Paranasal sinus occupancy assessed from magnetic resonance images-associations with clinical indicators in patients with systemic lupus erythematosus

OBJECTIVES

Nasal, paranasal sinus and mucosal disorders are common symptoms in autoimmune rheumatic diseases. Soft tissue changes and fluid accumulation in the osteomeatal complexes and paranasal sinuses manifest as opaqueness on radiological images which can be assessed using visual scoring and computational methods on CT scans, but their results do not always correlate. Using MRI, we investigate the applicability of different image analysis methods in SLE.

METHODS

We assessed paranasal sinus opaqueness on MRI from 51 SLE patients, using three visual scoring systems and expert-delineated computational volumes, and examined their association with markers of disease activity, inflammation, endothelial dysfunction and common small vessel disease (SVD) indicators, adjusting for age and sex-at-birth.

RESULTS

The average paranasal sinus volume occupation was 4.55 (6.47%) [median (interquartile range) = 0.67 (0.25-2.65) ml], mainly in the maxillary and ethmoid sinuses. It was highly correlated with Lund-Mackay (LM) scores modified at 50% opaqueness cut-off (Spearman's ρ: 0.71 maxillary and 0.618 ethmoids, P < 0.001 in all), and with more granular variations of the LM system. The modified LM scores were associated with SVD scores (0: B = 5.078, s.e. = 1.69, P = 0.0026; 2: B = -0.066, s.e. = 0.023, P = 0.0045) and disease activity (anti-dsDNA: B = 4.59, s.e. = 2.22, P = 0.045; SLEDAI 3-7: 2.86 < B < 4.30; 1.38 < s.e. < 1.63; 0.0083 ≤ P ≤ 0.0375). Computationally derived percent opaqueness yielded similar results.

CONCLUSION

In patients with SLE, MRI computational assessment of sinuses opaqueness and LM scores modified at a 50% cut-off may be useful tools in understanding the relationships among paranasal sinus occupancy, disease activity and SVD markers.

Paranasal sinuses opacification on magnetic resonance imaging in relation to brain health in sporadic small vessel disease - Systematic review and pilot analysis

BACKGROUND

The paranasal sinus mucosal thickening, visible in magnetic resonance imaging (MRI), maybe a source of inflammation in microvessels, but its relationship with small vessel disease (SVD) is unclear. We reviewed the literature and analysed a sample of patients with sporadic SVD to identify any association between paranasal sinus opacification severity and SVD neuroimaging markers.

METHODS

We systematically reviewed MEDLINE and EMBASE databases up to April 2020 for studies on paranasal sinus mucosal changes in patients with SVD, cerebrovascular disease (CVD), and age-related neurodegenerative diseases. We analysed clinical and MRI data from 100 participants in a prospective study, the Mild Stroke Study 3 (ISRCTN 12113543) at 1-3, 6 and 12 months following a minor stroke to test key outcomes from the literature review. We used multivariate linear regression to explore associations between modified Lund-Mackay (LM) scores and brain, white matter hyperintensities (WMH), enlarged perivascular spaces (PVS) volumes at each time point, adjusted for baseline age, sex, diabetes, hypercholesterolaemia, hypertension and smoking.

RESULTS

The literature review, after screening 3652 publications, yielded 11 primary studies, for qualitative synthesis with contradictory results, as positive associations/higher risk from 5/7 CVD studies were contradicted by the two studies with largest samples, and data from dementia studies was equally split in their outcome. From the pilot sample of patients analysed (female N = 33, mean age 67.42 (9.70) years), total LM scores had a borderline negative association with PVS in the centrum semiovale at baseline and 6 months (B = -0.25, SE = 0.14, p = 0.06) but were not associated with average brain tissue, WMH or normal-appearing white matter volumes.

CONCLUSION

The inconclusive results from the literature review and empirical study justify larger studies between PVS volume and paranasal sinuses opacification in patients with sporadic SVD.

Corrigendum to Correlational structure of 'frontal' tests and intelligence tests indicates two components with asymmetrical neurostructural correlates in old age Intelligence 46 (2014) 94-106

[This corrects the article DOI: 10.1016/j.intell.2014.05.006.].

A systematic review of neuroimaging in delirium: predictors, correlates and consequences

OBJECTIVE

Neuroimaging advances our understanding of delirium pathophysiology and its consequences. A previous systematic review identified 12 studies (total participants N = 764, delirium cases N = 194; years 1989-2007) and found associations with white matter hyperintensities (WMH) and cerebral atrophy. Our objectives were to perform an updated systematic review of neuroimaging studies in delirium published since January 2006 and summarise the available literature on predictors, correlates or outcomes.

METHODS

Studies were identified by keyword and MeSH-based electronic searches of EMBASE, MEDLINE and PsycINFO combining terms for neuroimaging, brain structure and delirium. We included neuroimaging studies of delirium in adults using validated delirium assessment methods.

RESULTS

Thirty-two studies (total N = 3187, delirium N = 1086) met the inclusion criteria. Imaging included magnetic resonance imaging (MRI; N = 9), computed tomography (N = 4), diffusion tensor imaging (N = 3), transcranial Doppler (N = 5), near infrared spectroscopy (N = 5), functional-MRI (N = 2), single photon emission computed tomography (N = 1), proton MRI spectroscopy (N = 1), arterial spin-labelling MRI (N = 1) and 2-¹³ fluoro-2-deoxyglucose positron emission tomography (N = 1). Despite heterogeneity in study design, delirium was associated with WMH, lower brain volume, atrophy, dysconnectivity, impaired cerebral autoregulation, reduced blood flow and cerebral oxygenation and glucose hypometabolism. There was evidence of long-term brain changes following intensive care unit delirium.

CONCLUSIONS

Neuroimaging is now used more widely in delirium research due to advances in technology. However, imaging delirious patients presents challenges leading to methodological limitations and restricted generalisability. The findings that atrophy and WMH burden predict delirium replicates findings from the original review, while advanced techniques have identified other substrates and mechanisms that warrant further investigation.

Visual Rating Scales of White Matter Hyperintensities and Atrophy: Comparison of Computed Tomography and Magnetic Resonance Imaging

GOAL

Magnetic resonance imaging (MRI) is the preferred modality for research on structural age-related brain changes. However, computed tomography (CT) is widely available and has practical and cost advantages over MRI for large-scale brain imaging research studies in acutely unwell patients. However, the relationships between MRI and CT measures of white matter hyperintensities (WMH) and atrophy are unclear. We examined the relationships between visual ratings of WMH, atrophy, and old infarcts in patients who had both CT and MRI scans.

MATERIALS AND METHODS

Patients who had both CT and MRI scans in the International Stroke Trial-3 were studied. In both modalities, 2 raters independently completed standardized visual rating scales for WMH, and for central and superficial atrophy using a 5-point scale. In addition, 1 rater recorded old infarcts according to size and location.

FINDINGS

Seventy patients with a mean age of 69 years were studied. There were moderate to substantial intrarater CT-MRI agreements for periventricular components of WMH scales (weighted Κappa = .55-.75). Agreements for basal ganglia ratings were lower (weighted Κappa = .18-.44), partly because of the misclassification of prominent perivascular spaces. Atrophy scales showed moderate to substantial CT-MRI agreements (weighted Κappa = .44-.70). MRI was more sensitive in the detection of smaller infarcts and cavitated lesions.

CONCLUSIONS

Standardized visual rating scales of white matter lesions and atrophy mostly show substantial agreement between CT and MRI. Clinical CT scans have a strong potential for wider exploitation in research studies, particularly in acutely unwell populations.

Associations between hippocampal morphology, diffusion characteristics, and salivary cortisol in older men

High, unabated glucocorticoid (GC) levels are thought to selectively damage certain tissue types. The hippocampus is thought to be particularly susceptible to such effects, and though findings from animal models and human patients provide some support for this hypothesis, evidence for associations between elevated GCs and lower hippocampal volumes in older age (when GC levels are at greater risk of dysregulation) is inconclusive. To address the possibility that the effects of GCs in non-pathological ageing may be too subtle for gross volumetry to reliably detect, we analyse associations between salivary cortisol (diurnal and reactive measures), hippocampal morphology and diffusion characteristics in 88 males, aged ∼73 years. However, our results provide only weak support for this hypothesis. Though nominally significant peaks in morphology were found in both hippocampi across all salivary cortisol measures (standardised β magnitudes<0.518, p_uncorrected>0.0000003), associations were both positive and negative, and none survived false discovery rate correction. We found one single significant association (out of 12 comparisons) between a general measure of hippocampal diffusion and reactive cortisol slope (β=0.290, p=0.008) which appeared to be driven predominantly by mean diffusivity but did not survive correction for multiple testing. The current data therefore do not clearly support the hypothesis that elevated cortisol levels are associated with subtle variations in hippocampal shape or microstructure in non-pathological older age.

Does white matter structure or hippocampal volume mediate associations between cortisol and cognitive ageing?

Elevated glucocorticoid (GC) levels putatively damage specific brain regions, which in turn may accelerate cognitive ageing. However, many studies are cross-sectional or have relatively short follow-up periods, making it difficult to relate GCs directly to changes in cognitive ability with increasing age. Moreover, studies combining endocrine, MRI and cognitive variables are scarce, measurement methods vary considerably, and formal tests of the underlying causal hypothesis (cortisol→brain→cognition) are absent. In this study, 90 men, aged 73 years, provided measures of fluid intelligence, processing speed and memory, diurnal and reactive salivary cortisol and two measures of white matter (WM) structure (WM hyperintensity volume from structural MRI and mean diffusivity averaged across 12 major tracts from diffusion tensor MRI), hippocampal volume, and also cognitive ability at age 11. We tested whether negative relationships between cognitive ageing differences (over more than 60 years) and salivary cortisol were significantly mediated by WM and hippocampal volume. Significant associations between reactive cortisol at 73 and cognitive ageing differences between 11 and 73 (r=-.28 to -.36, p<.05) were partially mediated by both WM structural measures, but not hippocampal volume. Cortisol-WM relationships were modest, as was the degree to which WM structure attenuated cortisol-cognition associations (<15%). These data support the hypothesis that GCs contribute to cognitive ageing differences from childhood to the early 70s, partly via brain WM structure.

Correlational structure of 'frontal' tests and intelligence tests indicates two components with asymmetrical neurostructural correlates in old age

Both general fluid intelligence (gf) and performance on some 'frontal tests' of cognition decline with age. Both types of ability are at least partially dependent on the integrity of the frontal lobes, which also deteriorate with age. Overlap between these two methods of assessing complex cognition in older age remains unclear. Such overlap could be investigated using inter-test correlations alone, as in previous studies, but this would be enhanced by ascertaining whether frontal test performance and gf share neurobiological variance. To this end, we examined relationships between gf and 6 frontal tests (Tower, Self-Ordered Pointing, Simon, Moral Dilemmas, Reversal Learning and Faux Pas tests) in 90 healthy males, aged ~ 73 years. We interpreted their correlational structure using principal component analysis, and in relation to MRI-derived regional frontal lobe volumes (relative to maximal healthy brain size). gf correlated significantly and positively (.24 ≤ r ≤ .53) with the majority of frontal test scores. Some frontal test scores also exhibited shared variance after controlling for gf. Principal component analysis of test scores identified units of gf-common and gf-independent variance. The former was associated with variance in the left dorsolateral (DL) and anterior cingulate (AC) regions, and the latter with variance in the right DL and AC regions. Thus, we identify two biologically-meaningful components of variance in complex cognitive performance in older age and suggest that age-related changes to DL and AC have the greatest cognitive impact.

Compensation or inhibitory failure? Testing hypotheses of age-related right frontal lobe involvement in verbal memory ability using structural and diffusion MRI

Functional neuroimaging studies report increased right prefrontal cortex (PFC) involvement during verbal memory tasks amongst low-scoring older individuals, compared to younger controls and their higher-scoring contemporaries. Some propose that this reflects inefficient use of neural resources through failure of the left PFC to inhibit non-task-related right PFC activity, via the anterior corpus callosum (CC). For others, it indicates partial compensation - that is, the right PFC cannot completely supplement the failing neural network, but contributes positively to performance. We propose that combining structural and diffusion brain MRI can be used to test predictions from these theories which have arisen from fMRI studies. We test these hypotheses in immediate and delayed verbal memory ability amongst 90 healthy older adults of mean age 73 years. Right hippocampus and left dorsolateral prefrontal cortex (DLPFC) volumes, and fractional anisotropy (FA) in the splenium made unique contributions to verbal memory ability in the whole group. There was no significant effect of anterior callosal white matter integrity on performance. Rather, segmented linear regression indicated that right DLPFC volume was a significantly stronger positive predictor of verbal memory for lower-scorers than higher-scorers, supporting a compensatory explanation for the differential involvement of the right frontal lobe in verbal memory tasks in older age.

Brain white matter integrity and cortisol in older men: the Lothian Birth Cohort 1936

Elevated glucocorticoid (GC) levels are hypothesized to be deleterious to some brain regions, including white matter (WM). Older age is accompanied by increased between-participant variation in GC levels, yet relationships between WM integrity and cortisol levels in older humans are underexplored. Moreover, it is unclear whether GC-WM associations might be general or pathway specific. We analyzed relationships between salivary cortisol (diurnal and reactive) and general measures of brain WM hyperintensity (WMH) volume, fractional anisotropy (g_FA), and mean diffusivity (g_MD) in 90 males, aged 73 years. Significant associations were predominantly found between cortisol measures and WMHs and g_MD but not g_FA. Higher cortisol at the start of a mild cognitive stressor was associated with higher WMH and g_MD. Higher cortisol at the end was associated with greater WMHs. A constant or increasing cortisol level during cognitive testing was associated with lower g_MD. Tract-specific bases of these associations implicated anterior thalamic radiation, uncinate, and arcuate and inferior longitudinal fasciculi. The cognitive sequelae of these relationships, above other covariates, are a priority for future study.

•

We correlated salivary cortisol and brain white matter (WM) measures in older males.

•

Cortisol was measured diurnally and in reaction to a cognitive challenge.

•

Diffusion tensor magnetic resonance imaging (fractional anisotropy and mean diffusivity) and total hyperintensity volume measured WM integrity.

•

WM-cortisol relations were found for mean diffusivity and hyperintensity volume but not fractional anisotropy.

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Higher cortisol in response to cognitive stressor denoted lower WM integrity.

Delirium and cerebrospinal fluid S100B in hip fracture patients: a preliminary study

OBJECTIVES

Delirium is associated with an increased risk of long-term cognitive decline, suggesting the possibility of concurrent central nervous system (CNS) injury. S100B is a putative biomarker of CNS injury and elevated serum levels in delirium have been reported. Here we hypothesize that delirium is associated with raised concentrations of cerebrospinal fluid (CSF) S100B.

METHODS

Forty-five patients with hip fracture aged over 60 and awaiting surgery under spinal anesthesia were assessed for delirium pre- and post-operatively. CSF S100B levels were measured in samples collected at the onset of surgery.

RESULTS

Participants with pre-operative delirium (N = 8) had elevated Log10 CSF S100B (mean: -0.156; SD: 0.238) compared with those without delirium (mean: -0.306; SD: 0.162), Student's t-test t = 2.18, df = 43, p = 0.035.

CONCLUSIONS

This study provides preliminary evidence of elevated CSF S100B in current delirium, consistent with findings in serum and with other studies showing elevated S100B in the presence of diverse forms of CNS injury.

New horizons in the pathogenesis, assessment and management of delirium

Delirium is one of the foremost unmet medical needs in healthcare. It affects one in eight hospitalised patients and is associated with multiple adverse outcomes including increased length of stay, new institutionalisation, and considerable patient distress. Recent studies also show that delirium strongly predicts future new-onset dementia, as well as accelerating existing dementia. The importance of delirium is now increasingly being recognised, with a growing research base, new professional international organisations, increased interest from policymakers, and greater prominence of delirium in educational and audit programmes. Nevertheless, the field faces several complex research and clinical challenges. In this article we focus on selected areas of recent progress and/or uncertainty in delirium research and practice. (i) Pathogenesis: recent studies in animal models using peripheral inflammatory stimuli have begun to suggest mechanisms underlying the delirium syndrome as well as its link with dementia. A growing body of blood and cerebrospinal fluid studies in humans have implicated inflammatory and stress mediators. (ii) Prevention: delirium prevention is effective in the context of research studies, but there are several unresolved issues, including what components should be included, the role of prophylactic drugs, and the overlap with general best care for hospitalised older people. (iii) Assessment: though there are several instruments for delirium screening and assessment, detection rates remain dismal. There are no clear solutions but routine screening embedded into clinical practice, and the development of new rapid screening instruments, offer potential. (iv) Management: studies are difficult given the heterogeneity of delirium and currently expert and comprehensive clinical care remains the main recommendation. Future studies may address the role of drugs for specific elements of delirium. In summary, though facing many challenges, the field continues to make progress, with several promising lines of enquiry and an expanding base of interest among researchers, clinicians and policymakers.

Cerebellar vermis size and cognitive ability in community-dwelling elderly men

The cerebellum participates in multiple cognitive functions, including those that are sensitive to decline with aging, and is also vulnerable to atrophy with aging. However, few studies have examined structure-function relationships in older adults. We measured the cross-sectional area of four areas of the cerebellar vermis in 45 community-dwelling men aged 71-76, and correlated this with individual cognitive test scores and two cognitive factors derived from principal components analysis. Two out of the four areas showed positive correlations; vermis area 4 (lobules VIII-X) correlated at r = 0.47 (p = 0.001) with a general cognitive factor accounting for almost half of the cognitive test variance. These findings support the hypothesis that variations in cerebellar structure are associated with cognitive ability in older adults.

Neck muscle cross-sectional area, brain volume and cognition in healthy older men: a cohort study

Background

Two important consequences of the normal ageing process are sarcopenia (the age-related loss of muscle mass and function) and age-related cognitive decline. Existing data support positive relationships between muscle function, cognition and brain structure. However, studies investigating these relationships at older ages are lacking and rarely include a measure of muscle size. Here we test whether neck muscle size is positively associated with cognition and brain structure in older men.

Methods

We studied 51 healthy older men with mean age 73.8 (sd 1.5) years. Neck muscle cross-sectional area (CSA) was measured from T1-weighted MR-brain scans using a validated technique. We measured multiple cognitive domains including verbal and visuospatial memory, executive functioning and estimated prior cognitive ability. Whole brain, ventricular, hippocampal and cerebellar volumes were measured with MRI. General linear models (ANCOVA) were performed.

Results

Larger neck muscle CSA was associated with less whole brain atrophy (t = 2.86, p = 0.01, partial eta squared 17%). Neck muscle CSA was not associated with other neuroimaging variables or current cognitive ability. Smaller neck muscle CSA was unexpectedly associated with higher prior cognition (t = −2.12, p < 0.05, partial eta squared 10%).

Conclusions

In healthy older men, preservation of whole brain volume (i.e. less atrophy) is associated with larger muscle size. Longitudinal ageing studies are now required to investigate these relationships further.

11β-hydroxysteroid dehydrogenase type 1, brain atrophy and cognitive decline

Excess cortisol levels are linked with brain atrophy and cognitive decline in older people. 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) potently amplifies intracellular glucocorticoid action by converting inert cortisone to active cortisol, but any causal importance in brain aging is unexplored. We tested the hypotheses that higher systemic 11β-HSD1 activity predicts brain atrophy and cognitive decline in older men. In a longitudinal study of 41 men (65-70 years old at baseline) we measured baseline systemic 11β-HSD1 activity, the urinary 5alpha- and 5beta-tetrahydrocortisol to tetrahydrocortisone ratio (ratio of tetrahydrometabolites of cortisol (THFs)/ratio of tetrahydrometabolites of cortisol (THE)), and assessed change in brain atrophy, white matter lesions and cognitive function over 6 years. Baseline THFs/THE correlated negatively with baseline hippocampal volumes (left: r = -0.37; right: r = -0.34; p < 0.05) and positively with ventricular volumes (r = 0.43, p = 0.006) and periventricular white matter lesions (rho = 0.31, p = 0.047). Importantly, baseline THFs/THE but not cortisol predicted increase in ventricular volumes (r = 0.33, p = 0.037) and decline in processing speed (r = -0.55, p = 0.0002) over 6 years. The predictive link between systemic 11β-HSD1 activity and progressive brain atrophy and cognitive decline suggests 11β-HSD1 inhibition as a plausible therapy for brain aging.

Quantifying the effects of normal ageing on white matter structure using unsupervised tract shape modelling

Quantitative tractography may provide insights into regional heterogeneity of changes in white matter structure in normal ageing. Here we examine how brain atrophy and white matter lesions affect correlations between tract shape, tract integrity and age in a range of frontal and non-frontal tracts in 90 non-demented subjects aged over 65 years using an enhanced version of probabilistic neighbourhood tractography. This novel method for automatic single seed point placement employs unsupervised learning and streamline selection to provide reliable and accurate tract segmentation, whilst also indicating how the shape of an individual tract compares to that of a predefined reference tract. There were significant negative correlations between tract shape similarity to reference tracts derived from a young brain white matter atlas and age in genu and splenium of corpus callosum. Controlling for intracranial and lateral ventricle volume, the latter of which increased significantly with age, attenuated these correlations by 40% and 84%, respectively, indicating that this age-related change in callosal tract topology is significantly mediated by global atrophy and ventricular enlargement. In accordance with the "frontal ageing" hypothesis, there was a significant positive correlation between mean diffusivity (D) and age, and a significant negative correlation between fractional anisotropy (FA) and age in corpus callosum genu; correlations not seen in splenium. Significant positive correlations were also observed between D and age in bilateral cingulum cingulate gyri, uncinate fasciculi and right corticospinal tract. This pattern of correlations was not, however, reproduced when those subjects with significant white matter lesion load were analyzed separately from those without. These data therefore suggest that brain atrophy and white matter lesions play a significant role in driving regional patterns of age-related changes in white matter tract shape and integrity.

New multispectral MRI data fusion technique for white matter lesion segmentation: method and comparison with thresholding in FLAIR images

Objective

Brain tissue segmentation by conventional threshold-based techniques may have limited accuracy and repeatability in older subjects. We present a new multispectral magnetic resonance (MR) image analysis approach for segmenting normal and abnormal brain tissue, including white matter lesions (WMLs).

Methods

We modulated two 1.5T MR sequences in the red/green colour space and calculated the tissue volumes using minimum variance quantisation. We tested it on 14 subjects, mean age 73.3 ± 10 years, representing the full range of WMLs and atrophy. We compared the results of WML segmentation with those using FLAIR-derived thresholds, examined the effect of sampling location, WML amount and field inhomogeneities, and tested observer reliability and accuracy.

Results

FLAIR-derived thresholds were significantly affected by the location used to derive the threshold (P = 0.0004) and by WML volume (P = 0.0003), and had higher intra-rater variability than the multispectral technique (mean difference ± SD: 759 ± 733 versus 69 ± 326 voxels respectively). The multispectral technique misclassified 16 times fewer WMLs.

Conclusion

Initial testing suggests that the multispectral technique is highly reproducible and accurate with the potential to be applied to routinely collected clinical MRI data.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-010-1718-6) contains supplementary material, which is available to authorized users.

Enlarged perivascular spaces on MRI are a feature of cerebral small vessel disease

BACKGROUND AND PURPOSE

Enlarged perivascular spaces in the brain are common but generally overlooked and of uncertain pathophysiology. They may reflect underlying cerebral small vessel disease. We determined whether enlarged perivascular spaces were associated with lacunar stroke subtype and white matter hyperintensities, markers of established small vessel disease.

MATERIALS AND METHODS

We prospectively recruited patients with acute ischemic lacunar or cortical stroke. Age-matched nonstroke control subjects were also recruited. We rated basal ganglia and centrum semiovale enlarged perivascular spaces 0 to 4 (0=none, 4=>40) on T2-weighted MRI and white matter hyperintensities. We compared enlarged perivascular spaces between stroke subtypes and control subjects and assessed associations with vascular risk factors and white matter hyperintensities.

RESULTS

We recruited 350 patients; 129 lacunar, 124 cortical stroke, and 97 age-matched control subjects. Adjusting for vascular risk factors and white matter hyperintensities, total enlarged perivascular spaces were associated with lacunar stroke subtype (P=0.04) in the acute stroke group (n=253); basal ganglia enlarged perivascular spaces were associated with lacunar stroke subtype (P=0.003), deep (P=0.02) and periventricular white matter hyperintensities (P=0.01); in all 350 subjects, total enlarged perivascular spaces were associated with deep (P<0.001) and periventricular (P<0.001) white matter hyperintensities.

CONCLUSIONS

Although prevalent in patients with vascular risk factors and stroke, enlarged perivascular spaces are specifically associated with lacunar ischemic stroke and white matter hyperintensities. Further studies should determine the mechanism of this association while including adequate controls to account for stroke and vascular risk factors. Enlarged perivascular spaces should not be overlooked in studies of small vessel disease.

Higher systolic blood pressure is associated with increased water diffusivity in normal-appearing white matter

BACKGROUND AND PURPOSE

Hypertension is associated with the development of white matter lesions in older people. Diffusion tensor MRI can detect subtle, previsible white matter damage, but relationships between diffusion tensor MRI parameters and blood pressure (BP) remain unclear. We examined correlations among mean diffusivity (MD), fractional anisotropy and BP in 45 men aged 71 to 76 years.

METHODS

MD and fractional anisotropy were measured in 6 regions of interest in normal-appearing white matter. Visible white matter lesions were quantified using the Fazekas scale. Both were correlated with systolic and diastolic BP.

RESULTS

Systolic BP was positively and significantly correlated with MD in all 6 regions (r=0.31 to 0.45; P=0.037 to 0.002). MD was also correlated with diastolic BP in the genu of the corpus callosum (r=0.34, P=0.018). A summary factor derived from principal component analysis of the MD measurements accounted for 53.8% of the variance and correlated at r=0.51 (P<0.001) with systolic BP and r=0.33 (P=0.028) with diastolic BP. Fractional anisotropy did not correlate significantly with BP. Deep white matter Fazekas scores correlated with diastolic BP (rho=0.35, P=0.019).

CONCLUSIONS

The increase in MD without change in fractional anisotropy indicates that, in normal-appearing white matter, higher BP may be associated with increased extracellular fluid before any cytoarchitectural damage occurs.

Quantitative and qualitative measures of hippocampal atrophy are not correlated in healthy older men

BACKGROUND AND PURPOSE

In neuroimaging studies of dementia and mild cognitive impairment, hippocampal atrophy (HA) is commonly assessed by qualitative ratings of hippocampal appearance, or by measuring hippocampal volumes. These estimates of HA are considered to be equivalent. However, few studies have examined their relationship, especially in healthy older individuals. We therefore examined the relationship between hippocampal qualitative atrophy scores and quantitative volumetric measurements in healthy older men.

METHODS

Ninety-seven healthy community-dwelling 65-70-year-old men underwent magnetic resonance imaging scanning. Hippocampal volumes were measured and adjusted for intracranial size. A validated 4-point visual rating scale was used to assess hippocampal atrophy.

RESULTS

There was a wide range of unadjusted hippocampal volumes among subjects (right: 2,582 to 5,196 mm(3)[mean 3,626 mm(3); SD 465.5 mm(3)] and left: 2,111 to 4,580 mm(3)[mean 3,501 mm(3); SD 439.5 mm(3)]), which was maintained following adjustment for intracranial size. However, only 9% of subjects were rated as having moderate or severe HA. Qualitative and quantitative measures were not significantly correlated (left hippocampus: rho = .07, P= .52; right hippocampus: rho = .10, P= .34).

CONCLUSIONS

This study shows that qualitative and quantitative indices of hippocampal atrophy in healthy older men are not equivalent. Small hippocampal volumes do not necessarily equate to hippocampal atrophy.

Unravelling the pathophysiology of delirium: a focus on the role of aberrant stress responses

Delirium is a common and serious acute neuropsychiatric syndrome with core features of inattention and cognitive impairment, and associated features including changes in arousal, altered sleep-wake cycle, and other changes in mental status. The main risk factors are old age, cognitive impairment, and other comorbidities. Though delirium has consistent core clinical features, it has a very wide range of precipitating factors, including acute illness, surgery, trauma, and drugs. The molecular mechanisms by which these precipitating factors lead to delirium are largely obscure. In this article, we attempt to narrow down some specific causal pathways. We propose a basic classification for the etiological factors: (a) direct brain insults and (b) aberrant stress responses. Direct brain insults are largely indiscriminate and include general and regional energy deprivation (e.g., hypoxia, hypoglycaemia, stroke), metabolic abnormalities (e.g., hyponatraemia, hypercalcaemia), and the effects of drugs. Aberrant stress responses are conceptually and mechanistically distinct in that they constitute adverse effects of stress-response pathways, which, in health, are adaptive. Ageing and central nervous system disease, two major predisposing factors for delirium, are associated with alterations in the magnitude or duration of stress and sickness behavior responses and increased vulnerability to the effects of these responses. We discuss in detail two stress response systems that are likely to be involved in the pathophysiology of delirium: inflammation and the sickness behavior response, and activity of the limbic-hypothalamic-pituitary-adrenal axis. We conclude by discussing the implications for future research and the development of new therapies for delirium.

Smaller left anterior cingulate cortex volumes are associated with impaired hypothalamic-pituitary-adrenal axis regulation in healthy elderly men

CONTEXT

Studies in animals suggest that the limbic prefrontal cortex, including the anterior cingulate cortex, is involved in regulation of the hypothalamic-pituitary-adrenal (HPA) axis, but human data are lacking.

OBJECTIVE

This study tested the hypothesis that smaller anterior cingulate cortex volumes are associated with HPA axis dysregulation in healthy older men.

DESIGN AND PARTICIPANTS

Comparison was made of volumes of bilateral anterior cingulate cortex, hippocampus, and superior frontal gyrus (control region) volumes in two groups of 10 healthy men, aged 65-70 yr, who showed nonsuppression or suppression of cortisol levels in response to low dose (250 microg) dexamethasone. Analysis of brain volumes was performed blind to the cortisol levels.

SETTING

This study was performed at a tertiary care clinical research center.

RESULTS

Nonsuppressors had significantly smaller left anterior cingulate cortex volumes than suppressors (5757 vs. 7817 mm(3); P = 0.01). Right anterior cingulate cortex, bilateral hippocampus, and bilateral superior frontal gyrus volumes were not significantly different between nonsuppressors and suppressors.

CONCLUSIONS

Smaller left anterior cingulate cortex volumes may be associated with HPA axis dysregulation in humans. These results substantiate evidence from animal studies indicating an important role for the anterior cingulate cortex in suprahypothalamic feedback regulation of the HPA axis. The results also have implications for disorders in which HPA axis dysregulation and abnormalities of the anterior cingulate cortex are frequently observed, such as depression and Alzheimer's disease.

Plasma cortisol levels, brain volumes and cognition in healthy elderly men

PURPOSE

In ageing animals, exposure to chronic high levels of glucocorticoids is associated with cognitive impairment and hippocampal atrophy. However, there are few studies examining relationships among glucocorticoids, brain volumes and cognitive function in healthy older humans. This study examined the hypotheses that higher plasma cortisol levels and altered sensitivity to glucocorticoids are associated with worse cognition and more brain atrophy in elderly men.

MATERIALS AND METHODS

Ninety-seven healthy men aged 65-70 had plasma cortisol measured at 09:00, 14:30 h, and post-dexamethasone (0.25mg, 09:00 h), and had dermal sensitivity to glucocorticoids measured. They also underwent cognitive testing, with scores adjusted for estimated prior mental ability, and had MRI measurements of intracranial area (a validated estimate of intracranial capacity), and hippocampus, temporal lobe and frontal lobe volumes.

RESULTS

Plasma cortisol levels at 09:00 h were significantly and negatively correlated with a summary General Cognitive Factor accounting for 51% of the variance of cognitive function (rho=-0.22, p=0.035), and specific cognitive tests: delayed paragraph recall (rho=-0.28, p=0.036) and processing speed (rho=-0.23, p=0.026). Regional brain volumes adjusted for intracranial area generally did not correlate with cortisol levels. Tissue glucocorticoid sensitivity did not correlate with any measure of cognition or brain volume.

CONCLUSIONS

In healthy older men, higher plasma cortisol levels are associated with worse ageing-related overall cognitive change but not ageing-related brain atrophy.

Size of the neocerebellar vermis is associated with cognition in healthy elderly men

Cerebellar volumes show small positive correlations with cognitive ability in young adults, but no studies have examined this relationship in older adults. Furthermore, no studies have examined relationships between sizes of subareas of the cerebellum and cognitive ability. We hypothesized that size of the two areas of the neocerebellar vermis would correlate with a battery of eight cognitive tests in 50 men aged 65-70. Size of the neocerebellar areas of the vermis correlated positively with several cognitive tests (r's=.29-.37, p<.05), whilst sizes of other parts of the vermis did not correlate with any cognitive tests. Total cerebellar volumes correlated significantly with a test of nonverbal reasoning (r=.030, p=.42). These findings suggest a specific association of neocerebellar vermis size with variations in cognitive ability in older adults.

Intracranial area: a validated method for estimating intracranial volume

BACKGROUND AND PURPOSE

Controlling for intracranial volume is crucial in magnetic resonance studies of changes in brain volumes. However, full intracranial volume measurement requires prolonged scanning and analysis, and simple, validated methods for intracranial volume estimation are lacking. The authors developed and evaluated a method of estimating intracranial volume using a single mid-sagittal slice, the intracranial cross-sectional area.

METHODS

Forty men aged 65-70 had whole skull magnetic resonance scans at 1.9 T, with slice thickness of 1.5 mm (no interslice gap). Intracranial cross-sectional area was traced in the midline sagittal slice of the 3-view localizer. Intracranial volume was measured using every slice. Ten intracranial cross-sectional area measurements were tested for interrater reliability.

RESULTS

Intracranial cross-sectional area and intracranial volume correlated highly (r = .88, P < .0001). A modified Bland-Altman plot showed good agreement between intracranial cross-sectional area and intracranial volume. The intraclass correlation (an indicator of reliability) for intracranial cross-sectional area was r = .976 (P < .005).

CONCLUSIONS

The rapid and simple technique of intracranial cross-sectional area measurement provides a valid and reliable estimate of intracranial volume.

Enlarged perivascular spaces are associated with cognitive function in healthy elderly men

OBJECTIVES

Increased white matter (WM) lesions on magnetic resonance imaging (MRI) are associated with worse cognitive function in older people. Enlarged perivascular spaces (EPVS) commonly coexist with and share some risk factors for WM lesions but are not quantified in published scales. It is not known whether the extent of EPVS is also associated with cognitive function. We tested the hypothesis that more EPVS would be associated with worse cognitive function.

METHODS

Ninety seven healthy men (65-70 years), not on medications, underwent MRI scanning and comprehensive cognitive testing. EPVS were quantified in both the basal ganglia/centrum semiovale and the hippocampus, and WM lesions were measured.

RESULTS

Scores on published WM lesion rating scales intercorrelated highly significantly and positively (rho = 0.61 to 0.91, p<0.0001). A summary (WML) factor derived from principal components analysis of the WM scales correlated with EPVS in the basal ganglia/centrum semiovale (rho = 0.48, p<0.0001) but not in the hippocampus. EPVS scores in the basal ganglia/centrum semiovale correlated significantly and negatively with non-verbal reasoning (rho = -0.21, p = 0.038) and general visuospatial ability (rho = -0.22, p = 0.032), adjusted for prior intelligence. The WML factor correlated significantly and negatively with visuospatial ability, as previously reported, and showed an unexpected positive correlation with one test of verbal memory (list-learning).

CONCLUSIONS

These findings suggest that increased EPVS are correlated with worse cognitive function. Future studies examining changes in WM with ageing should consider incorporating measures of EPVS and examine the sequence of EPVS and WM lesion development over time. More work is needed to develop valid and reliable measures of EPVS.

White matter hyperintensities and rating scales?observer reliability varies with lesion load

BACKGROUND

Cerebral white matter hyperintensities (WMHs) are common in older people. Their presence correlates with cognitive decline and vascular risk factors. Various scales have been developed to quantify the amount and type of WMH, but with few observer reliability studies. We evaluated several scales in different cohorts to determine their observer reliability.

METHODS

Two observers independently rated T2-weighted MR images from five groups (total n = 494: normal older subjects [97]; patients with minor stroke [221]; young insulin dependent diabetics [141]; maturity onset diabetics [10]; and hepatic encephalopathy [25]), using seven rating scales (Breteler, Fazekas, Longstreth, Mirsen, Shimada, Van Swieten and Wahlund). Inter-observer reliability was determined using Kappa statistics.

RESULTS

Patients with maturity onset diabetes had the most WMHs and young insulin-dependent diabetics the least. Inter-observer reliability varied with the amount of WMH. In maturity onset diabetics (most WMHs) the weighted Kappas were: Breteler 0.74; Fazekas 0.89 and 0.72; Van Swieten 0.76 and 0.88; and in young insulin-dependent diabetics (least WMH): Breteler 0.3; Fazekas 0.2 and 0.24; Van Swieten 0.39 and 0.30. These findings were consistent across the groups.

CONCLUSION

WMH rating scale performance varied with WMH prevalence, and hence with subject cohort. In patients with most WMHs the apparent better kappas may reflect a "ceiling effect" rather than true better agreement. These factors should be considered in studies where risk factors for, or associations with, the early development of WMHs are being determined.

Magnetic resonance spectroscopy and cognitive function in healthy elderly men

Subtle cognitive decrements in older people are important in terms of the associated morbidity and as a risk factor for dementia. However, their pathophysiological basis is poorly understood. Proton magnetic resonance spectroscopy ((1)H-MRS) may provide the means to investigate early changes in brain metabolite concentrations. We examined the relationships between N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) metabolite ratios in a voxel in the parietal cortex and cognitive function in 88 healthy, non-demented, unmedicated men aged 65-70 years. We also used linear regression to give a value for each metabolite adjusted for the levels of the other two metabolites. Both NAA/Cr and Cho/Cr ratios correlated positively with tests of verbal memory and a verbal memory factor (e.g. NAA/Cr and Logical Memory: r = 0.24, P < 0.05). Cho/Cr ratios also correlated positively with tests of visual memory (e.g. visual reproduction: r = 0.21, P < 0.05). Adjusted Cr levels correlated negatively and significantly with tests of verbal memory and the Verbal Memory Factor. The regression analysis suggested that Cr levels better explained the correlations between NAA/Cr and Cho/Cr ratios and cognitive variables than NAA or Cho levels. These results suggest that in healthy men aged 65-70 years, metabolite levels relate to cognitive performance. Rising Cr levels may be an early marker of cognitive decline.

Intracranial capacity and brain volumes are associated with cognition in healthy elderly men

BACKGROUND

Brain size and intracranial capacity are correlated with cognitive performance in young healthy adults, but data are lacking on these relationships in older healthy adults.

OBJECTIVE

To test the hypotheses that intracranial capacity, volumes of specific brain regions, and a measure of the shared variance between brain regions are positively associated with cognitive function in a sample of healthy, unmedicated elderly men (n = 97; mean age 67.8, SD 1.3).

METHODS

Individuals underwent MRI, with measurements of intracranial area and volumetric measurements of hippocampi, temporal lobes, and frontal lobes. Cognitive testing included measures of premorbid intelligence, fluid intelligence, verbal memory, visuospatial memory, verbal fluency, and attention and processing speed.

RESULTS

Cognitive tests showed significant positive intercorrelations throughout, and regional brain volumes were also universally, significantly, and positively intercorrelated. Intracranial area and several regional brain volumes correlated with tests of premorbid and fluid intelligence and tests of visuospatial memory. Tests of verbal memory and verbal fluency did not correlate significantly with brain volumes. Structural equation modeling demonstrated that the relationships between specific cognitive tests and regional brain volumes could best be summarized by a significant positive relationship between a general brain size factor and a general cognitive factor, and not by associations between individual tests and particular brain regions.

CONCLUSIONS

In healthy elderly men, there are significant relationships between multiple cognitive tests and both intracranial capacity and regional brain volumes. These relationships may be largely due to longstanding associations between general cognitive ability and overall brain size.

Examining the generalizability of ratings across clerkships using a clinical evaluation form

It is necessary to average multiple clinical evaluation form (CEF) observations to obtain a reliable score. Combining CEF observations across clerkships will provide more observations per student, but it is unknown how an across-clerkship generalization affects reliability. The authors conducted generalizability studies on balanced stratified random samples to examine the impact of averaging across clerkships. The study detected a student by clerkship interaction. Although the interaction magnitude was small, it had a large negative impact on the reliability of the mean score. The authors conclude that averaging across clerkships for the purpose of evaluating global clinical skills will produce a less reliable measure for a fixed number of observations than averages calculated within a clerkship for evaluating clerkship specific skills. The content specificity of clinical skills as measured by the CEF may resemble that found using other measurement methods.

Monitoring adherence to Standard Precautions

BACKGROUND

Health care workers (HCWs) do not consistently follow Standard Precautions (SP). This is a serious problem because inadequate compliance is associated with increased blood exposure thus predisposing HCWs to bloodborne pathogen transmission.

METHODS

The primary goal of this study was to identify institutional factors associated with adequacy of HCW training to monitor coworkers' adherence to SP. Surveys were sent to all community hospital infection control practitioners (ICPs) in Iowa and Virginia. ICPs indicated on a 5-point Likert scale, ranging from strongly disagree to strongly agree, their assessment of HCW training adequacy. Data from another statewide survey of HCWs in Iowa were assessed to validate this outcome measure. Multiple logistic regression models were developed to identify predictors of assessed training adequacy. Independent variables included methods of education, training, approaches to SP compliance assessment, provision of SP reinforcement by clinical leaders, and organizational data.

RESULTS

A total of 149 institutions (62%) participated. Models of training program adequacy varied across occupations. Management commitment to SP training programs, leadership support, frequency of providing bloodborne pathogen information, and safety climate were important institutional predictors of assessed adequacy of training. The outcome was validated by demonstrating an association between the ICPs' assessment of HCW training and workers who reported having sufficient information to comply with SP (P <.05).

CONCLUSIONS

Institutional safety climate, leadership support, and frequency of education play an important role in HCWs' training adequacy to monitor coworkers' adherence to SP. Occupational groups should be considered independently when strategies are developed to increase compliance. Interventions based on modifiable factors identified by this study may reduce bloodborne pathogen exposure among HCWs.

Hospital bloodborne pathogens programs: program characteristics and blood and body fluid exposure rates

OBJECTIVE

To describe hospital practices and policies relating to bloodborne pathogens and current rates of occupational exposure among healthcare workers.

PARTICIPANTS AND METHODS

Hospitals in Iowa and Virginia were surveyed in 1996 and 1997 about Standard Precautions training programs and compliance. The primary outcome measures were rates of percutaneous injuries and mucocutaneous exposures.

RESULTS

153 (64%) of 240 hospitals responded. New employee training was offered no more than twice per year by nearly one third. Most (79%-80%) facilities monitored compliance of nurses, housekeepers, and laboratory technicians; physicians rarely were trained or monitored. Implementation of needlestick prevention devices was the most common action taken to decrease sharps injuries. Over one half of hospitals used needleless intravenous systems; larger hospitals used these significantly more often. Protected devices for phlebotomy or intravenous placement were purchased by only one third. Most (89% of large and 80% of small) hospitals met the recommended infection control personnel-to-bed ratio of 1:250. Eleven percent did not have access to postexposure care during all working hours. Percutaneous injury surveillance relied on incident reports (99% of facilities) and employee health records (61%). The annual reported percutaneous injury incidence rate from 106 hospitals was 5.3 injuries per 100 personnel. Compared to single tertiary-referral institution rates determined more than 5 years previously, current injury rates remain elevated in community hospitals.

CONCLUSIONS

Healthcare institutions need to commit sufficient resources to Standard Precautions training and monitoring and to infection control programs to meet the needs of all workers, including physicians. Healthcare workers clearly remain at risk for injury. Further effective interventions are needed for employee training, improving adherence, and providing needlestick prevention devices.

Choice of spectroscopic lineshape model affects metabolite peak areas and area ratios

The use of Lorentzian model lineshapes leads to systematic errors in the quantification of in vivo (1)H NMR spectra. Experimental lineshapes are better modeled by the Voigt (mixed Lorentzian-Gaussian) function, leading to more accurate fits (reduced chi(2)). In this work, results from a group of 41 subjects are presented. It is shown that not only are the estimated metabolite peak areas affected by the choice of lineshape model, but so too are the metabolite ratios. For example, the NAA/choline ratio was 1.92 +/- 0.06 (mean +/- standard error) using the Lorentzian lineshape model and 1.85 +/- 0.05 using the Voigt lineshape model. The corresponding figures for NAA/creatine were 2.32 +/- 0.06 and 2. 10 +/- 0.05 respectively, which are significantly different for the two lineshape models. An explanation of this previously unreported effect is given. This finding clearly has serious implications for the methodology and reporting of spectroscopic studies.

Evaluation methods for prevention education

The knowledge, skills, and attitudes associated with prevention cut across clinical disciplines. Thus, they are often subsets of disciplines not otherwise present in the traditional curriculum (e.g., epidemiology or statistics) or considered the province of many disciplines (e.g., risk reduction or cancer screening). Evaluation of elements of prevention education can often become lost in the myriad other outcomes that are assessed in students, or they are intermingled with other content and skills. This article highlights the value of assessing students' competence in prevention knowledge, skills, and attitudes, provides general guidance for programs interested in evaluating their prevention instructional efforts, and gives specific examples of possible methods for evaluating prevention education. While it is important to tailor assessment methods to local institutional objectives, it is possible to share assessment methods and materials regionally and nationally. Sharing problems, as well as successes, encountered in developing appropriate assessment methods will advance the field of evaluation of prevention curricula.

Alcohol use, drug use, and sexual activity among pharmacy students at three institutions

OBJECTIVE

To determine alcohol and drug use and sexual activity among pharmacy students at three colleges of pharmacy.

DESIGN AND SETTING

A survey to obtain self-reported information on alcohol and drug use, and sexual activity was administered to professional pharmacy students at the University of Iowa (UI), Massachusetts College of Pharmacy, and Texas Southern University.

MAIN OUTCOME MEASURES

Information on sexual activity and condom use, alcohol and drug consumption, and the effect of alcohol on unintended sexual activity.

RESULTS

848 students (50% response rate) completed the survey. Alcohol use was high at all three institutions, and most students had consumed five or more drinks on one or more occasions within the last three months. The extent of drug use among pharmacy students was similar to that reported in other college students. The majority of students were sexually active. More men than women reported having been sexually active with one or more partners. Most students reported having had sexual intercourse without a condom. Significant numbers of students had engaged in unintended sex after alcohol use, especially at UI (chi 2 = 12.6, p = 0.002). Sexual contact and drinking were strongly correlated (Pearson r = 0.31, p = 0.0001).

CONCLUSION

Alcohol consumption among pharmacy students was high. Heavy drinking (five or more drinks on one occasion) was associated with unintended sexual contact. Given low condom use and increased sexual contact, pharmacy students are at an increased risk for HIV infection. Strategies should be developed to reduce alcohol intake and unprotected sexual activity among pharmacy students.

Teaching physical examination of the adult liver with use of real-time sonography

RATIONALE AND OBJECTIVES

The authors developed and evaluated an approach to teaching examination of the liver that incorporates real-time ultrasound (US) imaging as immediate feedback to improve diagnostic accuracy.

MATERIALS AND METHODS

Second-year medical students participating in a course in physical examination were assigned to receive instruction in measuring liver span without (group 1) or with (group 2) real-time sonography. Students from each group attended a practice session given by one of two physicians who were board certified in radiology and internal medicine with special expertise in US. During the practice session for group 2, students were shown the boundaries of the liver of the practice patient with real-time US. Both groups of students then made three measurements each of the liver span of a healthy practice patient and a single healthy test patient without US. The vertical liver span reference standard was determined by one of the authors.

RESULTS

Students in group 2 showed greater accuracy in measuring liver span during both the practice and the test sessions than did students in group 1. The differences were significant for the third practice measurement and all three test measurements (P < .05).

CONCLUSION

The use of real-time US as an aid in teaching physical examination improves students' accuracy in measuring liver size.

Lifelong self-directed learning using a computer database of clinical questions

Physicians often have self-perceived knowledge gaps when they are seeing patients. Traditional continuing medical education is designed to meet the knowledge gaps of groups rather than individual physicians with specific patient problems. Physicians with clinical information needs are advised to critically evaluate high-quality original research in order to practice "evidence-based medicine." But this advice may be unrealistic for busy clinicians. We propose a system for documenting self-perceived information needs using a computer database. Concise answers to these needs are included in the database along with reference citations supporting the answers. The system tracks continuing education efforts, directs patient care decisions, and focuses lifelong learning on relevant topics. We emphasize the importance of being sensitive to personal information needs and the benefits of maintaining a record of these needs.

Intervention research in agriculture: examples from the swine confinement and respiratory health project

The "Measurement and Analysis in Agricultural Interventions" workshop session of the "Intervention Research in Occupational Health and Safety: Science, Skills, Strategies" conference considered a variety of approaches to safety and health interventions in agriculture. The "Respiratory Health in Swine Confinement Project" in Iowa, an educational intervention to improve respiratory health and safety in swine confinement workers, was presented as a case study for the discussion. Results from the project were used to illustrate the advantages and disadvantages of a variety of research techniques in interventions and program evaluation, including specific issues related to measurement and analysis. The discussion reflects comments from workshop participants along with summary observations reported to conference attendees. Themes of the session include the complementary nature of quantitative and qualitative techniques, and the importance of developing interventions that are community based.

Predictors of hepatitis B vaccine acceptance in health care workers

This article examines the relative importance of occupational, epidemiologic, and attitudinal factors in hepatitis B vaccine acceptance. A stratified random sample of 1,018 health care workers at risk for occupational blood exposure at our university hospital were contacted in 1992 and 919 (90%) participated. Potential reasons for vaccine acceptance or refusal were evaluated with factor analysis. Logistic regression models were calibrated on a stratified random subsample to identify independent predictors of initiating and completing the series, then validated on the remaining subjects. Fifty-four percent (482 of 898) of previously nonimmune workers had completed the series, while 70% (626) had received one or more doses. Hepatitis B vaccine acceptance was related strongly to social influence (physicians, supervisors, role models, friends, and spouse) and knowledge of the disease and vaccine, whereas refusal was primarily related to concern about vaccine side effects and problems with vaccine access. Independent predictors of initiating the vaccine series included younger age (odds ratio [OR] 0.98 per year, 95% confidence interval [CI95] 0.96-0.997), occupation (housestaff: OR 2.9, CI95 1.1-7.9; nurses: OR 2.1, CI95 1.0-4.3 versus housekeepers), increased blood exposure frequency (OR 2.4, CI95 1.6-3.5 for 1-6 versus 0 exposures in past year), and increased frequency of recent influenza vaccination (OR 3.3, CI95 2.0-5.3 for 1 versus 0 doses in prior 3 years). Occupation (increased acceptance among housestaff, nurses, nursing assistants, laboratory technicians), increased frequency of blood exposure, and recent influenza vaccination also were predictors of series completion. Factors such as occupation, blood exposure frequency and acceptance of other preventive services may help identify health care worker groups with low vaccine acceptance most likely to benefit from targeted vaccine delivery. Hepatitis B vaccine should be offered routinely during evaluation for occupational blood exposure. Future vaccine implementation efforts should emphasize the involvement of physicians and supervisors and education about occupational disease risk, liability, and the safety of the vaccine.

Binge eating disorder in a community-based sample of successful and unsuccessful dieters

This study examined binge eating and weight cycling in a community-based sample of successful (46 women, 44 men) and unsuccessful (29 women, 25 men) dieters. Successful dieters had lost at least 15% of body weight, kept the weight off for at least 1 year, and regained no more than 10 lb (average weight loss = 48 lb). Subjects completed a written questionnaire and were interviewed by phone several weeks later. Unsuccessful dieters were more obese when starting on a diet (average body mass index = 35.6 compared to 32.1) and were much more likely to have lost and regained 20 lb. Six-month prevalence of binge eating disorder (BED) was 19% for unsuccessful dieters and 6% for successful dieters; lifetime prevalence was 15% and 13%, respectively. Unsuccessful dieters were two to three times more likely to perceive a lack of control during an episode of overeating, to be disgusted with themselves for overeating, and to eat alone because they were embarrassed. Encouraging dieters to set realistic goals, identify potential relapse situations, and interpret lapses may help them succeed.

Motivation for hepatitis B vaccine acceptance among medical and physician assistant students

PURPOSE

To evaluate the acceptance rate and motivation for acceptance of hepatitis B virus (HBV) vaccine among preclinical medical and physician assistant (PA) students in comparison with similar data obtained from resident and staff physicians.

METHODS

A cross-sectional survey of all second-year medical and PA students (n = 170) at the University of Iowa College of Medicine was conducted in Spring 1992, requesting demographic data, preventive health measure use, and reasons for HBV vaccine acceptance. Responses were compared with data obtained from resident and staff physicians during a concurrent hospital-wide survey. Rates of vaccine acceptance and use of other preventive health measures were compared across the physician groups. Factor analysis was performed to examine reasons for vaccine acceptance among the students.

RESULTS

The questionnaire was completed by 162 of the 170 students (95%). Nearly all (99%) of the eligible students had received at least one dose of the HBV vaccine. Vaccine acceptance rates were significantly higher among the students than among either the resident or the staff physicians (p = 0.003, p < 0.0001, respectively). Influenza vaccine acceptance and seat belt use were significantly higher among the resident and staff physicians than they were among the students. The students attributed their high HBV vaccine acceptance rate to the recommendations of authority figures. Threat of illness and issues of vaccine safety and efficacy were relatively unimportant among the students, though the residents and staff physicians reported threat of illness to be an important motivator for vaccination.

CONCLUSIONS

Excellent HBV vaccine acceptance rates may be achieved among preclinical medical and PA students. Recommendations of authority figures are important motivators for HBV vaccine acceptance among students.

Physician recommendation as the key factor in patients' decisions to participate in preoperative autologous blood donation programs: Preoperative Autologous Blood Donation Study Group

To determine whether the physician or patient had initiated the discussion regarding preoperative autologous blood donation (PABD) and to assess the relative importance of the physician's recommendation in patients' decision to donate, responses were obtained from 254 of 409 patients (62%) who had donated preoperatively during the 3 study months. Nearly all (96%) strongly agreed they would donate again for themselves and nearly all (94%) strongly agreed they would recommend PABD to others. Patients initiated the discussion about PABD 23% of the time, while 71% indicated strong surgeon input. The remaining respondents said their surgeon had "mentioned it, but said it was up to me." The importance of avoiding transfusion reactions was rated significantly greater among those whose surgeons had initiated the discussion, as was the relative weight of the surgeon's recommendation. The desire to alleviate the blood shortage was rated much less important among patients who had initiated the discussion themselves.

Surveying smokeless tobacco use, oral lesions and cessation among high school boys

We surveyed 821 Iowa teenage boys to establish patterns of smokeless tobacco use, occurrence of oral lesions and the effect of lesions on attitudes about quitting, current use and plans for future use. Results suggest that young ST users who currently have a lesion or have experienced lesions may be particularly receptive to discussion of quitting options and other information about ST health effects. Dentists and other oral health professionals should initiate ST intervention when establishing a lesion history or on discovering a lesion at examination.

Surgeons' knowledge, attitude, and use of preoperative autologous blood donation

Before a comprehensive educational program on preoperative autologous blood donation was begun, 118 surgeons from three different areas of the country were tested to assess their baseline knowledge and attitude about this practice. Test results were correlated with the percentage of eligible patients that the surgeons actually referred for preoperative donation during a period of observation. The purpose of this preliminary effort was to identify areas in the educational program that required emphasis. Overall, the surgeons' attitude toward preoperative donation was quite favorable, but their depth of knowledge varied. Misunderstandings may have led to diminished use of this service (eg, about 50% didn't realize that many patients with medical conditions or low hematocrits are permitted to donate). However, it is not clear that simply bolstering surgeons' knowledge will increase their appropriate use of preoperative donation. When all 118 surgeons were studied, their knowledge and attitude were unrelated to the percentage of eligible patients referred. However, when 44 surgeons who managed the largest number of eligible patients were analyzed separately, their use of preoperative donation was directly correlated with their knowledge and attitude. The local awareness of AIDS also significantly influenced the use of this service. It is proposed that knowledge of preoperative donation may be important for inducing surgeons to begin referring patients for this service. Once a pattern of successful participation is established, referral seems to increase with the acquisition of working knowledge.

Quality assessment of athletic trainers

This paper reports the first published assessment of the quality of services provided by athletic trainers. Medical coverage for the 1985 Junior Olympic Games was provided by certified athletic trainers (ATC), physicians, and other health care personnel. This study assessed the services of the 30 attending ATCs who managed 121 significant injuries. Standard injury information was collected by the ATCs and separately collected by their physicians. Nine months after the Games, phone interviews were conducted with the injured participants and assessment questionnaires were given to the attending physicians. Results revealed that young, injured, Junior Olympic participants generally did not inform their parents about their injuries or medical contact while at the Games. Athletes and physicians overwhelmingly agreed that they were positively impressed with the capabilities of the ATCs with whom they had contact. About 70% recovered from the symptoms and limitations of injury, as determined by the athlete, within the month following the Games. About 17% sustained some type of injury recurrence to the same body part, and at 9 months about 97% of the athletes had fully recovered from their injuries. These data not only indicate that athletic trainers can accurately identify minor athletic injury but signify the importance of long-term followup in our athletic populations. Multisport events, such as the Junior Olympic Games, impose considerable problems to a communication effort. The athletic trainer, as an ever-present figure in collegiate and professional circles, can be the central focus of an adequate communication effort regarding the patient care of other athletic populations.

Estrogen replacement therapy. A survey of women's knowledge and attitudes

Because the significant health risks related to postmenopausal osteoporosis can be reduced by estrogen replacement therapy (ERT), this study assessed women's attitudes toward ERT to assess factors that might increase its use. Results showed that women taking ERT were more likely to know that decreased estrogen levels lead to osteoporosis, to perceive that menopause is a medical condition, to believe that natural approaches to menopause are less preferable, to be seeing a gynecologist for care, and to believe that women should take ERT for hot flashes. The study suggests that a systematic educational approach could influence women's willingness to take ERT, especially if the recommended therapy does not cause withdrawal bleeding.

Should dentists advise smokers to stop?

This study surveyed 391 dentists to determine their current practices with patients who smoke. About two-thirds of respondents (71%) said they advise smokers to stop. Although most respondents advised patients of negative health effects of smoking, few provided suggestions to patients, referred them to smoking cessation programs, provided self-help materials, or scheduled follow-up sessions. Recent evidence suggests that even brief counseling interventions can help some patients stop smoking.