee with cancer would have cost on average if MA plans paid providers at TM payment rates, holding the observed utilization constant.

CONCLUSIONS

Checking the completeness of Encounter data is an important step to ensure the validity of research on MA resource use. Using Encounter data to measure MA resource use is feasible. It can compensate for the lack of payment information in Encounter data. It will be important to identify and refine ways to best use Encounter data to learn about care provision to MA enrollees.

Use of Direct-Acting Antiviral Agents and Survival Among Medicare Beneficiaries with Dementia and Chronic Hepatitis C

BACKGROUND

Many patients with Alzheimer's disease and related dementia (ADRD) have chronic hepatitis C due to the high prevalence of both conditions among elderly populations. Direct-acting antivirals (DAAs) are effective in treating hepatitis C virus (HCV). However, the complexity of ADRD care may affect DAA use and outcomes among patients with HCV and ADRD. Little information exists on uptake of DAAs, factors associated with DAA use, and health benefits of DAAs among patients with HCV and ADRD.

OBJECTIVE

To examine use and survival benefits of DAAs in Medicare patients with HCV and ADRD.

METHODS

The study included Medicare patients with HCV between 2014 and 2017. We estimated Cox proportional hazards regressions to examine the association between having ADRD and DAA use, and the relation between DAA use and survival among patients with HCV and ADRD.

RESULTS

The adjusted hazard of initiating a DAA was 50% lower in patients with ADRD than those without ADRD (adjusted HR = 0.50, 95% CI: 0.46-0.54). The hazard of DAA use among ADRD patients with behavioral disturbances was 68% lower than non-ADRD patients (adjusted HR = 0.32, 95% CI: 0.28-0.37). DAA treatment was associated with a significant reduction in mortality among ADRD patients (adjusted HR = 0.52, 95% CI: 0.44-0.61).

CONCLUSION

The rate of DAA treatment in patients with HCV and ADRD was low, particularly among those with behavioral disturbance. The survival benefits of DAA treatment for patients with ADRD were substantial.

Redesigning Primary Care to Improve Diabetes Outcomes (the UNITED Study)

OBJECTIVE

The effective redesign of primary care delivery systems to improve diabetes care requires an understanding of which particular components of delivery consistently lead to better clinical outcomes. We identified associations between common systems of care management (SysCMs) and the frequency of meeting standardized performance targets for Optimal Diabetes Care (NQF#0729) in primary care practices.

RESEARCH DESIGN AND METHODS

A validated survey of 585 eligible family or general internal medicine practices seeing ≥30 adult patients with diabetes in or near Minnesota during 2017 evaluated the presence of 62 SysCMs. From 419 (72%) practices completing the survey, NQF#0729 was determined in 396 (95%) from electronic health records, including 215,842 patients with type 1 or type 2 diabetes.

RESULTS

Three SysCMs were associated with higher rates of meeting performance targets across all practices: 1) a systematic process for shared decision making with patients (P = 0.001), 2) checklists of tests or interventions needed for prevention or monitoring of diabetes (P = 0.002), and 3) physician reminders of guideline-based age-appropriate risk assessments due at the patient visit (P = 0.002). When all three were in place, an additional 10.8% of the population achieved recommended performance measures. In subgroup analysis, 15 additional SysCMs were associated with better care in particular types of practices.

CONCLUSIONS

Diabetes care outcomes are better in primary care settings that use a patient-centered approach to systematically engage patients in decision making, remind physicians of age-appropriate risk assessments, and provide checklists for recommended diabetes interventions. Practice size and location are important considerations when redesigning delivery systems to improve performance.

Differences in Diabetes Care With and Without Certification as a Medical Home

PURPOSE

The purpose of this study was to assess whether primary care practices certified as medical homes differ in having the practice systems required for that designation and in attaining favorable outcomes for their patients with diabetes, and whether those systems are associated with better diabetes outcomes.

METHODS

We undertook a cross-sectional observational study, Understanding Infrastructure Transformation Effects on Diabetes (UNITED), of 586 Minnesota adult primary care practices, comparing those that were certified vs uncertified as medical homes in 2017, with analyses supplemented by previously published studies of these practices. We collected survey information about the presence of medical home practice systems for diabetes care and obtained 6 standardized measures of diabetes care collected yearly from all Minnesota practices.

RESULTS

Of 416 practices completing questionnaires (71% of all practices, 92% of participating practices), 394 had data on diabetes care measures. Uncertified practices (39%) were more likely than certified practices to be rural, but their patient populations were similar. Certified practices had more medical home practice systems (79.2% vs 74.9%, P =.01) and were more likely to meet a composite measure of optimal diabetes care (46.8% vs 43.2%, P <.001). A 1-SD increase in presence of practice systems was associated with a 1.4% higher probability of meeting that measure (P <.001).

CONCLUSIONS

Practices certified as medical homes have more practice systems and higher performance on diabetes care than uncertified practices, but there is extensive overlap, and any differences may reflect self-selection for certification.

A small proton charge radius from an electron-proton scattering experiment

Elastic electron-proton scattering (e-p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, r_p. In 2010, a new method using muonic hydrogen atoms¹ found a substantial discrepancy compared with previous results², which became known as the 'proton radius puzzle'. Despite experimental and theoretical efforts, the puzzle remains unresolved. In fact, there is a discrepancy between the two most recent spectroscopic measurements conducted on ordinary hydrogen^3,4. Here we report on the proton charge radius experiment at Jefferson Laboratory (PRad), a high-precision e-p experiment that was established after the discrepancy was identified. We used a magnetic-spectrometer-free method along with a windowless hydrogen gas target, which overcame several limitations of previous e-p experiments and enabled measurements at very small forward-scattering angles. Our result, r_p = 0.831 ± 0.007_stat ± 0.012_syst femtometres, is smaller than the most recent high-precision e-p measurement⁵ and 2.7 standard deviations smaller than the average of all e-p experimental results⁶. The smaller r_p we have now measured supports the value found by two previous muonic hydrogen experiments^1,7. In addition, our finding agrees with the revised value (announced in 2019) for the Rydberg constant⁸-one of the most accurately evaluated fundamental constants in physics.

A Bayesian Difference-in-Difference Framework for the Impact of Primary Care Redesign on Diabetes Outcomes

Although national measures of the quality of diabetes care delivery demonstrate improvement, progress has been slow. In 2008, the Minnesota legislature endorsed the patient-centered medical home (PCMH) as the preferred model for primary care redesign. In this work, we investigate the effect of PCMH-related clinic redesign and resources on diabetes outcomes from 2008 to 2012 among Minnesota clinics certified as PCMHs by 2011 by using a Bayesian framework for a continuous difference-in-differences model. Data from the Physician Practice Connections-Research Survey were used to assess a clinic's maturity in primary care transformation, and diabetes outcomes were obtained from the MN Community Measurement (MNCM) program. These data have several characteristics that must be carefully considered from a modeling perspective, including the inability to match patients over time, the potential for dynamic confounding, and the hierarchical structure of clinics. An ad-hoc analysis suggests a significant correlation between PCMH-related clinic redesign and resources on diabetes outcomes; however, this effect is not detected after properly accounting for different sources of variability and confounding. Supplementary materials for this article are available online.

Reduced Health Care Utilization among Elderly Patients with Informal Caregivers

CONTEXT

Prior literature has focused on the impact of informal caregiving (presence of a family member in the home or nearby) on caregiver employment, but little research has analyzed the impact of informal caregiving on health care utilization patterns.

OBJECTIVE

To study the effect of informal caregivers on postacute care and recovery of Medicare patients.

DESIGN

We used cross-sectional Health Plan administrative data to measure differences in health care utilization for Medicare patients who did and did not have coresident adult caregivers available. We identified coresident caregivers as those residing at the same postal address as discharged patients. Analysis was a combination of Poisson and logit models.

MAIN OUTCOME MEASURES

Length of hospitalization, type of hospitalization (ambulatory-care sensitive vs not), likelihood of discharge to postacute care (skilled nursing facility or home health), and likelihood of hospital readmission and postdischarge Emergency Department visits.

RESULTS

Patients with caregivers were discharged after shorter hospital lengths of stay and were less likely to require postacute emergency care, home health services, or discharge to skilled nursing facilities. Savings were smaller when caregivers were younger, in poor health, or female. We extrapolated the reduced utilization associated with a coresidential caregiver to estimate Medicare savings of $514 million in 2015.

CONCLUSION

By calculating the impact of informal caregiving on patterns of health care utilization, we support the need to integrate the availability of caregivers into discharge planning. Future quantification of differences by caregiver characteristics is important.

First Measurements of the Double-Polarization Observables F, P, and H in ω Photoproduction off Transversely Polarized Protons in the N^{*} Resonance Region

First measurements of double-polarization observables in ω photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry F has been measured using circularly polarized, tagged photons in the energy range 1200-2700 MeV, and the beam-target asymmetries H and P have been measured using linearly polarized, tagged photons in the energy range 1200-2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon (N^{*}) resonances. In particular, contributions from new N^{*} resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum.

Diabetes Treatment, Control, and Hospitalization Among Adults Aged 18 to 44 in Minnesota, 2013-2015

Introduction

Of more than 300,000 adult Minnesotans who have received a diagnosis of diabetes, 16% are younger than 45 years; however, state diabetes surveillance data primarily describe older adults. National reports suggest adults younger than 45 years are less likely than older adults with diabetes to meet blood glucose (hemoglobin A_1c [HbA_1c]) goals. For this study on age-specific differences, we examined Minnesota data sets to determine if younger adults (ie, aged 18–44 y) are less likely to meet HbA_1c goals and if hospitalization patterns differ from older adults (ie, aged 45–74 y) with diabetes.

Methods

We used Behavioral Risk Factor Surveillance System data to describe demographic characteristics and health behaviors of people with diabetes, clinical quality data to assess HbA_1c levels, and hospital discharge data to assess reasons for hospitalization.

Results

Compared with older adults with diabetes, adults aged 18 to 44 were more likely to use tobacco and to have had depression; these younger adults were less likely to report having HbA_1c levels checked in the last year. According to age-specific cutoffs, 40.5% of 18- to 44-year-olds met HbA_1c goals versus 74.7% of people aged 45 to 64 and 84.4% of people aged 65 to 74. Hospitalization rates for diabetes as a primary cause were highest among 18- to 44-year-olds at 47 per 1,000 adults with diabetes, much higher than older ages. Hospitalization rates for mental health problems were higher among younger adults.

Conclusion

Our analysis confirmed that 18- to 44-year-olds with diabetes have poorer HbA_1c control than older adults with diabetes. These results underscore the importance of age-based public health surveillance of diabetes. Age-stratified surveillance can inform efforts to monitor clinical care quality and to design clinical/public health interventions.

Measurement of the Q^{2} Dependence of the Deuteron Spin Structure Function g_{1} and its Moments at Low Q^{2} with CLAS

We measured the g_{1} spin structure function of the deuteron at low Q^{2}, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W≈1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ_{1}^{d} and the spin polarizability γ_{0}^{d} are precisely determined down to a minimum Q^{2} of 0.02  GeV^{2} for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain.

A comparison of retrospective attribution rules

OBJECTIVES

To compare the performance of methods to retrospectively attribute patients to provider systems by comparing the fraction attributed and the stability of assignment over time.

STUDY DESIGN

Retrospective cross-sectional study.

METHODS

Descriptive statistics are used to measure the fraction of patients attributed and stability of attribution from year to year. This study uses a panel of administrative claims data (2010-2011). Attribution rules were defined by unit of measure (count of physician visits, dollars paid), type of providers (primary care physicians [PCPs], all physicians), type of encounters (all visits, evaluation and management visits only), and level of concentration of care (majority, plurality). We created 32 retrospective attribution rules, spanning PCP-only rules, all-physician rules, hierarchical rules based on PCPs then all physicians, and lookback rules based on current-year PCP visits then prior-year experience.

RESULTS

All methods exhibit a tradeoff between stability of attribution and fraction of the population attributed. This tradeoff is minimized when PCP-based rules are supplemented by a 1-year lookback when the current-year experience does not result in attribution.

CONCLUSIONS

We recommend using this lookback method when multiple years of data are available. In absence of multiple years of data, PCP-based rules maximize stability; hierarchical rules result in a greater fraction attributed with less loss of stability than simple all-provider rules.

Longitudinal target-spin asymmetries for deeply virtual compton scattering

A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep→e^{'}p^{'}γ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q^{2}, x_{B}, t, and ϕ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even generalized parton distributions.

Timing of arteriovenous fistula placement and Medicare costs during dialysis initiation

BACKGROUND/AIMS

Arteriovenous fistulas (AVFs) appear to be clinically superior to catheters as vascular access for maintenance hemodialysis, but higher insertion costs and high disease burden and mortality obscure the issue of whether AVF placement before hemodialysis initiation represents a net cost savings. We aimed to investigate Medicare costs for patients beginning maintenance hemodialysis, as related to timing of AVF placement.

METHODS

Data were from Medicare claims for incident hemodialysis patients aged ≥67 years in 2006. The study period extended from 2 years before to 1 year after dialysis initiation. Patients identified as having AVFs were categorized by timing of placement (mature AVF at dialysis initiation, maturing AVF at initiation, postinitiation AVF placement). Because timing may be influenced by factors that also influence overall costs, the model accounted for this nonrandom treatment assignment. An ordered probit extension of the classic Heckman correction was employed after identifying an appropriate instrumental variable. A cohort with Medicare coverage before and after dialysis initiation was identified, and Medicare claims were used to identify comorbid conditions and treatment costs.

RESULTS

Principal findings are that earlier AVF placement leads to lower costs, with the potential for about USD 500 million in savings. Additionally, the effect of nonrandom treatment assignment is real and significant. In our data, the impact of AVF placement timing was understated when treatment selection was ignored.

CONCLUSIONS

For appropriate AVF candidates, having a mature AVF in place at the time of dialysis initiation appears to confer cost savings.

The effect of quality information on consumer health plan switching: evidence from the Buyers Health Care Action Group

We examine the factors that lead employees to search for health plan quality information and the effect of such information on the decision to switch plans. Extending Hirshleifer and Riley's model [Hirshleifer, J., Riley, J.G., 1979. The analytics of uncertainty and information--an expositional survey. Journal of Economic Literature 17 (December (4)), 1375-1421] of the economics of information, we develop a two-equation model of quality information awareness and switching behavior. We estimate the model using data from a random sample of 651 single employees from 16 firms that are members of the Buyers Health Care Action Group, a health care purchasing coalition in the Minneapolis-St. Paul region. Our empirical results do not support either a link between quality information and switching behavior, or between perceived health plan satisfaction and switching. We do, however, find that switching is influenced by changes in premiums and whether an individual has an existing relationship with a health care provider.

Gab1 signaling is regulated by EGF receptor sorting in early endosomes

Although combinatorial signaling through the ErbB network is implicated in certain types of human cancer, the specifics of how particular receptors contribute to the transformed phenotype are not well understood. The goal of this study was to identify epidermal growth factor (EGF) receptor-dependent cell signaling abnormalities specifically associated with mutations in a previously described 679-LL lysosomal sorting signal, which restrict ligand-dependent receptor downregulation by promoting recycling. Importantly, the 679-LL signal is not conserved in any of the other members of the ErbB receptor family suggesting its physiological function may be tightly regulated during EGF receptor-dependent signaling. Our data indicate that cells expressing receptors with an inactive 679-AA signal are rapidly transported to Rab4+ early endosomes after they are internalized in contrast to wild-type receptors that are localized to early endocytic antigen 1 (EEA1)+ early endosomes. Divergent trafficking in early endosomes is associated with prolonged activation of p44/42 mitogen-activated protein kinases (MAPK) but not Akt. Gab1 appears to be the critical signaling molecule facilitating prolonged MAPK signaling, and activated Gab1 is recruited to early endosomes in 679-AA receptor-expressing cells. Activated Gab1 is also recruited to early endosomes in breast cancer cells characterized by high levels of EGF receptor-ErbB2 heterodimers, suggesting 679-AA expressing cells recapitulate certain aspects of EGF receptor signaling and transformation by activated ErbB2. Phosphatidylinositol 3-kinase (PI3K)-dependent membrane translocation known to be important for maintaining Gab1 activity in other settings was dispensable. We conclude that 679-LL has dual functions in EGF receptor trafficking and threshold signaling through a subset of signaling molecules including p44/42 MAPK and Gab1.

Motifs that mediate dendritic targeting in hippocampal neurons: a comparison with basolateral targeting signals

One model for dendritic protein sorting in neurons is based on parallels with basolateral targeting in Madin-Darby Canine Kidney (MDCK) epithelial cells. The goal of this study was to further evaluate this model by analyzing the neuronal targeting of several proteins that contain well-defined basolateral sorting motifs. When we expressed FcRgammaII-B2 and CD44, two basolateral markers whose sorting depends on dihydrophobic motifs, they were unpolarized in hippocampal neurons. We also assessed the localization of the Epidermal Growth Factor Receptor (EGFR), a basolateral protein whose sorting signal contains a proline-rich motif and two dihydrophobic motifs. EGFR was restricted to the dendrites in neurons and relied on the same sorting signal for proper targeting. These results show that the dendritic sorting machinery in neurons does not recognize dihydrophobic-based basolateral sorting signals. In contrast, the sorting signal present in EGFR directs both basolateral and dendritic targeting and defines a novel dendritic targeting motif.

Are employees informed about their health care coverage? Evidence from the buyers health care action group

More than half of all Americans receive health insurance coverage through an employer. The rising costs and escalating complexity of health insurance has led many employers to embark on extensive employee education campaigns. In 2002, 1,365 randomly selected employees from 16 Buyers Health Care Action Group firms in the Minneapolis region were surveyed to evaluate their awareness of employer-provided health plan quality information and the extent to which this information influences their enrollment decisions. The study found mixed evidence with respect to the value of employer communication. On one hand, employer communication does not significantly increase the probability that an employee responded correctly to the pharmacy benefit question posed in the survey. However, employer communication has a large effect on the awareness of quality information. How well those campaigns work, and by extension how well employees are informed about the health benefits decisions they make, is a key issue in health care today.

Understanding employee awareness of health care quality information: how can employers benefit?

OBJECTIVE

To analyze the factors associated with employee awareness of employer-disseminated quality information on providers.

DATA SOURCES

Primary data were collected in 2002 on a stratified, random sample of 1,365 employees in 16 firms that are members of the Buyers Health Care Action Group (BHCAG) located in the Minneapolis-St. Paul region. An employer survey was also conducted to assess how employers communicated the quality information to employees.

STUDY DESIGN

In 2001, BHCAG sponsored two programs for reporting provider quality. We specify employee awareness of the quality information to depend on factors that influence the benefits and costs of search. Factors influencing the benefits include age, sex, provider satisfaction, health status, job tenure, and Twin Cities tenure. Factors influencing search costs include employee income, education, and employer communication strategies. We estimate the model using bivariate probit analysis.

DATA COLLECTION

Employee data were collected by phone survey.

PRINCIPAL FINDINGS

Overall, the level of quality information awareness is low. However, employer communication strategies such as distributing booklets to all employees or making them available on request have a large effect on the probability of quality information awareness. Employee education and utilization of providers' services are also positively related to awareness.

CONCLUSIONS

This study is one of the first to investigate employee awareness of provider quality information. Given the direct implications for medical outcomes, one might anticipate higher rates of awareness regarding provider quality, relative to plan quality. However, we do not find empirical evidence to support this assertion.

E3-13.7 integral membrane proteins encoded by human adenoviruses alter epidermal growth factor receptor trafficking by interacting directly with receptors in early endosomes

Animal cell viruses provide valuable model systems for studying many normal cellular processes, including membrane protein sorting. The focus of this study is an integral membrane protein encoded by the E3 transcription region of human adenoviruses called E3-13.7, which diverts recycling EGF receptors to lysosomes without increasing the rate of receptor internalization or intrinsic receptor tyrosine kinase activity. Although E3-13.7 can be found on the plasma membrane when it is overexpressed, its effect on EGF receptor trafficking suggests that the plasma membrane is not its primary site of action. Using cell fractionation and immunocytochemical experimental approaches, we now report that the viral protein is located predominantly in early endosomes and limiting membranes of endosome-to-lysosome transport intermediates called multivesicular endosomes. We also demonstrate that E3-13.7 physically associates with EGF receptors undergoing E3-13.7-mediated down-regulation in early endosomes. Receptor-viral protein complexes then dissociate, and EGF receptors proceed to lysosomes, where they are degraded, while E3-13.7 is retained in endosomes. We conclude that E3-13.7 is a resident early endocytic protein independent of EGF receptor expression, because it has identical intracellular localization in mouse cells lacking endogenous receptors and cells expressing a human cytomegalovirus-driven receptor cDNA. Finally, we demonstrate that EGF receptor residues 675-697 are required for E3-13.7-mediated down-regulation. Interestingly, this sequence includes a known EGF receptor leucine-based lysosomal sorting signal used during ligand-induced trafficking, which is also conserved in the viral protein. E3-13.7, therefore, provides a novel model system for determining the molecular basis of selective membrane protein transport in the endocytic pathway. Our studies also suggest new paradigms for understanding EGF receptor sorting in endosomes and adenovirus pathogenesis.

EGF receptor residues leu(679), leu(680) mediate selective sorting of ligand-receptor complexes in early endosomal compartments

Dileucine-based motifs have been shown to regulate endosomal sorting of a number of membrane proteins. Previously, we have shown that the dileucine motif Leu(679), Leu(680) in the juxtamembrane domain of the human epidermal growth factor receptor is involved in the endosome-to-lysosome transport of ligand-receptor complexes. Substitution of alanine residues for Leu(679), Leu(680) led to a reduction in ligand-induced receptor degradation without affecting internalization. In the current study, we have further characterized ligand-dependent intracellular sorting of EGF receptors containing a L679A, L680A. Immunocytochemical studies reveal that although mutant receptors redistribute from the cell surface to transferrin receptor-positive endocytic vesicles similar to wild-type following ligand stimulation, their accumulation in Lamp-1-positive late endosomes/lysosomes is retarded compared to wild-type. Kinetic analysis of (125)I-EGF trafficking shows that reduced accumulation of internalized mutant receptors in Lamp-1-positive vesicles is due to rapid recycling of ligand-receptor complexes from early endocytic compartments. In addition, the fraction of intracellular (125)I-EGF that is transported to late endocytic compartments in cells with mutant receptors is not as efficiently degraded as it is in cells with wild-type receptors. Furthermore, wild-type receptors in endocytic vesicles isolated by Percoll gradient fractionation are more resistant to in vitro digestion with proteinase K than mutant receptors. We propose that mutant receptors interact inefficiently with lysosomal sorting machinery, leading to their increased recycling. Our results are consistent with a model in which the Leu(679), Leu(680) signal facilitates sequestration of ligand-receptor complexes into internal vesicles of multivesicular endosome-to-lysosome transport intermediates.

Involvement of apolipoprotein E in multiple sclerosis: absence of remyelination associated with possession of the APOE epsilon2 allele

Lipids are a major constituent of myelin and apolipoprotein E (apoE) plays a key role in lipid transport. We therefore hypothesized that apoE is involved in the processes of demyelination and remyelination. Furthermore as there is a biologically significant polymorphism in the APOE gene, the APOE genotype may influence the course of multiple sclerosis (MS). Specifically, as there is reduced affinity of the apoE E2 isoform for receptors on glial cells, we hypothesized that remyelination is impaired in individuals with the apoE epsilon2 allele. We determined the apoE genotypes of 71 archival cases of multiple sclerosis and 41 controls, reviewed the neurohistology, and performed apoE immunohistochemistry. ApoE immunoreactivity was increased in demyelinated areas compared with control white matter. ApoE immunostaining was markedly increased in areas of active demyelination, specifically in macrophages and astrocytes. The APOE allele frequencies of the cases of MS (epsilon2 = 0.06, epsilon3 = 0.8, epsilon4 = 0.13) resembled those of controls. Evidence of remyelination was identified in 25/ 71 MS cases (35%): in 25/64 patients (39%) without an epsilon2 allele and 0/7 (0%) patients with an epsilon2 allele (p < 0.05). In conclusion, we provide evidence that apoE is involved in the trafficking of lipid in MS and, although the number of cases with this allele was small, remyelination may be defective in patients with the APOE epsilon2 allele.

A leucine-based determinant in the epidermal growth factor receptor juxtamembrane domain is required for the efficient transport of ligand-receptor complexes to lysosomes

Ligand binding causes the epidermal growth factor (EGF) receptor to undergo accelerated internalization with eventual degradation in lysosomes. The goal of this study was to investigate the molecular basis of endocytic sorting, focussing on post-internalization events. We have identified a sequence located between amino acid residues 675 and 697, encompassing a dileucine motif at residues 679 and 680, that enhances endosome-to-lysosome transport when conformational restraints in the EGF receptor carboxyl terminus are removed by truncation. The same dileucine motif is also necessary for efficient lysosomal transport of ligand-occupied full-length EGF receptors. A L679A,L680A substitution diminished the degradation of occupied full-length EGF receptors without affecting internalization but had a significant effect on recycling. Rapid recycling of mutant receptors resulted in reduced intracellular retention of occupied EGF receptors and delayed down-regulation of cell surface receptors. We propose that the L679A,L680A substitution acts primarily to impair transport of ligand-receptor complexes through an early endosomal compartment, diverting occupied receptors to a recycling compartment at the expense of incorporation into lysosome transport vesicles. We also found that mutant receptors with truncations at the distal half of tyrosine kinase domain (residues 809-957) were not efficiently delivered to the cell surface but were destroyed in an endoplasmic reticulum-associated degradative pathway.

A membrane setting for the sorting motifs present in the adenovirus E3-13.7 protein which down-regulates the epidermal growth factor receptor

The adenovirus E3-13.7 protein interferes with endosomal protein sorting to down-regulate the epidermal growth factor receptor and related tyrosine kinase receptors. The cytoplasmic C terminus of this protein contains three protein sorting motifs which are related to the function of E3-13.7. In this study, the structure of a 23-residue polypeptide corresponding to this domain was examined using solution NMR and CD spectroscopic methods. The peptide was observed to exist in a mostly random structural state in aqueous solution but underwent high affinity association with dodecylphosphocholine micelles, where it adopted an ordered structure. The affinity of this peptide for the micellar surface and the structure of the bound peptide were independent of pH variation, surface charge, or attachment of a myristoyl anchor to the N-terminal. Studies with phospholipid vesicles suggested that the micellar structural results can be extrapolated to a true lipid bilayer. On the micellar surface all three sorting motifs are closely associated with the water/apolar interface: 72-YLRH and 87-LL lie within interfacial amphipathic helices, while 76-HPQY is non-helical and dimples just above the surface. These results contribute to the development of an understanding of the basis for specificity in recognition of sorting motifs by components of the cellular protein trafficking machinery.

Cytoplasmic juxtamembrane domain of the human EGF receptor is required for basolateral localization in MDCK cells

Although it is well established that epidermal growth factor receptors (EGFRs) are asymmetrically expressed at the basolateral plasma membrane in polarized epithelial cells, how this process is regulated is not known. The purpose of this study was to address the mechanism of directed EGFR basolateral sorting using the Madin-Darby canine kidney (MDCK) cell model. The first set of experiments established sorting patterns for endogenous canine EGFRs. The polarity of the canine EGFR was not quantitatively affected by differences in electrical resistance exhibited by the MDCK I and MDCK II cell strains. In both cases, greater than 90% of total surface EGFRs was localized to the basolateral surface. Canine EGFRs sort directly to the basolateral membrane from the trans-Golgi network with a half-time of approximately 45 min and have an approximate t1/2 of 12.5 h once reaching the basolateral surface. Human holoreceptors expressed in stably transfected MDCK cells also localize to the basolateral membrane with similar efficiency. To identify EGFR sequences necessary for basolateral sorting, MDCK cells were transfected with cDNAs coding for cytoplasmically truncated human receptor proteins. Human EGFRs truncated at Arg-651 were localized predominantly at the apical surface of filter-grown cells, whereas receptors truncated at Leu-723 were predominantly basolateral. These results suggest that the cytoplasmic juxtamembrane domain contains a positive basolateral sorting determinant. Moreover, the EGFR ectodomain or transmembrane domain may possess a cryptic sequence that specifically interacts with the apical sorting machinery once the dominant basolateral sorting signal is removed. Further elucidation of the precise location of these signals will enhance our basic understanding of regulated plasma membrane sorting, as well as the functional consequences of inappropriate EGFR expression associated with certain pathophysiologic and malignant states.

Cleavage of the epidermal growth factor receptor by a membrane-bound leupeptin-sensitive protease active in nonionic detergent lysates of senescent but not young human diploid fibroblasts

Numerous studies suggest that epidermal growth factor (EGF) signaling is impaired in nonproliferating senescent human diploid fibroblasts downstream of receptor binding. One possible explanation for these results is that senescent cells possess unique enzymatic activities capable of regulating functional levels of the EGF receptor. To test that hypothesis, nonionic detergent lysates of young and senescent cells were compared for proteolytic activity directed towards the EGF receptor, and a protease that cleaves the 170 kDa EGF receptor was identified in lysates from senescent but not young cells. Although studies presented here were carried out with WI-38 cells, our data indicate that other senescent fibroblasts possess a similar activity. The degradation product immunoprecipitated by a monoclonal antibody specific for an EGF receptor exocytosolic epitope had an approximate molecular weight of 100,000. This product was also detected following cell surface labeling with 125I, and by cross-linking 125I-EGF to intact cells with disuccinimidyl suberate. The proteolytic activity in senescent cell lysates was specifically inhibited by leupeptin and did not require divalent cations; it was also inactivated by aprotic solvents such as dimethylsulfoxide (DMSO) or ethylene carbonate. Interestingly, this protease was not active during ligand-induced intracellular processing of the EGF receptor, suggesting that it does not normally function in endocytic or lysosomal compartments. The susceptibility of the protease to inactivation by cell surface trypsinization is consistent with a plasma membrane localization. Since EGF receptor cleavage is not observed unless senescent cells are solubilized with nonionic detergents, it seems likely that the protease is confined to specialized regions of the plasma membrane. Whether or not the EGF receptor is a physiologic target for this protease is unclear. Its expression at the cell surface is nevertheless significant, since it suggests there are mechanisms for regulating membrane-bound proteins, or biologically active peptides in the extracellular space, in senescent cells that are either absent or inactive in young cells.

Adenovirus E3 protein causes constitutively internalized epidermal growth factor receptors to accumulate in a prelysosomal compartment, resulting in enhanced degradation

We have previously identified and characterized an integral membrane protein coded for by the early transcription region 3 (E3) of human group C adenoviruses that down-regulates the epidermal growth factor receptor (EGFR). The goal of this study was to characterize the early receptor trafficking events leading to enhanced EGFR degradation in adenovirus-infected cells. Specifically, we wished to determine whether adenovirus increases the rate of EGFR internalization or alters the subcellular compartmentalization of internalized EGFRs. Once the optimal time for measuring early trafficking events was determined, surface EGFRs were labeled with a cleavable biotin reagent to measure internalization rates and with a receptor-specific monoclonal antibody (MAb) conjugated to colloidal gold for intracellular localization studies. We first showed that the rate of EGFR internalization in adenovirus-infected cells is indistinguishable from the constitutive internalization rate for unoccupied EGFRs. The possibility that the E3 protein can affect trafficking of EGFRs internalized at a low constitutive rate was further supported by studies showing that adenovirus-mediated down-regulation occurs independently of EGFR oligomerization and intrinsic EGFR tyrosine kinase activity, which are required for efficient ligand-induced internalization. Other tyrosine kinases inhibited by genistein are also not required for adenovirus-induced down-regulation. When the intracellular localization of EGFRs during adenovirus-mediated down-regulation was examined by electron microscopy, there was a threefold increase in the number of EGFRs localized to multivesicular bodies. The multivesicular body has been proposed to be important for regulating intracellular membrane protein sorting, since trafficking patterns for receptors that recycle and receptors that are degraded diverge in this organelle. These data therefore suggest that adenovirus may enhance EGFR degradation by causing constitutively internalized EGFRs to accumulate in a prelysosomal compartment. This is the first example of a mechanism that efficiently down-regulates EGFR without significantly increasing the rate of internalization or that does not require EGFR tyrosine kinase activity. Since viral proteins often mimic or modify a host counterpart, this suggests that there are normal physiological conditions when receptor destruction without tyrosine signalling is beneficial.

Adenovirus and protein kinase C have distinct molecular requirements for regulating epidermal growth factor receptor trafficking

The ligand-activated tyrosine kinase receptor for epidermal growth factor (EGF) is down-regulated by an integral membrane protein coded for by the E3 early transcription unit of group C adenoviruses. The E3 protein appears to block recycling of constitutively internalized receptors, causing them instead to traffic to lysosomes where they are degraded. Expression of functional EGF receptors is also regulated by protein kinase C (PKC), which directly phosphorylates the EGF receptor at Thr-654. The goal of this study was to determine potential interactions between PKC and the E3 protein, since membrane-bound PKC activity is elevated by the adenovirus E1A protein. Our results show that although tumor promoters which activate PKC cause a coordinate induction of E3 protein synthesis and EGF receptor degradation, the E3 protein-induced pathway for receptor down-regulation functions independently of PKC and other kinases that are inhibited by staurosporine. This suggests that in contrast to other mechanisms that modulate receptor expression (i.e., ligand and PKC), the E3 protein is not regulated by phosphorylation but is constitutively active. We also report that adenovirus-mediated degradation is the preferred pathway in infected cells stimulated with 12-O-tetradecanoylphorbol-13-acetate (TPA) to induce receptor recycling.

Ligand-induced protein tyrosine kinase activity in living cells coexpressing intact EGF receptors and receptors with an extensive cytosolic deletion

A population of stable NIH 3T3 transfectants with two molecular weight classes of membrane-bound EGF receptors encoded by a human EGF receptor cDNA has been identified and characterized. In addition to intact EGF receptors, these cells also express a molecule with an extensive cytosolic deletion. This deletion includes the ligand-activated intrinsic protein tyrosine kinase catalytic domain. Treatment with EGF caused dimerization of intact and truncated receptors, allowing us to assess protein tyrosine kinase activity in the heterodimer isolated from living cells. In contrast to homodimeric complexes with intact EGF receptor only, heterodimers were deficient in protein tyrosine kinase activity. Moreover, physical association between intact and truncated molecules suppressed receptor auto-phosphorylation by EGF receptor protein tyrosine kinase activated by antibody binding in vitro. Evidence presented here supports the idea that protein tyrosine kinase activation is facilitated by interaction between adjacent receptor molecules with intact catalytic domains. Furthermore, molecules with cytoplasmic deletions that are physically associated with kinase-active EGF receptors appear to behave as dominant negative mutations. The HerC cl cells used in this study were selected with methotrexate to amplify the EGF receptor cDNA, and in that sense may resemble certain tumor-derived cells characterized by overexpressed and rearranged EGF receptor genes.

Characterization of the adenovirus E3 protein that down-regulates the epidermal growth factor receptor. Evidence for intermolecular disulfide bonding and plasma membrane localization

We have characterized the biosynthesis and processing of a 91 amino acid hydrophobic integral membrane protein encoded by human group C adenoviruses which down-regulates the EGF receptor (Carlin, C. R., Tollefson, A. E., Brady, H. A., Hoffman, B. L., and Wold, W. S. M. (1989) Cell 57, 135-144). Previous studies have shown that two immunologically related proteins are produced in vivo, a 13.7-kDa protein encoded by E3 message f and a 11.3-kDa protein derived from 13.7 kDa by proteolysis (Hoffman, B. L., Ullrich, A., Wold, W. S. M., and Carlin, C. R. (1990) Mol. Cell. Biol. 10, 5521-5524; Tollefson, A. E., Krajcsi, P., Yei, S., Carlin, C. R., and Wold, W. S. M. (1990) J. Virol. 64, 794-801). We report here that the 13.7- and 11.3-kDa proteins form intermolecular disulfide bonds cotranslationally at Cys-31 and tend to migrate as high molecular weight aggregates under nonreducing conditions. Both proteins are also present at the cell surface, as evidenced by specific immunoprecipitation from intact monolayers enzymatically labeled with 125I. Moreover, an antiserum specific for a putative extracellular epitope recognizes the same viral proteins as antibodies directed against a C-terminal synthetic 15-mer. The 13.7- and 11.3-kDa proteins are detected at early time points during pulse-chase radiolabeling of infected cells, do not undergo any further changes in molecular weight, and focus at their predicted isoelectric points (7.4 and 7.2, respectively). Identical results are obtained in stable transfectants constitutively expressing only 13.7 and 11.3 kDa, suggesting that biosynthesis and processing is not dependent on other viral proteins. These results have been incorporated into a computer-based model to predict the orientation of 13.7 and 11.3 kDa in the lipid bilayer. This model provides a basis for testing predictions regarding the topology of the viral proteins, as well as putative interactions with heterologous proteins in the microenvironment of the plasma membrane that cause down-regulation of the epidermal growth factor receptor.

Pluripotent embryonal carcinoma clones derived from the human teratocarcinoma cell line Tera-2. Differentiation in vivo and in vitro

We have derived and characterized single cell clones from a xenograft tumor of the teratocarcinoma cell line Tera-2. Isozyme and chromosomal analyses confirmed their common origin. When cultures of the clones were maintained at a high cell density, many cells exhibited a morphology and cell surface antigen phenotype typical of human embryonal carcinoma cells. These features included a high nucleo-cytoplasmic ratio, prominent nucleoli, and the expression of the globoseries glycolipid antigen SSEA-3. In addition, other cells, in many respects resembling these typical embryonal carcinoma cells, were distinguished by a marked tendency to accumulate cytoplasmic glycogen. Similar cells, together with more differentiated cells, were seen in low passage cultures of Tera-2 itself. When the clones were grown at a low cell density many cells assumed a larger, flatter shape, a few with multiple nucleoli. Also, the fucosylated lactosamine antigen SSEA-1 appeared on some cells, whereas expression of SSEA-3 and HLA-A,B,C tended to be reduced. Often the synthesis of fibronectin was increased. However, no obvious cytoplasmic differentiation was seen upon ultrastructural examination, and synthesis of human chorionic gonadotropin, alpha-fetoprotein, and laminin was not detected. In contrast to the limited spontaneous changes seen in culture, marked differentiation occurred in tumors obtained following injection of the cells into athymic (nu/nu) mice. In additional to embryonal carcinoma cells, these tumors contained a variety of somatic tissues that included glandular structures, possibly related to the primitive gut, and neural elements. These cell lines derived from Tera-2 constitute the first example of clonal human embryonal carcinoma cells, adapted to growth in vitro, that have retained the capacity for differentiation into diverse somatic tissues.