Allostatic load and incident heart failure in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study

BACKGROUND

Allostatic load (AL) is the physiologic "wear and tear" on the body from stress. Yet, despite stress being implicated in the development heart failure (HF), it is unknown whether AL is associated with incident HF events.

METHODS

We examined 16,765 participants without HF at baseline from the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. The main exposure was AL score quartile. AL was determined according to 11 physiologic parameters, whereby each parameter was assigned points (0-3) based on quartiles within the sample, and points were summed to create a total AL score ranging from 0-33. The outcome was incident HF event. We examined the association between AL quartile (Q1-Q4) and incident HF events using Cox proportional hazards models, adjusted for demographics, socioeconomic factors, and lifestyle.

RESULTS

The mean age was 64 ± 9.6 years, 61.5% were women, and 38.7% were Black participants. Over a median follow up of 11.4 years, we observed 750 incident HF events (635 HF hospitalizations and 115 HF deaths). Compared to the lowest AL quartile (Q1), the fully adjusted hazards of an incident HF event increased in a graded fashion: Q2 HR 1.49 95% CI 1.12-1.98; Q3 HR 2.47 95% CI 1.89-3.23; Q4 HR 4.28 95% CI 3.28-5.59. The HRs for incident HF event in the fully adjusted model that also adjusted for CAD were attenuated, but remained significant and increased in a similar, graded fashion by AL quartile. There was a significant age interaction (p-for-interaction < 0.001), whereby the associations were observed across each age stratum, but the HRs were highest among those aged < 65 years.

CONCLUSION

AL was associated with incident HF events, suggesting that AL could be an important risk factor and potential target for future interventions to prevent HF.

Does Connectedness Matter? The Association Between Mutuality and Job Satisfaction Among Home Health Aides Caring for Adults With Heart Failure

Home health aides (HHAs) provide care to many adults with heart failure (HF) in the home. As the demand for HHAs increases, there is a need to promote HHAs' job satisfaction and retention. In this cross-sectional community-partnered study, we examined whether mutuality (e.g., quality of the HHA-patient relationship), is associated with job satisfaction among HHAs caring for adults with HF. Mutuality was assessed with the Mutuality Scale, which measures overall mutuality and its four domains (reciprocity, love and affection, shared pleasurable activities, and shared values). Our final sample of 200 HHAs was primarily female. The mean overall mutuality score was 2.92 out of 4 (SD 0.79). In our final model, overall mutuality and each of the four domains were associated with increased job satisfaction; however, only the shared pleasurable activities domain was significant (aPR: 1.15 [1.03-1.32]). Overall, mutuality may play a role in promoting job satisfaction among HHAs.

THE PHYSICAL AND MENTAL HEALTH OF HOME HEALTHCARE WORKERS: WHAT DO WE KNOW AND WHAT CAN WE DO ABOUT IT?

This presentation will use data from the 2014-2018 CDC's Behavioral Risk Factor Surveillance Survey to characterize the physical and mental health of home health care workers compared to other similar frontline, low-wage worker groups, before the COVID-19 pandemic. Next, using primary survey data collected in partnership with the 1199SEIU Training and Employment Fund, the health of the workforce during the COVID-19 pandemic will be presented, as well as the workforces' needs. The survey includes data from over 250 home health care workers employed in New York, NY who provided care during the pandemic. Finally, data from a pilot feasibility study of an intervention aimed at improving home care workers' well-being will be presented.

A systematic review of N-of-1 trials and single case experimental designs in physiotherapy for musculoskeletal conditions

BACKGROUND

Single Case Experimental Designs (SCEDs) are especially useful for small heterogeneous samples. Their role in evaluation of physiotherapy interventions for musculoskeletal conditions has not been systematically reviewed.

OBJECTIVES

Systematically review use, purpose, and outcomes of SCEDs for physiotherapy interventions for musculoskeletal conditions.

DATA SOURCES

Electronic databases and grey literature, searched using pre-defined terms.

STUDY SELECTION OR ELIGIBILITY CRITERIA

Studies of human participants enrolled in eligible SCEDs (individual or a series).

STUDY APPRAISAL AND SYNTHESIS METHODS

We extracted study characteristics, analytic methods and results, synthesising these descriptively. We used RoBiN-T scale to assess risk of bias.

RESULTS

We included 19 SCEDs comprising 92 participants, with wide variability in design, methodology, analysis and in conditions and interventions evaluated. 95% of participants responded favourably to the tested intervention. Overall risk of bias was high, due to poor internal validity, especially regarding randomisation, blinding, inter-rater agreement and measurement of treatment adherence. Visual analysis alone was performed in 55% of studies. Assessment of provider and participant satisfaction was limited.

CONCLUSIONS AND IMPLICATIONS

of key findings: SCEDs may be well-suited to evaluation of physiotherapy interventions for musculoskeletal conditions, but the risk of bias in studies to date is high. Following SCED guidelines to minimize the risk of bias and maximise clinical usefulness is recommended.

Forgotten Front Line: Understanding the Needs of Unionized Home Health Aides in Downstate New York During the COVID-19 Pandemic

During the coronavirus disease 2019 (COVID-19) pandemic, home health aides (HHAs) provided daily medical and personal care to community-dwelling older adults and those with chronic conditions. Prior qualitative studies have found that providing care during COVID-19 left HHAs susceptible to physical, financial, and emotional risks. However, limited quantitative data exist The objective of this study was to assess the impact of COVID-19 on HHAs and to understand the challenges and opportunities for current and future pandemic planning. A cross-sectional survey of 256 HHAs in the downstate New York region was conducted by telephone in English, French Creole, Chine, Spanish, and Russian between August and November 2020. The survey found that HHAs experienced a variety of physical, financial, and emotional challenges during COVID-19. To better support this work force, action by public health officials and policymakers is warranted, particularly with respect to workplace protections and safety, mental health, compensation, and access to basic resources.

The Impact of Covid‐19 on Certified Nursing Assistants in New York City: A Cross‐Sectional Study

Research Objective

In December 2020, the New York Times reported that nursing home (NH) residents and workers accounted for 38% of COVID‐19 related deaths in the U.S. Despite this toll, research documenting the impact of the pandemic from a worker perspective is limited. Focusing on the experience of certified nursing assistants (CNAs), the primary providers of direct care to NH residents, this study examined the physical, emotional, and financial impact of COVID‐19 and identified resource needs in the pandemic context.

Study Design

A phone survey was conducted between September and December 2020 with CNAs who are members of 1199SEIU, the largest healthcare union in the U.S. To be eligible, CNAs had to be union members and care for patients at NHs in New York City, Long Island, or the Lower Hudson Valley during the pandemic. The survey included 42 questions and focused on COVID‐19 exposure, mental and physical health, family economic security, and workplace resources and training.

Population Studied

This study focused on 216 CNAs working for unionized NH employers in downstate New York.

Principal Findings

A total of 216 CNAs from 98 unique NHs participated in the study. 78% of participants were between 40–69 years old, 93% were women, 87% were Black, and 61% had more than 10 years of experience in NHs. In addition to their role as paid care providers, 81% reported providing care or financial support to family members. With regard to COVID‐19 Exposure, 93% reported being tested since the beginning of the pandemic, with 33% testing positive. Significant majorities were “very concerned” about exposing themselves (75%), family members (86%), and patients (80%) to COVID‐19 given the nature of their work. With respect to Mental Health, 76% reported feeling emotionally drained and 60% reported feeling fatigued on a regular basis. 52% said support dealing with stress and anxiety would be “very useful.” Concerning Family Economic Security, 29% said the pandemic made it harder to pay for basic needs (e.g., food, rent, etc.) and 48% said it was harder to care for family members. Majorities said help accessing affordable housing (61%), paying for food (58%), and paying for work‐related transport (52%) would be “very useful.” With regard to Workplace Resources, 81% said they currently had enough PPE, and 33% reported having to provide their own PPE at some point during the pandemic. 92% experienced patient deaths in their unit or NHs during the pandemic, while 40% said services were made available to provide support in the grieving process. With respect to Training, most were “very interested” in training on stress management” (58%) and treating patients with COVID‐19 (55%).

Conclusions

Our survey results show significant challenges and resource needs among unionized CNAs in downstate New York.

Implications for Policy or Practice

Unionized CNAs have significant resource needs in the pandemic context, and other data suggests that the needs of non‐unionized CNAs may be even greater. To better support this workforce, action by public health officials and policymakers is warranted, particularly with respect to workplace safety and protection, mental health, compensation, and access to basic resources.

Association of cardiovascular disease and traditional cardiovascular risk factors with the incidence of dementia among patients with rheumatoid arthritis

OBJECTIVE

To determine the incidence of dementia in patients with rheumatoid arthritis (RA) 65 years and older, and compare the incidence of dementia in patients with RA with prevalent cardiovascular (CV) disease (CVD), CV risk factors but no prevalent CVD and neither (referent group).

METHODS

We analyzed claims data from the Center for Medicare & Medicaid Services (CMS) from 2006-2014. Eligibility criteria included continuous medical and pharmacy coverage for ≥ 12 months (baseline period 2006), > 2 RA diagnoses by a rheumatologist and at least 1 medication for RA. CVD and CV risk factors were identified using codes from the Chronic Condition Data Warehouse. Incident dementia was defined by 1 inpatient or 2 outpatient claims, or one dementia specific medication. Age-adjusted incident rates were calculated within each age strata. Univariate and multivariate Cox proportional hazard models were used to calculate Hazard Ratios (HR) and 95% confidence intervals.

RESULTS

Among 56,567 patients with RA, 11,789 (20.1%) incident cases of dementia were included in the main analysis. Age adjusted incident rates were high among all groups and increased with age. After adjustment for age, sex, comorbidities and baseline CV and RA medications, patients with CVD and CV risk factors between 65 and 74 years had an increased risk for incident dementia compared to those without CVD and without CV risk factors (HR 1.18 (95% CI 1.04-1.33) and HR 1.03 (95% CI 1.00-1.11), respectively). We observed a trend towards increased risk in patients between 75 and 84 years with CVD at baseline.

CONCLUSION

Patients with RA with both CVD and CV risk factors alone are at an increased risk for dementia compared to those with neither CVD nor CV risk factors; however, this risk is attenuated with increasing age. The impact of RA treatment and CV primary prevention strategies in the prevention of dementia in patients with RA warrants further studies.

Personalised treatments for acute whiplash injuries: A pilot study of nested N-of-1 trials in a multiple baseline single-case experimental design

BACKGROUND

Whiplash associated disorder (WAD), a common and disabling condition, incurs huge burden and costs to Australia. Yet, current treatments for whiplash are not very effective; improved outcomes are urgently needed. Clinical guidelines recommend simple analgesia (paracetamol and non-steroidal anti-inflammatory drugs) but there have been no trials of guideline-recommended drugs. This study will investigate the effectiveness of evidence-based advice (EBA), paracetamol, naproxen, and both paracetamol and naproxen, in reducing daily neck pain and preventing chronic neck pain after whiplash injury.

METHODS

This study is a pilot series of multi-cycle, double-blinded, randomised N-of-1 trials, nested in a multiple baseline design. The design will comprise three baselines of 5, 8 or 11 days duration. Post enrolment, participants will be randomly assigned to one of the baselines. Fifteen participants with acute (<2 weeks) Grade II WAD, experiencing at least moderate pain (NRS: ≥ 5/10), and at risk of poor recovery will be recruited from hospitals in Queensland, Australia, and through local physiotherapists. Patients will receive EBA plus a randomised sequence of three cycles of ten day treatment triplets (paracetamol designated as a C phase, naproxen, designated as a D phase, and both paracetamol and naproxen, designated as an E phase).

DISCUSSION

We will test the effects of different treatments on the primary outcome of average neck pain intensity collected daily and at 4 and 7 months post-injury. Secondary outcomes, including disability, depression, post-traumatic stress symptoms, pain catastrophizing, and feasibility of study procedures, will also be evaluated. The results of this study will inform a larger trial aiming to strengthen the evidence on EBA and simple analgesics for WAD.

TRIAL REGISTRATION

Clinical Trials Primary Registry: Australian and New Zealand Clinical Trials Registry.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12618001291279.

DATE OF REGISTRATION

31/07/2018.

PRIMARY TRIAL SPONSOR

The University of Queensland, Brisbane QLD 4072 Australia.

FUNDING

The University of Queensland.

HEART-FAILURE TRAINING FOR HOME CARE WORKERS IN NEW YORK CITY

Home care workers (HCWs), which include home health aides and personal care aides, are increasingly being used by community dwelling adults with heart failure (HF) for long-term assistance and post-acute care. Findings from our prior research suggest that HCWs are deeply involved in many aspects of HF patients’ self-care, including HF maintenance and management, but the majority have not received any HF training or HF-specific resources. Due to this, many HCWs do not feel confident caring for their clients with HF. In this symposium, we will present the findings of a qualitative study that used a nominal group technique to elicit the educational needs of 40 English and Spanish speaking agency-employed HCWs caring for HF patients in New York City. We will also present an overview of the HF training course that was developed from this data and its effect on HCWs’ HF knowledge and caregiving self-efficacy.

Nativity and Occupational Determinants of Physical Activity Participation Among Latinos

INTRODUCTION

Latinos in the U.S. bear a disproportionate burden of cardiovascular risk factors, including physical inactivity. Previous research among Latinos has focused on leisure-time physical activity, limiting understanding of the different ways in which populations, particularly working-class groups, achieve recommended levels of physical activity. This study examined associations of race/ethnicity; nativity; and leisure-time, transportation, and occupation-related physical activity among Latino and non-Latino white adults.

METHODS

Participants sampled in the 2007-2012 waves of the National Health and Nutrition Examination Survey self-reported domain-specific physical activity. Data were analyzed in 2016-2017 using multivariable log binomial regression models to examine differences in meeting guidelines for each physical activity domain separately and as total physical activity among Latinos (n=4,692) and non-Latino whites (n=7,788). Models were adjusted for sociodemographic characteristics and health status and tested interactions between nativity and occupational categories.

RESULTS

In adjusted models, foreign-born Latinos (prevalence ratio=0.70, 95% CI=0.63, 0.77) and U.S.-born Latinos (prevalence ratio=0.85, 95% CI=0.76, 0.95) were least likely to meet physical activity guidelines through occupation-related and leisure time physical activity, when compared with non-Latino whites. By contrast, foreign-born Latinos were more likely to meet physical activity guidelines through transportation physical activity than non-Latino whites (prevalence ratio=1.26, 95% CI=1.01, 1.56) and were proportionately more likely to participate in vigorous modes of physical activity. Interaction results indicated that foreign-born Latinos were the least likely to meet physical activity guidelines compared with U.S.-born Latinos and non-Latino whites if they worked in non-manual occupational categories. All racial/ethnic groups working in manual occupations saw the largest increase (40%-50%) in meeting physical activity guidelines when occupation-related physical activity was combined with leisure-time and transportation physical activity.

CONCLUSIONS

These findings suggest variability in the relationship between nativity and the physical activity domain Latinos engage in compared with non-Latino whites, with occupation contributing substantially to meeting physical activity recommendations for all population groups.

Pregabalin versus placebo in targeting pro-nociceptive mechanisms to prevent chronic pain after whiplash injury in at-risk individuals - a feasibility study for a randomised controlled trial

BACKGROUND

Whiplash-associated disorders (WAD) are an enormous and costly burden to Australian society. Up to 50% of people who experience a whiplash injury will never fully recover. Whiplash is resistant to treatment and no early management approach has yet been shown to prevent chronic pain. The early presence of central sensitization is associated with poor recovery. Pregabalin's effects on central sensitization indicate the potential to prevent or modulate these processes after whiplash injury and to improve health outcomes, but this has not been investigated. This paper describes the protocol for a feasibility study for a randomised controlled trial of pregabalin plus evidence-based advice compared to placebo plus evidence-based advice for individuals with acute whiplash injury who are at risk of poor recovery.

METHODS

This double blind, placebo-controlled randomised feasibility study will examine the feasibility and potential effectiveness of pregabalin and evidence-based advice (intervention) compared to placebo and evidence-based advice (control) for individuals with acute whiplash injury at risk of poor recovery. Thirty participants (15 per group) aged 18-65 years with Grade II WAD, within 48 hours of injury and currently experiencing at least moderate pain (NRS: ≥ 5/10) will be recruited from Emergency Departments of public hospitals in Queensland, Australia. Pregabalin will be commenced at 75 mg bd and titrated up to 300 mg bd as tolerated for 4 weeks followed by 1 week of weaning.

RESULTS

The feasibility of trial procedures will be tested, as well as the potential effect of the intervention on the outcomes. The primary outcome of neck pain intensity at 3 months from randomisation will be compared between the treatment groups using standard analysis of variance techniques.

DISCUSSION

Feasibility and potential effectiveness data will inform an appropriately powered full trial, which if successful, will provide an effective and cost-effective intervention for a costly and treatment resistant condition. It will also have implications for the early management of other traumatic conditions beyond whiplash.

TRIAL REGISTRATION

Clinical Trials Primary Registry: Australian and New Zealand Clinical Trials Registry.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12617000059369 . Date of Registration: 11/01/2017. Primary Trial Sponsor: The University of Queensland, Brisbane QLD 4072 Australia.

The Use of Social Media in Graduate Medical Education: A Systematic Review

PURPOSE

Despite the growing presence of social media in graduate medical education (GME), few studies have attempted to characterize their effect on residents and their training. The authors conducted a systematic review of the peer-reviewed literature to understand the effect of social media on resident (1) education, (2) recruitment, and (3) professionalism.

METHOD

The authors identified English-language peer-reviewed articles published through November 2015 using Medline, Embase, Cochrane, PubMed, Scopus, and ERIC. They extracted and synthesized data from articles that met inclusion criteria. They assessed study quality for quantitative and qualitative studies through, respectively, the Medical Education Research Study Quality Instrument and the Consolidated Criteria for Reporting Qualitative Studies.

RESULTS

Twenty-nine studies met inclusion criteria. Thirteen (44.8%) pertained to residency education. Twitter, podcasts, and blogs were frequently used to engage learners and enhance education. YouTube and wikis were more commonly used to teach technical skills and promote self-efficacy. Six studies (20.7%) pertained to the recruitment process; these suggest that GME programs are transitioning information to social media to attract applicants. Ten studies (34.5%) pertained to resident professionalism. Most were exploratory, highlighting patient and resident privacy, particularly with respect to Facebook. Four of these studies surveyed residents about their social network behavior with respect to their patients, while the rest explored how program directors use it to monitor residents' unprofessional online behavior.

CONCLUSIONS

The effect of social media platforms on residency education, recruitment, and professionalism is mixed, and the quality of existing studies is modest at best.

Abstract 262: The Predictive Ability of a 30-Day Heart Failure Readmission Model Improves with Multi-level Analysis

Background: Although readmission occurs following 25% of heart failure hospitalizations, identifying patients at greatest risk has been challenging. To date, prediction models have offered only modest discriminatory power (C-Statistic: 0.58-0.65). Their limitations underscore the need for novel approaches to risk prediction.

Hypothesis: Multi-level analysis and the inclusion of population-level factors will improve the predictive ability of our 30-day HF readmission model.

Methods: We studied patients with a principal diagnosis of HF who were discharged home from an academic hospital in 2013-2014. Index hospitalizations and 30-day readmissions were identified by query of the electronic medical record. Variables of analysis included demographics, HF characteristics, comorbidities, echocardiographic (echo) parameters and clinical indices. Heart failure with preserved ejection fraction (HFpEF) was defined as LVEF ≥ 50 on echo. Conventional logistic regression models were first used to examine the association between patient characteristics and 30-day readmissions. Next, multi-level modeling was used wherein hierarchical clustering techniques identified key drivers of readmission. The final predictive model incorporated these findings.

Results: Of the 821 patients admitted with HF, 242 (29.5%) were readmitted within 30 days. HFpEF (p = .008), LVEF (p= .03) and NYHA classification (p=.002) were associated with early readmission, as were end stage renal disease (p=.04) and gastrointestinal bleeding (p =.02). In addition, serum sodium (p =.02), creatinine (p =.03) and hemoglobin (p =.002) were also associated with readmission. The initial multivariable logistic regression model based on patient characteristics was significant (p=.01) with 66% convergence. This model found ventricular tachycardia (VT) (OR = 3.47 CI 1.49-8.08) and HFpEF (OR =1.49 CI 1.01-2.22) to be associated with readmission. As expected, NYHA Class II (OR = 0.28 CI 0.09-0.834) and Hemoglobin (OR = 0.89 CI 0.80-0.98) were inversely associated with readmission. Multi-level analysis revealed that beyond the characteristics of the individuals alone, patients with HFpEF represented a significant sub-population that was driving readmissions. The final model incorporated this nested sub-group and was found to have an improved convergence of 73% (p =.02). In this model, the association of HFpEF and readmission increased in magnitude (OR = 3.43 CI 1.39-8.45), whereas factors including VT, NYHA Class II, and hemoglobin were no longer significant.

Conclusion: Multi-level analysis increased the predictive ability of our 30-day HF readmission model (c stat 0.66 to 0.73) by accounting for both individual and population-level characteristics. HFpEF emerged as a key driver of readmission and its inclusion in the model led to a more accurate and clinically meaningful tool for our clinicians and medical center.

Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption

Precise pore size analysis of isoreticular series of UTL related zeolites is performed using high-resolution argon adsorption and positron annihilation spectroscopy.

Effect of different aerodynamic time trial cycling positions on muscle activation and crank torque

To reduce air resistance, time trial cyclists and triathletes lower their torso angle. The aim of this study was to investigate the effect of lowering time trial torso angle positions on muscle activation patterns and crank torque coordination. It was hypothesized that small torso angles yield a forward shift of the muscle activation timing and crank torque. Twenty-one trained cyclists performed three exercise bouts at 70% maximal aerobic power in a time trial position at three different torso angles (0°, 8°, and 16°) at a fixed cadence of 85 rpm. Measurements included surface electromyography, crank torques and gas exchange. A significant increase in crank torque range and forward shift in peak torque timing was found at smaller torso angles. This relates closely with the later onset and duration of the muscle activation found in the gluteus maximus muscle. Torso angle effects were only observed in proximal monoarticular muscles. Moreover, all measured physiological variables (oxygen consumption, breathing frequency, minute ventilation) were significantly increased with lowering torso angle and hence decreased the gross efficiency. The findings provide support for the notion that at a cycling intensity of 70% maximal aerobic power, the aerodynamic gains outweigh the physiological/biomechanical disadvantages in trained cyclists.

The effect of time trial cycling position on physiological and aerodynamic variables

To reduce aerodynamic resistance cyclists lower their torso angle, concurrently reducing Peak Power Output (PPO). However, realistic torso angle changes in the range used by time trial cyclists have not yet been examined. Therefore the aim of this study was to investigate the effect of torso angle on physiological parameters and frontal area in different commonly used time trial positions. Nineteen well-trained male cyclists performed incremental tests on a cycle ergometer at five different torso angles: their preferred torso angle and at 0, 8, 16 and 24°. Oxygen uptake, carbon dioxide expiration, minute ventilation, gross efficiency, PPO, heart rate, cadence and frontal area were recorded. The frontal area provides an estimate of the aerodynamic drag. Overall, results showed that lower torso angles attenuated performance. Maximal values of all variables, attained in the incremental test, decreased with lower torso angles (P < 0.001). The 0° torso angle position significantly affected the metabolic and physiological variables compared to all other investigated positions. At constant submaximal intensities of 60, 70 and 80% PPO, all variables significantly increased with increasing intensity (P < 0.0001) and decreasing torso angle (P < 0.005). This study shows that for trained cyclists there should be a trade-off between the aerodynamic drag and physiological functioning.

Optimal cycling time trial position models: aerodynamics versus power output and metabolic energy

The aerodynamic drag of a cyclist in time trial (TT) position is strongly influenced by the torso angle. While decreasing the torso angle reduces the drag, it limits the physiological functioning of the cyclist. Therefore the aims of this study were to predict the optimal TT cycling position as function of the cycling speed and to determine at which speed the aerodynamic power losses start to dominate. Two models were developed to determine the optimal torso angle: a 'Metabolic Energy Model' and a 'Power Output Model'. The Metabolic Energy Model minimised the required cycling energy expenditure, while the Power Output Model maximised the cyclists׳ power output. The input parameters were experimentally collected from 19 TT cyclists at different torso angle positions (0-24°). The results showed that for both models, the optimal torso angle depends strongly on the cycling speed, with decreasing torso angles at increasing speeds. The aerodynamic losses outweigh the power losses at cycling speeds above 46km/h. However, a fully horizontal torso is not optimal. For speeds below 30km/h, it is beneficial to ride in a more upright TT position. The two model outputs were not completely similar, due to the different model approaches. The Metabolic Energy Model could be applied for endurance events, while the Power Output Model is more suitable in sprinting or in variable conditions (wind, undulating course, etc.). It is suggested that despite some limitations, the models give valuable information about improving the cycling performance by optimising the TT cycling position.

Laypersons' expectations of recovery and beliefs about whiplash injury: a cross-cultural comparison between Australians and Singaporeans

BACKGROUND

Beliefs and expectations are thought to influence outcome following whiplash injury. Studies have proposed a link between rates of chronic whiplash and laypersons' expectations about outcome following a motor vehicle accident. The prevalence of chronic whiplash is relatively high in Australia and apparently low in Singapore. This study's objectives were to compare laypersons' beliefs and expectations of recovery of whiplash injury in Brisbane and Singapore and to assess the effect of demographic factors on whiplash beliefs.

METHODS

A cross-sectional study using online surveys was conducted on adult Internet users in Brisbane (Australia) and Singapore. The 14-item whiplash beliefs questionnaire (WBQ) was used to evaluate whiplash beliefs. Two additional items assessed expectations of recovery. Individual items of WBQ, WBQ score and expectations of recovery were analysed. Stratified analysis was performed to adjust for sampling bias due to quota sampling.

RESULTS

A total of 402 participants from Singapore and 411 participants from Brisbane, Australia, completed the survey. While participants from Singapore demonstrated slightly more negative whiplash beliefs than participants from Brisbane [t(811)  = -5.72; p < 0.0001], participants from both samples were similar in their expectations of quick recovery and return to normal activities following whiplash injury. Only gender had a significant effect on whiplash beliefs [estimated marginal means of WBQ score for men = 21.5; standard error (SE) = 0.20; women = 22.5; SE = 0.20; F(1,810)  = 11.2; p = 0.001].

CONCLUSIONS

Laypersons' expectations of recovery and beliefs about whiplash injury in Brisbane and Singapore were generally similar and mostly positive. Our results demonstrate that cultural differences reflected by laypersons' beliefs may not reflect the differences in prevalence of chronic whiplash between countries.

Does the presence of sensory hypersensitivity influence outcomes of physical rehabilitation for chronic whiplash? – A preliminary RCT

Patients with chronic whiplash associated disorders present with varied sensory, motor and psychological features. In this first instance it was questioned whether a multimodal program of physical therapies was an appropriate management to be broadly prescribed for these patients when it was known that some would have sensory features suggestive of a notable pain syndrome. A randomised controlled trial was conducted with 71 participants with persistent neck pain following a motor vehicle crash to explore this question. Participants were randomly allocated to receive either a multimodal physiotherapy program (MPT) or a self-management program (SMP) (advice and exercise). In the randomisation process, participants were stratified according to the presence or not of widespread mechanical or cold hyperalgesia. The intervention period was 10 weeks and outcomes were assessed immediately following treatment. Even with the presence of sensory hypersensitivity in 72.5% of subjects, both groups reported some relief of neck pain and disability (Neck Disability Index) and it was superior in the group receiving multimodal physiotherapy (p=0.04). Post-hoc observations however suggested that relief was marginal in the subgroup with both widespread mechanical and cold hyperalgesia. Further research is required to test the validity of this sub-group observation and to test the effect of the intervention in the long term.

Analysis of air contrast barium enema, computed tomographic colonography, and colonoscopy: prospective comparison

BACKGROUND

The usefulness of currently available colon imaging tests, including air contrast barium enema (ACBE), computed tomographic colonography (CTC), and colonoscopy, to detect colon polyps and cancers is uncertain. We aimed to assess the sensitivity of these three imaging tests.

METHODS

Patients with faecal occult blood, haematochezia, iron-deficiency anaemia, or a family history of colon cancer underwent three separate colon-imaging studies--ACBE, followed 7-14 days later by CTC and colonoscopy on the same day. The primary outcome was detection of colonic polyps and cancers. Outcomes were assessed by building an aggregate view of the colon, taking into account results of all three tests.

FINDINGS

614 patients completed all three imaging tests. When analysed on a per-patient basis, for lesions 10 mm or larger in size (n=63), the sensitivity of ACBE was 48% (95% CI 35-61), CTC 59% (46-71, p=0.1083 for CTC vs ACBE), and colonoscopy 98% (91-100, p<0.0001 for colonoscopy vs CTC). For lesions 6-9 mm in size (n=116), sensitivity was 35% for ACBE (27-45), 51% for CTC (41-60, p=0.0080 for CTC vs ACBE), and 99% for colonoscopy (95-100, p<0.0001 for colonoscopy vs CTC). For lesions of 10 mm or larger in size, the specificity was greater for colonoscopy (0.996) than for either ACBE (0.90) or CTC (0.96) and declined for ACBE and CTC when smaller lesions were considered.

INTERPRETATION

Colonoscopy was more sensitive than other tests, as currently undertaken, for detection of colonic polyps and cancers. These data have important implications for diagnostic use of colon imaging tests.

Responses to a clinical test of mechanical provocation of nerve tissue in whiplash associated disorder

Involvement of nerve tissue may contribute to the persistence of pain following a whiplash injury. This study aimed to investigate responses to the brachial plexus provocation test (BPPT) in 156 subjects with chronic whiplash associated disorder (WAD) with and without associated arm pain and 95 asymptomatic control subjects. The range of elbow extension (ROM) and visual analogue scale (VAS) pain scores were measured. Subjects with chronic WAD demonstrated significantly less ROM and higher VAS scores with the BPPT than the asymptomatic subjects (P<0.001). These effects occurred bilaterally. Within the whiplash population, subjects whose arm pain was reproduced by the BPPT demonstrated significantly less ROM on both the symptomatic and asymptomatic sides when compared to the whiplash subjects whose arm pain was not reproduced by the BPPT (P=0.003) and significantly less ROM and higher VAS scores than those whiplash subjects with no arm pain (P=0.003, 0.01). Only the whiplash subjects whose arm pain was reproduced by the BPPT demonstrated differences between the symptomatic and asymptomatic sides. These generalized hyperalgesic responses to the BPPT support the hypothesis of central nervous system hypersensitivity as contributing to persistent pain experienced by WAD patients.

The effect of musculoskeletal pain on motor activity and control

Aberrant movement patterns and postures are obvious to clinicians managing patients with musculoskeletal pain. However, some changes in motor function that occur in the presence of pain are less apparent. Clinical and basic science investigations have provided evidence of the effects of nociception on aspects of motor function. Both increases and decreases in muscle activity have been shown, along with alterations in neuronal control mechanisms, proprioception, and local muscle morphology. Various models have been proposed in an attempt to provide an explanation for some of these changes. These include the vicious cycle and pain adaptation models. Recent research has seen the emergence of a new model in which patterns of muscle activation and recruitment are altered in the presence of pain (neuromuscular activation model). These changes seem to particularly affect the ability of muscles to perform synergistic functions related to maintaining joint stability and control. These changes are believed to persist into the period of chronicity. This review shows current knowledge of the effect of musculoskeletal pain on the motor system and presents the various proposed models, in addition to other shown effects not covered by these models. The relevance of these models to both acute and chronic pain is considered. It is apparent that people experiencing musculoskeletal pain exhibit complex motor responses that may show some variation with the time course of the disorder.

Cervical mobilisation: concurrent effects on pain, sympathetic nervous system activity and motor activity

Recent findings that spinal manual therapy (SMT) produces concurrent hypoalgesic and sympathoexcitatory effects have led to the proposal that SMT may exert its initial effects by activating descending inhibitory pathways from the dorsal periaqueductal gray area of the midbrain (dPAG). In addition to hypoalgesic and sympathoexcitatory effects, stimulation of the dPAG in animals has been shown to have a facilitatory effect on motor activity. This study sought to further investigate the proposal regarding SMT and the PAG by including a test of motor function in addition to the variables previously investigated. Using a condition randomised, placebo-controlled, double blind, repeated measures design, 30 subjects with mid to lower cervical spine pain of insidious onset participated in the study. The results indicated that the cervical mobilisation technique produced a hypoalgesic effect as revealed by increased pressure pain thresholds on the side of treatment (P=0.0001) and decreased resting visual analogue scale scores (P=0.049). The treatment technique also produced a sympathoexcitatory effect with an increase in skin conductance (P<0.002) and a decrease in skin temperature (P=<0.02). There was a decrease in superficial neck flexor muscle activity (P<0.0002) at the lower levels of a staged cranio-cervical flexion test. This could imply facilitation of the deep neck flexor muscles with a decreased need for co-activation of the superficial neck flexors. The combination of all findings would support the proposal that SMT may, at least initially, exert part of its influence via activation of the PAG.

Pressure pain thresholds of upper limb peripheral nerve trunks in asymptomatic subjects

BACKGROUND AND PURPOSE

Palpation of peripheral nerve trunks has been advocated as a method of assessing the presence of hyperalgesic nerve tissue as a contributing factor to pain syndromes in musculoskeletal disorders of the upper quadrant. This study investigated, in the first instance, the pressure pain thresholds of the median, radial and ulnar nerve trunks of the upper limb in healthy, asymptomatic subjects.

METHOD

Forty-five male and 50 female healthy volunteer subjects participated in this study which involved measurement of pressure pain thresholds by use of pressure algometry bilaterally over the three peripheral nerve trunks in the upper limbs.

RESULTS

Pressure pain thresholds were shown to be lowest in the median nerve (p = 0.001) and lower in female subjects (p = 0.001). Laterality (p = 0.077) or the age of the subject (p = 0.254) did not significantly influence results.

CONCLUSIONS

The study demonstrated differences in pressure pain thresholds in the three nerve trunks of the upper limb. These findings should be taken into account when interpreting the findings of nerve palpation in musculoskeletal upper quadrant disorders.

Leukocystatin, a new Class II cystatin expressed selectively by hematopoietic cells

We describe a new cystatin in both mice and humans, which we termed leukocystatin. This protein has all the features of a Class II secreted inhibitory cystatin but contains lysine residues in the normally hydrophobic binding regions. As determined by cDNA library Southern blots, this cystatin is expressed selectively in hematopoietic cells, although fine details of the distribution among these cell types differ between the human and mouse mRNAs. In addition, we have determined the genomic organization of mouse leukocystatin, and we found that in contrast to most cystatins, the leukocystatin gene contains three introns. The recombinant proteins corresponding to these cystatins were expressed in Escherichia coli as N-terminal glutathione S-transferase or FLAGTM fusions, and studies showed that they inhibited papain and cathepsin L but with affinities lower than other cystatins. The unique features of leukocystatin suggests that this cystatin plays a role in immune regulation through inhibition of a unique target in the hematopoietic system.

The effect of corticosteroids and other antineoplastic agents on the generation of leukocyte migration inhibition factor

We have shown that hydrocortisone in physiological concentrations can inhibit the production of leukocyte migration inhibition factor (LMIF), but does not diminish the action of this lymphokine. Other agents tested failed to influence LMIF production. Inhibition of LMIF production by corticosteroids was influenced by the nature of the stimulus used for the production as an effect could be seen with PHA or Con A, but not Staphylococcal enterotoxin A (SEA). Production of LMIF was promptly restored after removal of the steroids. Furthermore, addition of a calcium ionophore to PHA restored the production of LMIF even in the presence of corticosteroids. In contrast, addition of exogenous IL-2 did not correct the defect in lymphokine secretion. We believe that inhibition of the production of LMIF by steroid may lead to defective granulocytic function and thus, predispose to infection.

Toxicity with intravenous injection of crude marijuana extract

Intravenous injection of crude marijuana extract led to development of an acute illness with multisystem involvement. Gastrointestinal manifestations consisted of severe vomiting, diarrhea, and crampy abdominal pain. Hypotension, tachycardia, and peripheral vasodilation constituted the main cardiovascular manifestations of the disease. Moderate azotemia and oliguria, presumed to be of prerenal origin, were present and rapidly resolved with administration of intravenous fluids. Hematologic manifestations consisted of leukocytosis with a left shift, thrombocytopenia, prolonged partial thromboplastin time, increased fibrin degradation products, and positive protamine sulfate test. The observed coagulation abnormalities may suggest intravascular coagulation. C3, C4, and total hemolytic complement were reduced, suggesting possible activation of the complement system. Hyperventilation, hypoxemia, pulmonary edema, obstructive, and restrictive pulmonary function abnormalities and bilateral pleural effusions highlighted the pulmonary manifestations of the disease. Rhadbomyolysis and mild hepatic function abnormalities were also present. All observed abnormalities reversed in a few days with no significant sequelae.