Low vs high hemoglobin trigger for transfusion in vascular surgery: a randomized clinical feasibility trial.

Current guidelines advocate to limit red blood cell (RBC) transfusion during surgery, but the feasibility and safety of such a strategy remain unclear, as the majority of evidence is based on postoperatively stable patients. We assessed the effects of a protocol aiming to restrict RBC transfusion throughout hospitalization for vascular surgery. Fifty-eight patients scheduled for lower limb bypass or open abdominal aortic aneurysm repair were randomly assigned, on hemoglobin drop below 9.7 g/dL, to either a low-trigger (hemoglobin < 8.0 g/dL) or a high-trigger (hemoglobin < 9.7 g/dL) group for RBC transfusion. Near-infrared spectroscopy assessed intraoperative oxygen desaturation in brain and muscle. Explorative outcomes included nationwide registry data on death and major vascular complications. The primary outcome, mean hemoglobin within 15 days of surgery, was significantly lower in the low-trigger group, at 9.46 vs 10.33 g/dL in the high-trigger group (mean difference, -0.87 g/dL; P = .022), as were units of RBCs transfused (median [interquartile range (IQR)], 1 [0-2] vs 3 [2-6]; P = .0015). Although the duration and magnitude of cerebral oxygen desaturation increased in the low-trigger group (median [IQR], 421 [42-888] vs 127 [11-331] minutes × %; P = .0036), muscle oxygenation was unaffected. The low-trigger group associated to a higher rate of death or major vascular complications (19/29 vs 8/29; hazard ratio, 3.20; P = .006) and fewer days alive outside the hospital within 90 days (median [IQR], 76 [67-82] vs 82 [76-84] days; P = .049). In conclusion, a perioperative protocol restricting RBC transfusion successfully separated hemoglobin levels and RBC units transfused. Exploratory outcomes suggested potential harm with the low-trigger group and warrant further trials before such a strategy is universally adopted. This trial was registered at www.clinicaltrials.gov as #NCT02465125.

A screening method to spot biomarkers that may warn of serious events in a chronic disease - illustrated by cardiological CLARICOR trial data.

OBJECTIVES: To develop a crude screening method for detecting biomarkers which frequently exhibit a rise (or fall) in level prior to a serious event (e.g. a stroke) in patients with a chronic disease, signalling that the biomarker may have an alarm-raising or prognostic potential. The subsequent assessment of the marker's clinical utility requires costly, difficult longitudinal studies. Therefore, initial screening of candidate-biomarkers is desirable. METHODS: The method exploits a cohort of patients with biomarkers measured at entry and with recording of first serious event during follow-up. Copying those individual records onto a common timeline where a specific event occurs on the same day (Day 0) for all patients, the baseline biomarker level, when plotted against the patient's entry time on the revised timeline, will have a positive (negative) regression slope if biomarker levels generally rise (decline) the closer one gets to the event. As an example, we study 1,958 placebo-treated patients with stable coronary artery disease followed for nine years in the CLARICOR trial (NCT00121550), examining 11 newer biomarkers. RESULTS: Rising average serum levels of cardiac troponin T and of N-terminal pro-B-type natriuretic peptide were seen prior to a fatal cardiovascular outcome. C-reactive protein rose prior to non-cardiovascular death. Glomerular filtration rate, seven lipoproteins, and nine newer cardiological biomarkers did not show convincing changes. CONCLUSIONS: For early detection of biomarkers with an alarm-raising potential in chronic diseases, we proposed the described easy procedure. Using only baseline biomarker values and clinical course of participants with coronary heart disease, we identified the same cardiovascular biomarkers as those previously found containing prognostic information using longitudinal or survival analysis.

Internet-based therapy with FearFighter for anxiety disorders: a randomised clinical trial.

Background: Internet-based cognitive behavioural self-help psychotherapy (ICBT) can be an important alternative or supplement to ordinary face-to-face therapy.Aim: To assess effectiveness of ICBT for adults with an anxiety disorder.Methods: Sixty-four participants were randomised to 9 weeks with the FearFighter ICBT program (n = 32) or no intervention (n = 32). Outcomes included complete remission, severity of symptoms and occurrence of adverse events.Results: No difference (p = 1.00) in remission between groups following 10 weeks of intervention nor at 37 weeks follow-up was found. There was significant reduction in the severity of symptoms (p < 0.05) at end of intervention of ICBT compared to the control group, while the reduction in symptoms at 37 weeks follow-up was equal for the two groups. Two participants in the ICBT group and none in the control group reported adverse events.Conclusion: We found no difference in remission, but a reduction of symptoms in the ICBT group compared with the control group at end of intervention. At six months follow-up the two groups showed the same level in the reduction of symptoms. Trial registration: Clinicaltrials.gov: NCT02499055. Registered 01 July 2015.

Storage time of red blood cells among ICU patients with septic shock.

BACKGROUND: We aimed to describe the exposure to blood transfusions and mortality among patients with septic shock. METHODS: We did a retrospective cohort study of two cohorts-patients with septic shock registered in a Danish ICU database (2008-2010) and patients from the Transfusion Requirements in Septic Shock (TRISS) trial (2011-2013). We extracted information on blood transfusions issued to all patients. We investigated the number of patients receiving very fresh blood (less than 7 days), very old blood (more than 24 days) and blood with a mixture of storage time. RESULTS: In the Danish cohort, 1637 patients were included of whom 1394 (85%) received 20,239 blood units from 14 days prior the ICU admission to 90 days after; 33% were transfused before, 77% in the ICU and 36% after ICU. The exposure to exclusively very fresh or very old blood was 3% and 4%, respectively. In the TRISS cohort, 77% of the 937 patients received 5047 RBC units; 3% received exclusively very fresh and 13% very old blood. The point estimate of mortality was higher among patients receiving large amounts of exclusively very fresh and very old blood, but the number of patients were very small. CONCLUSIONS: Patients with septic shock were transfused both before and after ICU. Exposure to blood of less than 7 days or more than 24 days old were limited. We were not able to detect higher mortality among the limited number of patients with septic shock transfused with very fresh or very old blood.

Simple, low-cost group-counselling programme vs treatment as usual for patients with newly notified occupational hand eczema-Exploratory analyses of effects on knowledge, behaviour and personal resources of the randomized PREVEX clinical trial.

BACKGROUND: Sickness absence in hand eczema patients has been associated with stress rather than disease severity, indicating that personal aspects regarding hand eczema should be investigated further. OBJECTIVES: To examine whether patient education vs treatment as usual can influence behaviour and knowledge regarding skin protection and care, as well as personal resources, in patients with occupational hand eczema. METHODS: PREVEX is an individually randomized clinical trial investigating the 1-year effects of a simple, low-cost group-counselling programme vs treatment as usual for patients with notified occupational hand eczema. Exploratory outcomes were behaviour, knowledge, self-efficacy, and self-evaluated skin care ability. RESULTS: In total, 1668 patients with notified occupational skin disease were invited to participate, of whom 769 were randomized and 756 were analysed: intervention group (n = 376) vs control group (n = 380). Behaviour was improved and the knowledge score increased in the intervention group as compared with the control group (respectively: estimate 0.08; 95%CI: 0.02-0.19; P = .01; and estimate 0.49; 95%CI: 0.28-0.70; P < .001). Self-efficacy was lower in the intervention group as compared with the control group (estimate -0.78; 95%CI: -1.25 to -0.30; P = .001). No difference was found regarding skin care abilities. CONCLUSIONS: The intervention had a positive influence on 1-year behaviour and knowledge, but was insufficient to result in long-term positive changes in personal resources regarding dealing with hand eczema.

Lower versus higher hemoglobin threshold for transfusion in septic shock.

BACKGROUND: Blood transfusions are frequently given to patients with septic shock. However, the benefits and harms of different hemoglobin thresholds for transfusion have not been established. METHODS: In this multicenter, parallel-group trial, we randomly assigned patients in the intensive care unit (ICU) who had septic shock and a hemoglobin concentration of 9 g per deciliter or less to receive 1 unit of leukoreduced red cells when the hemoglobin level was 7 g per deciliter or less (lower threshold) or when the level was 9 g per deciliter or less (higher threshold) during the ICU stay. The primary outcome measure was death by 90 days after randomization. RESULTS: We analyzed data from 998 of 1005 patients (99.3%) who underwent randomization. The two intervention groups had similar baseline characteristics. In the ICU, the lower-threshold group received a median of 1 unit of blood (interquartile range, 0 to 3) and the higher-threshold group received a median of 4 units (interquartile range, 2 to 7). At 90 days after randomization, 216 of 502 patients (43.0%) assigned to the lower-threshold group, as compared with 223 of 496 (45.0%) assigned to the higher-threshold group, had died (relative risk, 0.94; 95% confidence interval, 0.78 to 1.09; P=0.44). The results were similar in analyses adjusted for risk factors at baseline and in analyses of the per-protocol populations. The numbers of patients who had ischemic events, who had severe adverse reactions, and who required life support were similar in the two intervention groups. CONCLUSIONS: Among patients with septic shock, mortality at 90 days and rates of ischemic events and use of life support were similar among those assigned to blood transfusion at a higher hemoglobin threshold and those assigned to blood transfusion at a lower threshold; the latter group received fewer transfusions. (Funded by the Danish Strategic Research Council and others; TRISS ClinicalTrials.gov number, NCT01485315.).

When and how should multiple imputation be used for handling missing data in randomised clinical trials - a practical guide with flowcharts.

BACKGROUND: Missing data may seriously compromise inferences from randomised clinical trials, especially if missing data are not handled appropriately. The potential bias due to missing data depends on the mechanism causing the data to be missing, and the analytical methods applied to amend the missingness. Therefore, the analysis of trial data with missing values requires careful planning and attention. METHODS: The authors had several meetings and discussions considering optimal ways of handling missing data to minimise the bias potential. We also searched PubMed (key words: missing data; randomi*; statistical analysis) and reference lists of known studies for papers (theoretical papers; empirical studies; simulation studies; etc.) on how to deal with missing data when analysing randomised clinical trials. RESULTS: Handling missing data is an important, yet difficult and complex task when analysing results of randomised clinical trials. We consider how to optimise the handling of missing data during the planning stage of a randomised clinical trial and recommend analytical approaches which may prevent bias caused by unavoidable missing data. We consider the strengths and limitations of using of best-worst and worst-best sensitivity analyses, multiple imputation, and full information maximum likelihood. We also present practical flowcharts on how to deal with missing data and an overview of the steps that always need to be considered during the analysis stage of a trial. CONCLUSIONS: We present a practical guide and flowcharts describing when and how multiple imputation should be used to handle missing data in randomised clinical.

Targeted temperature management at 33°C versus 36°C after cardiac arrest.

BACKGROUND: Unconscious survivors of out-of-hospital cardiac arrest have a high risk of death or poor neurologic function. Therapeutic hypothermia is recommended by international guidelines, but the supporting evidence is limited, and the target temperature associated with the best outcome is unknown. Our objective was to compare two target temperatures, both intended to prevent fever. METHODS: In an international trial, we randomly assigned 950 unconscious adults after out-of-hospital cardiac arrest of presumed cardiac cause to targeted temperature management at either 33°C or 36°C. The primary outcome was all-cause mortality through the end of the trial. Secondary outcomes included a composite of poor neurologic function or death at 180 days, as evaluated with the Cerebral Performance Category (CPC) scale and the modified Rankin scale. RESULTS: In total, 939 patients were included in the primary analysis. At the end of the trial, 50% of the patients in the 33°C group (235 of 473 patients) had died, as compared with 48% of the patients in the 36°C group (225 of 466 patients) (hazard ratio with a temperature of 33°C, 1.06; 95% confidence interval [CI], 0.89 to 1.28; P=0.51). At the 180-day follow-up, 54% of the patients in the 33°C group had died or had poor neurologic function according to the CPC, as compared with 52% of patients in the 36°C group (risk ratio, 1.02; 95% CI, 0.88 to 1.16; P=0.78). In the analysis using the modified Rankin scale, the comparable rate was 52% in both groups (risk ratio, 1.01; 95% CI, 0.89 to 1.14; P=0.87). The results of analyses adjusted for known prognostic factors were similar. CONCLUSIONS: In unconscious survivors of out-of-hospital cardiac arrest of presumed cardiac cause, hypothermia at a targeted temperature of 33°C did not confer a benefit as compared with a targeted temperature of 36°C. (Funded by the Swedish Heart-Lung Foundation and others; TTM ClinicalTrials.gov number, NCT01020916.).

Cardiac rehabilitation versus usual care for patients treated with catheter ablation for atrial fibrillation: Results of the randomized CopenHeartRFA trial.

BACKGROUND: To assess the effects of comprehensive cardiac rehabilitation compared with usual care on physical activity and mental health for patients treated with catheter ablation for atrial fibrillation. METHODS: The patients were randomized 1:1 stratified by paroxysmal or persistent atrial fibrillation and sex to cardiac rehabilitation consisting of 12 weeks physical exercise and four psycho-educational consultations plus usual care (cardiac rehabilitation group) versus usual care. The primary outcome was Vo2 peak. The secondary outcome was self-rated mental health measured by the Short Form-36 questionnaire. Exploratory outcomes were collected. RESULTS: 210 patients were included (mean age: 59 years, 74% men), 72% had paroxysmal atrial fibrillation prior to ablation. Compared with usual care, the cardiac rehabilitation group had a beneficial effect on Vo2 peak at four months (24.3mL kg-1 min-1 versus 20.7mL kg-1 min-1, p of main effect=0.003, p of interaction between time and intervention=0.020). No significant difference between groups on Short Form-36 was found (53.8 versus 51.9 points, P=.20). Two serious adverse events (atrial fibrillation in relation to physical exercise and death unrelated to rehabilitation) occurred in the cardiac rehabilitation group versus one in the usual care group (death unrelated to intervention) (P=.56). In the cardiac rehabilitation group 16 patients versus 7 in the usual care group reported non-serious adverse events (P=.047). CONCLUSION: Comprehensive cardiac rehabilitation had a positive effect on physical capacity compared with usual care, but not on mental health. Cardiac rehabilitation caused more non-serious adverse events.

The SafeBoosC II randomized trial: treatment guided by near-infrared spectroscopy reduces cerebral hypoxia without changing early biomarkers of brain injury.

BACKGROUND: The SafeBoosC phase II multicentre randomized clinical trial investigated the benefits and harms of monitoring cerebral oxygenation by near-infrared spectroscopy (NIRS) combined with an evidence-based treatment guideline vs. no NIRS data and treatment as usual in the control group during the first 72 h of life. The trial demonstrated a significant reduction in the burden of cerebral hypoxia in the experimental group. We now report the blindly assessed and analyzed treatment effects on electroencephalographic (EEG) outcomes (burst rate and spectral edge frequency 95% (SEF95)) and blood biomarkers of brain injury (S100ß, brain fatty acid-binding protein, and neuroketal). METHODS: One hundred and sixty-six extremely preterm infants were randomized to either experimental or control group. EEG was recorded at 64 h of age and blood samples were collected at 6 and 64 h of age. RESULTS: One hundred and thirty-three EEGs were evaluated. The two groups did not differ regarding burst rates (experimental 7.2 vs. control 7.7 burst/min) or SEF95 (experimental 18.1 vs. control 18.0 Hz). The two groups did not differ regarding blood S100ß, brain fatty acid-binding protein, and neuroketal concentrations at 6 and 64 h (n = 123 participants). CONCLUSION: Treatment guided by NIRS reduced the cerebral burden of hypoxia without affecting EEG or the selected blood biomarkers.

Effect of escitalopram versus placebo on GRα messenger RNA expression in peripheral blood cells of healthy individuals with a family history of depression - a secondary outcome analysis from the randomized AGENDA trial.

Background Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed as first-line drugs for the treatment of depression. However, the mechanisms of action for SSRIs are unclear and besides neurotransmitter modulation may depend on modulation of the hypothalamic-pituitary-adrenal (HPA) system. The glucocorticoid receptor (GR) isoform α plays an important role in the negative feedback regulation of the HPA axis and reduced GRα messenger RNA (mRNA) expression has been shown in mood disorder patients and first-degree relatives compared to healthy individuals with no family history of psychiatric disorders. Aim Based on the AGENDA trial dataset, we analysed whether an intervention with SSRI versus placebo decreases the GRα mRNA expression in peripheral blood cells in healthy first-degree relatives of patients with major depression. Methods The participants (N = 80) were randomly allocated to receive daily tablets of escitalopram 10 mg versus placebo for 4 weeks. GRα mRNA expression levels in peripheral blood were measured using reverse transcription polymerase chain reaction. Results Four weeks of intervention with escitalopram decreased the relative change from baseline in the expression of GRα mRNA compared with placebo (p = 0.002). Conclusion These findings from a randomized trial suggest that a 4-week escitalopram administration to healthy participants results in a decrease in GRα mRNA expression levels in peripheral blood compared with inert placebo. The decrease in GRα mRNA expression levels may reflect a decrease in the HPA axis activity.

No effect of escitalopram versus placebo on brain-derived neurotrophic factor in healthy individuals: a randomised trial.

OBJECTIVE: Brain-derived neurotrophic factor (BDNF) seems to play an important role in the course of depression including the response to antidepressants in patients with depression. We aimed to study the effect of an antidepressant intervention on peripheral BDNF in healthy individuals with a family history of depression. METHODS: We measured changes in BDNF messenger RNA (mRNA) expression and whole-blood BDNF levels in 80 healthy first-degree relatives of patients with depression randomly allocated to receive daily tablets of escitalopram 10 mg versus placebo for 4 weeks. RESULTS: We found no statistically significant difference between the escitalopram and the placebo group in the change in BDNF mRNA expression and whole-blood BDNF levels. Post hoc analyses showed a statistically significant negative correlation between plasma escitalopram concentration and change in whole-blood BDNF levels in the escitalopram-treated group. CONCLUSION: The results of this randomised trial suggest that escitalopram 10 mg has no effect on peripheral BDNF levels in healthy individuals.

Hydroxyethyl starch 130/0.42 versus Ringer's acetate in severe sepsis.

BACKGROUND: Hydroxyethyl starch (HES) [corrected] is widely used for fluid resuscitation in intensive care units (ICUs), but its safety and efficacy have not been established in patients with severe sepsis. METHODS: In this multicenter, parallel-group, blinded trial, we randomly assigned patients with severe sepsis to fluid resuscitation in the ICU with either 6% HES 130/0.42 (Tetraspan) or Ringer's acetate at a dose of up to 33 ml per kilogram of ideal body weight per day. The primary outcome measure was either death or end-stage kidney failure (dependence on dialysis) at 90 days after randomization. RESULTS: Of the 804 patients who underwent randomization, 798 were included in the modified intention-to-treat population. The two intervention groups had similar baseline characteristics. At 90 days after randomization, 201 of 398 patients (51%) assigned to HES 130/0.42 had died, as compared with 172 of 400 patients (43%) assigned to Ringer's acetate (relative risk, 1.17; 95% confidence interval [CI], 1.01 to 1.36; P=0.03); 1 patient in each group had end-stage kidney failure. In the 90-day period, 87 patients (22%) assigned to HES 130/0.42 were treated with renal-replacement therapy versus 65 patients (16%) assigned to Ringer's acetate (relative risk, 1.35; 95% CI, 1.01 to 1.80; P=0.04), and 38 patients (10%) and 25 patients (6%), respectively, had severe bleeding (relative risk, 1.52; 95% CI, 0.94 to 2.48; P=0.09). The results were supported by multivariate analyses, with adjustment for known risk factors for death or acute kidney injury at baseline. CONCLUSIONS: Patients with severe sepsis assigned to fluid resuscitation with HES 130/0.42 had an increased risk of death at day 90 and were more likely to require renal-replacement therapy, as compared with those receiving Ringer's acetate. (Funded by the Danish Research Council and others; 6S ClinicalTrials.gov number, NCT00962156.).

Emotions and health: findings from a randomized clinical trial on psychoeducational nursing to patients with implantable cardioverter defibrillator.

BACKGROUND: Serious illness will inevitably lead to a fundamental emotional reaction. Traditionally, in interventional treatment or rehabilitation trials, the psychological status of patients with implantable cardioverter defibrillators has been evaluated with anxiety and depression as outcome measures. In caring for these patients, the aim of nursing is to help patients manage life with complex heart disease. The early detection and management of negative emotional response might prevent the development of pathological conditions such as depression. OBJECTIVE: The aims of this study were to (a) describe the trajectory of primary emotions over time in patients with implantable cardioverter defibrillators and (b) examine the potential effects of psychoeducational nursing on primary emotions. METHODS: During the inclusion period (October 2007 to November 2009), 196 patients with implantable cardioverter defibrillator were randomized (1:1) to rehabilitation versus usual care. Rehabilitation consisted of a psychoeducational nursing component and an exercise training component. This article concerns phase 1, psychoeducational nursing, guided by a theory of nursing, Rosemary Rizzo Parses Human Becoming Practice Methodologies. The outcome measure is the Emotions and Health Scale. The scale consists of 8 primary emotions: joy, agreeableness, surprise, fear, sadness, disgust, anger, and anticipation. RESULTS: Mean (SD) age was 58 (13) years, and 79% of the participants were men. Significant improvements were found in primary emotional responses over time (P < .05) when combining groups. However, no difference in emotional intensity was found between the groups after 3 months of psychoeducational nursing intervention (P > .05). CONCLUSIONS: Primary emotions are affected after implantable cardioverter defibrillator implantation. Improvements over time were found. However, it was not possible to detect any effect of a short-term psychoeducational nursing intervention. Evaluating the primary emotions might be a good way for nurses to monitor patients' psychological outcomes because the instrument is sensitive to changes over a short period. Further development of early psychoeducational nursing interventions for patients with implantable cardioverter defibrillators is needed.

Agreement between public register and adjudication committee outcome in a cardiovascular randomized clinical trial.

UNLABELLED: The objective of this study is to describe the agreement between randomized trial outcome assessment by committee and outcomes entirely identified through public registers. METHODS: In the CLARICOR trial, 4,372 patients with stable coronary heart disease received a short course of clarithromycin versus placebo and were followed up for 2.6 years. The pertinent hospital records and death certificates had originally been evaluated by the adjudication committee using common definitions of outcomes mapped into a 6-category list. We now mechanically converted the International Classification of Diseases-coded diagnoses of the public registries into the same categories. After cross-tabulation of the committee diagnoses with National Patient Register diagnoses and Register of Causes of Death, we calculate agreement and compare the estimated intervention effects of the 2 data sets. RESULTS: With public register data, the protocol-specified categories were slightly more frequent. Overall agreement was 74% for hospital discharges and 60% for cause of death, but the intervention effect, expressed as a hazard ratio, stayed within 4% of the value originally obtained with the adjudication committee (P ≥ .35). CONCLUSIONS: Our results show a modest agreement between formal adjudication and outcomes deducible from public registers. However, the estimated intervention effect did not differ noticeably between the 2 data sources. If studies on a wide range of public registers confirm these findings, register outcomes may be considered as a replacement for adjudication committees.

Thresholds for statistical and clinical significance in systematic reviews with meta-analytic methods.

BACKGROUND: Thresholds for statistical significance when assessing meta-analysis results are being insufficiently demonstrated by traditional 95% confidence intervals and P-values. Assessment of intervention effects in systematic reviews with meta-analysis deserves greater rigour. METHODS: Methodologies for assessing statistical and clinical significance of intervention effects in systematic reviews were considered. Balancing simplicity and comprehensiveness, an operational procedure was developed, based mainly on The Cochrane Collaboration methodology and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines. RESULTS: We propose an eight-step procedure for better validation of meta-analytic results in systematic reviews (1) Obtain the 95% confidence intervals and the P-values from both fixed-effect and random-effects meta-analyses and report the most conservative results as the main results. (2) Explore the reasons behind substantial statistical heterogeneity using subgroup and sensitivity analyses (see step 6). (3) To take account of problems with multiplicity adjust the thresholds for significance according to the number of primary outcomes. (4) Calculate required information sizes (≈ the a priori required number of participants for a meta-analysis to be conclusive) for all outcomes and analyse each outcome with trial sequential analysis. Report whether the trial sequential monitoring boundaries for benefit, harm, or futility are crossed. (5) Calculate Bayes factors for all primary outcomes. (6) Use subgroup analyses and sensitivity analyses to assess the potential impact of bias on the review results. (7) Assess the risk of publication bias. (8) Assess the clinical significance of the statistically significant review results. CONCLUSIONS: If followed, the proposed eight-step procedure will increase the validity of assessments of intervention effects in systematic reviews of randomised clinical trials.

The thresholds for statistical and clinical significance - a five-step procedure for evaluation of intervention effects in randomised clinical trials.

BACKGROUND: Thresholds for statistical significance are insufficiently demonstrated by 95% confidence intervals or P-values when assessing results from randomised clinical trials. First, a P-value only shows the probability of getting a result assuming that the null hypothesis is true and does not reflect the probability of getting a result assuming an alternative hypothesis to the null hypothesis is true. Second, a confidence interval or a P-value showing significance may be caused by multiplicity. Third, statistical significance does not necessarily result in clinical significance. Therefore, assessment of intervention effects in randomised clinical trials deserves more rigour in order to become more valid. METHODS: Several methodologies for assessing the statistical and clinical significance of intervention effects in randomised clinical trials were considered. Balancing simplicity and comprehensiveness, a simple five-step procedure was developed. RESULTS: For a more valid assessment of results from a randomised clinical trial we propose the following five-steps: (1) report the confidence intervals and the exact P-values; (2) report Bayes factor for the primary outcome, being the ratio of the probability that a given trial result is compatible with a 'null' effect (corresponding to the P-value) divided by the probability that the trial result is compatible with the intervention effect hypothesised in the sample size calculation; (3) adjust the confidence intervals and the statistical significance threshold if the trial is stopped early or if interim analyses have been conducted; (4) adjust the confidence intervals and the P-values for multiplicity due to number of outcome comparisons; and (5) assess clinical significance of the trial results. CONCLUSIONS: If the proposed five-step procedure is followed, this may increase the validity of assessments of intervention effects in randomised clinical trials.

Osteoprotegerin independently predicts mortality in patients with stable coronary artery disease: the CLARICOR trial.

OBJECTIVES: To elucidate the prognostic power of serum osteoprotegerin (OPG) in patients with stable coronary artery disease (CAD). METHODS: Serum OPG levels were measured in the CLARICOR trial cohort of 4063 patients with stable CAD on blood samples drawn at randomization. The follow-up was 2.6 years for detailed cardiovascular events and 6 years for all-cause mortality. RESULTS: OPG levels were significantly increased in non-survivors (21%) compared to survivors (median [quartiles] 2092 ng/L [1636; 2800] compared to 1695 ng/L [1322; 2193, p < 0.0001]). The 2.6-year follow-up showed that OPG adds to the prediction of both cardiovascular and all-cause mortality in combination with clinical risk factors (HR [one log10 unit increase] 6.1 [95% CI 2.4-15.6, p = 0.0001]) and HR 6.5 [95% CI 3.4-12.5, p < 0.0001], respectively). Similar, in the 6-year follow-up, OPG was found to be a strong predictor for all-cause mortality. Importantly, OPG remained an independent predictor of mortality even after adjustment for both clinical and conventional cardiovascular risk markers (HR 2.5 [95% CI 1.6-3.9, p < 0.0001]). CONCLUSIONS: Serum OPG has a long-lasting independent predictive power as to all-cause mortality and cardiovascular death in patients with stable CAD.

Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized trial.

OBJECTIVE: To investigate the impact of instructor feedback versus no instructor feedback when training a complex operational task on a laparoscopic virtual reality simulator. BACKGROUND: : Simulators are now widely accepted as a training tool, but there is insufficient knowledge about how much feedback is necessary, which is useful for sustainable implementation. METHODS: A randomized trial complying with CONSORT Statement. All participants had to reach a predefined proficiency level for a complex operational task on a virtual reality simulator. The intervention group received standardized instructor feedback a maximum of 3 times. The control group did not receive instructor feedback. Participants were senior medical students without prior laparoscopic experience (n = 99). Outcome measures were time, repetitions, and performance score to reach a predefined proficiency level. Furthermore, influence of sex and perception of own surgical skills were examined. RESULTS: Time (in minutes) and repetitions were reduced in the intervention group (162 vs 342 minutes; P < 0.005) and (29 vs 65 repetitions; P < 0.005). The control group achieved a higher performance score than the intervention group (57% vs 49%; P = 0.004). Men used less time (in minutes) than women (P = 0.037), but no sex difference was observed for repetitions (P = 0.20). Participants in the intervention group had higher self-perception regarding surgical skills after the trial (P = 0.011). CONCLUSIONS: Instructor feedback increases the efficiency when training a complex operational task on a virtual reality simulator; time and repetitions used to achieve a predefined proficiency level were significantly reduced in the group that received instructor feedback compared with the control group. TRIAL REGISTRATION NUMBER: NCT01497782.

Phantom shocks in patients with implantable cardioverter defibrillator: results from a randomized rehabilitation trial (COPE-ICD).

AIMS: The aim of this trial was to assess a combined rehabilitation intervention including an exercise training component and a psycho-educational component in patients treated with implantable cardioverter defibrillator (ICD). The hypothesis was that the intervention would reduce the occurrence of phantom shocks. METHODS AND RESULTS: The design was secondary explorative analyses of data from a randomized controlled trial. One hundred and ninety-six patients with first-time ICD implantation (79% male, mean age 58 years) were randomized (1 : 1) to either combined rehabilitation or a control group receiving 'treatment as usual'. A total of 144 participants completed the 12-month follow-up. Intervention consisted of 12 weeks of exercise training and 1 year of psycho-educational follow-up focusing on modifiable factors associated with poor outcomes, e.g. phantom shocks. Outcome measures were ancillary questions regarding the experience of phantom shocks, date, time, and place. Twelve patients (9.4%) experienced a phantom shock, 7 in the intervention group and 5 in the control group (NS). Neither age, sex, quality of life nor perceived health at baseline was significantly related to the probability of occurrence of phantom shock. CONCLUSION: Phantom shocks were experienced by about one in ten ICD patients, with no interventional effect found and no significant difference found regarding receiving an actual shock therapy among phantom shock patients. : TRIAL REGISTRATION: ClinicalTrials.gov (ID: NCT00569478).