Strategies for improving comorbidity measures based on Medicare and Medicaid claims data

Claims-based measures of comorbid illness severity have generally relied on the diagnoses listed for a single hospitalization. Unfortunately, such diagnostic information is often limited because patients have not been hospitalized during periods of interest, because of incomplete coding of diagnoses on claims forms, or because listed diagnoses represent complications of the hospitalization rather than pre-existing comorbid conditions. To address these limitations, we developed and tested four comorbidity index scores for patients with breast cancer, each based on different sources of health services claims from Medicare and Medicaid: hospitalization for breast cancer surgery; outpatient care prior to the hospitalization; other inpatient care prior to the hospitalization; and all sources combined. Varying the number and type of sources of diagnostic information yielded only very small improvements in the prediction of mortality at 1 and 3 years. Surprisingly, even simpler measures of comorbidity (crude number of diagnoses) and of prior health care utilization (total days spent in the hospital) performed at least as well in predicting mortality as did the more complex index scores which assigned points and weights for specific conditions. The greatest improvement in explanatory power was observed when another source of clinical information (cancer stage derived from a population-based cancer registry) was used to supplement claims information. Expanding the source of claims diagnoses and focusing on time periods prior to an index hospitalization are insufficient for substantially improving the explanatory power of claims-based comorbidity indices. Other improvements suggested by our results should include: increasing the completeness and accuracy of claims diagnoses; supplementing diagnoses with health care utilization information in claims data; and supplementing claims data with other sources of clinical information.     

人内耳显微结构的计算机三维重建

目的：建立一套人类耳蜗组织放大40倍的显微结构图像资料,探讨基于PC平台的显微结构三维重建技术。方法：应用火棉胶切片技术获得人类颞骨组织连续切片,在显微镜下放大40倍后对耳蜗组织摄像;在个人计算机上使用Photoshop6．0图像处理软件和AMIRA3．0三维重建软件对内耳结构进行图像拼接、图像对位和图像三维重建。结果：建立了一套人类耳蜗组织放大40倍的完整显微结构图像资料。结论：建立了基于PC平台上实现显微结构三维重建的一套办法。三维重建效果表明我们在显微结构的数据输入、图像拼接、内定位技术、三维重建的方法是可行的。     

Trunk muscle cocontraction: the effects of moment direction and moment magnitude.

This study investigated the cocontraction of eight trunk muscles during the application of asymmetric loads to the torso. External moments of 10, 20, 30, 40, and 50 Nm were applied to the torso via a harness system. The direction of the applied moment was varied by 30 degrees increments to the subjects' right side between the sagittally symmetric orientations front and rear. Electromyographic (EMG) data from the left and right latissimus dorsi, erector spinae, external oblique, and rectus abdominus were collected from 10 subjects. The normalized EMG data were tested using multivariate and univariate analyses of variance procedures. These analyses showed significant interactions between the moment magnitude and the moment direction for seven of the eight muscles. Most of the interactions could be characterized as due to changes in muscle recruitment with changes in the direction of the external moment. Analysis of the relative activation levels, which were computed for each combination of moment magnitude and direction, indicated large changes in muscle recruitment due to asymmetry, but only small adjustments in the relative activation levels due to increased moment magnitude.     

The heterogeneity of schizoaffective disorder: implications for treatment

Until the 1970s, schizophrenia tended to be broadly defined in the United States, and the diagnosis subsumed patients who had affective as well as schizophrenic symptoms. With the introduction of lithium, however, manic-depressive illness became susceptible to treatment and gained attractiveness as a diagnosis. The ambiguous position of patients with schizoaffective disorder became clear. Cross-sectionally they were seen to resemble schizophrenic patients, but longitudinally they were more akin to patients with affective disorder. Numerous studies have attempted to establish that they are diagnostically distinct, but without clear results. The authors suggest that schizoaffective disorder is heterogeneous and that its treatment should be determined by specific indices as to its subtype.     

铜、锌超氧化物歧化酶的实验研究

用碘标记超氧化物歧化酶(~(125)I-SOD)示踪研究牛SOD对RBC膜和实验性小鼠胃溃疡的保护效应。Iodogen固相法~(125)I标记SOD示踪结果表明,~(125)I-SOD经胃肠道能很快被吸收入血,分布于多种脏器,以肾放射性居首位.RBC放射性占全血18.2％(峰值相),血浆结合型放射性仅占12.5％,大部分~(125)I-SOD被解离脱~(125)I。RBC经外源O_2~-自由基的作用证明,SOD有明显抑制O_2~-对RBC膜的氧化损伤作用,并随SOD量增加,其抑制效应亦趋显著.SOD对IM-HCI诱发小鼠胃溃疡的影响,也表现有抑制和保护作用。接受SOD治疗组,粘膜脂质过氧化受抑制,病理变化减轻。     

Reliability and concordance in the subtyping of schizophrenia

The authors examined the reliability, frequency, concordance, and demographic characteristics of subtypes of schizophrenia in patients from the Iowa 500 study as defined by four major diagnostic systems: DSM-III, Research Diagnostic Criteria (RDC), ICD-9, and the Tsuang-Winokur criteria. Reliability was higher in diagnostic systems with operationalized than in those with unoperationalized criteria and consistently higher for the paranoid subtype. The frequency of individual subtypes varied widely for the different systems. Concordance for subtype diagnoses between systems ranged from quite high to quite low. Demographic characteristics of the individual subtypes were similar according to all systems.     

Are there sex differences in the long-term outcome of schizophrenia? Comparisons with mania, depression, and surgical controls

Female schizophrenics have been reported to have a better prognosis than male schizophrenics. However, earlier reports rarely used either operational criteria for schizophrenia or appropriate comparison groups. Using data collected as part of a long-term follow-up and family study, the authors examined outcome by sex of 186 schizophrenics, 212 depressives, 86 manics, and 145 surgical controls. When the authors controlled for differences in the age and sex distributions of the diagnostic groups, sex did not make a significant contribution to the explanation of outcome differences between diagnoses or within diagnoses. Examination of outcomes within diagnoses revealed only a nonsignificant trend for female manics to have a better long-term outcome than male manics.     

A family-genetic study of girls with DSM-III attention deficit disorder

OBJECTIVE: The authors evaluated family-genetic risk factors in girls with attention deficit disorder and compared these results to findings in the authors' previous study of boys with attention deficit disorder. METHOD: Twenty-one girls with attention deficit disorder and 20 normal comparison girls were consecutively ascertained from a pool of existing and new referrals from a pediatric psychopharmacology unit and a medical pediatric unit of the same urban hospital. First-degree relatives of the attention deficit disordered girls (N = 69) and of the normal girls (N = 71) were also assessed. Both groups of girls and their relatives were evaluated on the basis of structured diagnostic interviews conducted by raters who were blind to the clinical status of the probands. RESULTS: The relatives of the girls with attention deficit disorder had higher risks for attention deficit disorder, antisocial disorders, major depression, and anxiety disorders. The higher risk for attention deficit disorder could not be accounted for by gender or generation of relative, age of proband, social class, or family intactness. These findings are highly consistent with the findings in the authors' previous study of boys with attention deficit disorder, which was conducted with identical methods. CONCLUSIONS: This study provides further support for the validity of the diagnosis of attention deficit disorder in girls and suggests that the genders share a common biological substrate.     

Outcome after 40 years in DSM-III schizophreniform disorder

In an earlier report, we described the course of the index episode and the family history of patients with schizophreniform disorder, schizophrenia, or affective disorder. Those data indicated that DSM-III schizophreniform disorder defined a heterogeneous group that bore a closer relationship to schizophrenia than to affective disorder. The present report extends the study of these same patients to a 40-year field follow-up. As the earlier short-term and family history findings predicted, marital, occupational, mental, and residential status ratings for the schizophreniform group assumed intermediate positions between those for patients with affective disorder and those for schizophrenics but fell closer to the latter. Contrary to the short-term outcome findings, the present data show no relationship between illness duration at index admission and outcome status ratings after 40 years.     

Effects of smoking on nortriptyline plasma concentrations in depressed patients

The pharmacokinetic parameters of half-life, volume of distribution, and steady-state nortriptyline plasma concentration normalized to a 100-mg/day maintenance dose were calculated in nine smokers and 15 nonsmokers. The mean normalized total nortriptyline concentration for the smokers of 118 +/- 33 ng/ml was significantly lower than the nonsmokers' mean value of 158 +/- 35 ng/ml. The mean normalized free plasma concentrations for the smokers of 11.4 +/- 3.5 ng/ml was not different from the nonsmokers' mean concentrations of 11.5 +/- 2.6 ng/ml. The smokers had a slightly higher percentage free drug values of 10.2 +/- 4.0% (p = 0.08) as contrasted to 7.4 +/- 1.5% free nortriptyline for the nonsmokers. The nortriptyline half-life figures for both the free and total drug concentrations did not differ. Multiple linear regression analysis utilizing age, smoking status, sex, liver function, and the presence or absence of enzyme-inducing or -inhibiting drugs as the potential independent variables and percentage free nortriptyline or total nortriptyline concentration as the dependent variable, found that smoking status explained 21% of the variation in the percentage free nortriptyline in the patients and 26% of the variation in the total nortriptyline concentrations. These preliminary data suggest that smokers ideally should be dosed at the lower end of the nortriptyline therapeutic range, whereas nonsmokers should be dosed at the upper end to maximize the antidepressant effect and minimize adverse effects.