The influence of different error estimates in the detection of postoperative cognitive dysfunction using reliable change indices with correction for practice effects.

The reliable change index (RCI) expresses change relative to its associated error, and is useful in the identification of postoperative cognitive dysfunction (POCD). This paper examines four common RCIs that each account for error in different ways. Three rules incorporate a constant correction for practice effects and are contrasted with the standard RCI that had no correction for practice. These rules are applied to 160 patients undergoing coronary artery bypass graft (CABG) surgery who completed neuropsychological assessments preoperatively and 1 week postoperatively using error and reliability data from a comparable healthy nonsurgical control group. The rules all identify POCD in a similar proportion of patients, but the use of the within-subject standard deviation (WSD), expressing the effects of random error, as an error estimate is a theoretically appropriate denominator when a constant error correction, removing the effects of systematic error, is deducted from the numerator in a RCI.     

A comparison of methods for measuring cognitive change in older adults.

Well-researched statistical methods are required to guide clinicians in determining the significance of test score changes in serial neuropsychological assessment of older adults. The following six change score methods were examined using five-year test-retest data from the Canadian Study of Health and Aging: the standard deviation method, three reliable change indices (RCIs), and two standardized regression-based methods. Changes in scores on four memory measures were examined in cognitively healthy older adults, and the RCI with a correction for practice/aging effects most accurately classified this normal variability. Diagnostic change (i.e., developing dementia versus remaining cognitive healthy) was also examined in relation to memory test score changes. All change score methods were significantly associated with diagnostic change, though the strength of association varied by measure and method. In contrast to some previous research, RCIs were found to be useful when making diagnostic discriminations in older adults.     

Assessing change with the Automated Neuropsychological Assessment Metrics (ANAM): Issues and challenges

Accurately documenting cognitive change is important, as neuropsychologists are routinely asked to determine cognitive change following disease progression or medical intervention. Computerized testing batteries, such as the Automated Neuropsychological Assessment Metrics (ANAM), are good tools for assessing change, because they allow for randomization of stimuli, creating near limitless alternate forms and reducing practice effects. The question remains, however, as to how best to determine reliable change in performance using ANAM. The current study compared the use of Reliable Change Index (RCI) and regression based methods (REG) calculated from 28 individuals with migraine. These methods then were applied to an independent sample of 25 individuals with migraine assessed with ANAM at baseline, headache, and following pharmacologic treatment. Traditional repeated measures analyses revealed declines in cognitive efficiency following migraine onset on two of four ANAM tasks and significant improvement on all ANAM tasks following treatment. Rates of deterioration and improvement did not significantly differ between RCI and REG methods, although were slightly different across the ANAM tasks used in this study. A combined ANAM score categorized the most individuals as demonstrating cognitive change, revealing that 60% of subjects declined in performance following headache and 84% improved following migraine treatment.     

A battery approach for measuring neuropsychological change.

The accurate interpretation of serial neuropsychological testing is a fundamental activity of neuropsychologists in clinical and research settings. Although prior research supports the construct validity of several individual tests for the reliable measurement of cognitive change, neuropsychologists are often interested in detecting changes in cognitive functioning across a battery of tests. In the present study, we examined the specificity of a modified Reliable Change Index (RCI) methodology applied across a focused battery of commonly used neuropsychological tests. Fifty-seven healthy controls underwent neuropsychological assessment at two time points separated by approximately 1 year. Test-retest reliability coefficients and standard RCI confidence intervals for the individual tests were broadly comparable with prior research in healthy populations. Battery change scores were generated by calculating z-scores of change for each individual test, which were summed across the entire test battery. The RCI methodology was applied to the summed z-score to provide a 90% confidence interval as an indicator of overall cognitive stability. These battery RCI normative standards demonstrated adequate specificity when applied to 29 persons with HIV-1 infection who were classified as medically and neurologically stable. Findings from this study may be useful for both clinicians and researchers seeking normative standards for determining reliable changes in performance across a commonly used battery of neuropsychological tests.     

硬膜外镇痛与静脉镇痛对老年下肢关节置换及植入物内固定治疗后早期认知功能的影响

背景：术后认知功能障碍与老年人术后并发症的发生及死亡率密切相关。设定相同麻醉条件下硬膜外镇痛比静脉镇痛对老年患者下肢关节置换及内固定后早期认知功能的影响较小。 目的：比较两种不同的镇痛方法对老年患者下肢骨科手术后早期认知功能的影响。 方法：60例拟行择期下肢手术的老年患者,随机接受椎管内麻醉继以术后静脉镇痛或以硬膜外镇痛。 结果与结论：术后认知功能障碍发生率静脉镇痛组为47%(14/30),硬膜外镇痛组为30% (9/30例),两组间差异非常显著(P < 0.01 )。Logistic回归分析显示受教育年限短和髋关节置换术是发生术后早期认知功能障碍的独立危险因素。结果表明,老年患者在下肢关节置换及内固定后早期有38%的患者发生了认知功能障碍,且硬膜外镇痛较静脉镇痛发生术后认知功能障碍明显降低。受教育年限短和髋关节置换本身是术后早期认知功能障碍的危险因素。     

不同麻醉方式对老年患者术后早期认知功能障碍影响的评估

目的 建立老年手术患者术后早期认知功能障碍（POCD）预测模型,并确定POCD低风险人群。方法 选取2017年4月~2018年4月于遵化市人民医院接受下腹开腹手术老年患者406例,根据术后有无POCD将其分为POCD组20例,未发生POCD组386例。记录一般资料（年龄、BMI）、临床记录、术前辅助检测和麻醉方式等资料,建立POCD预测模型,通过ROC曲线分析计算ROC曲线下面积（AUC）反映POCD预测型区分度、灵敏度和特异度。结果 两组患者在ASA分级、手术时间、术中出血、术中补液量、性别比和合并慢性疾病（高血压、糖尿病）上比较,差异均无统计学意义（P＞0.05）;年龄≥66岁、BMI≥25.0 kg/m2和全身麻醉为POCD发生独立危险因素,AUC=0.678,95%CI:0.721~0.798,灵敏度50.59%、特异度为78.01%;低危人群定义为年龄＜66岁、BMI＜25.0 kg/m2且手术麻醉方式为腰麻联合硬膜外麻醉的下腹部手术老年患者。结论 老年患者术后发生POCD来自于多个因素,与患者年龄、BMI、和麻醉方式相关,建立POCD的预测模型有助于确定低风险POCD患者,为减少临床POCD发生提供新思路。     

Analysis of cognitive change: a commentary on Keith et al. (2002)

There have been significant advances in the study of cognitive change in recent years, evolving from traditional group-level parametric methods to new techniques such as the reliable change index (RCI) and the standardized regression-based (SRB) change score. In the very interesting study of cognitive change following cardiopulmonary bypass, Keith et al. (2002) opted for a more traditional group-level analysis of change (the mixed factor analysis of variance). They cited several limitations of the individual-level analytic techniques such as the RCI. In this commentary, the author attempts to address these specific concerns as well as some of the more general difficulties presented by the analysis of cognitive change. Advantages and disadvantages of the RCI and SRB methods are discussed.     

Reliable change scores and their relation to perceived change in memory: implications for the diagnosis of mild cognitive impairment.

The relation between the subjective report of memory problems and objective evidence of the same has been debated with mixed results appearing in the literature. Less is known about the relation between objective change in test performance and the perceptions of cognitive change from family members/friends and trained clinicians. These relations were explored using 5-year longitudinal data from the population-based Canadian Study of Health and Aging. Statistically reliable deterioration in memory test performance was determined using a standardized regression-based (SRB) approach and a Reliable Change Index (RCI) that accounts for aging and practice effects. Among a subsample of persons with no cognitive impairment (NCI) at baseline, there was a moderate relation between reliable test score decline and ratings made by clinicians and informants. No relation, however, was found with the subjective reports of memory difficulties. These findings hold implications for current mild cognitive impairment (MCI) criteria which include subjective, informant and/or clinician ratings of cognitive decline.     

Clinical Versus Reliable and Significant Change

Sheldrick, Kendall, and Heimberg have illustrated and compared the use of the reliable change index (RCI) and normative comparisons procedures for assessing the clinical meaningfulness of research findings. Their presentation illustrates how the method of normative comparisons, combined with a reliability of change index such as that offered by Jacobson and colleagues can be used to assess the clinical meaningfulness of treatments. Their comparisons of treatments that have been previously identified as empirically supported reveal that a definition of worth, based on statistical significance, fails to identify the power (or lack thereof) of the intervention. Reliable change and clinical meaningful change estimates add substantially to the interpretation of statistical significance. However, they are complementary, not equivalent methods. The RCI can only indicate whether the change noted exceeds what can be expected because of the unreliability of the instrument used. Although estimates of clinical utility should be routine in research reports of treatment effects wherever possible, there are still situations in which procedures for estimating clinical significance are lacking, and new methods are needed in these instances.     

Creating hospital-specific customized clinical pathways by applying semantic reasoning to clinical data

ObjectiveClinical pathways (CPs) are widely studied methods to standardize clinical intervention and improve medical quality. However, standard care plans defined in current CPs are too general to execute in a practical healthcare environment. The purpose of this study was to create hospital-specific personalized CPs by explicitly expressing and replenishing the general knowledge of CPs by applying semantic analysis and reasoning to historical clinical data.MethodsA semantic data model was constructed to semantically store clinical data. After querying semantic clinical data, treatment procedures were extracted. Four properties were self-defined for local ontology construction and semantic transformation, and three Jena rules were proposed to achieve error correction and pathway order recognition. Semantic reasoning was utilized to establish the relationship between data orders and pathway orders.ResultsA clinical pathway for deviated nasal septum was used as an example to illustrate how to combine standard care plans and practical treatment procedures. A group of 224 patients with 11,473 orders was transformed to a semantic data model, which was stored in RDF format. Long term order processing and error correction made the treatment procedures more consistent with clinical practice. The percentage of each pathway order with different probabilities was calculated to declare the commonality between the standard care plans and practical treatment procedures. Detailed treatment procedures with pathway orders, deduced pathway orders, and orders with probability greater than 80% were provided to efficiently customize the CPs.ConclusionsThis study contributes to the practical application of pathway specifications recommended by the Ministry of Health of China and provides a generic framework for the hospital-specific customization of standard care plans defined by CPs or clinical guidelines.     

老年病人的术后认知功能障碍

术后认知功能障碍（POCD）定义为术后通过反复多次神经心理测试,患者的基本认知功能出现不同程度的损害。而早期术后认知功能及精神障碍更多见于老年患者。虽然POCD多见于心脏手术术后，但非心脏手术后发生POCD亦不少见，老年患者（年龄大于65岁）行心脏手术或非心脏手术，术后1周POCD的发生率分别为50%及26%。POCD的高危因素包括：高龄、术前认知受损以及酗酒等。POCD影响生活质量，加重社会负担并干扰药物治疗效果，延长患者住院周期。有必要深入的研究POCD的病因和神经功能保护的策略。     

Relationship between perioperative inflammatory response and postoperative cognitive dysfunction in the elderly

After surgery and anesthesia, many elderly patients show a decline in cognitive function. This condition is called postoperative cognitive dysfunction (POCD). POCD, a distressing complication after surgery, is independently associated with poor short-term and long-term outcomes. Many pathophysiological mechanisms have been implicated in development of POCD, but the exact cascade leading to its development is unclear. Animal studies show that cytokines from inflammatory response are involved in with cognitive dysfunction. Simultaneously, emerging evidences indicate that inflammatory response represents a potential pathogenic factor in many central cognitive diseases. A similar story may be occurring during perioperative process in patients. Surgical trauma, anesthesia, and stress response induced perioperative nonspecific inflammatory response. We hypothesize that perioperative inflammatory response promotes the development of POCD in elderly surgical patients, and some measures against perioperative inflammatory response should be considered as a new pathway to prevention of POCD.     

Calculating clinically significant change in postnatal depression studies using the Edinburgh Postnatal Depression Scale

BACKGROUND: Statistical significance between test scores can sometimes be obtained even when the actual difference between the scores is very small. Because of this researchers have recommended that clinical significance also be calculated when reporting results of interventions. The calculation of clinical significance between scores on a particular test takes into account the reliability of the test, as well as normative data from clinical and non-clinical samples. Jacobson and Truax (1991) describe the calculation of the Reliable Change Index (RCI) as a method of calculating this clinical significance. RESULT: The RCI for the Edinburgh Postnatal Depression Scale (EPDS) is calculated to be four points. This is the size of difference between two scores which is needed for a clinician to be 95% confident that this change reflects a real change in the individual's mood, and is not likely to be due to measurement error. Using the accepted EPDS cut-off score of 12/13 for major depression (English-speaking women), examples are given of the clinical significance classification of individual's pre-post EPDS scores. A further example of reporting both statistical significance and clinical significance on the EPDS scores of 23 women is given, highlighting the improved information that is obtained when this clinical significance is calculated. CLINICAL IMPLICATIONS: Statistical significance allows the interpretation of whether women 'on average' improve more in one condition than another. Clinical significance allows the further interpretation of how many women show improvement in each condition. This improvement can be categorised into those who recover, those who improve but are still in the distressed range, those who show no reliable change in their EPDS score, and those who deteriorate. Calculating clinical significance, using the reliable change index and cut-off classification, therefore adds to our understanding of the impact of postnatal depression treatment studies.     

Narcotrend监测下麻醉深度对老年患者胃肠道肿瘤手术后认知功能障碍的影响

目的:探讨镇静深度监测系统Narcotrend(NT)监测下麻醉深度与局部脑氧饱和度(regional cerebral oxygen saturation, rSO2)的相关性,及其在预测老年胃肠道肿瘤患者术后认知功能障碍(post-operative cognitive dysfunction, POCD)的价值。方法:按照纳入标准择取2018年6月~2019年6月在安徽医科大学附属安庆医院行胃肠道肿瘤择期手术的老年患者90名,患者术中行NT监测麻醉深度,采用近红外光谱仪持续监测rSO2。分别采集患者术前1 d、手术结束时和术后24 h的外周血,ELISA法检测血浆中S100β和白细胞介素6(interleukin-6, IL-6)的表达变化。采用简易智力状况检测法(mini-mental state examination, MMSE)评估患者术后24 h的认知功能。结果:术后24 h共有25例患者被诊断为POCD,POCD患者术中Narcotrend指数(Narcotrend index, NTI)<35的时间显著高于非POCD组(P<0.05)。POCD患者术中ΔrSO2>13%和rSO2<55%的时间均显著高于非POCD组,术中NTI<35的时间与ΔrSO2>13%时间具有显著相关性(r=0.62,95%CI=0.35~0.89,P=0.004)。POCD患者外周血中S100β浓度显著高于非POCD组(P<0.05),但两组之间IL-6含量无明显差异。结论:深麻醉可能加剧老年患者术中脑内氧供需失衡,进而造成中枢神经系统的损伤。Narcotrend监测下合理调控麻醉深度可能有助于预防术后认知功能障碍的发生。     

Intact ability to learn internal models of arm dynamics in Huntington's disease but not cerebellar degeneration

Two different compensatory mechanisms are engaged when the nervous system senses errors during a reaching movement. First, on-line feedback control mechanisms produce in-flight corrections to reduce errors in the on-going movement. Second, these errors modify the internal model with which the motor plan is transformed into motor commands for the subsequent movements. What are the neural mechanisms of these compensatory systems? In a previous study, we reported that while on-line error correction was disturbed in patients with Huntington's disease (HD), it was largely intact in patients with cerebellar degeneration. Here we altered dynamics of reaching and studied the effect of error in one trial on the motor commands that initiated the subsequent trial. We observed that in patients with cerebellar degeneration, motor commands changed from trial-to-trial by an amount that was comparable to control subjects. However, these changes were random and were uninformed by the error in the preceding trial. In contrast, the change in motor commands of HD patients was strongly related to the error in the preceding trial. This error-dependent change had a sensitivity that was comparable to healthy controls. As a result, HD patients exhibited no significant deficits in adapting to novel arm dynamics, whereas cerebellar subjects were profoundly impaired. These results demonstrate a double dissociation between on-line and trial-to-trial error correction suggesting that these compensatory mechanisms have distinct neural bases that can be differentially affected by disease.     

An analytical approach to quantify uniformity artifacts for circular and noncircular detector motion in single photon emission computed tomography imaging

Uniformity artifacts in rotating gamma camera tomography will result if there are errors in the correction factors which are routinely calculated from a static uniformity flood image. The accuracy of the correction factors is a function of the statistics in the collected flood image. Since the factors are applied to each projection view, an error in a correction factor will propagate as a projection error at the same pixel location for each view. For circular detector motion, the error in each projection is reconstructed as a ring whose maximum amplitude varies approximately inversely proportional to the square root of the distance of the projection error from the center of rotation. For noncircular detector motion the artifacts are not rings but are more complicated geometric curves. Simulations show that statistical fluctuations in the reconstructed image will mask the uniformity artifacts provided the correction flood satisfies minimum count requirements. An analytical expression is derived for the percent root-mean-square (% rms) error in the reconstruction and is compared with the percent relative amplitude error (% RAE) of the reconstructed artifacts in order to obtain expressions for uniformity flood counting statistics. For an elliptical source distribution with total counts equal to CT, the uniformity statistics required to reconstruct elliptical disks is inversely proportional to the square root of the area: U greater than or equal to KCT/area 1/2. The constant K depends on the filter function and type of detector motion.     

Uncomplicated general anesthesia in the elderly results in cognitive decline: Does cognitive decline predict morbidity and mortality?

Elderly surgical patients constitute a unique surgical group. They require special consideration in order to preempt the long term adverse effects of anesthesia. This paper examines the proposition that general anesthesia causes harm to elderly patients with its impact being felt long after the anesthetic agents are cleared from the body. One complication, Postoperative Cognitive Decline (POCD), is associated with the administration of anesthesia and deep sedation. Its' occurrence may herald an increase in morbidity and mortality. Based on both human and animal data, this paper outlines a unitary theoretical framework to explain these phenomena. If this hypothesis proves to be correct, anesthesiologist should consider regional rather than general anesthesia for equivalent surgical procedures to reduce POCD and consequently achieving superior patient outcome.     

Minocycline may be useful to prevent/treat postoperative cognitive decline in elderly patients

Postoperative cognitive dysfunction (POCD) is reported to occur frequently after all types especially cardiac surgery in elderly patients. It can be short-term or long-term and some cases even develop into Alzheimer's disease (AD). Although multi-risk factors associated with POCD have been identified, the etiology and pathophysiological mechanisms of this surgical complication remain elusive. Therefore, developing strategies for preventing or treating POCD is still challenging. However, increasing evidence suggests that central and systemic inflammation triggered by surgery likely plays a fundamental role in POCD developing and progression. Minocycline, a tetracycline derivative with anti-inflammatory properties, has been shown to be effective in treating neuroinflammatory related conditions or neurodegenerative diseases such as AD, Parkinson's disease, Huntington's disease. Considering that inflammation may be a potential factor of POCD and minocycline is effective in improving cognitive dysfunction induced by inflammation, we hypothesize that minocycline may be useful to treat/prevent the POCD development after surgery in elderly patients.     

阈值校正方式对PET脑显像统计参数图分析显示结果的影响

目的 探讨各种阈值校正方法对统计参数图(SPM)软件统计比较结果显示的影响.方法 利用Hoffman标准脑模型制作缺损模型PET成像与正常模型PET成像,进行统计参数图的统计比较.并选取脑梗死患者与健康检查者进行统计参数图的统计比较.结果 校正与非校正产生的结果有差异,其中族错误率(FWE)校正(P=5×10-2)得到的统计分析结果激活区最少及最小,其次是错误发现率(FDR)校正(P=5×10-2),非校正方式(P=1×10-3)得到的激活区最多及最大.但FDR校正效果不稳定,有时不如不校正.结论 统计参数图软件中FWE校正方法可明显降低假阳性,得到的结果可信度稳定地高于非校正方法.