Molecular diagnostic strategies: a role in the practice of dermatology

Molecular diagnostic strategies are gaining wider acceptance and use in dermatology and dermatopathology as more practitioners in this field develop an understanding of the principles and applications of genomic technologies. Molecular testing is facilitating more accurate diagnosis, staging, and prognostication, in addition to guiding the selection of appropriate treatment, monitoring of therapy, and identification of novel therapeutic targets, for a wide variety of skin diseases.

The comparative effectiveness of statin therapy in selected chronic diseases compared with the remaining population

Background

Total cholesterol (TC) concentration is the most commonly used measure of statin efficacy in the UK. This study aimed to evaluate the effectiveness of statins in lowering TC, cardiovascular events (CV) and mortality five common chronic diseases (chronic obstructive pulmonary disease (COPD), osteoarthritis (OA), rheumatoid arthritis (RA), chronic kidney disease (CKD), and diabetes mellitus (DM)) and to compare effectiveness with the rest of the population not recorded as having these diseases.

Methods

A population-based cohort study was conducted in Tayside population who had at least two TC measurements between 1993 and 2007. There were 12,140 patients with chronic diseases and 9,481 patients in the rest of the population not recorded as having these chronic diseases. The main outcomes were TC change from baseline, CV events and all-cause mortality.

Results

Statin-associated TC reductions varied from 15% to 28% with baseline value of between 5.1 and 5.9 mmol/L in the primary prevention (PP) and from 7% to 23% with baseline value of 4.5 to 5.2 mmol/L in the secondary prevention (SP) among chronic diseases patients. In the rest of the population, TC reductions with statins were 31% in PP and 28% in SP with baselines of 6.3 mmol/L and 5.3 mmol/L, respectively (test of heterogeneity with chronic disease groups: p < 0.001). A notional reduction of 0.5 mmol/L in TC predicted variable reductions in incident CV events of 30% in RA, 19% in CKD, and 20% in DM, and recurrent CV events by 62% in COPD, 16% in CKD, and 19% in DM. The corresponding figures for the rest of population were 12% for incident CV events and 17% for the recurrent CV events, respectively. Risk reductions for all-cause mortality varied from 20% to 36% in PP and from 18% to 40% in SP, except in OA or RA patients in the chronic diseases and 11% in PP and 16% in the rest of population (test of heterogeneity: p > 0.05).

Conclusions

The effectiveness of statins in common chronic diseases varied. With the exception of diabetes, statins tends to be less effective in patients with the chronic diseases compared with the rest of the study population. Changes in TC with statins appear not to correlate well with the changes in cardiovascular events and all-cause mortality.

Lipid-modifying therapies and risk of pancreatitis: a meta-analysis

CONTEXT

Statin therapy has been associated with pancreatitis in observational studies. Although lipid guidelines recommend fibrate therapy to reduce pancreatitis risk in persons with hypertriglyceridemia, fibrates may lead to the development of gallstones, a risk factor for pancreatitis.

OBJECTIVE

To investigate associations between statin or fibrate therapy and incident pancreatitis in large randomized trials.

DATA SOURCES

Relevant trials were identified in literature searches of MEDLINE, EMBASE, and Web of Science (January 1, 1994, for statin trials and January 1, 1972, for fibrate trials, through June 9, 2012). Published pancreatitis data were tabulated where available (6 trials). Unpublished data were obtained from investigators (22 trials).

STUDY SELECTION

We included randomized controlled cardiovascular end-point trials investigating effects of statin therapy or fibrate therapy. Studies with more than 1000 participants followed up for more than 1 year were included.

DATA EXTRACTION

Trial-specific data described numbers of participants developing pancreatitis and change in triglyceride levels at 1 year. Trial-specific risk ratios (RRs) were calculated and combined using random-effects model meta-analysis. Between-study heterogeneity was assessed using the I2 statistic.

RESULTS

In 16 placebo- and standard care-controlled statin trials with 113,800 participants conducted over a weighted mean follow-up of 4.1 (SD, 1.5) years, 309 participants developed pancreatitis (134 assigned to statin, 175 assigned to control) (RR, 0.77 [95% CI, 0.62-0.97; P = .03; I2 = 0%]). In 5 dose-comparison statin trials with 39,614 participants conducted over 4.8 (SD, 1.7) years, 156 participants developed pancreatitis (70 assigned to intensive dose, 86 assigned to moderate dose) (RR, 0.82 [95% CI, 0.59-1.12; P = .21; I2 = 0%]). Combined results for all 21 statin trials provided RR 0.79 (95% CI, 0.65-0.95; P = .01; I2 = 0%). In 7 fibrate trials with 40,162 participants conducted over 5.3 (SD, 0.5) years, 144 participants developed pancreatitis (84 assigned to fibrate therapy, 60 assigned to placebo) (RR, 1.39 [95% CI, 1.00-1.95; P = .053; I2 = 0%]).

CONCLUSION

In a pooled analysis of randomized trial data, use of statin therapy was associated with a lower risk of pancreatitis in patients with normal or mildly elevated triglyceride levels.

Effectiveness of statins in chronic kidney disease

BACKGROUND

Previous studies show that statins reduce total cholesterol (TC) concentration by both 21% in primary prevention (PP) and secondary prevention (SP) in clinical trials and by ∼24% in the general population. There are few data about the efficacy of statins on TC concentration and cardiovascular (CV) outcome in patients with chronic kidney disease (CKD). We evaluated the reduction of TC concentration and subsequent risk of CV morbidity and mortality with statins in CKD patients.

METHODS

A population-based cohort study using a record-linkage database in Tayside, Scotland. A total of 2369 patients who had a primary diagnosis of CKD from Scottish Morbidity Record data or biochemistry database (serum creatinine of 220 μmol/l or higher) and who had at least two separate TC measurements between 1993 and 2007 were studied. Patients were categorized into statin-exposed and statin-unexposed groups according to statin use status during the follow-up. They were also classified into PP (n = 1325) and SP (n = 1044) cohorts at the entry date. The main outcomes were TC concentration change from baseline, CV events [Antiplatelet Trialist's Collaboration (APTC)] and all-cause mortality during the follow-up. Cox regression models, in which statin use was a time-dependent variable, were employed to assess the risk of outcome and adjusted for other known confounders.

RESULTS

Statin-associated TC concentrations decreased by 0.59 mmol/l (12%) in PP cohort and 0.56 mmol/l (13%) in SP cohort from 4.77 and 4.48 mmol/l at baselines, respectively. Statin use was associated with a reduced risk of APTC events, CV mortality or all-cause mortality in PP {adjusted hazard ratio (HR), 0.65 [95% confidence interval (CI) 0.48-0.88]; 0.73 (95% CI 0.52-0.98); 0.59 (95% CI 0.48-0.73)} and SP [adjusted HR, 0.66 (95% CI 0.52-0.84); 0.60 (95% CI 0.47-0.77); 0.56 (95% CI 0.47-0.68)], respectively.

CONCLUSION

Statin use reduced TC concentrations by ∼13% in patients with CKD. Statins were protective of APTC events, CV mortality and all-cause mortality in patients with or without established CV disease.

WE-E-213CD-05: A Non-Rigid Image Registration Algorithm That Accommodates Organ Segmentation Error

PURPOSE

To introduce a new deformable image registration algorithm based on surface matching that accommodates organ delineation error in daily Cone-beam CT images based on a priori knowledge of inter-observer segmentation uncertainty.

METHODS

The dataset includes four prostate cancer patients who underwent primary external beam radiotherapy and had tumors that were confined to the prostate. All imaging was performed without intravenous contrast. Organ surface segmentation errors in a multiple observer-contouring study on the pelvic organs in Fan-beam CT (FBCT) and Cone-beam CT (CBCT) were estimated from the training dataset. A novel deformable image registration algorithm is presented where the organ surface matching is penalized by this error. Portions of the organ surface that are delineated reliably are used to guide the registration whereas the portions that are highly uncertain are ignored. This approach reduces the impact of delineation errors in CBCT. An evaluation experiment compares three algorithms, namely intensity-only registration (INT), equally-weighted surface and image registration (EWSIR) and the proposed uncertainty- weighted surface and image registration.

RESULTS

The surface dissimilarity was reduced from 0.172 to 0.134, 0.043 and 0.044 respectively after registration. The Jacobian of the transformation found by the proposed method was closer to one than that of EWSIR in the prostate.

CONCLUSIONS

In prostate external-beam radiotherapy, slice-by-slice 2D manual contouring has variable spatial accuracy. For deformable image registration methods that match segmented surfaces, regions of high inaccuracy can misguide the registration. In contrast to the image registration methods where the FBCT and CBCT surfaces (or other features) are assumed to be exact, our method takes this uncertainty into account. Preliminary results show an improved registration performance suggesting a potential use in IGRT. This work was supported by National Cancer Institute Grant No. P01 CA 116602.

Ethical conundrums in research

Several ethical concerns are central to the field of medical research. A sampling of these ethical conundrums include fraudulent data, publication bias, conflict of interest, IRB compliance, and confidentiality. In this article we attempt to highlight some of the components central to these areas of concern. In doing so we hope to generate discussion regarding some of the main areas of ethical concern in dermatologic and scientific bench side research. Additionally, we suggest that the use of journal publications, presentations, and training sessions, in concert with the development of dermatoethics courses as components of dermatology residency program curricula, can be used to maintain the academic discourse on ethics and minimize the risk of ethical conflict in the field of dermatologic research. These efforts will serve to maintain the quality and integrity of research on skin diseases.

Effectiveness of statins on total cholesterol and cardiovascular disease and all-cause mortality in osteoarthritis and rheumatoid arthritis

OBJECTIVE

There is increasing prevalence of hypercholesterolemia among patients with osteoarthritis (OA) and rheumatoid arthritis (RA). We examined the effectiveness of statins on total cholesterol (TC), cardiovascular (CV) morbidity, and mortality in patients with OA or RA.

METHODS

A population-based cohort study was done using a record-linkage database in Tayside, Scotland. In total, 2024 OA or RA patients who had at least 2 separate TC measurements between 1993 and 2007 were studied. They were categorized into statin-exposed and statin-unexposed groups according to statin use status during followup. The main outcomes were TC concentration change from baseline, CV events, and all-cause mortality during the followup. Multivariate Cox regression models with a time-dependent variable for statins were employed to assess the risk of outcomes.

RESULTS

Statin-associated TC concentrations in OA decreased by 15% in patients without CV disease (primary prevention, n = 1269) and 7% in patients with CV disease (secondary prevention, n = 247) from baseline of 5.30 mmol/l and 4.54 mmol/l, respectively. Correspondingly, in RA TC was reduced by 16% (n = 430) and 15% (n = 78) with baselines of 5.54 mmol/l and 4.95 mmol/l. In primary prevention, statins were associated with reduced CV events and all-cause mortality in RA patients [adjusted HR 0.45 (95% CI 0.20-0.98) and 0.43 (95% CI 0.20-0.92), respectively] and all-cause mortality in OA patients [adjusted HR 0.43 (95% CI 0.25-0.72)]. Statins were not associated with reduced risk of CV events or all-cause mortality in the secondary prevention of RA or OA patients [adjusted HR 0.68 (95% CI 0.30-1.54) and 0.52 (95% CI 0.20-1.34) for OA patients, and HR 0.58 (95% CI 0.07-4.79) and 0.79 (95% CI 0.18-3.53) for RA patients].

CONCLUSION

Statins reduced TC concentrations between 7% and 16% in patients with OA or RA. Statins were associated with reduced CV events and mortality in RA and mortality in OA in primary prevention.

Treatment of animal toxicoses: a regulatory perspective

This article focuses on the regulatory issues to consider when veterinarians are called upon to treat animal toxicoses, in particular those involving food-producing animals. The lack of Food and Drug Administration-approved drugs to treat animal toxicoses has been a long-standing problem. This article reviews extralabel drug use regulations, and the responsibilities of the treating veterinarian. It discusses the legal implications of compounding and the use of unapproved drugs to treat animal toxicoses. Efforts should be made to increase the availability of life-saving antidotal therapies.

Safety of antibiotic drugs in food animals: comparison of findings from preapproval studies and postapproval experience in the United States with safety information in published literature

Antibiotics are among the most widely prescribed drugs and are generally considered safe for the target species. However, their use has been associated with various adverse toxic effects in target animals, such as allergic reactions, gastrointestinal signs, cardiovascular effects, hypoglycemia, hepatic/renal toxicity, thrombocytopenia, and anaphylaxis. This article provides a qualitative summary of the adverse events observed in target animals during the evaluation of antibiotics by the Food and Drug Administration during both preapproval and postapproval periods. As there is a marked scarcity of published data on safety of antibiotics in food animals, more research is needed in this area.

Temporal dynamics of cortical sources underlying spontaneous and peripherally evoked slow waves

Slow waves are the most prominent electroencephalographic feature of non-rapid eye movement (NREM) sleep. During NREM sleep, cortical neurons oscillate approximately once every second between a depolarized upstate, when cortical neurons are actively firing, and a hyperpolarized downstate, when cortical neurons are virtually silent (Destexhe et al., 1999; Steriade et al., 1993a, 2001). Intracellular recordings indicate that the origins of the slow oscillation are cortical and that corticocortical connections are necessary for their synchronization (Amzica and Steriade, 1995; Steriade et al., 1993b; Timofeev and Steriade, 1996; Timofeev et al., 2000). The currents produced by the near-synchronous slow oscillation of large populations of neurons appear on the scalp as electroencephalogram (EEG) slow waves (Amzica and Steriade, 1997). Despite this cellular understanding, questions remain about the role of specific cortical structures in individual slow waves. Early EEG studies of slow waves in humans were limited by the small number of derivations employed and by the difficulty of relating scalp potentials to underlying brain activity (Brazier, 1949; Roth et al., 1956). Functional neuroimaging methods offer exceptional spatial resolution, but lack the temporal resolution to track individual slow waves (Dang-Vu et al., 2008; Maquet, 2000). Intracranial recordings in patient populations are limited by the availability of medically necessary electrode placements and can be confounded by pathology and medications (Cash et al., 2009; Nir et al., 2011; Wenneberg 2010). Source modeling of high-density EEG recordings offers a unique opportunity for neuroimaging sleep slow waves. So far, the results have challenged several of the influential topographic observations about slow waves that had persisted since the original EEG recordings of sleep. These recent analyses revealed that individual slow waves are idiosyncratic cortical events and that the negative peak of the EEG slow wave often involves cortical structures not necessarily apparent from the scalp, like the inferior frontal gyrus, anterior cingulate, posterior cingulate, and precuneus (Murphy et al., 2009). In addition, not only do slow waves travel (Massimini et al., 2004), but they often do so preferentially through the areas comprising the major connectional backbone of the human cortex (Hagmann et al., 2008). In this chapter, we will review the cellular, intracranial recording, and neuroimaging results concerning EEG slow waves. We will also confront a long held belief about peripherally evoked slow waves, also known as K-complexes, namely that they are modality independent and do not involve cortical sensory pathways. The analysis included here is the first to directly compare K-complexes evoked with three different stimulation modalities within the same subject on the same night using high-density EEG.

Thalamic dysfunction in schizophrenia suggested by whole-night deficits in slow and fast spindles

OBJECTIVE

Slow waves and sleep spindles are the two main oscillations occurring during non-REM sleep. While slow oscillations are primarily generated and modulated by the cortex, sleep spindles are initiated by the thalamic reticular nucleus and regulated by thalamo-reticular and thalamo-cortical circuits. In a recent high-density EEG study, the authors found that 18 medicated schizophrenia patients had reduced sleep spindles, compared with healthy and depressed subjects, during the first non-REM episode. In the present study, the authors investigated whether spindle deficits were present in a larger sample of schizophrenia patients, were consistent across the night, were related to antipsychotic medications, and were suggestive of impairments in specific neuronal circuits.

METHOD

Whole-night high-density EEG recordings were performed in 49 schizophrenia patients, 20 nonschizophrenia patients receiving antipsychotic medication, and 44 healthy subjects. In addition to sleep spindles, several parameters of slow waves were assessed.

RESULTS

Schizophrenia patients had whole-night deficits in spindle power (12-16 Hz) and in slow (12-14 Hz) and fast (14-16 Hz) spindle amplitude, duration, number, and integrated activity in the prefrontal, centroparietal, and temporal regions. Integrated spindle activity and spindle number had the largest effect sizes (effect size: ≥ 2.21). In contrast, no slow wave deficits were found in schizophrenia patients.

CONCLUSIONS

These results indicate that spindle deficits can be reliably established in schizophrenia, are stable across the night, are unlikely to be due to antipsychotic medications, and point to deficits in the thalamic reticular nucleus and thalamo-reticular circuits.

The OARSI histopathology initiative - recommendations for histological assessments of osteoarthritis in sheep and goats

OBJECTIVE

Sheep and goats are commonly used large animal species for studying pathogenesis and treatment of osteoarthritis (OA). This review focuses on the macroscopic and microscopic criteria for assessing OA in sheep and goats and recommends particular assessment criteria to assist standardization in the conduct and reporting of preclinical trials of OA.

METHODS

A review was conducted of all published OA studies using sheep and goats and the most common macroscopic, microscopic, or ultrastructural scoring systems were summarised. General recommendations regarding methods of OA assessment in the sheep and goat have been made and a preliminary study of their reliability and utility was undertaken.

RESULTS

The modified Mankin scoring system is recommended for semiquantitative histological assessment of OA due to its already widespread adoption, ease of use, similarity to scoring systems used for OA in humans, and its achievable inter-rater reliability. Specific recommendations are also provided for histological scoring of synovitis and scoring of macroscopic lesions of OA.

CONCLUSIONS

The proposed system for assessment of sheep and goat articular tissues appears to provide a useful versatile method to quantify OA change. It is hoped that by adopting more standardised quantitative outcome measures, better comparison between different studies and arthritis models will be possible. The suggested scoring systems can be modified in the future as our knowledge of disease pathophysiology advances.

Increased mortality and morbidity in mild primary hyperparathyroid patients. The Parathyroid Epidemiology and Audit Research Study (PEARS)

OBJECTIVE

To describe mortality and disease-specific morbidities in patients with mild primary hyperparathyroidism (PHPT).

DESIGN

Retrospective population-based observational study.

SETTING

Tayside, Scotland, from 1997 to 2006.

PARTICIPANTS

Patients with mild PHPT were selected from a predefined PHPT cohort between 1997 and 2006.

MAIN OUTCOME MEASURES

Standardised mortality ratios (SMRs) were examined for all-cause mortality, as well as cardiovascular and cancer mortality. Standardised morbidity ratios and standardised incidence ratios were also calculated for eleven observed co-morbidities.

RESULTS

In total, there were 1683 (69.1% female) patients identified with mild PHPT in Tayside. Patients were found to have an increased risk of all-cause mortality and cardiovascular mortality (SMR-all cause 2.62, 95% CI 2.39-2.86; SMR-cardiovascular 2.68, 95% CI 2.34-3.05). Patients with mild PHPT had a significantly increased risk of developing cardiovascular and cerebrovascular disease, renal dysfunction and fractures compared to the age- and sex-adjusted general population.

CONCLUSIONS

Mortality and morbidity were increased for patients with mild untreated PHPT, which is similar to more severe PHPT.

Insulin resistance before and after parathyroidectomy in patients with primary hyperparathyroidism--a pilot study

BACKGROUND

Primary hyperparathyroidism (PHPT) is associated with insulin resistance and an increased cardiovascular mortality. We aimed to see if parathyroidectomy improved insulin resistance.

METHODS

Twelve PHPT patients undergoing parathyroidectomy and ten control patients undergoing non-neck surgery were recruited to the study. Fasting venous blood samples were collected immediately pre-operatively and again at five to six weeks post-operatively. Samples were assayed for plasma glucose, serum insulin, total cholesterol, triglycerides, calcium, alkaline phosphatase, magnesium, parathyroid hormone (PTH), and haemoglobin A1c (HbA1c). Insulin resistance was calculated from fasting insulin and glucose values using Homeostasis Model Assessment (HOMA).

RESULTS

Parathyroidectomy decreased serum calcium (mean pre-op = 2.85 mmol/L, post-op 2.28 mmol/L, P < 0.001) and PTH concentrations (mean pre-op = 23.33 pmol/L, post-op = 10.23 pmol/L, P < 0.001) and increased phosphate concentration. However, there was no improvement in insulin resistance in the PHPT group at between 5 and 6 weeks post-operatively (geometric mean; pre-op = 0.88 (95% CI 0.59 - 1.33) vs. post-op = 0.88 (0.66 - 1.17) P = 0.95). In the control group, an increase in serum calcium was observed post-operatively (mean pre-op = 2.29 mmol/L, post-op = 2.35 mmol/L, P = 0.03). No change in insulin resistance was observed (geometric mean; pre-op = 1.37 (95% CI 0.89 - 2.11) vs. post-op = 1.38 (0.72 - 2.67) P = 0.96).

CONCLUSION

In summary, no significant change in insulin resistance post-parathyroidectomy in patients with PHPT was observed. This indicates that surgical treatment of PHPT does not improve insulin resistance for patients currently selected for parathyroidectomy.

Reflex and reflective testing: efficiency and effectiveness of adding on laboratory tests

Background

Laboratory investigations may be added to existing requests either automatically on the basis of algorithms (reflex testing) or by laboratory professionals (reflective testing). The clinical utility of reflex and reflective testing is not fully established. We studied efficiency (number of tests that needs to be added to make a diagnosis) and effectiveness (number of diagnoses) of reflex and reflective testing in selected biochemical scenarios.

Methods

Using fixed rules, we prospectively measured efficiency and effectiveness of reflex and reflective testing in the following scenarios (reflex initiators in parentheses): (1) hypovitaminosis D (hypocalcaemia plus elevated alkaline phosphatase activity); (2) hypomagnesaemia (hypokalaemia or hypocalcaemia); (3) hypothyroidism (high thyroid-stimulating hormone [TSH]); (4) hyperthyroidism (low TSH); (5) haemochromatosis (reflex or reflective addition of iron studies, followed by reflective addition of genetic studies). Separately, using a different data-set, we examined the impact of varying TSH thresholds on outcomes in the biochemical diagnosis of hyper- and hypothyroidism.

Results

In patients aged over 55 y, 25-hydroxy-vitamin D <50 nmol/L could be predicted with ≥90% certainty when albumin-adjusted calcium was ≤2.1 mmol/L plus alkaline phosphatase >150 U/L. Higher numbers of tests were needed to make a diagnosis in other scenarios. In general, more diagnoses were made by reflex testing. Outside the euthyroid TSH range, efficiency of diagnosis of hyper- and hypothyroidism became asymptotic, while effectiveness declined.

Conclusions

Near-maximal efficiency of reflex testing can be achieved, depending on the reflex and diagnostic thresholds applied. Reflective and reflex testing are complementary activities, the clinical utility of which depends on the initiators used.

Note: The full function test explosive generator

We have conducted three tests of a new pulsed power device called the full function test. These tests represented the culmination of an effort to establish a high energy pulsed power capability based on high explosive pulsed power (HEPP) technology. This involved an extensive computational modeling, engineering, fabrication, and fielding effort. The experiments were highly successful and a new U.S. record for magnetic energy was obtained.

The advanced helical generator

A high explosive pulsed power generator called the advanced helical generator (AHG) has been designed, built, and successfully tested. The AHG incorporates design principles of voltage and current management to obtain a high current and energy gain. Its design was facilitated by the use of modern modeling tools as well as high precision manufacture. The result was a first-shot success. The AHG delivered 16 MA of current and 11 MJ of energy to a quasistatic 80 nH inductive load. A current gain of 160 times was obtained with a peak exponential rise time of 20 micros. We will describe in detail the design and testing of the AHG.

Statins and total (not LDL) cholesterol concentration and outcome of myocardial infarction: results from a meta-analysis and an observational study

PURPOSE

The purpose of this study was to evaluate how total cholesterol (TC) concentration in subjects treated with statins predicts myocardial infarction (MI) risk in the absence of low density lipoprotein cholesterol (LDL-C) measurement in clinical trials and in the setting of usual care.

METHODS

A systematic review of published English language randomised clinical trials comparing statins with placebo that reported TC changes in subjects with or without prior MI between 1993 and 2008 was carried out using Medline, the Cochrane Library, Web of Science and the ISI Web of Knowledge. In addition, a cohort study of MI patients who had at least two TC measurements in Tayside, Scotland, between 1989 and 2002 was performed. The main outcome was TC concentration changes and risk of subsequent MI.

RESULTS

In the meta-analyses of secondary and primary prevention trials statins decreased TC by 1.54 mmol/L and 1.37 mmol/L versus placebo. Statin-associated TC reduction translated into a risk reduction of 18% per mmol (RR 0.82; 95%CI 0.72-0.93) for secondary prevention and 24% per mmol (RR 0.76; 95%CI 0.62-0.93) for primary prevention. In the cohort study, statin use reduced TC by 0.98 mmol/L compared with non statin-use. Statin use was associated with a 28% reduction (adjusted HR 0.72; 95%CI 0.51-0.98) for recurrent MI.

CONCLUSIONS

Total cholesterol measurements can be used with confidence in the absence of LDL measurements to make decisions about statin drug introduction or titration. Randomised trials of statin therapy had good external validity and cholesterol changes and outcomes in trials were comparable to those observed in the setting of usual care.

'Hawks' and 'doves': effect of feedback on grades awarded by supervisors of student selected components

BACKGROUND

Supervisors of some student selected components (SSCs) may appear to give higher grades than others. It is not known if feedback can influence the behaviour of supervisors in the grades they award. We have introduced feedback letters in our institution.

AIMS

(1) To assess the feasibility of objectively identifying SSCs where grades awarded are consistently higher or lower than the average; (2) To assess the effect of feedback on the grades awarded by supervisors of SSCs.

METHODS

The breakdown of SSC grades was examined over four consecutive years, before and after feedback letters were introduced in 2005. The grades awarded globally, and in five individual SSCs, were compared using the chi(2) goodness-of-fit test.

RESULTS

(1) Individual SSCs were identified which awarded grades that were consistently different from the average. (2) Overall grades awarded in 2003/04 and 2004/05 (before feedback) were similar (chi2=0.37, df=2, p=0.83). Likewise, overall grades awarded in 2005/06 and 2006/07 (after feedback) were similar (chi2=1.72, df=2, p=0.42). Comparison of 2003/04 with 2005/06 (chi2=16.0, df=2, p<0.001), and 2006/07 (chi2=26.6, df=2, p<0.001), and of 2004/05 with 2005/06 (chi2=13.5, df=2, p=0.001), and 2006/07 (chi2=23.7, df=2, p<0.001), revealed highly significant differences. The grades awarded after feedback were higher than the grades awarded before feedback.

CONCLUSIONS

The chi2 goodness-of-fit test may be used to identify individual SSCs where the grades awarded are different from the average, although the interpretation of the results thus obtained is fraught with difficulty. Our data also suggest that it is possible to influence assessors in the grades they award.