Corrigendum: Perceptions and experiences of community-based healthcare professionals in the state of Qatar having do not attempt resuscitation discussions during the COVID-19 pandemic.

[This corrects the article DOI: 10.3389/fmed.2023.1232954.].

Perceptions and experiences of community-based healthcare professionals in the state of Qatar having do not attempt resuscitation discussions during the COVID-19 pandemic.

Introduction: The values and attitudes of healthcare professionals influence their handling of "do-not-attempt-resuscitation" (DNAR) orders, as does that of the families they interact with. The aim of this study was to describe attitudes, perceptions, and practices among community-based medical practitioners towards discussing cardiopulmonary resuscitation and DNAR orders with patients and their relatives, and to investigate if the COVID-19 pandemic affected their practice in having these discussions. Methods: This is a researcher-developed online survey-based study which aimed to recruit a convenience sample of respondents from a total population of 106 healthcare professionals working for the Mobile Healthcare Service (MHS), Hamad Medical Corporation Ambulance Service in the State of Qatar. Results: 33 family physicians, 38 nurses, and 20 paramedics (n = 91) responded to the questionnaire, of who around 40, 8, and 50%, respectively, had engaged in Do Not Attempt Resuscitation discussions during their work with MHS. 15% of physicians who had experience with Do Not Attempt Resuscitation discussions in Qatar felt that the family or patient were not open to having such discussions. 90% of paramedics thought that Do Not Attempt Resuscitation was a taboo topic for their patients in Qatar, and this view was shared by 75% of physicians and 50% of nurses. Per the responses, the COVID-19 pandemic had not affected the likelihood of most of the physicians or nurses (and 50% of the paramedics) identifying patients with whom having a Do Not Attempt Resuscitation discussion would be clinically appropriate. Discussion: Overall, for all three groups, the COVID-19 pandemic did not affect the likelihood of identifying patients with whom a Do Not Attempt Resuscitation discussion would be clinically appropriate. We found that the greatest barriers in having Do Not Attempt Resuscitation discussions were perceived to be the religious or cultural beliefs of the patient and/or their family, along with the factor of feeling the staff member did not know the patient or their family well enough. All three groups said they would be more likely to have a conversation about Do Not Attempt Resuscitation if barriers were addressed.

Trait groups as management entities in a complex, multispecies reef fishery.

Localized stressors compound the ongoing climate-driven decline of coral reefs, requiring natural resource managers to work with rapidly shifting paradigms. Trait-based adaptive management (TBAM) is a new framework to help address changing conditions by choosing and implementing management actions specific to species groups that share key traits, vulnerabilities, and management responses. In TBAM maintenance of functioning ecosystems is balanced with provisioning for human subsistence and livelihoods. We first identified trait-based groups of food fish in a Pacific coral reef with hierarchical clustering. Positing that trait-based groups performing comparable functions respond similarly to both stressors and management actions, we ascertained biophysical and socioeconomic drivers of trait-group biomass and evaluated their vulnerabilities with generalized additive models. Clustering identified 7 trait groups from 131 species. Groups responded to different drivers and displayed divergent vulnerabilities; human activities emerged as important predictors of community structuring. Biomass of small, solitary reef-associated species increased with distance from key fishing ports, and large, solitary piscivores exhibited a decline in biomass with distance from a port. Group biomass also varied in response to different habitat types, the presence or absence of reported dynamite fishing activity, and exposure to wave energy. The differential vulnerabilities of trait groups revealed how the community structure of food fishes is driven by different aspects of resource use and habitat. This inherent variability in the responses of trait-based groups presents opportunities to apply selective TBAM strategies for complex, multispecies fisheries. This approach can be widely adjusted to suit local contexts and priorities.

Grupos de Atributos como Entidades de Manejo en una Pesquería de Arrecife Compleja y Multiespecie Resumen Los estresantes localizados agravan la continua declinación de los arrecifes de coral causada por el clima, lo que requiere que los administradores de recursos naturales trabajen con paradigmas en constante cambio. El manejo adaptativo basado en caracteres (TBAM, en inglés) es un marco de trabajo nuevo que ayuda a enfrentar las condiciones cambiantes mediante la selección e implementación de acciones de manejo específicas para grupos de especies que comparten atributos, vulnerabilidades y respuestas al manejo esenciales. En el TBAM, el mantenimiento de los ecosistemas funcionales está balanceado con el suministro para la subsistencia humana. Identificamos mediante un agrupamiento jerárquico los grupos basados en atributos de peces para la alimentación en un arrecife de coral del Pacífico. Al plantear que los grupos basados en atributos que desempeñan funciones comparables responden similarmente a los estresantes y las acciones de manejo, determinamos los impulsores biofísicos y socioeconómicos de la biomasa de un grupo de atributos y evaluamos sus vulnerabilidades mediante modelos aditivos generalizados. Identificamos siete grupos de atributos a partir de 131 especies. Los grupos respondieron a diferentes impulsores y desplegaron vulnerabilidades divergentes; las actividades humanas aparecieron como predictores importantes de la estructuración de la comunidad. La biomasa de las especies solitarias asociadas al arrecife incrementó con la distancia desde puertos importantes de pesca y los piscívoros solitarios de gran tamaño exhibieron una declinación en la biomasa junto con la distancia desde un puerto. La biomasa de los grupos también varió en respuesta a los diferentes tipos de hábitat, la presencia o ausencia reportada de actividad pesquera con dinamita y la exposición a la energía del oleaje. Las vulnerabilidades diferenciales de los grupos de atributos revelaron cómo la estructura de la comunidad de peces para la alimentación está impulsada por aspectos diferentes del uso de recursos y del hábitat. Esta variabilidad inherente en las respuestas de los grupos basados en atributos presenta la oportunidad de aplicar estrategias selectivas de manejo basado en atributos en las pesquerías complejas y multiespecie. Este enfoque puede ajustarse abiertamente para adaptarse a los contextos y las prioridades locales.

Improved outcomes in CABG patients with atrial fibrillation associated with surgical left atrial appendage exclusion.

BACKGROUND: We sought to determine the impact of left atrial appendage clip exclusion (LAACE) on coronary artery bypass grafting (CABG) outcomes among patients with pre-existing atrial fibrillation (AF). METHODS: From October 1, 2015 to October 1, 2017, 4210 Medicare beneficiaries with pre-existing AF underwent isolated CABG (i.e., without ablation) with (n = 931) or without (n = 3279) LAACE. Inverse probability of treatment weighting was used to evaluate the effect of concomitant LAACE on short- and long-term outcomes after CABG. Long term risks of thromboembolism and mortality were assessed using competing-risk regression and Cox proportional hazard models. RESULTS: Operative mortality, length of stay, and 30-day readmission did not differ between groups. Thromboembolism risk was 26% lower for the CABG + LAACE group compared with isolated CABG over a 2-year time-to-event analysis (sub hazard ratio [sHR] 0.74, 95% confidence interval [CI] 0.54-1.00, p = .049). There were no differences in ischemic stroke rates. All-cause mortality risk was 45% lower for CABG + LAACE during the late follow-up period (91-730 days; HR 0.55, 95% CI 0.32-0.95, p = .031). The late period annual absolute all-cause mortality rate was 3.7% for CABG + LAACE and 6.9% for isolated CABG. There were lower readmission rates (31% vs. 43%, p < .001) and total inpatient days (4.0 days vs. 7.2 days, p < .01.) for the CABG + LAACE during follow-up. Total hospital in and out-patient treatment costs were similar between groups through one year. CONCLUSIONS: Concomitant LAA exclusion via an epicardial closure device is associated with reduced CABG mortality, thromboembolic events, and readmissions in patients with pre-existing atrial fibrillation.

Comparison of perioperative costs with fast-track vs standard endovascular aneurysm repair.

BACKGROUND: Perioperative health care utilization and costs in patients undergoing elective fast-track vs standard endovascular aneurysm repair (EVAR) remain unclear. METHODS: The fast-track EVAR group included patients treated with a 14 Fr stent graft, bilateral percutaneous access, no general anesthesia or intensive care monitoring, and next-day hospital discharge. The standard EVAR group was identified from Medicare administrative claims using a matching algorithm to adjust for imbalances in patient characteristics. Hospital outcomes included operating room time, intensive care monitoring, hospital stay, secondary interventions, and major adverse events (MAEs). Perioperative outcomes occurring from hospital discharge to 30 days postdischarge included MAE, secondary interventions, and unrelated readmissions. RESULTS: Among 1000 matched patients (250 fast-track; 750 standard), hospital outcomes favored the fast-track EVAR group, including shorter operating room time (2.30 vs 2.83 hrs, P<0.001), shorter hospital stay (1.16 vs 1.69 d, P<0.001), less need for intensive care monitoring (4.4% vs 48.0%, P<0.001), and lower secondary intervention rate (0% vs 2.4%, P=0.01). Postdischarge outcomes also favored fast-track EVAR with a lower rate of MAE (0% vs 7.2%, P<0.001) and all-cause readmission (1.6% vs 6.8%, P=0.001). The total cost to the health care system during the perioperative period was $26,730 with fast-track EVAR vs $30,730 with standard EVAR. Total perioperative health care costs were $4000 (95% CI: $3130-$4830) lower with fast-track EVAR vs standard EVAR, with $2980 in savings to hospitals and $1030 savings to health care payers. CONCLUSION: A fast-track EVAR protocol using a 14 Fr stent graft resulted in shorter procedure time, lower intensive care utilization, faster discharge, lower incidence of MAE, lower readmission rates, and lower perioperative costs compared to standard EVAR.

Association of Ambulatory Ability on Complications and Medical Costs in Patients with Traumatic Spinal Cord Injury: A Decision-analytic Model.

Purpose  The objective of this study was to determine the independent association of ambulatory ability with complications and medical costs in patients with spinal cord injury (SCI). Methods Patients with SCI between T1-T12 enrolled in the National Spinal Cord Injury Database (NSCID) provided a minimum one-year follow-up. Covariate-adjusted annual rates of important medical complications (pressure sore, urinary tract infection, hospitalization) and associated medical costs were determined over five years post-injury.  Results A total of 1,753 patients provided data at one-year follow-up and 1,340 patients provided five-year data. At one-year post-injury, 82% of patients were non-ambulatory and 18% were ambulatory. After adjusting for important covariates, ambulatory status was associated with a lower annual probability of urinary tract infection (43% vs. 68%), pressure sore (12% vs. 35%), and hospitalization (23% vs. 34%). Covariate-adjusted base-case medical costs due to urinary tract infection, pressure sore, and hospitalization were 34% lower in ambulatory vs. non-ambulatory patients ($31,358 vs. $47,266) over five years. Probabilistic sensitivity analyses confirmed the base-case results. Conclusion In spinal cord-injured individuals, the ability to ambulate is independently associated with lower complication risks and associated medical costs over the five-year period following injury. Long-term clinical benefit and cost savings may be realized with assisted or unassisted ambulation in spinal cord-injured patients.

Endovascular Interventions for Femoropopliteal Peripheral Artery Disease: A Network Meta-Analysis of Current Technologies.

PURPOSE: To use network meta-analysis (NMA) to determine the optimal endovascular strategy for management of femoropopliteal peripheral artery disease (PAD) given the lack of multiple prospective randomized trials to guide treatment decisions. MATERIALS AND METHODS: NMA is a new meta-analytic method that permits comparisons among any 2 therapies by combining results of a collection of clinical trials conducted in the same or similar patient population. NMA was used to analyze data from 15 randomized controlled trials (RCTs) and 10 prospective, multicenter, single-arm trials (combined evidence [CE] NMA) that evaluated target lesion revascularization (TLR) for 5 endovascular strategies: bare metal stent (BMS), polymer-covered metal stent (CMS), drug-eluting stent (DES), drug-coated balloon (DCB) and percutaneous transluminal angioplasty (PTA). RESULTS: The RCT and CE NMAs included 2,912 (6,091) patients with 3,151 (6,786) person-years of follow-up. In the CE NMA, DCB provided a statistically significant 68% reduction in TLR compared with PTA and a statistically significant 53% reduction in TLR compared with BMS. BMS, CMS, and DES provided reductions in TLR of 33%, 48%, and 58% compared with PTA, with statistical significance achieved for CMS and DES. The significant reductions in TLR for DCB compared with PTA and BMS were replicated in the RCT NMA. CONCLUSIONS: This NMA demonstrated that DCB provided better reduction in TLR rates compared with PTA and BMS.

In situ Detection of Microbial Life in the Deep Biosphere in Igneous Ocean Crust.

The deep biosphere is a major frontier to science. Recent studies have shown the presence and activity of cells in deep marine sediments and in the continental deep biosphere. Volcanic lavas in the deep ocean subsurface, through which substantial fluid flow occurs, present another potentially massive deep biosphere. We present results from the deployment of a novel in situ logging tool designed to detect microbial life harbored in a deep, native, borehole environment within igneous oceanic crust, using deep ultraviolet native fluorescence spectroscopy. Results demonstrate the predominance of microbial-like signatures within the borehole environment, with densities in the range of 10(5) cells/mL. Based on transport and flux models, we estimate that such a concentration of microbial cells could not be supported by transport through the crust, suggesting in situ growth of these communities.

Cost-effectiveness of three treatment strategies for lumbar spinal stenosis: Conservative care, laminectomy, and the Superion interspinous spacer.

BACKGROUND: Lumbar spinal stenosis is a painful and debilitating condition resulting in healthcare costs totaling tens of billions of dollars annually. Initial treatment consists of conservative care modalities such as physical therapy, NSAIDs, opioids, and steroid injections. Patients refractory to these therapies can undergo decompressive surgery, which has good long-term efficacy but is more traumatic and can be associated with high post-operative adverse event (AE) rates. Interspinous spacers have been developed to offer a less-invasive alternative. The objective of this study was to compare the costs and quality adjusted life years (QALYs) gained of conservative care (CC) and decompressive surgery (DS) to a new minimally-invasive interspinous spacer. METHODS: A Markov model was developed evaluating 3 strategies of care for lumbar spinal stenosis. If initial therapies failed, the model moved patients to more invasive therapies. Data from the Superion FDA clinical trial, a prospective spinal registry, and the literature were used to populate the model. Direct medical care costs were modeled from 2014 Medicare reimbursements for healthcare services. QALYs came from the SF-12 PCS and MCS components. The analysis used a 2-year time horizon with a 3% discount rate. RESULTS: CC had the lowest cost at $10,540, while Spacers and DS were nearly identical at about $13,950. CC also had the lowest QALY increase (0.06), while Spacers and DS were again nearly identical (.28). The incremental cost-effectiveness ratios (ICER) for Spacers compared to CC was $16,300 and for DS was $15,200. CONCLUSIONS: Both the Spacer and DS strategies are far below the commonly cited $50,000/QALY threshold and produced several times the QALY increase versus CC, suggesting that surgical care provides superior value (cost / effectiveness) versus sustained conservative care in the treatment of lumbar spinal stenosis.

Human Skin Allograft for Patients With Diabetic Foot Ulcers, Venous Leg Ulcers, or Surgical/Traumatic Wounds Retrospective, Descriptive Study.

Chronic wounds such as diabetic foot ulcers (DFU) and venous leg ulcers (VLU) may take a long time to heal and increase the risk of complications. Previous studies have suggested human skin allograft may facilitate healing of these chronic wounds. A retrospective, descriptive study was conducted among outpatients with nonhealing DFU, VLU, surgical, or traumatic wounds managed with a meshed, partial-thickness, cryopreserved human skin allograft. Charts of all patients who received an allograft from 2011 to 2013 were abstracted if the wound was >1 cm2, had a duration>30 days, was adequately debrided, and was free of infection before the first allograft application. Primary outcome was percentage of wounds healed (ie, 100% epithelialized) at 12 and 20 weeks. Secondary outcome was the number of recorded adverse events. Wound measurements (area--calculated as width x length in cm2), wound type and duration, number of allograft applications, number of adverse events, and race, smoking status, and body mass index were abstracted. Of the 49 patients (average age 64.3 [SD 15.0]; 64% male) who met the inclusion criteria, 13 did not have medical follow-up through the primary outcomes at 12 and 20 weeks, leaving 36 patients (average age 65.1 [SD 15.4]; 67% male) available for analysis. The most common diagnoses were VLU (18 patients, 50%) and traumatic wounds (9 patients, 25%). Average wound size was 19.4 cm2 (SD 29.3, range 1.2-156, median 9.5), and average wound duration at initial treatment was 17.2 (SD 17.0, range 4-72, excluding outlier) weeks. Seventeen (17) wounds (47%) healed by 12 weeks, and 21 (58%) were healed by week 20 with an average of 3.3 (SD 2.0) allograft applications. No serious adverse events occurred. The results of this study are encouraging and add to the currently available literature on the use of allograft skin for chronic wounds, but the study design and sample size limit the ability to interpret the observations. Prospective, controlled clinical studies are needed to compare the efficacy, effectiveness, and cost-effectiveness of human skin allograft to standard care and to other advanced care modalities.

Healthcare utilization and costs in persons with insomnia in a managed care population.

OBJECTIVES: To better understand the direct costs of insomnia. Our study aimed to compare healthcare costs and utilization of patients diagnosed with insomnia who received care in a managed care organization with a set of matched controls. DESIGN: Our observational, retrospective cohort study compared 7647 adults with an insomnia diagnosis with an equally sized matched cohort of health plan members without an insomnia diagnosis between 2003 and 2006. We also compared a subset of patients diagnosed with and treated for insomnia with those diagnosed with insomnia but not treated. SETTING: A large Midwestern health plan with more than 600,000 members. RESULTS: Multivariate analysis was used to estimate the association between insomnia diagnosis and costs, controlling for covariates, in the baseline and follow-up periods. Although we cannot conclude a causal relationship between insomnia and healthcare costs, our analysis found that insomnia diagnosis was associated with 26% higher costs in the baseline and 46% in the 12 months after diagnosis. When comorbidities were recognized, the insomnia cohort had 80% higher costs, on average, than the matched control cohort. CONCLUSIONS: These outcomes suggest the need to look beyond the direct cost of insomnia to how its interaction with comorbid conditions drives healthcare cost and utilization.

Cost-effectiveness of the convergent procedure and catheter ablation for non-paroxysmal atrial fibrillation.

OBJECTIVE: Patients with persistent or longstanding atrial fibrillation have modest success achieving sinus rhythm with catheter ablation or rhythm control medications. Their high risk of stroke, bleed, and heart failure leads to significant morbidity and health care costs. The convergent procedure has been shown to be successful in this population, with 80% of patients in sinus rhythm after 1 year. This study evaluated the cost-effectiveness of the convergent procedure, catheter ablation, and medical management for non-paroxysmal AF patients. METHODS: A Markov micro-simulation model was used to estimate costs and effectiveness from a payer perspective. Parameter estimates were from the literature. Three patient cohorts were simulated, representing lower, medium, and higher risks of stroke, bleed, heart failure, and hospitalization. Effects were estimated by quality-adjusted life-years (QALYs). Single-variable sensitivity analysis was performed. RESULTS: After 5 years, convergent procedure patients averaged 1.10 procedures, with 75% of survivors in sinus rhythm; catheter ablation patients had 1.65 procedures, with 49% in sinus rhythm. Compared to medical management, catheter ablation and the convergent procedure were cost-effective for the lower risk (ICER <$35,000) and medium risk (ICER <$15,000) cohorts. The procedures dominated medical management for the higher risk cohort (lower cost and higher QALYs). The convergent procedure dominated catheter ablation for all risk cohorts. RESULTS were subject to simplifying assumptions and limited by uncertain factors such as long-term maintenance of sinus rhythm after successful procedure and incremental AF-associated event rates for AF patients relative to patients in sinus rhythm. In the absence of clinical trial data, convergent procedure efficacy was estimated with observational evidence. Limitations were addressed with sensitivity analyses and a moderate 5 year time horizon. CONCLUSION: The convergent procedure results in superior maintenance of post-ablation sinus rhythm with fewer repeat ablation procedures compared to catheter ablation, leading to lower cost and higher QALYs after 5 years.

Cost effectiveness of radiofrequency microremodeling for stress urinary incontinence.

INTRODUCTION AND HYPOTHESIS: Stress urinary incontinence (SUI) is a common and growing problem among adult women and affects individuals and society through decreased quality of life (QoL), decreased work productivity, and increased health care costs. A new, nonsurgical treatment option has become available for women who have failed conservative therapy, but its cost effectiveness has not been evaluated. This study examined the cost effectiveness of transurethral radiofrequency microremodeling of the female bladder neck and proximal urethra compared with synthetic transobturator tape (TOT), retropubic transvaginal tape (TVT) sling, and Burch colposuspension surgeries for treating SUI. METHODS: A Markov model was used to compare the cost effectiveness of five strategies for treating SUI for patients who had previously failed conservative therapy. The strategies were designed to compare the value of starting with a less invasive treatment. The cost-effectiveness analysis was conducted from the health care system perspective. Efficacy and adverse event rates were obtained from the literature; reimbursement costs were based on Medicare fee schedule. The model cycle was 3 months, with a 3-year time horizon. Single-variable sensitivity analyses were conducted to assess stability of base-case results. RESULTS: Two of the five strategies employed the use of transurethral radiofrequency microremodeling and achieved 17-30 % lower mean costs relative to their comparative sling or Burch strategies. CONCLUSIONS: Superior safety and cost effectiveness are recognized when patients are offered a sequential approach to SUI management that employs transurethral radiofrequency microremodeling before invasive surgical procedures. This sequential approach is consistent with treatment strategies for other conditions and offers a solution for women with SUI who want to avoid the inherent risks and costs of invasive continence surgery.

Stress state in the largest displacement area of the 2011 Tohoku-Oki earthquake.

The 2011 moment magnitude 9.0 Tohoku-Oki earthquake produced a maximum coseismic slip of more than 50 meters near the Japan trench, which could result in a completely reduced stress state in the region. We tested this hypothesis by determining the in situ stress state of the frontal prism from boreholes drilled by the Integrated Ocean Drilling Program approximately 1 year after the earthquake and by inferring the pre-earthquake stress state. On the basis of the horizontal stress orientations and magnitudes estimated from borehole breakouts and the increase in coseismic displacement during propagation of the rupture to the trench axis, in situ horizontal stress decreased during the earthquake. The stress change suggests an active slip of the frontal plate interface, which is consistent with coseismic fault weakening and a nearly total stress drop.

A qualitative study of continuing education needs of rural nursing unit staff: the nurse administrator's perspective.

BACKGROUND: This study reports perceptions of the continuing education (CE) needs of nursing unit staff in 40 rural healthcare facilities (10 hospitals and 30 long-term care facilities) in a rural Midwestern U.S. region from the perspective of nurse administrators in an effort to promote a community-based academic-practice CE partnership. METHODS: Qualitative data collection involving naturalistic inquiry methodology was based on key informant interviews with nurse administrators (n=40) working and leading in the participating health care facilities. RESULTS: Major themes based on nurse administrators' perceptions of CE needs of nursing unit staff were in four broad conceptual areas: "Cultural issues", "clinical nursing skills", "patient care", and "patient safety". Major sub-themes for each conceptual area are highlighted and discussed with narrative content as expressed by the participants. Related cultural sub-themes expressed by the nurse administrators included "horizontal violence" (workplace-hospital and LTC nursing unit staff) and "domestic violence" (home-LTC nursing unit staff). CONCLUSIONS: The uniqueness of nurses' developmental learning needs from a situational point of view can be equally as important as knowledge-based and/or skill-based learning needs. Psychological self-reflection is discussed and recommended as a guiding concept to promote the development and delivery of relevant, empowering and evidence-based CE offerings for rural nursing unit staff.

Patient-centered medical home cost reductions limited to complex patients.

OBJECTIVES: To examine the long-term relationships between costs, utilization, and patient-centered medical home (PCMH) clinical practice systems. STUDY DESIGN: Clinical practice systems were evaluated at baseline by the Physician Practice Connections-Research Survey (PPC-RS). Annual costs and utilization of a retrospectively constructed cohort of 58,391 persons receiving primary care at 1 of 22 medical groups over a 5-year period (2005-2009) were compared. METHODS: Multivariate regressions adjusting for patient demographics, health status, and autoregressive errors compared PPC-RS scores and study outcomes for the entire cohort and 3 subcohorts defined by medical complexity (medication count 0-2 [n = 29,657], 2-6 [n = 19,505], >7 [n = 9229]). Outcomes (adjusted to 2005 dollars) were total costs, outpatient costs, inpatient costs, inpatient days, and emergency department (ED) use. RESULTS: For the entire cohort, a 10% increase in PPC-RS scores was associated with 3.9 (medication count: 0-2), 6 (3-6), and 11.6 (>7) fewer ED visits per 1000 in 2005; and 5.1, 7.6, and 13.6 fewer ED visits in 2009. That 10% increase was not associated with the 0-2 medication subcohort's total (-$22/person in 2005; $184/person in 2009), outpatient (-$11/person in 2005; $42/person in 2009), or inpatient ($26/person in 2005; $29/person in 2009) costs. However, it was associated with significantly decreased total (-$446/person in 2005; -$184/person in 2009) and outpatient (-$241/person in 2005; -$54/person in 2009) costs for the most medically complex subcohort (>7 medications). CONCLUSIONS: Association of PCMH clinical practice systems with reduced costs appears limited to the most medically complex patients.

A Cenozoic record of the equatorial Pacific carbonate compensation depth.

Atmospheric carbon dioxide concentrations and climate are regulated on geological timescales by the balance between carbon input from volcanic and metamorphic outgassing and its removal by weathering feedbacks; these feedbacks involve the erosion of silicate rocks and organic-carbon-bearing rocks. The integrated effect of these processes is reflected in the calcium carbonate compensation depth, which is the oceanic depth at which calcium carbonate is dissolved. Here we present a carbonate accumulation record that covers the past 53 million years from a depth transect in the equatorial Pacific Ocean. The carbonate compensation depth tracks long-term ocean cooling, deepening from 3.0-3.5 kilometres during the early Cenozoic (approximately 55 million years ago) to 4.6 kilometres at present, consistent with an overall Cenozoic increase in weathering. We find large superimposed fluctuations in carbonate compensation depth during the middle and late Eocene. Using Earth system models, we identify changes in weathering and the mode of organic-carbon delivery as two key processes to explain these large-scale Eocene fluctuations of the carbonate compensation depth.

Patient medical group continuity and healthcare utilization.

OBJECTIVES: To measure continuity among medical groups of insured patients over a 5-year period and to test whether group continuity of care is associated with healthcare utilization and costs. STUDY DESIGN: Retrospective observational study. METHODS: We studied natural patient behavior by using insurance claims data in the absence of any medical group or health plan incentives for continuity. We conducted the study through a retrospective analysis of administrative data of 121,780 patients enrolled from 2005 to 2009 in HealthPartners, a large nonprofit Minnesota health plan. Each year, patients were attributed to the medical group where they received the greatest number of primary care visits. Multilevel multiple regression models were used to estimate the association of annualized medical cost and utilization with attribution and continuity categories. RESULTS: Although patients with high medical group continuity were older and had more comorbidities than patients with medium or low continuity of care, they had a consistently lower probability of any inpatient expenditure or any emergency department (ED) utilization and lower total medical costs. CONCLUSIONS: Although a small proportion, health plan members who visited a primary care provider but had low or medium continuity among medical groups had higher inpatient and ED use than those with high continuity. Improved coordination and integration has potential to lower utilization and costs in this group.

Trends in quality during medical home transformation.

PURPOSE We describe changes over time in performance on measures of technical quality and patient experience as a group of primary care clinics transformed themselves into level III patient-centered medical homes. METHODS A group of 21 Minnesota primary care clinics achieving level III recognition as medical homes by the National Committee for Quality Assurance has been tracking a variety of quality and patient satisfaction measures for years. We analyzed trends in these measures and compared them with those of other medical groups in the community to estimate what we might expect as other primary care sites gear up to achieve medical home status. RESULTS The clinics in this group achieved a 1% to 3% increase per year in patient satisfaction and a 2% to 7% increase per year in performance on quality measures for diabetes, coronary artery disease, preventive services, and generic medication use. When compared with the average for other medical groups in the region, the rates of increase were greater for satisfaction, but similar for the quality measures. CONCLUSIONS Achieving medical home recognition was associated with improvements in quality and patient satisfaction for these clinics, but the rate of improvement is slow and does not always exceed levels in the surrounding community in Minnesota (which are also improving). Expectations for large and rapid change are probably unrealistic.

Monte Carlo simulations of single- and multistep enzyme-catalyzed reaction sequences: effects of diffusion, cell size, enzyme fluctuations, colocalization, and segregation.

Following the discovery of slow fluctuations in the catalytic activity of an enzyme in single-molecule experiments, it has been shown that the classical Michaelis-Menten (MM) equation relating the average enzymatic velocity and the substrate concentration may hold even for slowly fluctuating enzymes. In many cases, the average velocity is that given by the MM equation with time-averaged values of the fluctuating rate constants and the effect of enzyme fluctuations is simply averaged out. The situation is quite different for a sequence of reactions. For colocalization of a pair of enzymes in a sequence to be effective in promoting reaction, the second must be active when the first is active or soon after. If the enzymes are slowly varying and only rarely active, the product of the first reaction may diffuse away before the second enzyme is active, and colocalization may have little value. Even for single-step reactions the interplay of reaction and diffusion with enzyme fluctuations leads to added complexities, but for multistep reactions the interplay of reaction and diffusion, cell size, compartmentalization, enzyme fluctuations, colocalization, and segregation is far more complex than for single-step reactions. In this paper, we report the use of stochastic simulations at the level of whole cells to explore, understand, and predict the behavior of single- and multistep enzyme-catalyzed reaction systems exhibiting some of these complexities. Results for single-step reactions confirm several earlier observations by others. The MM relationship, with altered constants, is found to hold for single-step reactions slowed by diffusion. For single-step reactions, the distribution of enzymes in a regular grid is slightly more effective than a random distribution. Fluctuations of enzyme activity, with average activity fixed, have no observed effects for simple single-step reactions slowed by diffusion. Two-step sequential reactions are seen to be slowed by segregation of the enzymes for each step, and results of the calculations suggest limits for cell size. Colocalization of enzymes for a two-step sequence is seen to promote reaction, and rates fall rapidly with increasing distance between enzymes. Low frequency fluctuations of the activities of colocalized enzymes, with average activities fixed, can greatly reduce reaction rates for sequential reactions.