Testing a Measurement Model of Acute Dyspnea

描述（由申请人提供）：没有现有的呼吸困难测量侧重于患者在呼吸困难的强度、感觉质量和痛苦方面的感知，并且没有一个在理论上或心理测量学上适合于急性护理环境中呼吸困难的系列评估。本非实验研究的目的是在心力衰竭（HF）住院患者中验证一种呼吸困难测量模型，该模型来源于对急诊科加重慢性阻塞性肺疾病（COPD）患者呼吸困难的初步研究。该研究的具体目的是：(1)在心衰患者中验证一种以临床为重点的呼吸困难强度和感觉质量的急性变化测量模型，该模型足够简单，可以在急性护理环境中用于临床；(2)通过评估呼吸困难评分与(a)患者对变化的主观总体估计（过渡评分）和(b)在同一时间间隔内临床状况变化标记（即体重、护理水平或62要求的变化）的评分差异来评估评分量表或由模型衍生的量表的反应性。研究假设是：(1)单一的三到五个因素测量模型将适用于心衰患者和COPD患者，(2)从模型中得出的一个或多个评分将对心衰患者的病情变化和自我报告的变化（过渡评分）做出反应。在为期2年的研究中，将招募200名心衰住院患者作为样本。参与者将被要求完成每日呼吸困难问卷，并连续三天进行床边高温测量（第一秒用力肺活量和用力呼气量）；在研究开始和结束时分析b型利钠肽（BNP）。探索性分析将检查呼吸困难、强度或感觉质量的变化在多大程度上与研究期间肺活量测定或BNP值的变化相关。测量模型包括三到五个感官品质因子。验证性因子分析在结构方程建模的背景下，将被用来检验模型。这些方法支持相对于模型的内部有效性和构造有效性。如果该模型在该患者群体中是有效的，而该患者群体与导出该模型的人群不同，则外部有效性将得到支持，并且单一测量方法可能在诊断中是有效的和响应的。如果该模型在心衰患者中没有得到充分的支持，则意味着需要开发特定的测量模型和量表来测量不同诊断的患者的呼吸困难。该研究旨在通过提高结构效度、对变化的反应性和呼吸困难感觉质量、强度和痛苦的急性变化的外部效度，从而开发一种简短的多维呼吸困难评分，最大限度地减少当前呼吸困难措施的局限性。

DESCRIPTION (provided by applicant): No existing dyspnea measure is focused on what patients perceive in terms of intensity, sensory quality, and distress of dyspnea, and none is theoretically or psychometrically suitable for serial assessment of dyspnea in acute care settings. The purpose of this nonexperimental study is to validate, among inpatients with heart failure (HF), a dyspnea measurement model derived from a preliminary study of dyspnea in emergency department patients with exacerbated chronic obstructive pulmonary disease (COPD). Specific aims for the study are: (1) To validate among patients with HF a clinically focused measurement model of acute changes in dyspnea intensity and sensory quality that is simple enough to be clinically useful in acute care settings; and (2) To assess responsiveness of a rating scale or scales derived from the model by evaluating score differences in dyspnea ratings against (a) patients' subjective global estimates of change (transition ratings) and (b) markers of change in clinical condition over the same interval (i.e., changes in weight, level of care, or 62 requirements). Study hypotheses are: (1) a single three to five factor measurement model will apply as well to patients with HF as to patients with COPD, and (2) a rating or ratings derived from the model will be responsive to changes in condition and self-reported change (transition ratings) in patient with HF. A sample of 200 inpatients with HF will be recruited over the 2 years of the study. Participants will be asked to complete a daily dyspnea questionnaire and perform bedside pyrometer (forced vital capacity and forced expiratory volume in the 1st sec) on three consecutive days; b-type natriuretic peptide (BNP) will be analyzed at study entry and exit. Exploratory analyses will examine the degree to which changes in dyspnea distress, intensity, or sensory quality are associated with changes in spirometry or BNP values over the study interval. The measurement model comprises three to five sensory quality factors. Confirmatory factor analysis in the context of structural equation modeling will be used to test the model. These methods support internal and construct validity with respect to the model. If the model is valid in this patient population, which is distinct from the population in which it was derived, external validity will be supported, and a single measurement approach may be valid and responsive across diagnoses (i.e.,. If the model is not adequately supported in patients with HF, it would imply that specific measurement models and scales need to be developed for measuring dyspnea in patients of different diagnoses. The study is expected to lead to development of a brief multidimensional dyspnea rating that minimizes limitations of current dyspnea measures by enhancing construct validity, responsiveness to change, and external validity with respect to acute changes in dyspnea sensory quality, intensity, and distress.