Measuring asthma patient satisfaction in Sweden using partial least squares

Examines the relationships between different aspects involved in asthma treatment. Analyses each aspect's impact on overall patient satisfaction with asthma treatment. Also studies how outcome variables such as compliance with physician's recommendations, health-related quality of life and resource use are affected by the degree of patient satisfaction. The results refer to asthma patients as a group but not necessarily to each patient as an individual. The statistical technique applied for this analysis is partial least squares. Tests the suggested generic model on 599 respondents from a questionnaire survey. The structure of the suggested model is well supported by the data.     

Prognostic factors affecting survival in multiple myeloma

70 patients suffering from multiple myeloma were observed by authors in the last 15 years and three months. In the meantime fifty-two out of them have died, and 18 patients are under permanent care. 43 IgG, 17 IgA, 6 Bence-Jones, 2 IgD types were diagnosed according to the paraprotein distribution, one patient proved to be nonsecretory, and an other one to osteosclerotic form as well. The median survival time was 27 months in the group of deceased patients. In the group followed-up 50.8 months survival time was observed up to the closing of the study. Several prognostic factors were investigated. According to the classification by Durie and Salmon the survival time was 60 months in the patients with stage I, 33 months in stage II., and 9 months in stage III respectively. The prognosis is much poorer in patients into the "B" category: the survival time was 14 months. Classified in the basis of the type of the myeloma-cell, the cases with well matured cells have had the best prognosis with survival time of 46 months, while the most unfavourable prognosis was observed in patients with blast-cell type, with a median survival time of 10 months. The greatest number of patients suffered from multiple myeloma of IgG paraprotein type, in this group the serum IgA level was found to be significantly decreased in the patients died due to inevitable infections. The survival was injured significantly by the occurrence of concomitant severe diseases, to.(ABSTRACT TRUNCATED AT 250 WORDS)     

Addressing the identification problem in age-period-cohort analysis: a tutorial on the use of partial least squares and principal components analysis

In the analysis of trends in health outcomes, an ongoing issue is how to separate and estimate the effects of age, period, and cohort. As these 3 variables are perfectly collinear by definition, regression coefficients in a general linear model are not unique. In this tutorial, we review why identification is a problem, and how this problem may be tackled using partial least squares and principal components regression analyses. Both methods produce regression coefficients that fulfill the same collinearity constraint as the variables age, period, and cohort. We show that, because the constraint imposed by partial least squares and principal components regression is inherent in the mathematical relation among the 3 variables, this leads to more interpretable results. We use one dataset from a Taiwanese health-screening program to illustrate how to use partial least squares regression to analyze the trends in body heights with 3 continuous variables for age, period, and cohort. We then use another dataset of hepatocellular carcinoma mortality rates for Taiwanese men to illustrate how to use partial least squares regression to analyze tables with aggregated data. We use the second dataset to show the relation between the intrinsic estimator, a recently proposed method for the age-period-cohort analysis, and partial least squares regression. We also show that the inclusion of all indicator variables provides a more consistent approach. R code for our analyses is provided in the eAppendix.     

A multiple myeloma long term survival case

Multiple myeloma is a malignant plasma cells proliferation in the bone marrow leading to a monoclonal immunoglobulin hypersecretion. The survival duration of this disease ranges usually from 2 to 3 years. However, as this reported case, a long-term survival remains possible. A 29 year old woman was admitted to the internal medicine department for bone pain, weight loss and pathologic fractures. The clinical examination revealed an anaemia, a spinal compression (D10) and atrophia of quadriceps and gluteus muscle. The radiologic findings observed were multiple fractures. The bone marrow aspiration confirmed the plasmocytosis greater than 50%, with immature plasma cells and other lineages rarefication. The disease belonged to the stage III A of the Salmon and Durie classification. Chemotherapy with melphalan associated to prednisone was started with a two to three months biological and clinical follow-up. This treatment allowed 12 years survival. Because of this variety, the search for new prognostic factors would be relevant.     

Patient-reported outcomes as predictors of 10-year survival in women after acute myocardial infarction

Background  

Patient-reported outcomes are increasingly seen as complementary to biomedical measures. However, their prognostic importance has yet to be established, particularly in female long-term myocardial infarction (MI) survivors. We aimed to determine whether 10-year survival in older women after MI relates to patient-reported outcomes, and to compare their survival with that of the general female population.     

Gain in efficiency from using generalized least squares in the Haseman-Elston test

Techniques that test for linkage between a marker and a trait locus based on the regression methods proposed by Haseman and Elston [1972] involve testing a null hypothesis of no linkage by examination of the regression coefficient. Modified Haseman-Elston methods accomplish this using ordinary least squares (OLS), weighted least squares (WLS), in which weights are reciprocals of estimated variances, and generalized estimating equations (GEE). Methods implementing the WLS and GEE currently use a diagonal covariance matrix, thus incorrectly treating the squared trait differences of two sib pairs within a family as uncorrelated. Correctly specifying the correlations between sib pairs in a family yields the best linear unbiased estimator of the regression coefficient [Scheffe, 1959]. This estimator will be referred to as the generalized least squares (GLS) estimator. We determined the null variance of the GLS estimator and the null variance of the WLS/OLS estimator. The correct null variance of the WLS/OLS estimate of the Haseman-Elston (H-E) regression coefficient may be either larger or smaller than the variance of the WLS/OLS estimate calculated assuming that the squared sib-pair differences are uncorrelated. For a fully informative marker locus, the gain in efficiency using GLS rather than WLS/OLS under the null hypothesis is approximately 11% in a large multifamily study with three siblings per family and 25% for families with four siblings each. © 1995 Wiley-Liss, Inc.     

An in-depth discussion and illustration of partial least squares structural equation modeling in health care

Partial least squares structural equation modeling (PLS-SEM) has become more popular across many disciplines including health care. However, articles in health care often fail to discuss the choice of PLS-SEM and robustness testing is not undertaken. This article presents the steps to be followed in a thorough PLS-SEM analysis, and includes a conceptual comparison of PLS-SEM with the more traditional covariance-based structural equation modeling (CB-SEM) to enable health care researchers and policy makers make appropriate choices. PLS-SEM allows for critical exploratory research to lay the groundwork for follow-up studies using methods with stricter assumptions. The PLS-SEM analysis is illustrated in the context of residential aged care networks combining low-level and high-level care. Based on the illustrative setting, low-level care does not make a significant contribution to the overall quality of care in residential aged care networks. The article provides key references from outside the health care literature that are often overlooked by health care articles. Choosing between PLS-SEM and CB-SEM should be based on data characteristics, sample size, the types and numbers of latent constructs modelled, and the nature of the underlying theory (exploratory versus advanced). PLS-SEM can become an indispensable tool for managers, policy makers and regulators in the health care sector.     

Patient-reported outcomes as predictors of survival in patients with bowel cancer: a systematic review

Quality of Life Research - The prognostic value of patient-reported outcomes (PROs) has been determined in some cancers, but a focussed review in colorectal cancer (CRC) has not yet been conducted....     

Understanding neural networks using regression trees: an application to multiple myeloma survival data

Neural networks are becoming very popular tools for analysing data. It is however quite difficult to understand the neural network output in terms of the original covariates or input variables. In this paper we provide, using readily available software, an easy way of understanding the output of the neural network using regression trees. We focus on the problem in the context of censored survival data for patients with multiple myeloma, where identifying groups of patients with different prognosis is an important aspect of clinical studies. The use of regression trees to help understand neural networks can be easily applied to uncensored situations.     

Single index of multimorbidity did not predict multiple outcomes

BACKGROUND AND OBJECTIVES: Measurement of multimorbidity and comorbidity is important in epidemiologic and health services research. The aim of this research was to derive a generic multimorbidity index based on patient self-report, incorporating severity, for predicting a range of outcomes. METHODS: The dataset was obtained from a trial including 1,541 Veterans and war widows aged 70 years and over. The survey included sociodemographics, hospital admissions, SF-36, and information on deaths was obtained. The methods of Charlson were used to derive Multimorbidity Indices. RESULTS: All indices predicted quality of life, with decreasing quality of life for each increase in multimorbidity category. Multimorbidity scores incorporating severity significantly contributed to the prediction of mortality, hospital admission, and follow-up quality of life, regardless of adjustment for baseline quality of life. CONCLUSIONS: Our results indicate that a single index cannot predict a variety of relevant outcomes. Consequently, research undertaken to assess the impact of intervention or illness on health outcomes should use an index that is valid for predicting the specific outcome of interest.     

67例多发性骨髓瘤患者尿蛋白分析

目的:检测多发性骨髓瘤( MM)患者尿蛋白及其肾功能相关指标,以探讨尿蛋白是否能作为肾脏早期损伤最灵敏的 诊断指标.方法:对 67例 MM患者在诊断时进行尿蛋白测定,然后分别测定尿蛋白阳性结果、阴性结果两组患者的 血清免疫球蛋白、肌肝、尿素、白蛋白、血钙.结果:肾功能不良的 MM患者,用血清指标(肌肝、尿素)评估只有 19例 (28.3% ),而用尿蛋白评估是 46例 (68.7% ).大多数 IgG型(占总体 IgG69.7%)和所有的轻链型 MM患者中尿蛋白 阳性.在尿蛋白阳性和尿蛋白阴性患者的生化结果对比分析中,发现血清肌肝 (P<0.01),尿素 (P<0.001)、β 2-微 球蛋白 (P<0.05).白蛋白 (P<0.05)在两类 MM患者之间有显著差异,没有发现血清钙有显著差异( P>0.05).结 论:尿蛋白比其他生化指标能更好地识别早期阶段的肾损伤,是 MM患者肾损伤灵敏的诊断指标.     

多发性骨髓瘤合并HBV感染的临床分析

目的探讨多发性骨髓瘤合并乙型肝炎病毒(HBV)感染的临床特点。方法选择2010年1月-2016年12月医院多发性骨髓瘤患者250例作为多发性骨髓瘤组,体检者250名作为对照组,多发性骨髓瘤患者根据HBsAg是否阳性分为HBsAg阳性患者22例和HBsAg阴性患者228例;测定HBsAg阳性与阴性患者血清肝炎病毒标记物。结果多发性骨髓瘤组HBsAg阳性率为8.8%,高于对照组的2.8%(P<0.05);多发性骨髓瘤患者中,HBsAg阳性患者肝硬化率高于HBsAg阴性患者(P<0.05);HBsAg阳性患者治疗前、治疗中和治疗后肝损伤比例均高于HBsAg阴性患者(P<0.05);HBsAg阳性患者HBV再激活率高于HBsAg阴性患者(P<0.05)。结论多发性骨髓瘤患者HBsAg阳性率高,多发性骨髓瘤合并HBsAg阳性患者肝硬化、治疗前后肝损伤及HBV再激活率均升高。     

Patient-reported outcomes in rehabilitation research: instruments and current developments in Germany

Monitoring the health status of patients has become a major activity in rehabilitation research in recent years. As a result, various self-assessment instruments have been developed, adapted or improved with the aim of measuring patient-reported outcomes and predictors. Among these are international instruments, such as the NHP or the SF-36, as well as those developed in Germany, such as the IRES, the FREM-17 or the SPE-scale. Some of the widely used international instruments, such as the NHP and SF-36, have been translated into German for application in Germany. All of these instruments have been thoroughly tested and validated in several studies. Current trends in statistical methods (e.g. responsiveness, Rasch scaling) as well as classical test-theoretical standards were taken into consideration in the development of these instruments. In this article, we provide a comprehensive review of five important assessment fields of rehabilitation research in Germany: health-related quality of life (generic, disease-specific, children and adolescents, preference-based), evaluation of specific therapy and education programs, motivation, screening for vocational problems and screening for comorbid disorders. The questionnaires are critically discussed, and perspectives for further research are specified. Although assessment instruments as the IRES or the SF-36 are well-established in rehabilitation research studies, there is still a need for further research to determine the best choice of instruments for a given purpose. The limitations of the questionnaires with respect to health care studies are also discussed.     

202例多发性骨髓瘤医院感染临床分析

目的 探讨多发性骨髓瘤发生医院感染的临床特征,为临床提供指导以降低医院感染率.方法 回顾性分析202例多发性骨髓瘤患者发生医院感染率、感染部位、病原菌特点、感染发生与中性粒细胞及淋巴细胞数的关系.结果 多发性骨髓瘤患者发生医院感染率24.75％、例次感染率为40.59％;感染部位以呼吸道为主,占53.66％;检出病原菌革兰阴性杆菌占48.98％,以肺炎克雷伯菌为主,占12.24％;革兰阳性球菌占24.49％,以葡萄球菌属为主,占18.37％;真菌占26.53％,以白色假丝酵母菌为主,占18.37％;感染率与中性粒细胞计数呈负相关,淋巴细胞计数与感染发生率成反比.结论 多发性骨髓瘤极易引发医院感染,应将呼吸道感染的预防放在首位.     

Plasma electrolytes in multiple myeloma

The plasma cell myeloma (multiple myeloma, myelomatosis) is a progressive disease, characterized by bone marrow plasmacytomas and the presence of monoclonal antibodies (IgG, IgA, IgD, IgE), or free kappa or lambda immunoglobulin side chains. The monoclonal antibodies or Bence-Jones protein may precipitate in the tubuli and impair kidney function. In addition, the plasma protein concentration may increase at the expense of plasma water level causing unrealistically low electrolyte levels. Since the isoelectric points of immunoglobulins are higher than those of most other plasma proteins, the net charge of plasma proteins may change causing new electrolyte balance. In addition, some monoclonal antibodies are more hydrated than others, and their high concentration may cause not only increased plasma viscosity but further electrolyte imbalance. In the present work the relationship between plasma protein and electrolyte levels is studied in samples of 100 multiple myeloma patients.     

Patient-reported outcomes in non-muscle invasive bladder cancer: a mixed-methods systematic review

Quality of Life Research - Non-muscle invasive bladder cancer (NMIBC) is a chronic condition requiring repeated treatment and endoscopic examinations that can occur life-long. In this context,...     

Patient-reported outcomes in randomized clinical trials: development of ISOQOL reporting standards

Purpose

To develop expert consensus on a suite of reporting standards for HRQL outcomes of RCTs.

Methods

A Task Force of The International Society of Quality of Life Research (ISOQOL) undertook a systematic review of the literature to identify candidate reporting standards for HRQL in RCTs. Subsequently, a web-based survey was circulated to the ISOQOL membership. Respondents were asked to rate candidate standards on a 4-point Likert scale based on their perceived value in reporting studies in which HRQL was a study outcome (primary or secondary). Results were synthesized into draft reporting guidelines, which were further reviewed by the membership to inform the final guidance.

Results

Forty-six existing candidate standards for reporting HRQL results in RCTs were synthesized to produce a 40 item survey that was completed electronically by 161 respondents. The majority of respondents rated all 40 items to be either ‘essential’ or ‘desirable’ when HRQL was a primary RCT outcome. Ratings changed when HRQL was a secondary study outcome. Feedback on the survey findings resulted in the Task Force generalizing the guidance to include patient-reported outcomes (PROs). The final guidance, which recommends standards for use in reporting PROs generally, and more specifically, for PROs identified as primary study outcomes, was approved by the ISOQOL Board of Directors.

Conclusions

ISOQOL has developed a suite of recommended standards for reporting PRO results of RCTs. Improved reporting of PROs will enable accurate interpretation of evidence to inform patient choice, aid clinical decision making, and inform health policy.     

Bayesian analysis of survival on multiple time scales

We propose a Bayesian approach to the analysis of survival data on multiple time scales. Non-parametric modelling of variation of rates with more than one time scale is achieved using priors which specify smooth variation. Computations are conveniently carried out using Gibbs sampling. We discuss the extension of the method to Bayesian forecasting of rates. Numerical experience of two examples is described.