Global migration of clinical research during the era of trial registration

BACKGROUND

Since the site of human subjects research has public health, regulatory, ethical, economic, and social implications, we sought to determine the global distribution and migration of clinical research using an open-access trial registry.

METHODS

We obtained individual clinical trial data including location of trial sites, dates of operation, funding source (United States government, pharmaceutical industry, or organization), and clinical study phase (1, 1/2, 2, 2/3, or 3) from ClinicalTrials.gov. We used the World Bank's classification of each country's economic development status ["High Income and a Member of the Organization for Economic Co-operation and Development (OECD)", "High Income and Non-Member of the OECD", "Upper-Middle Income", "Lower-Middle Income", or "Low Income"] and United Nations Populations Division data for country-specific population estimates. We analyzed data from calendar year 2006 through 2012 by number of clinical trial sites, cumulative trial site-years, trial density (trial site-years/106 population), and annual growth rate (%) for each country, and by development category, funding source, and clinical study phase.

RESULTS

Over a 7-year period, 89,647 clinical trials operated 784,585 trial sites in 175 countries, contributing 2,443,850 trial site-years. Among those, 652,200 trial sites (83%) were in 25 high-income OECD countries, while 37,195 sites (5%) were in 91 lower-middle or low-income countries. Trial density (trial site-years/106 population) was 540 in the United States, 202 among other high-income OECD countries (excluding the United States), 81 among high-income non-OECD countries, 41 among upper-middle income countries, 5 among lower-middle income countries, and 2 among low-income countries. Annual compound growth rate was positive (ranging from 0.8% among low-income countries to 14.7% among lower-middle income countries) among all economic groups, except the United States (-0.5%). Overall, 29,191 trials (33%) were funded by industry, 4,059 (5%) were funded by the United States government, and 56,397 (63%) were funded by organizations. Countries with emerging economies (low- and middle-income) operated 19% of phase 3 trial sites, as compared to only 6% of phase 1 trial sites.

CONCLUSION

Human clinical research remains concentrated in high-income countries, but operational clinical trial sites, particularly for phase 3 trials, may be migrating to low- and middle-income countries with emerging economies.

Impact of Medication Adherence on Virologic Failure in A5202: A Randomized, Partially Blinded, Phase 3B Study

In AIDS Clinical Trials Group A5202, participants who reported missing their medication within the past month or not providing adherence reports at both 8 and 24 weeks had 5 times the hazard of virological failure compared to more adherent participants. Adherence interventions should focus on such patients.

Implementing Generalized Additive Models to Estimate the Expected Value of Sample Information in a Microsimulation Model: Results of Three Case Studies

BACKGROUND

The expected value of sample information (EVSI) can help prioritize research but its application is hampered by computational infeasibility, especially for complex models. We investigated an approach by Strong and colleagues to estimate EVSI by applying generalized additive models (GAM) to results generated from a probabilistic sensitivity analysis (PSA).

METHODS

For 3 potential HIV prevention and treatment strategies, we estimated life expectancy and lifetime costs using the Cost-effectiveness of Preventing AIDS Complications (CEPAC) model, a complex patient-level microsimulation model of HIV progression. We fitted a GAM-a flexible regression model that estimates the functional form as part of the model fitting process-to the incremental net monetary benefits obtained from the CEPAC PSA. For each case study, we calculated the expected value of partial perfect information (EVPPI) using both the conventional nested Monte Carlo approach and the GAM approach. EVSI was calculated using the GAM approach.

RESULTS

For all 3 case studies, the GAM approach consistently gave similar estimates of EVPPI compared with the conventional approach. The EVSI behaved as expected: it increased and converged to EVPPI for larger sample sizes. For each case study, generating the PSA results for the GAM approach required 3 to 4 days on a shared cluster, after which EVPPI and EVSI across a range of sample sizes were evaluated in minutes. The conventional approach required approximately 5 weeks for the EVPPI calculation alone.

CONCLUSION

Estimating EVSI using the GAM approach with results from a PSA dramatically reduced the time required to conduct a computationally intense project, which would otherwise have been impractical. Using the GAM approach, we can efficiently provide policy makers with EVSI estimates, even for complex patient-level microsimulation models.

Lung Cancer Mortality Associated With Smoking and Smoking Cessation Among People Living With HIV in the United States

Importance

Lung cancer has become a leading cause of death among people living with human immunodeficiency virus (HIV) (PLWH). Over 40% of PLWH in the United States smoke cigarettes; HIV independently increases the risk of lung cancer.

Objective

To project cumulative lung cancer mortality by smoking exposure among PLWH in care.

Design

Using a validated microsimulation model of HIV, we applied standard demographic data and recent HIV/AIDS epidemiology statistics with specific details on smoking exposure, combining smoking status (current, former, or never) and intensity (heavy, moderate, or light). We stratified reported mortality rates attributable to lung cancer and other non-AIDS-related causes by smoking exposure and accounted for an HIV-conferred independent risk of lung cancer. Lung cancer mortality risk ratios (vs never smokers) for male and female current moderate smokers were 23.6 and 24.2, respectively, and for those who quit smoking at age 40 years were 4.3 and 4.5. In sensitivity analyses, we accounted for nonadherence to antiretroviral therapy (ART) and for a range of HIV-conferred risks of death from lung cancer and from other non-AIDS-related diseases (eg, cardiovascular disease).

Main Outcomes and Measures

Cumulative lung cancer mortality by age 80 years (stratified by sex, age at entry to HIV care, and smoking exposure); total expected lung cancer deaths, accounting for nonadherence to ART.

Results

Among 40-year-old men with HIV, estimated cumulative lung cancer mortality for heavy, moderate, and light smokers who continued to smoke was 28.9%, 23.0%, and 18.8%, respectively; for those who quit smoking at age 40 years, it was 7.9%, 6.1%, and 4.3%; and for never smokers, it was 1.6%. Among women, the corresponding mortality for current smokers was 27.8%, 20.9%, and 16.6%; for former smokers, it was 7.5%, 5.2%, and 3.7%; and for never smokers, it was 1.2%. ART-adherent individuals who continued to smoke were 6 to 13 times more likely to die from lung cancer than from traditional AIDS-related causes, depending on sex and smoking intensity. Due to greater AIDS-related mortality risks, individuals with incomplete ART adherence had higher overall mortality but lower lung cancer mortality. Applying model projections to the approximately 644 200 PLWH aged 20 to 64 in care in the United States, 59 900 (9.3%) are expected to die from lung cancer if smoking habits do not change.

Conclusions and Relevance

Those PLWH who adhere to ART but smoke are substantially more likely to die from lung cancer than from AIDS-related causes.

The cascade of HIV care among refugees and nationals in Nakivale Refugee Settlement in Uganda

OBJECTIVES

Refugees living in Uganda come from HIV-endemic countries, and many remain in refugee settlements for over a decade. Our objective was to evaluate the HIV care cascade in Nakivale Refugee Settlement and to assess correlates of linkage to care.

METHODS

We prospectively enrolled individuals accessing clinic-based HIV testing in Nakivale Refugee Settlement from March 2013 to July 2014. Newly HIV-diagnosed clients were followed for 3 months post-diagnosis. Clients underwent a baseline survey. The following outcomes were obtained from HIV clinic registers in Nakivale: clinic attendance ('linkage to HIV care'), CD4 testing, antiretroviral therapy (ART) eligibility, and ART initiation within 90 days of testing. Descriptive data were reported as frequency with 95% confidence interval (CI) or median with interquartile range (IQR). The impact of baseline variables on linkage to care was assessed with logistic regression models.

RESULTS

Of 6850 adult clients tested for HIV, 276 (4%; CI: 3-5%) were diagnosed with HIV infection, 148 (54%; CI: 47-60%) of those were linked to HIV care, 54 (20%; CI: 15-25%) had a CD4 test, 22 (8%; CI: 5-12%) were eligible for ART, and 17 (6%; CI: 3-10%) initiated ART. The proportions of refugees and nationals at each step of the cascade were similar. We identified no significant predictors of linkage to care.

CONCLUSIONS

Less than a quarter of newly HIV-diagnosed clients completed ART assessment, considerably lower than in other reports from sub-Saharan Africa. Understanding which factors hinder linkage to and engagement in care in the settlement will be important to inform interventions specific for this environment.

Predictors of HIV infection: a prospective HIV screening study in a Ugandan refugee settlement

BACKGROUND

The instability faced by refugees may place them at increased risk of exposure to HIV infection. Nakivale Refugee Settlement in southwestern Uganda hosts 68,000 refugees from 11 countries, many with high HIV prevalence. We implemented an HIV screening program in Nakivale and examined factors associated with new HIV diagnosis.

METHODS

From March 2013-November 2014, we offered free HIV screening to all clients in the Nakivale Health Center while they waited for their outpatient clinic visit. Clients included refugees and Ugandan nationals accessing services in the settlement. Prior to receiving the HIV test result, participants were surveyed to obtain demographic information including gender, marital status, travel time to reach clinic, refugee status, and history of prior HIV testing. We compared variables for HIV-infected and non-infected clients using Pearson's chi-square test, and used multivariable binomial regression models to identify predictors of HIV infection.

RESULTS

During the HIV screening intervention period, 330 (4%) of 7766 individuals tested were identified as HIV-infected. Refugees were one quarter as likely as Ugandan nationals to be HIV-infected (aRR 0.27 [0.21, 0.34], p < 0.0001). Additionally, being female (aRR 1.43 [1.14, 1.80], p = 0.002) and traveling more than 1 h to the clinic (aRR 1.39 [1.11, 1.74], p = 0.003) increased the likelihood of being HIV-infected. Compared to individuals who were married or in a stable relationship, being divorced/separated/widowed increased the risk of being HIV-infected (aRR 2.41 [1.88, 3.08], p < 0.0001), while being single reduced the risk (aRR 0.60 [0.41, 0.86], p < 0.0001). Having been previously tested for HIV (aRR 0.59 [0.47, 0.74], p < 0.0001) also lowered the likelihood of being HIV-infected.

CONCLUSIONS

In an HIV screening program in a refugee settlement in Uganda, Ugandan nationals are at higher risk of having HIV than refugees. The high HIV prevalence among clients seeking outpatient care, including Ugandan nationals and refugees, warrants enhanced HIV screening services in Nakivale and in the surrounding region. Findings from this research may be relevant for other refugee settlements in Sub-Saharan Africa hosting populations with similar demographics, including the 9 other refugee settlements in Uganda.

Impact of Cigarette Smoking and Smoking Cessation on Life Expectancy Among People With HIV: A US-Based Modeling Study

BACKGROUND

 In the United States, >40% of people infected with human immunodeficiency virus (HIV) smoke cigarettes.

METHODS

 We used a computer simulation of HIV disease and treatment to project the life expectancy of HIV-infected persons, based on smoking status. We used age- and sex-specific data on mortality, stratified by smoking status. The ratio of the non-AIDS-related mortality risk for current smokers versus that for never smokers was 2.8, and the ratio for former smokers versus never smokers was 1.0-1.8, depending on cessation age. Projected survival was based on smoking status, sex, and initial age. We also estimated the total potential life-years gained if a proportion of the approximately 248 000 HIV-infected US smokers quit smoking.

RESULTS

 Men and women entering HIV care at age 40 years (mean CD4⁺ T-cell count, 360 cells/µL) who continued to smoke lost 6.7 years and 6.3 years of life expectancy, respectively, compared with never smokers; those who quit smoking upon entering care regained 5.7 years and 4.6 years, respectively. Factors associated with greater benefits from smoking cessation included younger age, higher initial CD4⁺ T-cell count, and complete adherence to antiretroviral therapy. Smoking cessation by 10%-25% of HIV-infected smokers could save approximately 106 000-265 000 years of life.

CONCLUSIONS

 HIV-infected US smokers aged 40 years lose >6 years of life expectancy from smoking, possibly outweighing the loss from HIV infection itself. Smoking cessation should become a priority in HIV treatment programs.

Clinical Impact and Cost-effectiveness of Diagnosing HIV Infection During Early Infancy in South Africa: Test Timing and Frequency

BACKGROUND

 Diagnosis of human immunodeficiency virus (HIV) infection during early infancy (commonly known as "early infant HIV diagnosis" [EID]) followed by prompt initiation of antiretroviral therapy dramatically reduces mortality. EID testing is recommended at 6 weeks of age, but many infant infections are missed.

DESIGN/METHODS

 We simulated 4 EID testing strategies for HIV-exposed infants in South Africa: no EID (diagnosis only after illness; hereafter, "no EID"), testing once (at birth alone or at 6 weeks of age alone; hereafter, "birth alone" and "6 weeks alone," respectively), and testing twice (at birth and 6 weeks of age; hereafter "birth and 6 weeks"). We calculated incremental cost-effectiveness ratios (ICERs), using discounted costs and life expectancies for all HIV-exposed (infected and uninfected) infants.

RESULTS

 In the base case (guideline-concordant care), the no EID strategy produced a life expectancy of 21.1 years (in the HIV-infected group) and 61.1 years (in the HIV-exposed group); lifetime cost averaged $1430/HIV-exposed infant. The birth and 6 weeks strategy maximized life expectancy (26.5 years in the HIV-infected group and 61.4 years in the HIV-exposed group), costing $1840/infant tested. The ICER of the 6 weeks alone strategy versus the no EID strategy was $1250/year of life saved (19% of South Africa's per capita gross domestic product); the ICER for the birth and 6 weeks strategy versus the 6 weeks alone strategy was $2900/year of life saved (45% of South Africa's per capita gross domestic product). Increasing the proportion of caregivers who receive test results and the linkage of HIV-positive infants to antiretroviral therapy with the 6 weeks alone strategy improved survival more than adding a second test.

CONCLUSIONS

 EID at birth and 6 weeks improves outcomes and is cost-effective, compared with EID at 6 weeks alone. If scale-up costs are comparable, programs should add birth testing after strengthening 6-week testing programs.

The Impact of Reporting a Prior Penicillin Allergy on the Treatment of Methicillin-Sensitive Staphylococcus aureus Bacteremia

Background

Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral β-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy.

Objective

To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia.

Design

Retrospective cohort.

Participants

Adult inpatients with MSSA bacteremia, January 2009 through October 2013.

Main Measures

The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes.

Key Results

Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]).

Conclusions

Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the likelihood of OT. Allergy evaluation, coupled with ID consultation, may improve outcomes in MSSA bacteremic patients.

Proceedings of the First International Conference on Stepped Wedge Trial Design

I1 Introduction

Mona Kanaan, Noreen Dadirai Mdege, Ada Keding

O1 The HiSTORIC trial: a hybrid before-and-after and stepped wedge design

RA Parker, N Mills, A Shah, F Strachan, C Keerie, CJ Weir

O2 Stepped wedge trials with non-uniform correlation structure

Andrew Forbes, Karla Hemming

O3 Challenges and solutions for the operationalisation of the ENHANCE study: a pilot stepped wedge trial within a general practice setting

Sarah A Lawton, Emma Healey, Martyn Lewis, Elaine Nicholls, Clare Jinks, Valerie Tan, Andrew Finney, Christian D Mallen, on behalf of the ENHANCE Study Team

O4 Early lessons from the implementation of a stepped wedge trial design investigating the effectiveness of a training intervention in busy health care settings: the Thistle study

Erik Lenguerrand, Graeme MacLennan, John Norrie, Siladitya Bhattacharya, Tim Draycott, on behalf of the Thistle group

O5 Sample size calculation for longitudinal cluster randomised trials: a unified framework for closed cohort and repeated cross-section designs

Richard Hooper, Steven Teerenstra, Esther de Hoop, Sandra Eldridge

O6 Restricted randomisation schemes for stepped-wedge studies with a cluster-level covariate

Alan Girling, Monica Taljaard

O7 A flexible modelling of the time trend for the analysis of stepped wedge trials: results of a simulation study

Gian Luca Di Tanna, Antonio Gasparrini

P1 Tackling acute kidney injury – a UK stepped wedge clinical trial of hospital-level quality improvement interventions

Anna Casula, Fergus Caskey, Erik Lenguerrand, Shona Methven, Stephanie MacNeill, Margaret May, Nicholas Selby

P2 Sample size considerations for quantifying secondary bacterial transmission in a stepped wedge trial of influenza vaccine

Leon Danon, Hannah Christensen, Adam Finn, Margaret May

P3 Sample size calculation for time-to-event data in stepped wedge cluster randomised trials

Fumihito Takanashi, Ada Keding, Simon Crouch, Mona Kanaan

P4 Sample size calculations for stepped-wedge cluster randomised trials with unequal cluster sizes

Caroline A. Kristunas, Karen L. Smith, Laura J. Gray

P5 The design of stepped wedge trials with unequal cluster sizes

John N.S. Matthews

P6 Promoting Recruitment using Information Management Efficiently (PRIME): a stepped wedge SWAT (study-within-a-trial)

R Al-Shahi Salman, RA Parker, A Maxwell, M Dennis, A Rudd, CJ Weir

P7 Implications of misspecified mixed effect models in stepped wedge trial analysis: how wrong can it be?

Jennifer A Thompson, Katherine L Fielding, Calum Davey, Alexander M Aiken, James R Hargreaves, Richard J Hayes

S1 Stepped Wedge Designs with Multiple Interventions

Vivian H Lyons, Lingyu Li, James Hughes, Ali Rowhani-Rahbar

S2 Analysis of the cross-sectional stepped wedge cluster randomised trial

Karla Hemming, Monica Taljaard, Andrew Forbes

Potential Clinical and Economic Value of Long-Acting Preexposure Prophylaxis for South African Women at High-Risk for HIV Infection

BACKGROUND

For young South African women at risk for human immunodeficiency virus (HIV) infection, preexposure prophylaxis (PrEP) is one of the few effective prevention options available. Long-acting injectable PrEP, which is in development, may be associated with greater adherence, compared with that for existing standard oral PrEP formulations, but its likely clinical benefits and additional costs are unknown.

METHODS

Using a computer simulation, we compared the following 3 PrEP strategies: no PrEP, standard PrEP (effectiveness, 62%; cost per patient, $150/year), and long-acting PrEP (effectiveness, 75%; cost per patient, $220/year) in South African women at high risk for HIV infection (incidence of HIV infection, 5%/year). We examined the sensitivity of the strategies to changes in key input parameters among several outcome measures, including deaths averted and program cost over a 5-year period; lifetime HIV infection risk, survival rate, and program cost and cost-effectiveness; and budget impact.

RESULTS

Compared with no PrEP, standard PrEP and long-acting PrEP cost $580 and $870 more per woman, respectively, and averted 15 and 16 deaths per 1000 women at high risk for infection, respectively, over 5 years. Measured on a lifetime basis, both standard PrEP and long-acting PrEP were cost saving, compared with no PrEP. Compared with standard PrEP, long-acting PrEP was very cost-effective ($150/life-year saved) except under the most pessimistic assumptions. Over 5 years, long-acting PrEP cost $1.6 billion when provided to 50% of eligible women.

CONCLUSIONS

Currently available standard PrEP is a cost-saving intervention whose delivery should be expanded and optimized. Long-acting PrEP will likely be a very cost-effective improvement over standard PrEP but may require novel financing mechanisms that bring short-term fiscal planning efforts into closer alignment with longer-term societal objectives.

Relationship Between Upper Respiratory Tract Influenza Test Result and Clinical Outcomes Among Critically Ill Influenza Patients

Among critically ill patients with lower respiratory tract (LRT)-confirmed influenza, we retrospectively observed worse 28-day clinical outcomes in upper respiratory tract (URT)-negative versus URT-positive subjects. This finding may reflect disease progression and highlights the need for influenza testing of both URT and LRT specimens to improve diagnostic yield and possibly inform prognosis.

The Cost-effectiveness and Budget Impact of 2-Drug Dolutegravir-Lamivudine Regimens for the Treatment of HIV Infection in the United States

BACKGROUND

Recommended human immunodeficiency virus (HIV) treatment regimens in the United States contain 3 antiretroviral agents, costing >$30 000/person/year. Pilot studies are evaluating the efficacy of dual therapy with dolutegravir (DTG) and lamivudine (3TC). We examined the potential cost-effectiveness and budget impact of DTG + 3TC regimens in the United States.

METHODS

Using a mathematical model, we projected the clinical and economic outcomes of antiretroviral therapy (ART)-naive patients under 4 strategies: (1) no ART (for modeling comparison); (2) 2-drug: initial regimen of DTG + 3TC; (3) induction-maintenance: 48-week induction regimen of 3 drugs (DTG/abacavir [ABC]/3TC), followed by DTG + 3TC maintenance if virologically suppressed; and (4) standard of care: 3-drug regimen of DTG/ABC/3TC. Strategy-dependent model inputs, varied widely in sensitivity analyses, included 48-week virologic suppression (88%-93%), subsequent virologic failure (0.1%-0.6%/month), and Medicaid-discounted ART costs ($15 200-$39 600/year). A strategy was considered cost-effective if its incremental cost-effectiveness ratio (ICER) was <$100 000/quality-adjusted life-year (QALY).

RESULTS

The 3 ART strategies had the same 5-year survival rates (90%). The ICER was $22 500/QALY for induction-maintenance and >$500 000/QALY for standard of care. Two-drug was the preferred strategy only when DTG + 3TC 48-week virologic suppression rate exceeded 90%. With 50% uptake of either induction-maintenance or 2-drug for ART-naive patients, cost savings totaled $550 million and $800 million, respectively, within 5 years; savings reached >$3 billion if 25% of currently suppressed patients were switched to DTG + 3TC maintenance.

CONCLUSIONS

Should DTG + 3TC demonstrate high rates of virologic suppression, this regimen will be cost-effective and would save >$500 million in ART costs in the United States over 5 years.

Prioritizing HIV comparative effectiveness trials based on value of information: generic versus brand-name ART in the US

BACKGROUND

Value of Information (VOI) analysis examines whether to acquire information before making a decision. We introduced VOI to the HIV audience, using the example of generic antiretroviral therapy (ART) in the US.

METHODS AND FINDINGS

We used a mathematical model and probabilistic sensitivity analysis (PSA) to generate probability distributions of survival (in quality-adjusted life years, QALYs) and cost for three potential first-line ART regimens: three-pill generic, two-pill generic, and single-pill branded. These served as input for a comparison of two hypothetical two-arm trials: three-pill generic versus single-pill branded; and two-pill generic versus single-pill branded. We modeled pre-trial uncertainty by defining probability distributions around key inputs, including 24-week HIV-RNA suppression and subsequent ART failure. We assumed that, without a trial, patients received the single-pill branded strategy. Post-trial, we assumed that patients received the most cost-effective strategy. For both trials, we quantified the probability of changing to a generic-based regimen upon trial completion and the expected VOI in terms of improved health outcomes and costs. Assuming a willingness to pay (WTP) threshold of $100 000/QALY, the three-pill trial led to more treatment changes (84%) than the two-pill trial (78%). Estimated VOI was $48 000 (three-pill trial) and $35 700 (two-pill trial) per future patient initiating ART.

CONCLUSIONS

A three-pill trial of generic ART is more likely to lead to post-trial treatment changes and to provide more value than a two-pill trial if policy decisions are based on cost-effectiveness. Value of Information analysis can identify trials likely to confer the greatest impact and value for HIV care.

Evaluating Academic Scientists Collaborating in Team-Based Research: A Proposed Framework

Criteria for evaluating faculty are traditionally based on a triad of scholarship, teaching, and service. Research scholarship is often measured by first or senior authorship on peer-reviewed scientific publications and being principal investigator on extramural grants. Yet scientific innovation increasingly requires collective rather than individual creativity, which traditional measures of achievement were not designed to capture and, thus, devalue. The authors propose a simple, flexible framework for evaluating team scientists that includes both quantitative and qualitative assessments. An approach for documenting contributions of team scientists in team-based scholarship, nontraditional education, and specialized service activities is also outlined. Although biostatisticians are used for illustration, the approach is generalizable to team scientists in other disciplines.The authors offer three key recommendations to members of institutional promotion committees, department chairs, and others evaluating team scientists. First, contributions to team-based scholarship and specialized contributions to education and service need to be assessed and given appropriate and substantial weight. Second, evaluations must be founded on well-articulated criteria for assessing the stature and accomplishments of team scientists. Finally, mechanisms for collecting evaluative data must be developed and implemented at the institutional level. Without these three essentials, contributions of team scientists will continue to be undervalued in the academic environment.

Improving Clinical Outcomes in Patients With Methicillin-Sensitive Staphylococcus aureus Bacteremia and Reported Penicillin Allergy

BACKGROUND

Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection. First-line MSSA therapies (nafcillin, oxacillin, cefazolin) are generally avoided in the 10% of patients reporting penicillin (PCN) allergy, but most of these patients are not truly allergic. We used a decision tree with sensitivity analyses to determine the optimal evaluation and treatment for patients with MSSA bacteremia and reported PCN allergy.

METHODS

Our model simulates 3 strategies: (1) no allergy evaluation, give vancomycin (Vanc); (2) allergy history-guided treatment: if history excludes anaphylactic features, give cefazolin (Hx-Cefaz); and (3) complete allergy evaluation with history-appropriate PCN skin testing: if skin test negative, give cefazolin (ST-Cefaz). Model outcomes included 12-week MSSA cure, recurrence, and death; allergic reactions including major, minor, and potentially iatrogenic; and adverse drug reactions.

RESULTS

Vanc results in the fewest patients achieving MSSA cure and the highest rate of recurrence (67.3%/14.8% vs 83.4%/9.3% for Hx-Cefaz and 84.5%/8.9% for ST-Cefaz) as well as the greatest frequency of allergic reactions (3.0% vs 2.4% for Hx-Cefaz and 1.7% for ST-Cefaz) and highest rates of adverse drug reactions (5.2% vs 4.6% for Hx-Cefaz and 4.7% for ST-Cefaz). Even in a "best case for Vanc" scenario, Vanc yields the poorest outcomes. ST-Cefaz is preferred to Hx-Cefaz although sensitive to input variations.

CONCLUSIONS

Patients with MSSA bacteremia and a reported PCN allergy should have the allergy addressed for optimal treatment. Full allergy evaluation with skin testing seems to be preferred, although more data are needed.

Peripheral blood eosinophilia and hypersensitivity reactions among patients receiving outpatient parenteral antibiotics

BACKGROUND

Although drug-induced peripheral eosinophilia complicates antimicrobial therapy, little is known about its frequency and implications.

OBJECTIVE

We aimed to determine the frequency and predictors of antibiotic-induced eosinophilia and subsequent hypersensitivity reactions (HSRs).

METHODS

We evaluated a prospective cohort of former inpatients receiving intravenous antibiotic therapy as outpatients with at least 1 differential blood count. We used multivariate Cox proportional hazards models with time-varying antibiotic treatment indicators to assess the effect of demographic data and antibiotic exposures on eosinophilia and subsequent HSRs, including documented rash, renal injury, and liver injury. Possible drug rash with eosinophilia and systemic symptoms (DRESS) syndrome cases were identified and manually validated.

RESULTS

Of 824 patients (60% male; median age, 60 years; median therapy duration, 41 days), 210 (25%) had eosinophilia, with median peak absolute eosinophil counts of 726/mL (interquartile range, 594-990/mL). Use of vancomycin, penicillin, rifampin, and linezolid was associated with a higher hazard of having eosinophilia. There was a subsequent HSR in 64 (30%) of 210 patients with eosinophilia, including rash (n = 32), renal injury (n = 31), and liver injury (n = 13). Patients with eosinophilia were significantly more likely to have rash (hazard ratio [HR], 4.16; 95% CI, 2.54-6.83; P < .0001) and renal injury (HR, 2.13; 95% CI, 1.36-3.33; P = .0009) but not liver injury (HR, 1.75; 95% CI, 0.92-3.33; P = .09). Possible DRESS syndrome occurred in 7 (0.8%) of 824 patients; 4 (57%) were receiving vancomycin.

CONCLUSIONS

Drug-induced eosinophilia is common with parenteral antibiotics. Although most patients with eosinophilia do not have an HSR, eosinophilia increases the hazard rate of having rash and renal injury. DRESS syndrome was more common than previously described.

When one becomes more: minimum renal artery length in laparoscopic live donor nephrectomy

BACKGROUND

Laparoscopic donor nephrectomy may convert short main arteries into multiple arteries, increasing the technical challenge of implantation. We evaluated our experience to identify factors predictive of multiple arteries after laparoscopic nephrectomy.

METHODS

All laparoscopic nephrectomies from the start of our program in November 2002 until June 2013 were studied, and preoperative imaging reviewed for donor artery length and multiplicity together with operative findings.

RESULTS

A total of 287 consecutive laparoscopic live donor nephrectomies (64 right and 223 left nephrectomies) were studied. Renal artery length was measured from preoperative donor magnetic resonance or computed tomography angiogram and nephrectomy performed using a laparoscopic stapling device. Nine left kidneys with a single artery (6, 7, 9, 10, 11, 12, 13, 14, and 16 mm in length) and five right kidneys with a single artery (5, 13, 15, 20, and 26 mm) on imaging resulted in multiple renal arteries at implantation. Complex renal vein anatomy was associated with multiple arteries following retrieval.

CONCLUSION

A main renal artery length of more than 16 mm on the left and 26 mm on the right is unlikely to result in multiple arteries to implant. The possibility of multiple arteries should be borne in mind when the donor renal artery is short.

Thoracic central venous evaluation: comparison of first-pass direct versus delayed-phase indirect multidetector CT venography

PURPOSE

The purpose was to compare first-pass and delayed-phase thoracic computed tomography (CT) venography for the evaluation of suspected central thoracic venous pathology.

MATERIAL AND METHODS

CT images and medical records of all patients who underwent thoracic CT venography over a 5-year period were retrospectively reviewed. Both first-pass (18s) and delayed-phase (60s) venous images were obtained in all patients. The images were reviewed in random order by three readers using a semiquantitative visual grading scheme for image quality, including artifacts and the uniformity of venous enhancement. In addition, enhancement was quantitatively evaluated. The presence and type of venous pathology, and overall diagnostic confidence were recorded and compared. Reference verification was performed when available.

RESULTS

Eighteen patients formed the study group, mean age 49.5years and 28% male. Dual-arm injection was successful in 72% of exams. All readers reported more streak artifacts on first-pass imaging than delayed imaging (72%-94% vs. 27%-44%, respectively; P<.05). First-pass imaging had significantly higher measured enhancement across all central venous segments than delayed imaging (mean HU range 212-906 HU vs. 173-414 HU; P<.05) but also had significantly more heterogeneous enhancement (mean S.D. range 75-1058 HU vs. 67-378 HU; P<.05). For overall diagnosis, reader agreement, accuracy, and confidence levels were higher for delayed-phase images (P<.05).

CONCLUSION

Indirect thoracic CT venography using delayed-phase imaging alone may be sufficient for evaluating clinically suspected central venous abnormality.

Clinic-based routine voluntary HIV testing in a refugee settlement in Uganda

We implemented and evaluated a clinic-based routine voluntary HIV testing intervention in Nakivale Refugee Settlement in Uganda. Comparing the standard of care period (40 d) with the intervention period (168 d), the mean HIV-infected clients identified per week increased from 0.9 to 5.6, and there was no significant difference between the HIV prevalence in the 2 periods (standard of care: 3.3%; intervention: 4.5%; P > 0.5). Clinic-based routine HIV testing in a refugee settlement is effective and should be considered for implementation in refugee settlements in other high-prevalence regions in sub-Saharan Africa.

Model for a university-based clinical research development infrastructure

The Research Development Core (RDC) is housed within the Michigan Institute for Clinical & Health Research (MICHR) at the University of Michigan (U-M). Established in 2006, RDC provides no-cost, in-person consultations to help U-M investigators strengthen their grant proposals. RDC offers investigators feedback and critique on all aspects of their study design, plus partnerships, funding mechanisms, and future directions. This article describes RDC's model and provides data describing the success of its services.RDC is composed of a multidisciplinary team of professionals in grant development. It comprises two senior faculty codirectors from the U-M Medical School, two senior biostatisticians, outside faculty content experts, and RDC administrative staff. Investigators contact RDC to request a consultation and submit advance grant materials for review by the RDC team. During the consultation, investigators explain their project and identify challenges. The RDC team and additional experts offer feedback that is captured in meeting notes and provided to investigators. RDC commitments beyond the meetings are implemented and carefully tracked. Investigators may also request grant editing, budgeting, or proposal submission assistance. Investigators using RDC have been awarded $44.5 million since 2011.The demand for RDC consultations doubled from 2010 to 2011 and reached a high of 131 consultations in 2012. Investigator feedback has been positive: 80% reported that RDC had a strong impact on their proposal, and over 90% indicated that they would recommend RDC to colleagues. MICHR is committed to providing investigators with RDC services to better ensure strong grant applications and successful research careers.

Prediction of complications after partial nephrectomy by RENAL nephrometry score

INTRODUCTION

Discussing and planning the appropriate management for suspicious renal masses can be challenging. With the development of nephrometry scoring methods, we aimed to evaluate the ability of the RENAL nephrometry score to predict both the incidence of postoperative complications and the change in renal function after a partial nephrectomy.

METHODS

This was a retrospective study including 128 consecutive patients who underwent a partial nephrectomy (open and laparoscopic) for renal lesions in a tertiary UK referral centre. Univariate and multivariate ordinal regression models were used to identify associations between Clavien-Dindo classification and explanatory variables. The Kendall rank correlation coefficient was used to examine an association between RENAL nephrometry score and a drop in estimated glomerular filtration rate (eGFR) following surgery.

RESULTS

An increase in the RENAL nephrometry score of one point resulted in greater odds of being in a higher Clavien-Dindo classification after controlling for RENAL suffix and type of surgical procedure (odds ratio [OR]: 1.29, 95% confidence interval [CI]: 1.04-1.64, p=0.043). Furthermore, a patient with the RENAL suffix 'p' (ie posterior location of tumour) had increased odds of developing more serious complications (OR: 2.60, 95% CI: 1.07-6.30, p=0.042). A correlation was shown between RENAL nephrometry score and postoperative drop in eGFR (Kendall's tau coefficient -0.24, p=0.004).

CONCLUSIONS

To our knowledge, this is the first study that has shown the predictive ability of the RENAL nephrometry scoring system in a UK cohort both in terms of postoperative complications and change in renal function.

The yield of colorectal cancer among fast track patients with normocytic and microcytic anaemia

INTRODUCTION

We receive fast track referrals on the basis of iron deficiency anaemia (IDA) for patients with normocytic anaemia or for patients with no iron studies. This study examined the yield of colorectal cancer (CRC) among fast track patients to ascertain whether awaiting confirmation of IDA is necessary prior to performing bowel investigations.

METHODS

A review was undertaken of 321 and 930 consecutive fast track referrals from Centre A and Centre B respectively. Contingency tables were analysed using Fisher's exact test. Logistic regression analyses were performed to investigate significant predictors of CRC.

RESULTS

Overall, 229 patients were included from Centre A and 689 from Centre B. The odds ratio for microcytic anaemia versus normocytic anaemia in the outcome of CRC was 1.3 (95% confidence interval [CI]: 0.5-3.9) for Centre A and 1.6 (95% CI: 0.8-3.3) for Centre B. In a logistic regression analysis (Centre B only), no significant difference in CRC rates was seen between microcytic and normocytic anaemia (adjusted odds ratio: 1.9, 95% CI: 0.9-3.9). There was no statistically significant difference in the yield of CRC between microcytic and normocytic anaemia (p=0.515, Fisher's exact test) in patients with anaemia only and no colorectal symptoms. Finally, CRC cases were seen in both microcytic and normocytic groups with or without low ferritin.

CONCLUSIONS

There is no significant difference in the yield of CRC between fast track patients with microcytic and normocytic anaemia. This study provides insufficient evidence to support awaiting confirmation of IDA in fast track patients with normocytic anaemia prior to requesting bowel investigations.

Assessing efficient patient care: should length of stay be calculated independently of local admission rates?

OBJECTIVE

To compare the length of hospitalisation for infants with bronchiolitis across the Eastern region and to assess the impact of the varying admission rates in each hospital.

DESIGN

Data collection through the Hospital Episode Statistics (HES) using the ICD clinical coding for bronchiolitis across all hospitals in east of England for three winter seasons (October to March for the years 2009/10, 2010/11 and 2011/12).

MAIN OUTCOME MEASURE

Length of hospital stay, corrected to adjust for local population.

RESULTS

Seventeen hospitals across the east of England were included in this study. Overall admission rate (as a percentage of the population) for the region was 3.3% and consistent with national data, but rates within individual hospitals varied between 1.5% and 5.7% over the 3-year period. Bed days per 1000 population ('standardised bed days') per year varied almost fourfold, from 34.5 to 122.3 in different hospitals. Corrected length of stay showed high discordance when compared to average length of stay.

CONCLUSIONS

The average length of stay is substantially affected by admission rates, with hospitals who admit a greater proportion of infants appearing to have a shorter uncorrected length of stay. We propose that a single corrected measure for length of stay should be used when assessing the efficiency of care because it is unaffected by variations in local admission rates and is adjusted for local population size.

Quantification and comparison of psychiatric distress in African patients with albinism and vitiligo: a 5-year prospective study

BACKGROUND

Vitiligo and albinism are two disorders of pigmentation that make the affected African highly visible and strikingly different from their peers. Both pose considerable management challenges, attract significant stigma and profound impairment of quality of life.

OBJECTIVE AND METHODS

To determine and compare psychiatric distress in vitiligo and albinism using the Hospital Anxiety and Depression Scale (HADS). Participants were 87 albinos and 102 vitiligo adult patients seen at an urban tertiary hospital in Nigeria between 2004 and 2009.

RESULTS

Prevalence of psycho morbidity was 59% (60/102) in vitiligo compared with 26% (23/87) in the albinos. The mean anxiety score was estimated to be 2.55 points lower for albino patients (95% CI: 1.47 to 3.64), and the mean depression score 2.76 points lower (95% CI: 1.84 to 3.68), after adjustment for age, sex and marital status. However, significant differences were not observed when comparing the vitiligo patients with the subset of albino patients with skin cancer. Older patients had significantly higher anxiety and depression scores. Females had significantly higher anxiety scores (but not depression scores) compared to males. Genital involvement in vitiligo was significantly associated with anxiety but not depression.

CONCLUSIONS

We found that the African with vitiligo suffers significantly higher psychiatric distress than the African albino on average. Clinical evaluation of these patients would be incomplete without assessment of their psycho morbidity. There is need for increased focus on cancer prevention strategies in the African albino.

Spinal dural arteriovenous fistulas: clinical experience with endovascular treatment as a primary therapy at 2 academic referral centers

BACKGROUND AND PURPOSE

Spinal dural arteriovenous fistulas are a rare entity that, if left untreated, can lead to considerable morbidity with progressive spinal cord symptoms. The aim of this study was to evaluate the clinical outcome of patients with spinal dural arteriovenous fistulas that were primarily treated with endovascular embolization.

MATERIALS AND METHODS

A retrospective review was performed of all patients from 1997-2010 who underwent treatment at 2 academic referral centers for a spinal dural arteriovenous fistula. Follow-up was performed by clinical examination, and functional status was measured by use of the Aminoff-Logue Disability Scale, McCormick classification grading, and mRS scores. The nonparametric Wilcoxon signed rank test was used to compare pretreatment and posttreatment Aminoff-Logue Disability Scale gait and micturition scores, McCormick classification grading, and mRS scores. P values < .05 were considered significant.

RESULTS

A total of 38 patients were included. Five patients (2 endovascular, 3 surgical) were lost to follow-up and therefore were excluded from the analysis, 29 patients were initially treated from an endovascular approach (9 Onyx, 20 cyanoacrylate), and 4 patients were treated from a standard surgical approach. Five patients in the endovascular group subsequently underwent surgery for various reasons. The clinical improvements in the Aminoff-Logue Disability Scale gait and micturition scores, McCormick classification grading, and the mRS scores were statistically significant (P < .05, Wilcoxon signed rank test).

CONCLUSIONS

We conclude that endovascular treatment of spinal dural arteriovenous fistulas can result in good clinical outcomes. Surgery remains the treatment of choice when safe embolization of the proximal radicular draining vein cannot be obtained or because the shunting artery of the spinal dural arteriovenous fistula also supplies the anterior spinal, posterior spinal, or a radiculomedullary artery.

Predictors of early mortality among hospitalized nursing home residents

BACKGROUND

Emergency admissions from nursing homes (NHs) are associated with high mortality. Understanding the predictors of early mortality in these patients may guide clinicians in choosing appropriate site and level of care.

METHODS

We identified all consecutive admissions from NHs (all ages) to an Acute Medical Assessment Unit between January 2005 and December 2007. Analysis was performed at the level of the admission. The predictors of in-patient mortality at 7 days were examined using a generalized estimating equations analysis.

RESULTS

A total of 314 patients [32% male, mean age: 84.2 years (SD: 8.3 years)] were admitted during the study period constituting 410 emergency episodes. Twenty-three percent of admissions resulted in hospital mortality with 73% of deaths occurring within 1 week (50% within the first 3 days). For 7-day mortality outcome, patients with a modified early warning score (MEWS) of 4-5 on admission had 12 times the odds of death [95% confidence interval (CI) 1.40-103.56], whereas those with a score of ≥6 had 21 times the odds of death (95% CI 2.71-170.57) compared with those with a score of ≤1. An estimated glomerular filtration rate (eGFR) of 30-60 and <30 ml/min/m(2) was associated with nearly a 3-fold increase in the odds of death at 1 week (95% CI 1.10-7.97) and a 5-fold increase in the odds of death within 1 week (95% CI 1.75-14.96), respectively, compared with eGFR > 60 ml/min/m(2). C-reactive protein (CRP) >100 mg/l on admission was also associated with a 2.5 times higher odds of death (95% CI 1.23-4.95). Taking eight or more different medication items per day was associated with only a third of the odds of death (95% CI 0.09-0.98) compared with patients taking only three or fewer per day.

CONCLUSION

In acutely ill NH residents, MEWS is an important predictor of early hospital mortality and can be used in both the community and the hospital settings to identify patients whose death maybe predictable or unavoidable, thus allowing a more holistic approach to management with discussion with patient and relatives for planning of immediate care. In addition, CRP and eGFR levels on admission have also been shown to predict early hospital mortality in these patients and can be used in conjunction with MEWS in the same way to allow decision making on the appropriate level of care at the point of hospital admission.

Spatial and temporal characteristics of V1 microstimulation during chronic implantation of a microelectrode array in a behaving macaque

OBJECTIVE

It has been hypothesized that a vision prosthesis capable of evoking useful visual percepts can be based upon electrically stimulating the primary visual cortex (V1) of a blind human subject via penetrating microelectrode arrays. As a continuation of earlier work, we examined several spatial and temporal characteristics of V1 microstimulation.

APPROACH

An array of 100 penetrating microelectrodes was chronically implanted in V1 of a behaving macaque monkey. Microstimulation thresholds were measured using a two-alternative forced choice detection task. Relative locations of electrically-evoked percepts were measured using a memory saccade-to-target task.

MAIN RESULTS

The principal finding was that two years after implantation we were able to evoke behavioural responses to electric stimulation across the spatial extent of the array using groups of contiguous electrodes. Consistent responses to stimulation were evoked at an average threshold current per electrode of 204 ± 49 µA (mean ± std) for groups of four electrodes and 91 ± 25 µA for groups of nine electrodes. Saccades to electrically-evoked percepts using groups of nine electrodes showed that the animal could discriminate spatially distinct percepts with groups having an average separation of 1.6 ± 0.3 mm (mean ± std) in cortex and 1.0° ± 0.2° in visual space. Significance. These results demonstrate chronic perceptual functionality and provide evidence for the feasibility of a cortically-based vision prosthesis for the blind using penetrating microelectrodes.

Stopping guidelines for harm in a study designed to establish the safety of a marketed drug

In a study designed to establish the safety of a marketed drug, interim analyses performed to detect harm can protect trial participants and the wider public before the final analysis occurs. Monitoring for harm within a safety study is different from monitoring for benefit, so techniques commonly used in an efficacy study of an experimental drug may not apply. We propose potentially more suitable techniques in this setting, including a novel spending function and conditional power. These techniques have reasonable operating characteristics in a simulation. The appropriate technique to implement will depend on circumstances of specific to the individual safety study.

Assessing Similarity to Existing Drugs to Decide Whether to Continue Drug Development

Developing a drug requires large investments, over many years, with dramatic increases in development costs at later stages. Thus, one wants to make a No Go decision on a compound early, unless evidence continues to suggest that the project will ultimately be successful, so that resources can be focused on the most promising compounds to benefit patients. Instead of predicting the probability of success of a Phase III study, our approach to this decision uses the Phase II study results to assess similarity of the novel compound to existing drugs that are classified by different decision categories, such as a clear Go decision (e.g., a clearly effective drug), a (unfortunately common) Not Sure decision (e.g., a potentially useful but not outstanding drug), and a clear No Go decision (e.g., a clearly not effective drug). We describe how this modeling can be done using both individual and binary endpoints and how results can be combined for several different endpoints. Potential extensions of the method are also discussed.

Risk factors for nonvertebral fracture in obese older women

CONTEXT

A high prevalence of obesity has recently been reported in postmenopausal women with low trauma fracture, suggesting that higher bone mineral density (BMD) in obese individuals may not be protective against fracture.

OBJECTIVE

The aim of this study was to compare BMD and other risk factors for nonvertebral fracture in 1377 obese postmenopausal women.

DESIGN

Characteristics of obese women with and without incident nonvertebral fracture were investigated among the prospective cohort in the Study of Osteoporotic Fractures.

SETTING

The Study of Osteoporotic Fractures is a multicenter study of 9704 women (>99% Caucasian) aged 65 yr and over who were recruited between September 1986 and October 1988 from population-based listings at four U.S. clinical centers.

MAIN OUTCOME MEASURE

The main outcome measure was nonvertebral fracture.

RESULTS

BMD T-scores in the spine, femoral neck, and total hip were significantly lower in obese women who experienced fractures than in obese women without fracture: mean differences, -0.56 [95% confidence interval (CI) = -0.73 to -0.39], -0.46 (95% CI = -0.57 to -0.36), and -0.51 (95% CI = -0.62 to -0.39), respectively (P < 0.0001 for all). A previous history of fracture [odds ratio = 1.69 (95% CI = 1.33-2.14); P < 0.0001] and femoral neck BMD [1.62 (95% CI = 1.42-1.85) per sd decrease in BMD; P < 0.0001] were independently associated with incident nonvertebral fracture.

CONCLUSIONS

Obese postmenopausal women who sustain nonvertebral fractures have significantly lower BMD on average than obese women without fracture and are more likely to have a past history of fracture. Fractures in obese postmenopausal women thus exhibit some characteristics of fragility fractures.

Assessment of quality of life in equine patients

REASONS FOR PERFORMING STUDY

Assessing patients' quality of life (QOL) is a core part of clinical decision making. Various methodologies for assessing patients' QOL have been developed in human medicine and small animal veterinary disciplines. In contrast, the lack of aids for QOL assessment in equine veterinary practice leaves practitioners reliant on subjective assessments of QOL, which may be prone to avoidable errors.

OBJECTIVES

This paper suggests pragmatic ways in which QOL may be enhanced, while remaining appropriate for the time, financial and owner-based constraints within equine practice.

METHODS

Through interdisciplinary research, this paper identifies, adapts and applies insights from several areas of research and practical experience in order to develop an overarching approach to making QOL-based decisions in clinical cases.

RESULTS

The paper identifies 6 steps involved in QOL-based decision making and provides examples of how these steps may be practically applied. These include deciding what each clinician feels is important; deciding how to evaluate it, including taking owners' views into consideration; making decisions about each case and achieving the desired clinical outcomes.

CONCLUSIONS

Practitioners can draw their own conclusions on how they may improve QOL assessment in practice and may usefully share these with colleagues. Reporting cases and sharing practical examples of QOL tools used on the ground are vital to the development of this field and appropriate methodologies.

POTENTIAL RELEVANCE

Improvements in QOL assessment are relevant to all areas of equine veterinary practice, and several areas of research. Further research may develop QOL assessment in practice, but more important are the personal improvements that each practitioner may achieve.

Fracture incidence after liver transplantation: results of a 10-year audit

BACKGROUND

High rates of fracture following liver transplantation were reported in earlier years, but the impact of subsequent changes in immune suppression and the introduction of bone-protective therapy on fracture rate have not been reported.

AIM

The aim of this study was to document clinical fracture incidence during the period 1998-2008 in a single transplant centre, following the introduction of a bone management protocol.

DESIGN

It was designed as a retrospective cohort.

METHODS

Records were retrieved from 531 of 592 eligible patients in an audit of all patients undergoing a first liver transplant during the 10-year period. All fractures were verified radiologically.

RESULTS

The mean follow-up period was 61.4 months. Prior to transplantation 5.6% of patients had a history of fracture. Incident clinical fractures following transplantation were recorded in just 15 (3.5%) patients. The most common fracture site was the spine and the median time from transplant to fracture was 26 months (range 2-83 months).

CONCLUSION

There was a low fracture rate in patients undergoing liver transplantation in this centre over the past 10 years. This rate is lower than that in previous reports, which is likely to reflect the use of lower doses of prednisolone for immune suppression and the administration of bone-protective therapy to high-risk patients.

Accuracy of hepatocellular carcinoma detection on multidetector CT in a transplant liver population with explant liver correlation

AIM

To evaluate the diagnostic accuracy of multidetector computed tomography (MDCT) for hepatocellular carcinoma (HCC) in cirrhotic patients undergoing liver transplantation. Secondary aims were to examine the effect of radiologist experience and lesion size on diagnostic accuracy.

MATERIALS AND METHODS

Thirty-nine patients (72% male with a mean age of 56.5 years) underwent liver transplantation following preoperative triple-phase MDCT examination of the liver. MDCT examinations were retrospectively independently reviewed by three radiologists for the presence and location of suspected HCCs, with the diagnostic confidence recorded using a five-point confidence scale. MDCT examinations were compared with explant specimens for histopathological correlation.

RESULTS

Histopathological results demonstrated 46 HCCs in 29 of the 39 patients. Analysis demonstrated a sensitivity of 65-75% and specificity of 47-88% for detection of HCC lesions. The sensitivity dropped to 48-57% for lesions of size ≤20mm. As the diagnostic confidence increased, there was a further decrease in the sensitivity (4-26%). The radiologist with the greatest number of years experience was found to have a significantly higher accuracy of detection of HCC lesions compared with the least experienced radiologist.

CONCLUSION

Larger lesion size of HCC and greater number of years experience of the radiologist resulted in significantly higher accuracy of HCC lesion detection. The overall sensitivity and specificity results for MDCT detection of HCC are comparable to previous helical CT imaging.

Accuracy of hepatocellular carcinoma detection on multidetector CT in a transplant liver population with explant liver correlation

AIM

To evaluate the diagnostic accuracy of multidetector computed tomography (MDCT) for hepatocellular carcinoma (HCC) in cirrhotic patients undergoing liver transplantation. Secondary aims were to examine the effect of radiologist experience and lesion size on diagnostic accuracy.

MATERIALS AND METHODS

Thirty-nine patients (72% male with a mean age of 56.5 years) underwent liver transplantation following preoperative triple-phase MDCT examination of the liver. MDCT examinations were retrospectively independently reviewed by three radiologists for the presence and location of suspected HCCs, with the diagnostic confidence recorded using a five-point confidence scale. MDCT examinations were compared with explant specimens for histopathological correlation.

RESULTS

Histopathological results demonstrated 46 HCCs in 29 of the 39 patients. Analysis demonstrated a sensitivity of 65-75% and specificity of 47-88% for detection of HCC lesions. The sensitivity dropped to 48-57% for lesions of size ≤20mm. As the diagnostic confidence increased, there was a further decrease in the sensitivity (4-26%). The radiologist with the greatest number of years experience was found to have a significantly higher accuracy of detection of HCC lesions compared with the least experienced radiologist.

CONCLUSION

Larger lesion size of HCC and greater number of years experience of the radiologist resulted in significantly higher accuracy of HCC lesion detection. The overall sensitivity and specificity results for MDCT detection of HCC are comparable to previous helical CT imaging.

Payload crew members' view of spacelab operations

Various operational aspects of the Spacelab 1 mission are reviewed by the four payload crew members. Two-shift operations, voice communication with ground investigators, joint participation in experiment activity, Spacelab performance, and recent advances are discussed.

Testing for qualitative interactions between stages in an adaptive study

I consider the underlying structure for a test of qualitative interaction of a treatment when assessing heterogeneity between stages in an adaptive trial. Since decisions about the clinical utility of a drug are based on the balance of risks and benefits, a quantitative interaction in treatment efficacy across different groups could lead to qualitatively different decisions. Thus, the difference between quantitative and qualitative interactions is not a true dichotomy. I show that the standard tests for qualitative interactions (Gail and Simon,Biometrics 1985; 41:361-372; Piantadosi and Gail, Statist. Med. 1993; 12:1239-1248) are very conservative in this application. Theoretical calculations in a simpler situation confirm that the published criteria are very conservative, which may help explain why the tests are known to have very low power to detect interaction. I introduce the concept of 'minimum detectable effect', which is the smallest effect that a study could identify as statistically significant. I propose that important heterogeneity between stages in an adaptive trial be identified when two criteria are met. First, at least one individual stage must be below the overall study mean by at least the minimum detectable effect. Second, using an appropriate critical value based on simulations, there must be statistically significant heterogeneity between the stages.

Low rates of treatment in postmenopausal women with a history of low trauma fractures: results of audit in a Fracture Liaison Service

BACKGROUND

A past history of low trauma fracture is a strong risk factor for future fractures in postmenopausal women and national guidance recommends treatment in the majority of such women

AIM

To establish the prevalence of bone protective therapy use in postmenopausal women with a history of low trauma fracture Design and

METHODS

Clinical audit of 1641 postmenopausal women presenting with a low trauma fracture to the Fracture Liaison Service at Addenbrooke's Hospital, Cambridge between January 2006 and December 2007.

RESULTS

A total of 526 (31%) women presenting with a fracture had a past history of fracture, defined as a low trauma fracture after the age of 45 years. The wrist was the most common site of previous fracture, followed by hip, hand or foot, lower leg and humerus. Of these women, only 27.6% were receiving bone protective therapy with a bisphosphonate (89%) or other medication. Calcium and vitamin D supplements were received by 35.6%. The highest rates of treatment were seen for spine and hip fracture (61.9 and 49.3%, respectively). Only 45.1% of women aged 75 years and over with a previous history of fracture were receiving bone protective therapy.

CONCLUSION

The results of our audit demonstrate low rates of treatment in postmenopausal women with a history of low trauma fracture. Better education of healthcare professionals, more consistent recording of fractures in primary care and the use of clearly defined care pathways that involve patients and their carers provide rational approaches to reducing this care gap.

Lipoprotein Changes in HIV-Infected Antiretroviral-Naïve Individuals after Starting Antiretroviral Therapy: ACTG Study A5152s Stein: Lipoprotein Changes on Antiretroviral Therapy

BACKGROUND: Dyslipidemia is a frequent complication of antiretroviral therapy (ART) for patients with human immunodeficiency virus infection (HIV). The effects of ART on lipoproteins are less well-understood, and have not been investigated in a prospective study where assignment to ART is randomized. OBJECTIVE: To evaluate the effects of three class-sparing ART regimens on lipids and lipoproteins. METHODS: This was a substudy of a prospective, multicenter study treatment-naïve HIV-infected individuals randomly assigned to receive a regimen of nucleoside reverse transcriptase inhibitors (NRTIs) + the non-nucleoside reverse transcriptase inhibitor efavirenz, NRTIs + the protease inhibitor lopinavir/ritonavir, or a NRTI-sparing regimen of efavirenz + lopinavir/ritonavir. Lipoproteins were measured by nuclear magnetic resonance spectroscopy. RESULTS: Among the 82 participants, total and small low-density lipoprotein concentrations increased (median, interquartile range) by 152 (-49 - +407, p<0.01) and 130 (-98 - +417, p<0.01) nmol/L, respectively, especially in the arms containing lopinavir/ritonavir (p(KW)<0.04). Very low-density lipoproteins also increased (p<0.01), with a larger increase in the arms that contained lopinavir/ritonavir (p=0.022). High-density lipoproteins increased by 6.0 nmol/L (2.8 - 10.4, p<0.01), but differences between arms were not significant (p(KW)=0.069). Changes were not related to changes in markers of insulin/glucose metabolism. CONCLUSIONS: Total and small low-density lipoprotein concentrations increased, especially in the arms containing lopinavir/ritonavir, as did increases in total very low-density lipoproteins. Adverse changes were especially prominent in the arm with efavirenz + lopinavir/ritonavir.

Endothelial function in human immunodeficiency virus-infected antiretroviral-naive subjects before and after starting potent antiretroviral therapy: The ACTG (AIDS Clinical Trials Group) Study 5152s

OBJECTIVES

This study evaluated the effects of 3 class-sparing antiretroviral therapy (ART) regimens on endothelial function in human immunodeficiency virus (HIV)-infected subjects participating in a randomized trial.

BACKGROUND

Endothelial dysfunction has been observed in patients receiving ART for HIV infection.

METHODS

This was a prospective, multicenter study of treatment-naive subjects who were randomly assigned to receive a protease inhibitor-sparing regimen of nucleoside reverse transcriptase inhibitors (NRTIs) + efavirenz, a non-nucleoside reverse transcriptase inhibitor-sparing regimen of NRTIs + lopinavir/ritonavir, or a NRTI-sparing regimen of efavirenz + lopinavir/ritonavir. The NRTIs were lamivudine + stavudine, zidovudine, or tenofovir. Brachial artery flow-mediated dilation (FMD) was determined by B-mode ultrasound before starting on ART, then after 4 and 24 weeks.

RESULTS

There were 82 subjects (median age 35 years, 91% men, 54% white). Baseline CD4 cell counts and plasma HIV ribonucleic acid (RNA) values were 245 cells/mm(3) and 4.8 log(10) copies/ml, respectively. At baseline, FMD was 3.68% (interquartile range [IQR] 1.98% to 5.51%). After 4 and 24 weeks of ART, plasma HIV RNA decreased by 2.1 and 3.0 log(10) copies/ml, respectively. FMD increased by 0.74% (IQR -0.62% to +2.74%, p = 0.003) and 1.48% (IQR -0.20% to +4.30%, p < 0.001), respectively, with similar changes in each arm (Kruskal-Wallis p value >0.600). The decrease in plasma HIV RNA at 24 weeks was associated with greater FMD (r(s) = -0.30, p = 0.017).

CONCLUSIONS

Among treatment-naive individuals with HIV, 3 different ART regimens rapidly improved endothelial function. Benefits were similar for all ART regimens, appeared quickly, and persisted at 24 weeks.

Long-term body fat outcomes in antiretroviral-naive participants randomized to nelfinavir or efavirenz or both plus dual nucleosides. Dual X-ray absorptiometry results from A5005s, a substudy of Adult Clinical Trials Group 384

BACKGROUND

Long-term regional body fat outcomes have not been well described in randomized antiretroviral drug trials.

METHODS

Dual x-ray absorptiometry (DXA) scans were performed every 16 weeks on a subset of 157 antiretroviral-naive participants who were randomized to receive nelfinavir, efavirenz, or both, combined with zidovudine and lamivudine or stavudine and didanosine, in a multicenter trial. Participants with any available data after baseline up to week 144 contributed to this as-treated analysis.

RESULTS

Limb fat increased similarly in all groups during the first 32 weeks. After week 32, limb fat changed by - 1.7% per year for zidovudine-lamivudine and by -19.0% per year for didanosine-stavudine (mixed model analysis of variance [MMANOVA], P < 0.0001). Adjusting for nucleoside backbone, there was an additional decrease in limb fat of -8.7% per year for the combined nelfinavir and nelfinavir + efavirenz group compared with the efavirenz group (MMANOVA, P = 0.03). Among participants receiving zidovudine-lamivudine, after week 32, limb fat changed by +2.7% per year with efavirenz and by -7.9% per year for the combined nelfinavir and nelfinavir + efavirenz group (MMANOVA, P = 0.03).

CONCLUSIONS

Over 144 weeks, zidovudine-lamivudine was superior to didanosine-stavudine with regard to limb fat loss. The combination of zidovudine, lamivudine, and efavirenz showed no overall pattern suggesting limb fat loss over time and was significantly superior to the pooled zidovudine-lamivudine-nelfinavir (with and without efavirenz) arms.

When to stop treatment arms in a clinical trial assessing time to event with more than two arms against a common control

Two-arm time-to-event (or survival) trials are powered to continue until a required number of events is reached. The authors discuss how the required number of events should be defined for a study with three or more arms with various pairwise comparisons and a common control arm. They advocate stopping one active arm when the required number of events is observed in the applicable pairwise comparison but continuing with the other active arm and the control arm until the required number of events is observed in that pairwise comparison, thereby ensuring that the study continues until enough events are observed in each pairwise comparison. This article is the result of considerations during the design of a three-arm microbicide trial.

Effects of potent antiretroviral therapy on free testosterone levels and fat-free mass in men in a prospective, randomized trial: A5005s, a substudy of AIDS Clinical Trials Group Study 384

BACKGROUND

Low testosterone levels are commonly reported in patients with advanced human immunodeficiency virus disease. The effects of initiation of different antiretroviral regimens on testosterone levels and changes in fat-free mass have not been reported.

METHODS

Antiretroviral-naive men (n=213) were randomized to receive nelfinavir, efavirenz, or both plus either zidovudine and lamivudine or stavudine and didanosine. Patients underwent measurements of metabolic parameters, including determination of free testosterone level by equilibrium dialysis and bioelectrical impedance analysis, over a 64-week period.

RESULTS

At baseline, the median free testosterone level was 92 pg/mL; the level was subnormal (i.e., <50 pg/mL) in 6%. Lower CD4 cell count at the time of study entry, higher weight, and greater age were independently associated with lower baseline free testosterone level. At week 64, the median free testosterone level increased more in zidovudine-lamivudine recipients (48 of whom had paired values available; change, +31 pg/mL) than in stavudine-didanosine recipients (57 of whom had paired values; change, +3 pg/mL; P=.001, by Wilcoxon rank sum test), and it increased more in efavirenz recipients (37 of whom had paired values; change, +30 pg/mL) than in nelfinavir recipients (28 of whom had paired values; change, -3 pg/mL; P=.05). The median fat-free mass for the entire group increased by 1.2 kg at week 64 (change, +2.0%; P<.001); the increase was greater in the zidovudine-lamivudine group (n=70; change, +1.8 kg) than in the stavudine-didanosine group (n=79; change, +0.5 kg; P=.04), and the increase was also greater for efavirenz recipients (n=53; change, +2.1 kg) than among nelfinavir recipients (n=47; change, +0.4 kg; P=.003). White race, lower CD4 cell count at study entry, assignment to the efavirenz treatment arm, and assignment to the zidovudine-lamivudine treatment arm independently predicted greater absolute change in fat-free mass at week 64.

CONCLUSIONS

Subnormal free testosterone levels occurred infrequently among these antiretroviral-naive men. Free testosterone and fat-free mass levels increased after initiation of antiretroviral therapy, with greater increases at 64 weeks among zidovudine-lamivudine recipients than among stavudine-didanosine recipients and among efavirenz recipients than among nelfinavir recipients.

Age- and gender-related differences in mitochondrial oxygen consumption and calcium with cardioplegia and diazoxide

BACKGROUND

We have recently shown that the cardioprotection afforded by cardioplegia is affected by age and gender and is less effective in the aged female rabbit heart compared with the aged male rabbit heart. We hypothesized that these differences were due to age and gender-specific modulation of mitochondrial oxygen consumption and mitochondrial free matrix calcium ([Ca2+](Mito)) content occurring during early reperfusion.

METHODS

To test this hypothesis, 104 male and female rabbit hearts, mature (15 to 20 weeks) and aged (>32 months), were subjected to Langendorff perfusion. Control hearts were perfused for 75 minutes. Global ischemia hearts were underwent 30 minutes of equilibrium, 30 minutes of global ischemia, and 15 minutes of reperfusion. Cardioplegia (potassium/magnesium) +/- diazoxide was infused 5 minutes before global ischemia. Mitochondria were isolated from left ventricular tissue and used for the measurement of oxygen consumption and [Ca2+](Mito).

RESULTS

Mitochondrial oxygen consumption was significantly increased in the mature and aged female hearts in all treatment groups (p < 0.001 versus male). Cardioplegia +/- diazoxide modulated mitochondrial oxygen consumption, but these effects were significantly decreased in the aged heart and in the female heart (p < 0.001 each versus male). Cardioplegia (potassium/magnesium) significantly decreased [Ca2+](Mito) (p < 0.001 versus global ischemia) in aged but not mature hearts. The addition of diazoxide to potassium/magnesium significantly decreased [Ca2+](Mito) in mature and aged males (p < 0.001 versus potassium/magnesium) but not in females.

CONCLUSIONS

These results demonstrate that mitochondrial oxygen consumption and [Ca2+](Mito) are modulated by age and gender and play an important role in the differences observed between mature and aged male and female response to global ischemia and the cardioprotection afforded by cardioplegia +/- diazoxide.

Farnesyl diphosphate synthase: a novel genotype association with bone mineral density in elderly women

OBJECTIVE

We evaluated the association between a single nucleotide polymorphism in the farnesyl diphosphate synthase gene (FDPS), BMD and bone turnover markers.

METHODS

Two hundred and eighty-three community-dwelling Caucasian women aged 65 or older were screened from the greater Boston area. A validated FDPS SNP (rs2297480, A/C) was genotyped and evaluated for effect on bone mineral density (spine, hip, forearm) and bone turnover markers (urine N-telopeptide cross-linked collagen type 1, osteocalcin and bone-specific alkaline phosphatase).

RESULTS

BMD was lower at all sites measured in women with the C/C or C/A genotypes. Statistically significant differences (p<0.05) were found at the PA spine, trochanter, distal radius, and proximal ulna after adjustment for age and BMI. No significant differences were found in bone turnover markers.

CONCLUSION

These findings suggest that a single nucleotide polymorphism in the FDPS gene (rs2297480) may be a genetic marker for lower BMD in postmenopausal Caucasian women.

Effects of testosterone supplementation on whole body and regional fat mass and distribution in human immunodeficiency virus-infected men with abdominal obesity

BACKGROUND

Whole body and abdominal obesity are associated with increased risk of diabetes mellitus and heart disease. The effects of testosterone therapy on whole body and visceral fat mass in HIV-infected men with abdominal obesity are unknown.

OBJECTIVE

The objective of this study was to determine the effects of testosterone therapy on intraabdominal fat mass and whole body fat distribution in HIV-infected men with abdominal obesity.

METHODS

IN this multicenter, randomized, placebo-controlled, double-blind trial, 88 HIV-positive men with abdominal obesity (waist-to-hip ratio > 0.95 or mid-waist circumference > 100 cm) and total testosterone 125-400 ng/dl, or bioavailable testosterone less than 115 ng/dl, or free testosterone less than 50 pg/ml on stable antiretroviral regimen, and HIV RNA less than 10,000 copies per milliliter were randomized to receive 10 g testosterone gel or placebo daily for 24 wk. Fat mass and distribution were determined by abdominal computerized tomography and dual energy x-ray absorptiometry during wk 0, 12, and 24. We used an intention-to-treat approach and nonparametric statistical methods.

RESULTS

Baseline characteristics were balanced between groups. In 75 subjects evaluated, median percent change from baseline to wk 24 in visceral fat did not differ significantly between groups (testosterone 0.3%, placebo 3.1%, P = 0.75). Total (testosterone -1.5%, placebo 4.3%, P = 0.04) and sc (testosterone-7.2%, placebo 8.1%, P < 0.001) abdominal fat mass decreased in testosterone-treated men, but increased in placebo group. Testosterone therapy was associated with significant decrease in whole body, trunk, and appendicular fat mass by dual energy x-ray absorptiometry (all P < 0.001), whereas whole body and trunk fat increased significantly in the placebo group. The percent of individuals reporting a decrease in abdomen (P = 0.01), neck (P = 0.08), and breast size (P = 0.01) at wk 24 was significantly greater in testosterone-treated than placebo-treated men. Testosterone-treated men had greater increase in lean body mass than placebo (testosterone 1.3%, placebo -0.3, P = 0.02). Plasma insulin, fasting glucose, and total high-density lipoprotein and low-density lipoprotein cholesterol levels did not change significantly. Testosterone therapy was well tolerated.

CONCLUSIONS

Testosterone therapy in HIV-positive men with abdominal obesity and low testosterone was associated with greater decrease in whole body, total, and sc abdominal fat mass and a greater increase in lean mass compared to placebo. However, changes in visceral fat mass were not significantly different between groups. Further studies are needed to determine testosterone effects on insulin sensitivity and cardiovascular risk.