Integrating Community Health Workers' Dual Clinic-Community Role in Safety-Net Primary Care: Implementation Lessons from a Pragmatic Diabetes-Prevention Trial

BACKGROUND

Over a third of US adults carry a diagnosis of prediabetes, 70% of whom may progress to type 2 diabetes mellitus ("diabetes"). Community health workers (CHWs) can help patients undertake healthy behavior to prevent diabetes. However, there is limited guidance to integrate CHWs in primary care, specifically to address CHWs' dual clinic-based and community-oriented role.

OBJECTIVE

Using evidence from CHWs' adaptations of a diabetes-prevention intervention in safety-net hospitals in New York City, we examine the nature, intent, and possible consequences of CHWs' actions on program fidelity. We propose strategies for integrating CHWs in primary care.

DESIGN

Case study drawing on the Model for Adaptation Design and Impact (MADI) to analyze CHWs' actions during implementation of CHORD (Community Health Outreach to Reduce Diabetes), a cluster-randomized pragmatic trial (2017-2022) at Manhattan VA and Bellevue Hospital.

PARTICIPANTS

CHWs and clinicians in the CHORD study, with a focus in this analysis on CHWs.

APPROACH

Semi-structured interviews and focus group discussion with CHWs (n=4); semi-structured interviews with clinicians (n=17). Interpretivist approach to explain CHWs' adaptations using a mix of inductive and deductive analysis.

KEY RESULTS

CHWs' adaptations extended the intervention in three ways: by extending social assistance, healthcare access, and operational tasks. The adaptations were intended to improve fit, reach, and retention, but likely had ripple effects on implementation outcomes. CHWs' focus on patients' complex social needs could divert them from judiciously managing their caseload.

CONCLUSIONS

CHWs' community knowledge can support patient engagement, but overextension of social assistance may detract from protocolized health-coaching goals. CHW programs in primary care should explicitly delineate CHWs' non-health support to patients, include multiprofessional teams or partnerships with community-based organizations, establish formal communication between CHWs and clinicians, and institute mechanisms to review and iterate CHWs' work to resolve challenges in their community-oriented role.

Implementation fidelity to a behavioral diabetes prevention intervention in two New York City safety net primary care practices

BACKGROUND

It is critical to assess implementation fidelity of evidence-based interventions and factors moderating fidelity, to understand the reasons for their success or failure. However, fidelity and fidelity moderators are seldom systematically reported. The study objective was to conduct a concurrent implementation fidelity evaluation and examine fidelity moderators of CHORD (Community Health Outreach to Reduce Diabetes), a pragmatic, cluster-randomized, controlled trial to test the impact of a Community Health Workers (CHW)-led health coaching intervention to prevent incident type 2 Diabetes Mellitus in New York (NY).

METHODS

We applied the Conceptual Framework for Implementation Fidelity to assess implementation fidelity and factors moderating it across the four core intervention components: patient goal setting, education topic coaching, primary care (PC) visits, and referrals to address social determinants of health (SDH), using descriptive statistics and regression models. PC patients with prediabetes receiving care from safety-net patient-centered medical homes (PCMHs) at either, VA NY Harbor or at Bellevue Hospital (BH) were eligible to be randomized into the CHW-led CHORD intervention or usual care. Among 559 patients randomized and enrolled in the intervention group, 79.4% completed the intake survey and were included in the analytic sample for fidelity assessment. Fidelity was measured as coverage, content adherence and frequency of each core component, and the moderators assessed were implementation site and patient activation measure.

RESULTS

Content adherence was high for three components with nearly 80.0% of patients setting ≥ 1 goal, having ≥ 1 PC visit and receiving ≥ 1 education session. Only 45.0% patients received ≥ 1 SDH referral. After adjusting for patient gender, language, race, ethnicity, and age, the implementation site moderated adherence to goal setting (77.4% BH vs. 87.7% VA), educational coaching (78.9% BH vs. 88.3% VA), number of successful CHW-patient encounters (6 BH vs 4 VA) and percent of patients receiving all four components (41.1% BH vs. 25.7% VA).

CONCLUSIONS

The fidelity to the four CHORD intervention components differed between the two implementation sites, demonstrating the challenges in implementing complex evidence-based interventions in different settings. Our findings underscore the importance of measuring implementation fidelity in contextualizing the outcomes of randomized trials of complex multi-site behavioral interventions.

TRIAL REGISTRATION

The trial was registered with ClinicalTrials.gov on 30/12/2016 and the registration number is NCT03006666 .

Policy by Pilot? Learning From Demonstration Projects for Integrated Care Comment on "Integration or Fragmentation of Health Care? Examining Policies and Politics in a Belgian Case Study"

Analysis of policy implementation for chronic disease in Belgium highlights the difficulties of launching experiments for integrated care in a health system with fragmented governance. It also entreats us to consider the inherent challenges of piloting integrated care for chronic disease. Sociomedical characteristics of chronic disease -political, social, and economic aspects of improving outcomes - pose distinct problems for pilot projects, particularly because addressing health inequity requires collaboration across health and social sectors and a long-term, life-course perspective on health. Drawing on recent US experience with demonstration projects for health service delivery reform and on chronic disease research, I discuss constraints of and lessons from pilot projects. The policy learning from pilots lies beyond their technical evaluative yield. Pilot projects can evince political and social challenges to achieving integrated chronic disease care, and can illuminate overlooked perspectives, such as those of community-based organizations (CBOs), thereby potentially extending the terms of policy debate.

Ensuring the ordinary: Politics and public service in municipal primary care in India

This paper examines the political embeddedness of public-sector primary care in urban India. The low quality of urban healthcare in many low- and middle-income countries is well documented. But there is relatively little analysis showing how the politics of urban healthcare delivery contribute to quality shortfalls. This study integrates urban and political theory and draws on ethnographic fieldwork in municipal government-run primary care clinics in Pune, India. I conceptualize Pune's municipal doctors as street-level bureaucrats: frontline state agents charged with delivering public services, who regularly confront conflicts between their mandate and its realization in practice. I observe how the municipal doctors experience and respond to these conflicts; delineate the historical design of the municipal institutions in which they operate; and interview doctors, nurses, nonclinical staff, administrators, and elected officials, who collectively shape primary care delivery in municipal clinics. My findings show how the doctors' work is characterized by routine departures from public service ideals. The departures stem from local electoral politics (politicians' patronage and clientelistic relations with municipal employees and patients) and weak administrative capacity (misuse and incompetent planning of public resources). The doctors are compelled to follow extra-policy directives, meaning instructions that have little to do with healthcare goals and that emphasize the political utility rather than medical purpose of their work. In response, the doctors circumscribe their clinical practice. They aim, as one doctor put it, only to "ensure the ordinary," or to sustain a deficient status quo. In these conditions, improving quality of care requires not just behavioral interventions targeted at doctors. It requires normative, social, and organizational shifts in public service planning and delivery so that doctors are positioned - materially and affectively - to meet urban healthcare challenges in low-resource contexts.

Influence of organizational and social contexts on the implementation of culturally adapted hypertension control programs in Asian American-serving grocery stores, restaurants, and faith-based community sites: a qualitative study

Hypertension affects a third of U.S. adults and is especially high among Asian American groups. The Racial and Ethnic Approaches to Community Health for Asian AmeRicans (REACH FAR) project delivers culturally adapted, evidence-based hypertension-related programs to Bangladeshi, Filipino, Korean, and Asian Indian communities in New York and New Jersey through 26 sites: ethnic grocery stores, restaurants, and Muslim, Christian, and Sikh faith-based organizations. Knowledge of the implementation mechanisms of culturally adapted programs is limited and is critical to inform the design and execution of such programs by and in community sites. We applied four categories of the Consolidated Framework for Implementation Research-intervention and individuals' characteristics, inner and outer setting-to analyze factors influencing implementation outcomes, that is, site leaders' perceptions about adopting, adapting, and sustaining REACH FAR. We conducted semistructured interviews with 15 leaders, coded them for implementation outcomes, and recoded them to identify contextual factors. Our findings show that REACH FAR resonated in sites where leaders perceived unhealthy diet and lifestyles in their communities (intervention characteristics), sites had historically engaged in health programs as a public-service mission (inner setting), and leaders identified with this mission (individuals' characteristics). Site leaders strived to adapt programs to respond to community preferences (outer setting) without compromising core objectives (inner setting). Leaders noted that program sustainability could be impeded by staff and volunteer turnover (inner setting) but enhanced by reinforcing programs through community networks (outer setting). The findings suggest that to facilitate implementation of culturally adapted health behavior programs through community sites, interventions should reinforce sites' organizational commitments and social ties.

AB0470 EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS (EGPA) - ONE-YEAR FOLLOW-UP STUDY USING MEPOLIZUMAB ANTI-IL5 THERAPY AS A STEROID SPARING THERAPEUTIC APPROACH

Background:

EGPA is a small vessel vasculitis characterised by the presence of tissue eosinophilia, necrotising vasculitis and granulomatous inflammation1. Typically, a prodromal asthmatic phase, leads to an eosinophilic stage, which can evolve to include the presence of vasculitis with renal manifestations. In the recent randomised, placebo-controlled MIRRA trial for relapsing and refractory EGPA, adjuvant therapy with anti-IL5 mAB Mepolizumab [MEPO] at 300mg s/c monthly, accrued longer times in remission, reduced steroid exposure and reduced relapse rates2.

Objectives:

The aim of our study was to analyse the response and outcome for EGPA patients who received 100mg s/c of MEPO monthly for a minimum of 52 weeks, with particular focus on the steroid minimisation benefits.

Methods:

This retrospective, descriptive study analysed 13 patients with EGPA, who received 100mg s/m monthly MEPO therapy under the eosinophilic asthma care-pathway. Time points of assessment included MEPO commencement [M0] and 12 [M12] months.

Results:

Table 1.

EGPA patients receiving Mepolizumab therapy for one year [100mg s/c]

DemographicsAll [n=13]Gender ratio M/F4M:9FANCA positive/ negativeANCA: 3MPO, 1 PR3 positive/ 9 ANCA negativeAge of diagnosis of asthma35 yrs [IQR 28.5-40]Age of diagnosis of EGPA47 yrs [IQR 43.5-53.5]Median age51 yrs [IQR 47.5- 60.5]EGPA disease characteristicsN=13 [%]Asthma 13 [100]Serum eosinophilia or biopsy evidence [N= 12] 12 [100]Pulmonary infiltrates, non-fixed 8[61.5]Neuropathy, mono/poly 4[30.7]Sino-nasal abnormality 12[92.3]Glomerulonephritis 3[23]Cardiovascular 4[30.7]Prior ImmunosuppressantsN=13 [%]Steroids13[100%]Cyclophosphamide 6[46%]Rituximab6[46%]Azathioprine10[77%]Mycophenolate mofetil8[62%]Methotrexate4[31%]Campath 1[7%]Response to therapyM0 [%] Post M12 [%]Prednisolone dose N= 13Mean ±SD 18.925 mg ±11.44 10.575mg ± 5.85Eosinophil count X109/L N=13Mean ±SD 0.415mg ±0.25 0.035±0.039Asthma Control Questionnaire [ACQ] N=5Mean ±SD 2.92 ±1.27 1.31± 0.79BVAS N= 13Mean ±SD 7.307±6.29 2.2307±1.69Creatinine N=9Mean ±SD 68.44±15.03 69.11±17.84Continuation of anti-IL5 therapy N=13 12/13 [92.3%]

Conclusion:

The relapsing nature of EGPA places a potential dependency of therapy on steroids for asthmatic and vasculitic flares. This underscores the importance of targeted pathway specific biologic therapy to minimise steroid exposure, prevent tissue damage and ensure early response to therapy. This study demonstrates that anti-IL5 serves as a favourable model with steroid minimisation, improvement in asthma control questionnaire, reduction in BVAS and eosinophil counts at the 100mg s/c dosage. ANCA positive serology normalised in all four patients, independent of subtype. Well tolerated, it demonstrated considerable clinical benefit, with 12 patients [92.3%] continuing anti-IL5 therapy beyond 12 months.

Long term plan > 12 monthsN=13 [%] Current Months Adjuvant therapy 12M1 Continue15 Aza2 Switched Benralizumab 26 MMF [+], IVIG [-]3 Continue 184 Switched Benralizumab 145 Discontinued Rituximab 12 MTX6 Continue 147 Continue 24 MMF Reduced8 Continue 18 MTX [+]9 Continue 15 MMF [-]10 Continue 1411 Continue 1312 Continue 13 Aza13 Continue 12

References:

[1]J.C.Jenette,et alRevised International Chapel Hil Consensus Conference Nomenclature of Vasculitides.65, 1–11 (2013).

[2]Wechsler, M. E.et al.Mepolizumab or Placebo for Eosinophilic Granulomatosis with Polyangiitis.N. Engl. J. Med.376, 1921–1932 (2017).

Disclosure of Interests:

Allyson Egan: None declared, pasupathy Sivasothy: None declared, Robin Gore: None declared, Marcos Martinez Del-Pero: None declared, Caroline Owen: None declared, Lisa Willcocks: None declared, Rona Smith: None declared, Stella Burns: None declared, David Jayne Grant/research support from: ChemoCentryx, GSK, Roche/Genentech, Sanofi-Genzyme, Consultant of: Astra-Zeneca, ChemoCentryx, GSK, InflaRx, Takeda, Insmed, Chugai, Boehringer-Ingelheim

Integrating Community Health Workers into Safety-Net Primary Care for Diabetes Prevention: Qualitative Analysis of Clinicians' Perspectives

BACKGROUND

Evidence shows community health workers (CHWs) can effectively deliver proven behavior-change strategies to prevent type 2 diabetes mellitus (diabetes) and enhance preventive care efforts in primary care for minority and low-income populations. However, operational details to integrate CHWs into primary care practice remain less well known.

OBJECTIVE

To examine clinicians' perceptions about working with CHWs for diabetes prevention in safety-net primary care.

SETTING

Clinicians are primary care physicians and nurses at two New York City safety-net hospitals participating in CHORD (Community Health Outreach to Reduce Diabetes). CHORD is a cluster-randomized trial testing a CHW intervention to prevent diabetes.

DESIGN

Guided by the Consolidated Framework for Implementation Research, we studied how features of the CHW model and organizational context of the primary care practices influenced clinicians' perspectives about the acceptability, appropriateness, and feasibility of a diabetes-prevention CHW program. Data were collected pre-intervention using semi-structured interviews (n = 18) and a 20-item survey (n = 54).

APPROACH

Both survey and interview questions covered clinicians' perspectives on diabetes prevention, attitudes and beliefs about CHWs' role, expectations in working with CHWs, and use of clinic- and community-based diabetes- prevention resources. Survey responses were descriptively analyzed. Interviews were coded using a mix of deductive and inductive approaches for thematic analysis.

KEY RESULTS

Eighty-seven percent of survey respondents agreed CHWs could help in preventing diabetes; 83% reported interest in working with CHWs. Ninety-one percent were aware of clinic-based prevention resources; only 11% were aware of community resources. Clinicians supported CHWs' cultural competency and neighborhood reach, but expressed concerns about the adequacy of CHWs' training; public and professional emphasis on diabetes treatment over prevention; and added workload and communication with CHWs.

CONCLUSIONS

Clinicians found CHWs appropriate for diabetes prevention in safety-net settings. However, disseminating high-quality evidence about CHWs' effectiveness and operations is needed to overcome concerns about integrating CHWs in primary care.

Analysing power and politics in health policies and systems

This special issue of Global Public Health presents a collection of articles that analyse power and its mechanisms in health systems and health policy processes. Researchers have long noted that the influence of power is implicated throughout the global health field, yet theories and methods for examining power-its sources, workings, and effects-are rarely applied in health policy and systems research. By engaging with the social sciences and humanities, contributors to this collection aim to analytically sharpen and thematically broaden the study of power and politics in global health. Contributors analyse the exercise of power by actors typically considered powerful on the global stage as well as actors across the health system who may be powerful in national or local contexts. Additionally, the papers draw attention to actors, interest groups, and practices not usually viewed as politically salient in health policy and systems research in low- and middle-income countries. The papers not only analyse power but also identify ways to counteract it, such as by using human rights-based frameworks to investigate and challenge power asymmetries. Collectively, they show how researchers working on global health issues can theorise power and deepen political analysis of health policy and systems.

Feasibility and Outcomes of an Electronic Health Record Intervention to Improve Hypertension Management in Immigrant-serving Primary Care Practices

BACKGROUND

South Asians experience a disproportionate burden of high blood pressure (BP) in the United States, arguably the most preventable risk factor for cardiovascular disease.

OBJECTIVE

We report 12-month results of an electronic health record (EHR)-based intervention, as a component of a larger project, "Implementing Million Hearts for Provider and Community Transformation." The EHR intervention included launching hypertension patient registries and implementing culturally tailored alerts and order sets to improve hypertension control among patients treated in 14 New York City practices located in predominantly South Asian immigrant neighborhoods.

DESIGN

Using a modified stepped-wedge quasi-experimental study design, practice-level EHR data were extracted, and individual-level data were obtained on a subset of patients insured by a Medicaid insurer via their data warehouse. The primary aggregate outcome was change in proportion of hypertensive patients with controlled BP; individual-level outcomes included average systolic BP (SBP) and diastolic BP (DBP) at last clinic visit. Qualitative interviews were conducted to assess intervention feasibility.

MEASURES

Hypertension was defined as having at least 1 hypertension ICD-9/10 code. Well-controlled hypertension was defined as SBP<140 and DBP<90 mm Hg.

RESULTS

Postintervention, we observed a significant improvement in hypertension control at the practice level, adjusting for age and sex patient composition (adjusted relative risk, 1.09; 95% confidence interval, 1.04-1.14). Among the subset of Medicaid patients, we observed a significant reduction in average SBP and DBP adjusting for time, age, and sex, by 1.71 and 1.13 mm Hg, respectively (P<0.05). Providers reported feeling supported and satisfied with EHR components.

CONCLUSIONS

EHR initiatives in practices serving immigrants and minorities may enhance practice capabilities to improve hypertension control.

The impact of housing type on low-income asthmatic children receiving multifaceted home interventions

OBJECTIVES

This study sought to evaluate whether government-assisted vs market-rate housing type influences the frequency of asthma symptoms or the quality of life scores among low-income urban children. In addition, the study sought to evaluate whether housing type influenced the success of in-home environmental and educational interventions in improving children's asthma symptoms or quality of life scores.

STUDY DESIGN

This was a before-and-after intervention design. Comprehensive health and environmental assessments and subsequent interventions were completed in 176 low-income households with 257 asthmatic children living in government-assisted housing and market-rate housing in Lowell, Massachusetts.

METHODS

We collected environmental and health data with questionnaires at a baseline and a 12-month follow-up visit using the Children's Health Survey for Asthma and a walk-through environmental checklist. Education, tools to remove asthma triggers from the home, and home repairs and remediation were included in the interventions.

RESULTS

As in other studies of multifaceted home interventions, there were significant improvements in all asthma symptoms, reductions in healthcare utilization related to asthma, and improvements in quality of life domains for children in both housing types. Environmental indices also improved from the baseline to the final assessment for both housing types. However, the housing type was an important factor in predicting a child's asthma status at the start of the study, with children living in government-assisted housing having significantly better physical health scores (76.8 of 100) and family emotional health scores (74.8 of 100) and fewer overnight hospital stays (mean of 0.02 in the previous 4 weeks) than children living in market-rate housing (67.6, 71.6, and 0.06, respectively). Examination of the change in the health status over the 1-year study period found that children living in market-rate housing had significantly larger reductions in the number of asthma attacks (0.43 in the previous 4 weeks versus 0.24 in assisted housing) and overnight hospital stays (0.06 in the previous 4 weeks versus 0.01 in assisted housing) and larger improvements in physical health quality of life scores (54% improved versus 25.5% in assisted housing).

CONCLUSIONS

Public assistance for low-income urban housing is associated with better health among children with asthma, and may influence the impact the in-home interventions have on health outcomes because children in market-rate housing have more prospects for improvement in their asthma-related health.

The power of popular opinion in everyday primary care provision in urban India

Studies of power in health care settings in low- and middle-income countries largely describe providers' exercise of discretionary power in frontline roles, leaving under-specified the macro-institutions and mechanisms of power that drive health care outcomes. In this study I conceptualise providers' actions not in terms of discretionary power but as obligatory responses to 'authority' over them. Authority denotes an actor's rightfully held social power over others, who accept to follow that actor's directives. Explaining authority's workings entails studying how it operates from its subjects' perspectives. I analyse in particular the authority of popular opinion-which derives from citizens' claims to state services-over primary care doctors in municipal health facilities in Pune, India. Through year-long ethnographic fieldwork, I examine doctors' experience of popular opinion, social relations between doctors and communities, and the institutional history of state-provided urban primary care. Findings show that doctors routinely confront popular disregard for their services. But under conditions of long-standing neglect of municipal services, tenuous state-society relations, and an avid, widely preferred private sector, doctors appear unable and wary to deliver more than minimum clinical care. Their circumscribed response reflects mechanisms by which the power of popular opinion, under policy neglect, impels them to maintain a deficient status quo.

Protocol for the CHORD project (community health outreach to reduce diabetes): a cluster-randomized community health worker trial to prevent diabetes

BACKGROUND

Type 2 diabetes mellitus (DM) affects 9.4% of US adults and children, while another 33.9% of Americans are at risk of DM. Health care institutions face many barriers to systematically delivering the preventive care needed to decrease DM incidence. Community health workers (CHWs) may, as frontline public health workers bridging clinic and community, help overcome these challenges. This paper presents the protocol for a pragmatic, cluster-randomized trial integrating CHWs into two primary care clinics to support DM prevention for at-risk patients.

METHODS

The trial will randomize 15 care teams, stratified by practice site (Bellevue Hospital and Manhattan VA), totaling 56 primary care physicians. The study cohort will consist of ~ 2000 patients who are 18-75 years of age, actively enrolled in a primary care team, able to speak English or Spanish, and have at least one glycosylated hemoglobin (HbA1c) result in the prediabetic range (5.7-6.4%) since 2012. Those with a current DM diagnosis or DM medication prescription (other than metformin) are ineligible. The intervention consists of four core activities - setting health goals, health education, activation for doctor's appointments, and referrals to DM prevention programs - adjustable according to the patient's needs and readiness. The primary outcome is DM incidence. Secondary outcomes include weight loss, HbA1C, and self-reported health behaviors. Clinical variables and health behaviors will be obtained through electronic medical records and surveys, respectively. Implementation outcomes, namely implementation fidelity and physicians' perspectives about CHW integration into the clinic, will be assessed using interviews and CHW activity logs and analyzed for the influence of moderating organizational factors.

DISCUSSION

This is the first rigorous, pragmatic trial to test the effectiveness of integrating CHWs into primary care for DM prevention reaching a population-based sample. Our study's limitations include language-based eligibility and the use of HbA1c as a measure of DM risk. It will measure both clinical and implementation outcomes and potentially broaden the evidence base for CHWs and patient-centered medical home implementation. Further, the intervention's unique features, notably patient-level personalization and referral to existing programs, may offer a scalable model to benefit patients at-risk of DM.

TRIAL REGISTRATION

Clinicaltrials.gov NCT03006666 (Received 12/27/2016).

Developments in the field of allergy in 2013 through the eyes of Clinical and Experimental Allergy

2013 was another exciting year for allergy in general and Clinical and Experimental Allergy in particular. In the field of asthma and rhinitis, there continued to be a focus on heterogeneity and phenotypes with increasing use of biostatistical techniques to determine clusters of similar populations. Obesity- and aspirin-associated disease are intriguing associations with asthma which were explored in a number of papers. We published a number of excellent papers on mechanisms of airway inflammation and how this relates to physiology, pathology, genetics and biomarkers in both human and experimental model systems. In terms of mechanisms, there is less on individual cell types in allergic disease at the moment, but the immunology of allergic disease continued to fascinate our authors. Another area that was popular both in the mechanisms and in the epidemiology sections was early life events and how these lead to allergic disease, with an increasing focus on the role of the microbiome and how this influences immune tolerance. In the clinical allergy section, oral immunotherapy for food allergy is clearly a major topic of interest at the moment as was in vitro testing to distinguish between sensitization and allergic disease. There was less on inhalant allergy this year, but a good representation from the drug allergy community including some interesting work on non-IgE-mediated mechanisms. In the allergen section, important new allergens continue to be discovered, but the major focus as in the last couple of years was on working out how component-resolved approaches can improve diagnosis and management of food and venom allergy.

University students' notebook computer use: lessons learned using e-diaries to report musculoskeletal discomfort

The objective of this pilot study was to identify if notebook accessories (ergonomic chair, desktop monitor and notebook riser) combined with a wireless keyboard, mouse and participatory ergonomics training would have the greatest impact on reducing self-reported upper extremity musculoskeletal discomfort in university students. In addition to pre-post computing and health surveys, the Ecological Momentary Assessment was used to capture change in discomfort over time using a personal digital assistant (PDA) as the e-diary. The PDA was programmed with a survey containing 45 questions. Four groups of university students were randomised to either intervention (three external computer accessories) or to control. Participants reported less discomfort with the ergonomic chair and notebook riser based on the pre-post survey data and the e-diary/PDA ANOVA analysis. However, the PDA data, adjusted for the effect of hours per day of computer use, showed no benefit of the chair and limited benefit from the riser. Statement of Relevance:University students' use of notebook computers has increased. This study found evidence of a positive effect of an adjustable chair or notebook riser when combined with ergonomic training on reducing discomfort. Daily notebook computer use of 4 h was confirmed as a risk factor. Without some form of ergonomic intervention, these students are likely to enter the workforce with poor computing habits, which places them on the road to future injuries as technology continues to play a dominant role in their lives.

National income, self-reported wheezing and asthma diagnosis from the World Health Survey

The aims of this study were to quantify and describe the variations in respiratory symptoms and diagnosis prevalence across regions of the world according to national income. In 2002 and 2003, the World Health Organization implemented the World Health Survey (WHS), which used a standardised survey instrument to compile comprehensive baseline information on health and healthcare expenditure. We analysed the WHS data to assess the global patterns of self-reported wheeze and doctor-diagnosed asthma, two commonly reported measures of respiratory health. In total there were 308,218 participants with complete records, from 64 countries. The weighted mean age of the survey population was 43 yrs. Global prevalence of current wheezing symptoms ranged from 2.4% in Vietnam to 24% in Brazil; the prevalence of diagnosed asthma ranged from 1.8% in Vietnam to 32.8% in Australia. Overall, the prevalence of symptoms and diagnosis showed a U-shaped pattern with the largest prevalence reported in low- and high-income countries. The smallest prevalence was consistently found in middle-income countries. These WHS analyses have provided global prevalence estimates of wheeze and doctor-diagnosed asthma using data gathered simultaneously and consistently across six continents. These findings support the need for continued global respiratory illness surveillance for disease prevention, health policy and management.

Dry and wet weather microbial characterization of the Chicago area waterway system

The Chicago Area Waterway System (CAWS) is a man-made channel, which serves the Chicago area for the drainage of urban storm water and the conveyance of secondary treated effluent from the Metropolitan Water Reclamation District of Greater Chicago's (District) North Side, Stickney and Calumet water reclamation plants (WRPs). A microbial characterization of the CAWS upstream and downstream of the WRPs and from the WRP outfall was initiated by collecting dry and wet weather samples and analyzing for indicators and pathogens. During dry weather, indicator bacteria (fecal coliform [FC], E. coli [EC], enterococci [EN]) were the most abundant microbial species detected in the CAWS compared to pathogens (Salmonella spp [SA], enteric viruses [EV], adenovirus [AV], norovirus [NV] and Giardia and Cryptosporidium). Pseudomonas aeruginosa [PA] levels in the outfall samples were either lower or equivalent to the CAWS. The wet weather samples had a higher frequency of detection of indicator bacteria and pathogens compared to dry weather samples. Overall, the concentrations of pathogens in the CAWS, representing the weather conditions experienced in a recreational year, were relatively low. The study concluded that the presence of pathogens in the CAWS downstream of the WRPs were due to secondary loading of the waterway under wet weather conditions from combined sewer overflows (CSOs) and other discharges.

Antibiotic resistant bacteria in wastewater processed by the Metropolitan Water Reclamation District of Greater Chicago system

The Metropolitan Water Reclamation District of Greater Chicago (District) initiated a research study to determine the total numbers and percentages of antibiotic resistant fecal coliform (FC) bacteria in raw sewage (RS) entering and final effluents (FE) discharged from its seven Water Reclamation Plants (WRPs). The density of FC was determined on m-FC agar containing ampicillin (ampR-16 microg/ml), gentamycin (genR-8 microg/ml), tetracycline (tetR-8 microg/ml), or all three antibiotics. The study was primarily undertaken to determine whether secondary sewage treatment at the District WRPs adequately reduces the numbers and percentages of FC(ampR), FC(tetR), FC(genR), FC(amp/tet/genR) in the FE. The numbers of ampR, tetR, genR, and amp/tet/genR FC observed in RS ranged from 2.0 x 10(5) to 1.1 x 10(7), 9.5 x 10(4) to 2.2 x 10(6), 95 to 1.5 x 10(4) and 90 to 9.5 x 10(3) per 100 mL, respectively. Secondary sewage treatment without disinfection was shown to reduce the number of antibiotic resistant FC by two-three orders of magnitude. The numbers of FC(ampR), FC(tetR), FC(genR), and FC(amp/tet/genR) observed in non-disinfected FE ranged from 2.0 x 10(2) to 6.4 x 10(3), 2.2 x 10(2) to 4.1 x 10(3), 9 to <20 and 9 to <20 per 100 mL, respectively. The relative percentages of antibiotic resistant FC observed in FE followed the same trend observed in RS: FC(ampR) > FC(tetR) > FC(genR) > FC(amp/tet/genR). Only one FC(amp/tet/genR) bacteria was found in this study indicating that multiple-antibiotic resistant FC was virtually eliminated by secondary sewage treatment. The results of multivariate regression analysis showed that the percentages of antibiotic resistant FC in the FE from all seven District WRPs were lower than the percentages of these organisms in RS (p<0.01). These results support the conclusion that secondary sewage treatment in the District effectively reduces the number of antibiotic resistant FC and that the environments of the District's seven WRPs are not conducive to the propagation or survival of antibiotic resistant fecal coliform bacteria.

Hospital injury rates in relation to socioeconomic status and working conditions

OBJECTIVES

To describe the risk of work injury by socioeconomic status (SES) in hospital workers, and to assess whether SES gradient in injury risk is explained by differences in psychosocial, ergonomic or organisational factors at work.

METHODS

Workforce rosters and Occupational Safety and Health Administration injury logs for a 5-year period were obtained from two hospitals in Massachusetts. Job titles were classified into five SES strata on the basis of educational requirements and responsibilities: administrators, professionals, semiprofessionals, skilled and semiskilled workers. 13 selected psychosocial, ergonomic and organisational exposures were assigned to the hospital jobs through the national O*NET database. Rates of injury were analysed as frequency records using the Poisson regression, with job title as the unit of analysis. The risk of injury was modelled using SES alone, each exposure variable alone and then each exposure variable in combination with SES.

RESULTS

An overall annual injury rate of 7.2 per 100 full-time workers was estimated for the two hospitals combined. All SES strata except professionals showed a significant excess risk of injury compared with the highest SES category (administrators); the risk was highest among semiskilled workers (RR 5.3, p<0.001), followed by nurses (RR 3.7, p<0.001), semiprofessionals (RR 2.9, p = 0.006) and skilled workers (RR 2.6, p = 0.01). The risk of injury was significantly associated with each exposure considered except pause frequency. When workplace exposures were introduced in the regression model together with SES, four remained significant predictors of the risk of injury (decision latitude, supervisor support, force exertion and temperature extremes), whereas the RR related to SES was strongly reduced in all strata, except professionals.

CONCLUSIONS

A strong gradient in the risk of injury by SES was reported in a sample population of hospital workers, which was greatly attenuated by adjusting for psychosocial and ergonomic workplace exposures, indicating that a large proportion of that gradient can be explained by differences in working conditions.

Ergonomic stressors and upper extremity musculoskeletal disorders in automobile manufacturing: a one year follow up study

AIMS

To estimate the one year cumulative incidence and persistence of upper extremity (UE) soft tissue disorders, in a fixed cohort of automotive manufacturing workers, and to quantify their associations with ergonomic exposures.

METHODS

At baseline and at follow up, cases of UE musculoskeletal disorders were determined by interviewer administered questionnaire and standardised physical examination of the upper extremities. The interview obtained new data on psychosocial strain and updated the medical and work histories. An index of exposure to ergonomic stressors, obtained at baseline interview, was the primary independent variable. Cumulative incidence and persistence of UE disorders (defined both by symptoms and by physical examination plus symptoms) were analysed in relation to baseline ergonomic exposures, adjusting for other covariates. The incidence of new disorders was modelled using multivariate proportional hazards regression among workers who were not cases in the first year and the prevalence on both occasions was modelled by repeated measures analysis.

RESULTS

A total of 820 workers (69% of eligible cohort members) was examined. Follow up varied slightly by department group but not by baseline exposure level or other characteristics. Among the non-cases at baseline, the cumulative incidence of UE disorders was 14% by symptoms and 12% by symptoms plus examination findings. These rates increased with index of physical exposures primarily among subjects who had the same jobs at follow up as at baseline. Increased exposure during follow up increased risk of incidence. The persistence of UE disorders from baseline to follow up examination was nearly 60% and somewhat associated with baseline exposure score.

CONCLUSIONS

These longitudinal results confirm the previous cross sectional associations of UE musculoskeletal disorders with exposure to combined ergonomic stressors. The exposure-response relation was similar for incident cases defined by symptoms alone and those confirmed by physical examination.

Risk of upper aerodigestive tract cancers in a case-cohort study of autoworkers exposed to metalworking fluids

AIMS

To re-examine aerodigestive cancer risk in a cohort of autoworkers exposed to metal working fluids (MWF), using improved case definition and more recently diagnosed cases.

METHODS

The autoworker cohort included 31 100 hourly workers alive on 1 January 1985 who worked at three automobile plants in Michigan. A case-cohort design was carried out that included incident cases of cancers of the larynx, oesophagus, and stomach, and a 10% sample of the cohort. A Cox proportional hazards model was used to estimate MWF exposure effects. The smoothing method of penalised splines was used to explore the shape of the underlying exposure-response curves.

RESULTS

The most important finding was the association between larynx cancer incidence and cumulative straight MWF exposure. The results for oesophageal cancer were less consistent. For stomach cancer there was no evidence of excess risk.

CONCLUSION

This association between larynx cancer and straight MWF exposures was consistent with a previous finding in this cohort, providing further support for a causal relation.

Qualified rescue by ski patrols -- safety for the skier

This study aims to determine whether the training of ski-patrol teams is still adequate in view of a marked change in injury patterns. All accidents which occurred during two winter seasons (n = 579, 583 patients) in the Oberwallis ski area in Switzerland are analysed retrospectively. As the analysis of the accidents' data are similar to other studies and first aid training is standardised throughout Switzerland, the results of this study can be viewed as representative for other areas of Switzerland. The generally high level of training is reflected by the accuracy of "on-scene" diagnoses: 77.5 % were "correct", 12 % "mainly correct". In the remainder, the most frequent problems were underestimation or failure of recognition of multiple injuries (n = 25), head injury (n = 10), injuries to the trunk (n = 9) and to the spine (n = 7). Special emphasis on these topics during the training of ski patrols should result in the further improvement in on-scene first aid and rescue.

Measurement error correction in nutritional epidemiology based on individual foods, with application to the relation of diet to breast cancer

Nutrient intake is often measured with error by commonly used dietary instruments such as the food frequency questionnaire (FFQ) or 24-hour recall. More accurate assessments of true intake are obtained by using weighed diet records, in which subjects record what they eat on a real-time basis, but these records are expensive to administer. Validation studies are often performed to relate "gold standard" intake to intake according to surrogate instruments and to correct relative risk estimates obtained in the main study for measurement error. Most measurement error correction methods use validation study data at the nutrient level. However, subjects almost always report intake at the food rather than the nutrient level. In addition, the validity of measurement of different foods can vary considerably; it is relatively high for some foods (e.g., beverages) but relatively low for others (e.g., meats, vegetables). This differential validity could be incorporated into measurement error methods and potentially improve on nutrient-based measurement error methods. In this paper, the authors discuss correction methods for food-based measurement error and apply them to study the relation between FFQ intake in 1980 and incident breast cancer in 1980-1994 among approximately 89,000 women in the Nurses' Health Study, in whom approximately 3,000 incident breast cancers were observed.

Exposure-response models based on extended follow-up of a cohort mortality study in the automobile industry

OBJECTIVE

This report describes the extended follow-up of a cohort of 46 399 automobile manufacturing workers with potential exposure to metalworking fluids (MWF). The outcomes of interest were cancers of the esophagus, stomach, colon, rectum, liver, pancreas, larynx, skin, prostate, and brain, as well as leukemia. Additional follow-up increased the power to detect modest elevations in mortality rates in association with specific types of MWF, including synthetic fluids not in widespread use until the 1970s.

METHODS

Standardized mortality ratios (SMR) were computed for the most recent 10 years of follow-up, as well as for the entire study period. Adjusted relative risks (RR) were estimated in Poisson regression models with categorical variables for cumulative exposure to each type of MWF and in proportional hazards models with continuous exposure variables.

RESULTS

Associations were found between straight MWF and esophageal, laryngeal and rectal cancer; soluble MWF and cancer of the esophagus, larynx, skin, and brain; synthetic MWF and cancer of the esophagus, liver, and prostate. The elevated RR values were modest in magnitude (1.5 to 2.0). SMR values were increased for stomach, liver, and pancreatic cancer and also for leukemia in the last 10 years of follow-up. The SMR values were also elevated for stomach and liver cancer among the persons recently hired.

CONCLUSIONS

The results provide further evidence that exposure to metalworking fluids causes cancer among workers in automobile manufacturing. Although airborne exposures declined over the study period, this study suggests that modest risk of several digestive cancers, as well as prostatic cancer and leukemia, may persist at current levels of exposure to water-based metalworking fluids.

Subclinical immunologic and physiologic responses in hexamethylene diisocyanate-exposed auto body shop workers

BACKGROUND

Diisocyanates are potent sensitizing agents and currently the most commonly identified cause of occupational asthma in industrialized countries. However, diisocyanate asthma is difficult to diagnose and exposure and host risk factors are unclear. Auto body shops, one of the most common hexamethylene diisocyanate (HDI) exposure settings, are particularly difficult to study due to their small size and episodic exposures. Surveillance studies of such workers are limited.

OBJECTIVES

We have initiated a cross-sectional field epidemiologic study, Survey of Painters and Repairers of Auto bodies by Yale (SPRAY), to characterize the effects of diisocyanate exposures on actively employed auto body shop workers. Methods and Results We present here questionnaire, physiologic, immunologic, and exposure data on 75 subjects enrolled in the study. No overt cases of clinically apparent diisocyanate asthma were identified based on spirometry, methacholine challenge, peak flows, and symptoms. HDI-specific lymphocyte proliferation was present in 30% of HDI-exposed workers and HDI-specific IgG in 34% of HDI-exposed workers, but they were not associated. HDI-specific IgE was detected in two workers. HDI-specific lymphocyte proliferation, increased methacholine responsiveness, and symptoms of chest tightness and shortness of breath were more common in the most heavily HDI-exposed workers, the painters. More long-term follow-up of this cohort should clarify the significance of these HDI-specific immunologic responses, physiologic changes, and symptoms.

CONCLUSIONS

These findings demonstrate the presence of HDI-specific immune responses in a large proportion of healthy HDI-exposed workers.

Dual-energy X-ray absorptiometry: analysis of pediatric fat estimate errors due to tissue hydration effects

Dual-energy X-ray absorptiometry (DXA) percent (%) fat estimates may be inaccurate in young children, who typically have high tissue hydration levels. This study was designed to provide a comprehensive analysis of pediatric tissue hydration effects on DXA %fat estimates. Phase 1 was experimental and included three in vitro studies to establish the physical basis of DXA %fat-estimation models. Phase 2 extended phase 1 models and consisted of theoretical calculations to estimate the %fat errors emanating from previously reported pediatric hydration effects. Phase 1 experiments supported the two-compartment DXA soft tissue model and established that pixel ratio of low to high energy (R values) are a predictable function of tissue elemental content. In phase 2, modeling of reference body composition values from birth to age 120 mo revealed that %fat errors will arise if a "constant" adult lean soft tissue R value is applied to the pediatric population; the maximum %fat error, approximately 0.8%, would be present at birth. High tissue hydration, as observed in infants and young children, leads to errors in DXA %fat estimates. The magnitude of these errors based on theoretical calculations is small and may not be of clinical or research significance.

Rate of bone loss is associated with mortality in older women: a prospective study

Older women with low bone density have an increased risk of fracture, cardiovascular disease, and mortality. However, it is not known whether this association is caused by ongoing bone loss or by lower bone mass earlier in life. To determine whether rate of bone loss is associated with total and cause-specific mortality, we prospectively studied 6046 women aged 65 years or older who had serial bone mineral density (BMD) measurements as a part of the Study of Osteoporotic Fractures. Rates (mean +/- SD) of loss of BMD at the heel (for a mean of 5.7 years) and hip (for a mean of 3.5 years) were estimated. Cause-specific mortality was ascertained from death certificates and hospital records. BMD loss at the heel was 5.9 +/- 6.0 mg/cm2 per year (1.5 +/- 1.5%) and BMD loss at the hip was 4.1 +/- 10.2 mg/cm2 per year (0.6 +/- 1.4%). During an average follow-up of 3.2 years after the second measurement of BMD, 371 deaths occurred. Each SD increase in BMD loss at the hip was associated with a 1.3-fold (95% CI, 1.1-1.4) increase in total mortality, adjusted for age, baseline BMD, diabetes, hypertension, incident fractures, smoking, physical activity, health status, weight loss, and calcium use. In particular, hip BMD loss was associated with increased mortality from coronary heart disease (relative hazard [RH] = 1.3 per SD; 95% CI, 1.0-1.8) and pulmonary diseases (RH = 1.6 per SD; 95% CI, 1.1-2.5). The findings were similar for bone loss at the heel, except there was no significant association with pulmonary mortality. These results raise the possibility that bone loss may share common etiologies with coronary and pulmonary diseases.

Pressure monitoring of the femoral nerve during total hip replacement: an explanation for iatropathic palsy

Pressure changes around the femoral nerve were monitored throughout 10 consecutive primary total hip replacements to identify any surgical steps that might raise pressure around the nerve and be implicated in iatropathic palsy. The only notable variable was the patient himself/herself. The only step that consistently raised pressure around the nerve, sometimes to alarming levels, was use of a retractor sited on the anterior lip of the acetabulum. Pressure changes were modest in patients with an endomorphic body type suggesting relative protection from this injury by a thicker soft cushion.

Fluorescence microscopy of mycobacteria in pleural effusions

The diagnostic advantage of fluorescence microscopy (FM) of Papanicolaou-stained cytological specimens obtained by bronchoscopy has been described previously. This study was designed to evaluate the method's diagnostic benefit in cytological preparations of pleural effusions in cases of active pulmonary tuberculosis. In contrast to bronchial material there is no advantage in cytological evaluation of pleural effusions by FM.

Prevention of human diaphragm atrophy with short periods of electrical stimulation

We determined whether prolonged complete inactivation of the human diaphragm results in atrophy and whether this could be prevented by brief periods of electrical phrenic nerve stimulation. We studied a subject with high spinal cord injury who required removal of his left phrenic nerve pacemaker (PNP) and the reinstitution of positive-pressure ventilation for 8 mo. During this time, the right phrenic nerve was stimulated 30 min per day. Thickness of each diaphragm (tdi) was determined by ultrasonography. Maximal tidal volume (VT) was measured during stimulation of each diaphragm separately. After left PNP reimplantation, VT and tdi were measured just before the resumption of electrical stimulation and serially for 33 wk. On the previously nonfunctioning side, there were substantial changes in VT (from 220 to 600 ml) and tdi (from 0.18 to 0.34 cm). On the side that had been stimulated, neither VT nor tdi changed appreciably (VT from 770 to 900 ml; tdi from 0.25 to 0.28 cm). We conclude that prolonged inactivation of the diaphragm causes atrophy which may be prevented by brief periods of daily phrenic nerve stimulation.

Depressive symptoms and cognitive decline in nondemented elderly women: a prospective study

BACKGROUND

The association between depressive disorders and subsequent cognitive decline is controversial. We tested the hypothesis that elderly women (aged 65 years and older) without dementia but with depressive symptoms have worse cognitive function and greater cognitive decline than women with few or no symptoms.

METHODS

As part of an ongoing prospective study, we evaluated 5781 elderly, mostly white, community-dwelling women. Women completed the Geriatric Depression Scale short form. Three cognitive tests--Trails B, Digit Symbol, and a modified Mini-Mental State Examination--were administered at baseline and approximately 4 years later. Baseline, follow-up, and change scores for the cognitive tests were analyzed by analysis of covariance and Kruskal-Wallis analysis; the odds of cognitive deterioration (> or =3-point decline on the modified Mini-Mental State Examination) were determined by logistic regression.

RESULTS

At baseline, 211 (3.6%) of the women had 6 or more depressive symptoms. Only 16 (7.6%) of these women were receiving antidepressant medication. Increasing symptoms of depression were associated with worse performance at baseline and follow-up on all 3 tests of cognitive function (P<.001 for all comparisons). For example, the baseline Digit Symbol score (mean +/- SD) was 45.5 +/- 10.7 among women with 0 to 2 symptoms of depression, 40.3 +/- 10.7 for women with 3 to 5 symptoms, and 39.0 +/- 11.3 for women with 6 or more symptoms. After adjusting for the baseline score, cognitive change scores were also inversely associated with the number of depressive symptoms (P<.001 for all comparisons). Odds ratios for cognitive deterioration using 0 to 2 symptoms as the reference were 1.6 (95% confidence interval, 1.3-2.1) for 3 to 5 symptoms and 2.3 (95% confidence interval, 1.6-3.3) for 6 or more symptoms. Results were similar after being adjusted for education, age, health status, exercise, alcohol use, functional status, and clinic site.

CONCLUSIONS

Depressive symptoms in older women are associated with both poor cognitive function and subsequent cognitive decline. Mechanisms underlying the association between these 2 common conditions need further exploration.

Characterization of highly purified, inactivated HIV-1 particles isolated by anion exchange chromatography

This report characterizes inactivated, gp120 depleted, HIV-1 particles purified by an anion exchange chromatography production process. This antigen formulated with incomplete Freund's adjuvant constitutes Remune, which is being evaluated in a phase III clinical endpoint trial to determine the effect of this immune-based therapy on clinical progression of HIV-1 seropositive patients. Multiple production lots of the inactivated HIV-1 antigen strain HZ321, isolated by anion exchange chromatography, exhibit purity of > 95% by gel filtration. These findings are corroborated by thin section electron microscopy showing a homogenous field of intact particles. Analyses of the purified virus particles for protein, lipid, carbohydrate and RNA show structural retention of the envelope proteins, lipid bilayer and core components after large scale processing. The qualitative identification of at least 85% of total HIV-1 protein is determined by ELISA, Western blot, HPLC and amino acid sequencing analyses. Quantitative values are assigned to 50% of these proteins. The data confirm the presence of virally encoded proteins p6, p7, pI15, p17, p24, p32, pI39Gag, gp41, pp55Gag, p66/51, Vpr, Vif and Nef. Excellent consistency between production lots and equivalency to HIV-1 preparations purified by sucrose density gradient sedimentation has been established for protein and lipid composition, and overall purity. These findings further establish that non-viral encoded proteins and lipids are integral structural components of the intact virion and are not contaminants unique to a particular isolation method. The data confirm the presence of multicomponent antigens in the viral particles for stimulating a broad HIV-1 specific immune response. Finally, the work demonstrates that the two inactivation procedures (beta-propiolactone and gamma irradiation), which achieve efficient viral inactivation meeting US FDA guidelines, do not damage the protein antigens of the viral particles.

Effects of child-rearing by schizophrenic mothers: a 25-year follow-up

We conducted a 25-year follow-up study of 50 children of schizophrenic mothers, consisting of 25 children reared by their mothers and 25 children reared apart. The children's adult psychiatric status was evaluated in a 3-h structured interview employing a battery of syndrome check-lists and scales. A slightly higher incidence of psychopathology (including schizophrenia-spectrum disorders) was found among the reared-apart subjects. This may possibly be attributed to their greater genetic predisposition, as suggested by their mothers' more severe illnesses. Lifetime diagnoses do not provide evidence that psychopathology in offspring at genetic risk is increased by rearing by a schizophrenic mother.

Acetabular dysplasia and osteoarthritis of the hip in elderly white women

OBJECTIVES

To examine the association of acetabular dysplasia and osteoarthritis (OA) of the hip among elderly white women.

METHODS

Pelvic radiographs from a sample of 165 white women aged 65 and above with radiographic hip OA and 88 white women aged 65 and above without radiographic changes of hip OA were read for evidence of acetabular dysplasia by a single trained investigator. Acetabular dysplasia was assessed using measurements of the centre edge angle and the acetabular depth, which are both reduced in this condition. Odds ratios for the association between acetabular dysplasia and hip OA were estimated using logistic regression analysis.

RESULTS

Fourteen (3.4%) hips had a centre edge angle < 25 degrees, 46 (11.2%) hips had an acetabular depth of < 9 mm, and 54 (13.2%) hips had acetabular dysplasia defined as either of the above. Hips with OA had a small, but not statistically significant, increased prevalence of abnormal centre edge angle (odds ratio: 1.43; 95% confidence intervals: 0.46, 4.46), abnormal acetabular depth (1.47; 0.78, 2.77) and acetabular dysplasia (1.33; 0.74, 2.40).

CONCLUSION

These results do not support the hypothesis that mild acetabular dysplasia accounts for a substantial proportion of hip OA in elderly white women. A study with a much larger sample size would be required to rule out a weak association between dysplasia and hip OA of the magnitude actually observed in our study.

Impact of Plant Nutrition on Pratylenchus penetrans Infection of Prunus avium Rootstocks

A hypothesis that cherry rootstocks grown under optimal nutrient conditions are affected less by Pratylenchus penetrans infection than those grown under deficient nutrient conditions was tested by growing four Prunus avium L. rootstocks ('Mazzard', 'Mahaleb', 'GI148-1', and 'GI148-8') at a soil pH of 7.0 over a period of 3 months under greenhouse conditions (25 ñ 2 degrees C). Pratylenchus penetrans was inoculated at 0 (control) or 1,500 nematodes per g fresh root weight for a total of 3,600, 4,200, 10,500, and 11,400 per plant on Mazzard, Mahaleb, GI148-1, and GI148-8, respectively, with nutrients (commercial fertilizer) applied once at planting (deficient) or twice weekly (optimal). The experiment was repeated once. The optimum nutrient regime resulted in greater soil nutrient levels and plant growth; higher leaf concentrations of N, P, K, and Mg; and fewer P. penetrans than under the deficient nutrient regime. The addition of fertilizer either may increase nematode mortality in the soil or improve rootstock resistance to nematode infection. Increases in Ca in leaves from the nutrient-deficient and nematode-infected treatments suggested the plants were physiologically stressed. The Pf/Pi ratios indicated that these rootstocks may have had resistance to P. penetrans; however, because of the dominant role of nutrition in the experimental design, the question of resistance could not be properly addressed.

Free fibular bone grafting for femoral neck fractures: precise graft placement using a 'cannulated screw' technique

Use of the fibula as a free bone graft has been advocated in the treatment of femoral neck fractures, either fresh or where there is established non-union. There is debate about the best surgical technique; we present ours, which is simple and trouble-free.

Optimization of a recombinant von Willebrand factor fragment as an antagonist of the platelet glycoprotein Ib receptor

The binding of von Willebrand factor (vWF) to platelet glycoprotein (GP) Ib receptor is one of the initial events in thrombus formation. Previous studies have shown that RG12986, a reduced and alkylated recombinant fragment of vWF (Ser445-Val733), can inhibit binding of native vWF to GP Ib and offers potential as an anti-thrombotic agent. We have now evaluated a series of deletion mutants of RG12986 and found that reduced and alkylated rvWF508-704 is close to the minimal sequence with optimal RG12986-like activity (IC50 for inhibition of GP Ib-dependent platelet aggregation in the absence of modulators: 0.022 microM +/- 0.01, n = 3) and that it too binds directly to GP Ib. Under in vitro conditions, with no exogenous modulators present and in the absence of shear stress, oxidized rvWF508-704 (containing a disulfide bond between Cys508 and Cys659) is approximately 5-fold less active than reduced and alkylated rvWF508-704; the two fragments, however, display comparable activity in the presence of the modulator botrocetin. The smaller rvWF508-704 fragment offers distinct advantages over RG 12986. In particular, removal of non-active NH2 and COOH terminal sequences may reduce the risk of antigenicity and may contribute to rendering the molecule mostly monomeric in solution, as opposed to the monomer-dimer equilibrium previously described for RG12986.