Isomorphic coalescence of aster cores formed in vitro from microtubules and kinesin motors

We report fluorescence microscopy studies of the formation of aster-like structures emerging from a cellular element-based active system and a novel analysis of the aster condensation. The system consists of rhodamine labeled microtubules which are dynamically coupled by functionalized kinesin motor proteins cross-linked via streptavidin-coated quantum dots (QDs). The aster-shaped objects contain core structures. The cores are aggregates of the QD-motor protein complexes, and result from the dynamic condensation of sub-clusters that are connected to each other randomly. The structural specificity of the aster core reflects a configuration of the initial connectivity between sub-clusters. Detailed image analysis allows us to extract a novel correlation between the condensation speed and the sub-cluster separation. The size of the core is scaled down during the condensation process, following a power law dependence on the distance between sub-clusters. The exponent of the power law is close to two, as expected from a geometric model. This single exponent common to all the contractile lines implies that there exists a time regime during which an isomorphic contraction of the aster core continues during the condensation process. We analyze the observed contraction by using a model system with potential applicability in a wide range of emergent phenomena in randomly coupled active networks, which are prevalent in the cellular environment.

Patterns of Care for Metastatic Colorectal Cancer in Appalachia, and the Clinical, Sociodemographic, and Service Provider Determinants

BACKGROUND

Appalachia has high colorectal cancer (CRC) incidence and mortality, at least in part due to screening disparities. This paper examines patterns and determinants of metastatic colorectal cancer care.

METHODS

CRC patients diagnosed in 2006-2008 from 4 cancer registries (Kentucky, Ohio, Pennsylvania, and North Carolina) were linked to Medicare claims (2005-2009.) The final sample after exclusions included 855 stage IV and 590 stages I-III patients with metachronous or synchronous metastases. We estimate bivariate and multivariate analyses for several surgical and chemotherapeutic strategies of care using clinical, sociodemographic, and contextual determinants.

RESULTS

Among 1,445 CRC patients, 84% had primary tumor resection and 44% received chemotherapy. Of the chemotherapy patients, 44% received newer systemic agents for at least 75% of the cycles. One year survivors with liver or lung metastases were more likely to have their primary tumor resected immediately (86.1% vs 69.5% for liver, and 78.2% vs 64.9% for lung) and have their metastases resected/ablated (15.7% vs 2.6% for liver and 15.0% vs 0.5% for lung). Patients with stages I-III primary tumors (versus IV) were much more likely to be resected, but they were less likely to receive chemotherapy. Patients with comorbidities (congestive heart failure, dementia, or respiratory disease) had lower odds of chemotherapy. Smaller hospital size and surgical volume had higher odds of immediate versus delayed surgery. The newer chemotherapeutic agents were more common with higher surgical volume.

CONCLUSIONS

Metastatic colorectal cancer has clinical, sociodemographic, and service provider determinants.

Adherence to adjuvant endocrine therapy for breast cancer: importance in women with low income

There are wide disparities in breast cancer-specific survival by patient sociodemographic characteristics. Women of lower income, for instance, have higher relapse and death rates from breast cancer. One possible contributing factor for this disparity is low use of adjuvant endocrine therapy-an extremely efficacious therapy in women with early stage, hormone receptor positive breast cancer, the most common subtype of breast cancer. Alone, adjuvant endocrine therapy decreases breast cancer recurrence by 50% and death by 30%. Data suggest that low use of adjuvant endocrine therapy is a potentially important and modifiable risk factor for poor outcome in low-income breast cancer patients.

Persistent high utilization in a privately insured population

OBJECTIVES

To describe individuals characterized as persistent high users--that is, individuals who are in the top 10% of users every year over the 3-year study period.

STUDY DESIGN

Retrospective cohort study of 4 groups in a privately insured population. Groups were defined by the number of years an enrollee was in the top 10% of the spending group (top decile) for the period from 2009 to 2011: persistent high-user group (3 out of 3 years in the top decile spending group); frequent high-user group (2 out of 3 years in top decile); incidental high-user group (1 out of 3 years in top decile); and never high user group (0 out of 3 years in top decile).

METHODS

This study used insurance claims data to examine enrollees with persistently high health service utilization. Data for the year 2008 were utilized to assess baseline individual characteristics. Annual data for 2009 to 2011 were used to examine healthcare expenditures, utilization patterns, and specific clinical conditions among the 4 groups of the study sample.

RESULTS

Among 42,038 enrollees, 1216 (2.9%) met the criteria as persistent high users. Over a 3-year period, this group accounted for 21% of total healthcare expenditure. Compared with the other groups, persistent high users had higher overall disease burden due to multiple chronic conditions and incurred significantly higher expenses in medication and professional services (including primary and specialty care).

CONCLUSIONS

This study highlights the need to proactively engage employees and their dependents for primary and secondary prevention of common chronic diseases before an individual's health status, healthcare utilization, and medical cost become difficult to manage.

Receipt of Regular Primary Care and Early Cancer Detection in Appalachia

PURPOSE

The objective was to examine the impact of regular primary care encounters (PCE) on early breast cancer detection in an Appalachian sample of Medicare beneficiaries diagnosed 2006-2008. Determinants of PCE were investigated and a mediation analysis was conducted where PCE was a mediator to cancer stage.

METHODS

A total of 3,589 cases were identified from Appalachian areas in Pennsylvania, Kentucky, Ohio, and North Carolina, and health care services were examined 2 months to 2 years prior to diagnosis. A regular care PCE variable was constructed with 4 ordinal levels: none, any, "annual," and "semi-annual." Association of PCE with stage, mortality and covariables was conducted using ordinal logistic regressions and Cox Proportional Hazards survival models.

RESULTS

Sixty-eight percent of the cases had semi-annual PCE. Regular PCE was strongly associated with late-stage cancer rates (39%-13% by increasing PCE level, P < .0001) and 5-year all-cause mortality (42%-24%, P < .0001). Subgroup analysis revealed variations by hypertension and urban status, with nonhypertensives with no PCE being at particularly increased risk. Significant determinants of PCE included age, rural/urban status, comorbidity, dual Medicaid insurance, Appalachian region economic classification, state, select comorbidities, hypertension, and minimum distance to provider. Mediation analysis results were consistent with lower number of comorbidities leading to increased late cancer detection due to patients having a decreased PCE.

CONCLUSION

PCE is an important determinant of cancer detection, with a dose-response relationship. Variations exist by geography and hypertension. Comorbidity may influence both PCE and late-stage rates with partial mediation through PCE.

Individual, Area, and Provider Characteristics Associated With Care Received for Stages I to III Breast Cancer in a Multistate Region of Appalachia

PURPOSE

We describe individual, area, and provider characteristics associated with care patterns for early-stage breast cancer in Appalachian counties of Kentucky, North Carolina, Ohio, and Pennsylvania.

METHODS

Cases of stages I to III breast cancer from 2006 to 2008 were linked to Medicare claims occurring within 1 year of diagnosis. Rates of guideline-concordant endocrine therapy (n = 1,429), chemotherapy (n = 1,480), and radiation therapy (RT) after breast-conserving surgery were studied; RT was studied in women age ≥ 70 years with stage I estrogen receptor (ER) -positive/progesterone receptor (PR) -positive cancer, for whom RT was optional (n = 1,108), and in all others, for whom RT was guideline concordant (n = 1,422). Univariable and multivariable analyses were performed. Independent variables included age, race, county-level economic status, state, surgeon graduation year and volume, comorbidity, diagnosis year, Medicaid/Medicare dual status, histology, tumor size, tumor sequence, positive lymph nodes, ER/PR status, stage, trastuzumab use, and surgery type.

RESULTS

Population mean age was 74 years; 97% were white. For endocrine therapy, chemotherapy, and RT, guideline concordance was 76%, 48%, and 83%, respectively. Where it was optional, 77% received RT. Guideline-concordant endocrine therapy was lower in North Carolina versus Pennsylvania (odds ratio [OR], 0.60; 95% CI, 0.41 to 0.88) and higher if surgeon graduated between 1984 and 1988 versus ≥ 1989 (OR, 1.58; 95% CI, 1.06 to 2.34). Guideline-concordant chemotherapy varied significantly by state, county-level economic status, and surgeon volume. In guideline-concordant RT, lower surgeon volume (v highest) predicted RT use (OR, 1.63; 95% CI, 1.61 to 2.36). In optional RT, North Carolina residence (v Pennsylvania; OR, 0.29; 95% CI, 0.17 to 0.48) and counties with higher economic status (OR, 0.61; 95% CI, 0.40 to 0.94) predicated RT omission.

CONCLUSION

Notable variation in care by geographic and surgical provider characteristics provides targets for further research in underserved areas.

Treatment patterns for prostate cancer: comparison of Medicare claims data to medical record review

BACKGROUND

As evidence-based guidelines increasingly define standards of care, the accurate reporting of patterns of treatment becomes critical to determine if appropriate care has been provided. We explore the level of agreement between claims and record abstraction for treatment regimens for prostate cancer.

METHODS

Medicare claims data were linked to medical records abstraction using data from the Centers for Disease Control and Prevention's National Program of Cancer Registry-funded Breast and Prostate Patterns of Care study. The first course of therapy included surgery, radiation therapy (RT), and hormonal therapy with luteinizing hormone-releasing hormone agonists.

RESULTS

The linked sample included 2765 men most (84.7%) of whom had stage II prostate cancer. Agreement was excellent for surgery (κ=0.92) and RT (κ=0.92) and lower for hormonal therapy (κ=0.71); however, most of the discrepancies were due to greater number of patients reported who received hormonal therapy in the claims database than in the medical records database. For some standard multicomponent management strategies sensitivities were high, for example, hormonal therapy with either combination RT (86.9%) or cryosurgery (96.6%).

CONCLUSIONS

Medicare claims are sensitive for determining patterns of multicomponent care for prostate cancer and for detecting use of hormonal therapy when not reported in the medical records abstracts.

PaTH: towards a learning health system in the Mid-Atlantic region

The PaTH (University of Pittsburgh/UPMC, Penn State College of Medicine, Temple University Hospital, and Johns Hopkins University) clinical data research network initiative is a collaborative effort among four academic health centers in the Mid-Atlantic region. PaTH will provide robust infrastructure to conduct research, explore clinical outcomes, link with biospecimens, and improve methods for sharing and analyzing data across our diverse populations. Our disease foci are idiopathic pulmonary fibrosis, atrial fibrillation, and obesity. The four network sites have extensive experience in using data from electronic health records and have devised robust methods for patient outreach and recruitment. The network will adopt best practices by using the open-source data-sharing tool, Informatics for Integrating Biology and the Bedside (i2b2), at each site to enhance data sharing using centrally defined common data elements, and will use the Shared Health Research Information Network (SHRINE) for distributed queries across the network.

Comorbidity burden and guideline-concordant care for breast cancer

OBJECTIVES

To explore the relationship between level and type of comorbidity and guideline-concordant care for early-stage breast cancer.

DESIGN

Cross-sectional.

SETTING

National Program of Cancer Registry (NPCR) Breast and Prostate Cancer Patterns of Care study, which re-abstracted medical records from 2004 in seven cancer registries.

PARTICIPANTS

Individuals with stage 0-III breast cancer.

MEASUREMENTS

Multicomponent guideline-concordant management was modeled based on tumor size, node status, and hormone receptor status, according to consensus guidelines. Comorbid conditions and severity were measured using the Adult Comorbidity Evaluation Index (ACE-27). Multivariate logistic regression models determined factors associated with guideline-concordant care and included overall ACE-27 scores and 26 separate ACE comorbidity categories, age, race, stage, and source of payment.

RESULTS

The study sample included 6,439 women (mean age 58.7, range 20-99; 76% white; 44% with no comorbidity; 70% estrogen- or progesterone-receptor positive, or both; 31% human epidermal growth factor receptor 2 positive). Care was guideline concordant in 60%. Guideline concordance varied according to overall comorbidity burden (70% for none; 61% for minor; 58% for moderate, 43% for severe; P < .05). In multivariate analysis, the presence of hypertension (odds ratio (OR) = 1.15, 95% confidence interval (CI) = 1.01-1.30) predicted guideline concordance, whereas dementia (OR = 0.45, 95% CI = 0.24-0.82) predicted lack of guideline concordance. Older age (≥ 50) and black race were associated with less guideline concordance, regardless of comorbidity level.

CONCLUSION

When reporting survival outcomes in individuals with breast cancer with comorbidity, adherence to care guidelines should be among the covariates.

Hospital patient safety grades may misrepresent hospital performance

Nationally, there is strong interest in measuring hospital performance in patient safety. The Leapfrog Group uses a survey, along with other data sources, to calculate patient safety scores for 2600 hospitals across the United States. Under this methodology, every hospital is assigned 1 of 5 letter grades (A, B, C, D, F) depending on how the hospital stands in safety performance relative to all other hospitals. The results have been widely marketed and disseminated to employers, payors, and the public. Leapfrog strongly encourages employers and payors to negotiate hospital reimbursement rates based on the safety grade the hospital receives. Leapfrog's effort to develop a standardized method to provide patient safety information should be commended. However, less than one-half of the 2600 hospitals participated in the Leapfrog survey. For those nonparticipating hospitals, certain safety measures were absent and alternative measures were used to calculate the safety score. A sample of the nation's most prestigious hospitals (n = 35) was drawn from the U.S. News & World Report's "Best Hospitals." Overall, the group of participating hospitals (n = 18) received an average grade of A (mean safety score = 3.165), whereas the group of nonparticipating hospitals received an average grade of B (mean safety score = 3.012). These nonparticipating hospitals were rescored using the methodology for participating hospitals. The results show that the majority of nonparticipating hospitals would have received a better safety grade. This demonstrates a potential shortcoming of Leapfrog's method and its tendency to discriminate against nonparticipating hospitals.

Towards a global system of vigilance and surveillance in unrelated donors of haematopoietic progenitor cells for transplantation

Safety of living donors is critical to the success of blood, tissue and organ transplantation. Structured and robust vigilance and surveillance systems exist as part of some national entities, but historically no global systems are in place to ensure conformity, harmonisation and the recognition of rare adverse events (AEs). The World Health Assembly has recently resolved to require AE/reaction (AE/R) reporting both nationally and globally. The World Marrow Donor Association (WMDA) is an international organisation promoting the safety of unrelated donors and progenitor cell products for use in haematopoietic progenitor cell (HPC) transplantation. To address this issue, we established a system for collecting, collating, analysing, distributing and reacting to serious adverse events and reactions (SAE/R) in unrelated HPC donors. The WMDA successfully instituted this reporting system with 203 SAE/R reported in 2011. The committee generated two rapid reports, reacting to specific SAE/R, resulting in practice changing policies. The system has a robust governance structure, formal feedback to the WMDA membership and transparent information flows to other agencies, specialist physicians and transplant programs and the general public.

Clinical, sociodemographic, and service provider determinants of guideline concordant colorectal cancer care for Appalachian residents

BACKGROUND

Colorectal cancer represents a significant cause of morbidity and mortality, particularly in Appalachia where high mortality from colorectal cancer is more prevalent. Adherence to treatment guidelines leads to improved survival. This paper examines determinants of guideline concordance for colorectal cancer.

METHODS

Colorectal cancer patients diagnosed in 2006-2008 from 4 cancer registries (Kentucky, Ohio, Pennsylvania, and North Carolina) were linked to Medicare claims (2005-2009). Final sample size after exclusions was 2,932 stage I-III colon, and 184 stage III rectal cancer patients. The 3 measures of guideline concordance include adjuvant chemotherapy (stage III colon cancer, <80 years), ≥12 lymph nodes assessed (resected stage I-III colon cancer), and radiation therapy (stage III rectal cancer, <80 years). Bivariate and multivariate analyses with clinical, sociodemographic, and service provider covariates were estimated for each of the measures.

RESULTS

Rates of chemotherapy, lymph node assessment, and radiation were 62.9%, 66.3%, and 56.0%, respectively. Older patients had lower rates of chemotherapy and radiation. Five comorbidities were significantly associated with lower concordance in the bivariate analyses: myocardial infarction, congestive heart failure, respiratory diseases, dementia with chemotherapy, and diabetes with adequate lymph node assessment. Patients treated by hospitals with no Commission on Cancer (COC) designation or lower surgical volumes had lower odds of adequate lymph node assessment.

CONCLUSIONS

Clinical, sociodemographic, and service provider characteristics are significant determinants of the variation in guideline concordance rates of 3 colorectal cancer measures.