Decision analysis in the clinical neurosciences

Diagnostic and therapeutic choice in neurology can fortunately be made without formal decision support in the majority of cases. in many patients a diagnosis and treatment choice are relatively easy to establish. This study however, concerns the application of a decision support methodology - clinical decision analysis - to several problems in the clinical neurosdences where diagnosis, prognosis and therapeutic choice are not obvious. Sometimes decision making in clinical medicine can be extremely difficult There may be large interests atstake,and theamount of information that has to beprocessed can be enormous. Data from the patient's history, physical examination, diagnostic procedures, clinical knowledge and the scientific information have to be combined in order to arrive at a prognosis and to develop a diagnostic and therapeutic strategy. Add to this that most diagnostic tests are not completely accurate, that therapy is not always and entirely effective, that diagnostic and therapeutic procedures may be risky, unpleasant, expensive and time-consuming, and that prognosis is most of the times uncertain. The decision process itself is limited by time and by budgetary constraints. The clinician has to recognize situations where the patient's preferences are important, and he has to know when the clinical situation needs a doctor - patient relationship characterized by activity - passivity, guidance - cooperation or mutual participation. Moreover, physicians and their patients (as any human being) find it difficult to handle uncertainty.'" Oinicians often discuss the pro' s and con' sof altemativemanagementstrategies with their senior and junior colleagues, but a language that effectively and explicitly addresses uncertainty and preferences for health outcomes is not part of the physician's standard equipment. Several other factors influence the decision process as welL It has been demonstrated that patient characteristics, (such as social class), physician's personal characteristics (such as age, type of specialty), and the physician's interaction with his profession (for example whether he is in a solo- of group-practice) all may be of influence

Effect of Workflow Improvements in Endovascular Stroke Treatment A Systematic Review and Meta-Analysis

Background and Purpose—Rapid initiation of endovascular stroke treatment is associated with better clinical outcome. The effect of specific improvements is not well known. We performed a systematic review and meta-analysis on the effectiveness of specific workflow improvements on time to treatment and outcome. Methods—A random-effects meta-analysis was used to evaluate the difference in mean time to treatment between intervention group and control group. Secondary outcomes included good functional outcome at 90 days (modified Rankin Scale score 0–2). Results—Fifty-one studies (3 randomized controlled trials, 13 prepost intervention studies, and 35 observational studies) with in total 8467 patients were included. Most frequently reported workflow intervention types concerned anesthetic management (n=26), in-hospital patient transfer management (n=14), and prehospital management (n=11). Patients in the intervention group had shorter time to treatment intervals (weighted mean difference, 26 minutes; 95% CI, 19–33; P<0.001) compared with controls. Subgroup meta-analysis of intervention types also showed a shorter time to treatment in the intervention group: a mean difference of 12 minutes (95% CI, 6–17; P<0.001) for anesthetic management, 37 minutes (95% CI, 22–52; P<0.001) for prehospital management, 41 minutes (95% CI, 27–54; P<0.001) for in-hospital patient transfer management, 47 minutes (95% CI, 28–67; P<0.001) for teamwork, and 64 minutes (95% CI, 24–104; P=0.002) for feedback. The mean difference in time to treatment of studies with multiple interventions implemented simultaneously was 50 minutes (95% CI, 31–69; P<0.001) in favor of the intervention group. Patients in the intervention group had increased likelihood of favorable outcome (risk ratio [RR], 1.39; 95% CI, 1.15–1.66; P<0.001). Conclusions—Interventions in the workflow of endovascular stroke treatment lead to a significant reduction in time to treatment and results in an increased likelihood of favorable outcome. Acute stroke care should be reorganized by making use of the examples of workflow interventions described in this review to ensure the best medical care for stroke patients

Interobserver agreement for 10% categories of angiographic carotid stenosis

BACKGROUND AND PURPOSE: Although the reliability of the assessment of severe 70% to 99% carotid stenosis by carotid angiography has been proven excellent, this may not necessarily be the case for a more detailed classification of carotid stenoses by 10% categories. METHODS: Angiograms of the carotid arteries were assessed pairwise by three independent, experienced observers. The measurements of the degree of stenosis of both the carotid bifurcation and the internal carotid artery were made according to the European Carotid Surgery Trial method. Kappa statistics were used to assess the agreement beyond chance for severe (70% to 99%) carotid stenosis (kappa 1) and for 10% categories of carotid stenosis (kappa 2). The penalty scores were adjusted by weights for the relative difference in risk (RDR) of stroke in the ipsilateral carotid distribution between the 10% categories (kappa 3). An adjustment of the RDR method was made by assuming that only patients with a severe carotid stenosis would undergo surgery, and the penalty would be 0 if no disagreement would exist about the indication for surgery (kappa 4). An even further adjustment (kappa 5) was made by assuming that assessment of the rate of carotid stenosis by one or both observers would lead to different treatment recommendations in 50% of the cases, and accordingly the penalty for disagreement (RDR) was halved. RESULTS: One hundred twenty-one carotid bifurcations in 65 patients with a transient ischemic attack or nondisabling stroke were assessed. The intraclass correlation between the exact estimates of carotid stenosis was .90 (95% confidence interval, .85 to .92). The mean difference in stenosis between the two raters was 0.8% (95% confidence interval, -2.1% to 3.7%). kappa 1 to kappa 5 equaled 0.80, 0.40, 0.79, 0.91, and 0.92, respectively. CONCLUSIONS: Interobserver agreement for distinct 10% categories of angiographic carotid stenosis is moderate, but when realistic risk- and decision-based weights are used, agreement between experienced observers can be almost perfect

Platelet activation and lipid peroxidation in patients with acute ischemic stroke

BACKGROUND AND PURPOSE: Both platelet activation and lipid peroxidation are potential sources of vasoactive eicosanoids that can be produced via the cyclooxygenase pathway, ie, thromboxane (TX) A2, or by free radical-catalyzed peroxidation of arachidonic acid, ie, isoprostanes. We investigated the biosynthesis of TXA2 and F2-isoprostanes, as reflected by the urinary excretion of 11-dehydro-TXB2 and 8-epi-prostaglandin (PG) F2 alpha respectively, in 62 consecutive patients (30 men, 32 women; mean age, 67 +/- 14 years) with acute ischemic stroke. METHODS: At least two consecutive 6-hour urine samples were obtained during the first 72 hours after onset of symptoms. Urinary eicosanoids were measured by previously described radioimmunoassays. RESULTS: Repeated periods of enhanced thromboxane biosynthesis were found in 52% of patients. Urinary 11-dehydro-TXB2 averaged 221 +/- 207 (mean +/- SD; n = 197; range, 13 to 967) pmol/mmol creatinine in 30 patients treated with cyclooxygenase inhibitors (mostly aspirin) at the time of study versus 392 +/- 392 (n = 186; range, 26 to 2533) in 32 untreated patients (P .05). The correlation between the two metabolites was moderate in both untreated patients (r = .41, P < .001) and patients with cyclooxygenase inhibitors (r = .31, P < .001). In a multiple regression analysis, increased thromboxane production was independently associated with severity of stroke on admission, atrial fibrillation, and treatment with cyclooxygenase-inhibiting drugs. CONCLUSIONS: We conclude that during the first few days after an acute ischemic stroke (1) platelet activation occurs repeatedly in a cyclooxygenase-dependent fashion; (2) platelet activation is not associated with concurrent changes in isoprostane biosynthesis; (3) platelet activation is independently associated with stroke severity and atrial fibrillation; and (4) isoprostane biosynthesis is largely independent of platelet cyclooxygenase activity

A short screening instrument for poststroke dementia : the R-CAMCOG

BACKGROUND AND PURPOSE: The CAMCOG is a feasible cognitive screening instrument for dementia in patients with a recent stroke. A major disadvantage of the CAMCOG, however, is its lengthy and relatively complex administration for screening purposes. We therefore developed the Rotterdam CAMCOG (R-CAMCOG), based on the original version. Our aim was to reduce the estimated administration time to 15 minutes or less and to retain or perhaps even improve its diagnostic accuracy. METHODS: We analyzed the item scores on the CAMCOG of 300 consecutive stroke patients, after exclusion of patients with a severe aphasia or lowered consciousness level, who were entered in the Rotterdam Stroke Databank. The diagnosis of dementia was made independent of the R-CAMCOG score, on the basis of clinical examination and neuropsychological test results. The R-CAMCOG was constructed in 3 steps. First, items with floor and ceiling effects were removed. Next, subscales with no additional diagnostic value were excluded. Finally, we removed items that did not contribute to the homogeneity of the subscales. The diagnostic accuracy of the R-CAMCOG and the original CAMCOG was determined by means of the area under the receiver operating characteristic (ROC) curve. RESULTS: In the 3 steps, the number of items was reduced from 59 to 25, divided over the subscales orientation, memory (recent, remote, and learning), perception, and abstraction. The subscale orientation did not reach significance in a logistic regression model but was included in the R-CAMCOG because of its high face validity in dementia screening. Internal validation with ROC analysis suggests that the R-CAMCOG and the CAMCOG are equally accurate in screening for poststroke dementia (area under the curve was 0.95 for both tests). CONCLUSIONS: The R-CAMCOG has overcome the disadvantages of the original CAMCOG. It is a promising, short, and easy-to-administer screening instrument for poststroke dementia. It seems to be sufficiently accurate for this purpose, but the test has yet to be validated in a separate, independent study

Noninvasive detection of a ruptured aneurysm at a basilar artery fenestration with submillimeter multisection CT angiography

The criterion standard for the detection of intracranial aneurysms is digital subtraction angiography. MR imaging and CT provide good accuracy in the evaluation of brain arteries and aneurysms. We herein report a case of a ruptured aneurysm at a basilar artery fenestration. The diagnosis was assessed with 16-row multisection CT angiography and was confirmed by using digital subtraction angiography. The patient was successfully treated with coil placement

Impact of guidelines for the management of minor head injury on the utilization and diagnostic yield of CT over two decades, using natural language processing in a large dataset

Objectives We investigated the impact of clinical guidelines for the management of minor head injury on utilization and diagnostic yield of head CT over two decades. Methods Retrospective before-after study using multiple electronic health record data sources. Natural language processing algorithms were developed to rapidly extract indication, Glasgow Coma Scale, and CT outcome from clinical records, creating two datasets: one based on all head injury CTs from 1997 to 2009 (n = 9109), for which diagnostic yield of intracranial traumatic findings was calculated. The second dataset (2009–2014) used both CT reports and clinical notes from the emergency department, enabling selection of minor head injury patients (n = 4554) and calculation of both CT utilization and diagnostic yield. Additionally, we tested for significant changes in utilization and yield after guideline implementation in 2011, using chi-square statistics and logistic regression. Results The yield was initially nearly 60%, but in a decreasing trend dropped below 20% when CT became routinely used for head trauma. Between 2009 and 2014, of 4554 minor head injury patients overall, 85.4% underwent head CT. After guideline implementation in 2011, CT utilization significantly increased from 81.6 to 87.6% (p = 7 × 10−7 ), while yield significantly decreased from 12.2 to 9.6% (p = 0.029). Conclusions The number of CTs performed for head trauma gradually increased over two decades, while the yield decreased. In 2011, despite implementation of a guideline aiming to improve selective use of CT in minor head injury, utilization significantly increased

Ordinal outcome analysis improves the detection of between-hospital differences in outcome

Background: There is a growing interest in assessment of the quality of hospital care, based on outcome measures. Many quality of care comparisons rely on binary outcomes, for example mortality rates. Due to low numbers, the observed differences in outcome are partly subject to chance. We aimed to quantify the gain in efficiency by ordinal instead of binary outcome analyses for hospital comparisons. We analyzed patients with traumatic brain injury (TBI) and stroke as examples.Methods: We sampled patients from two trials. We simulated ordinal and dichotomous outcomes based on the modified Rankin Scale (stroke) and Glasgow Outcome Scale (TBI) in scenarios with and without true differences between hospitals in outcome. The potential efficiency gain of ordinal outcomes, analyzed with ordinal logistic regression, compared to dichotomous outcomes, analyzed with binary logistic regression was expressed as the possible reduction in sample size while keeping the same statistical power to detect outliers.Results: In the IMPACT study (9578 patients in 265 hospitals, mean number of patients per hospital = 36), the analysis of the ordinal scale rather than the dichotomized scale ('unfavorable outcome'), allowed for up to 32% less patients in the analysis without a loss of power. In the PRACTISE trial (1657 patients in 12 hospitals, mean number of patients per hospital = 138), ordinal analysis allowed for 13% less patients. Compared to mortality, ordinal outcome analyses allowed for up to 37 to 63% less patients.Conclusions: Ordinal analyses provide the statistical power of substantially larger studies which have been analyzed with dichotomization of endpoints. We advise to exploit ordinal outcome measures for hospital comparisons, in order to increase efficiency in quality of care measurements.Development and application of statistical models for medical scientific researc