More data on major depression as an antecedent risk factor for first onset of chronic back pain

BACKGROUND: Few epidemiological studies have examined the temporal relationship between chronic pain and depression using longitudinal data. In the present study, we examined major depression as both an antecedent risk factor and consequence of chronic back pain (CBP) in the general population. METHOD: Data on 9909 pain-free individuals 15 years and older with no history of back problems were drawn from cycle 1 of the National Population Health Survey and followed up 24 months later. Major depression was assessed using a structured diagnostic interview. RESULTS: At cycle 2, the rate of new cases of CBP in persons who were depressed at cycle 1 was 3.6% compared to 1.1% in non-depressed persons. Compared to pain-free individuals, new cases of CBP were more likely to perceive their health status as poor or fair at cycle 1, were less likely to be working, reported more chronic health problems, and sustained a back or neck injury in the preceding 12 months. After controlling for other factors, pain-free individuals diagnosed as major depressed at cycle 1 were almost three times more likely (OR 2.9, 95% CI 1.2-7.0) to develop CBP at cycle 2. CONCLUSIONS: Consistent with other longitudinal studies major depression increases the risk of developing future chronic pain. The causal mechanism linking these conditions is unknown however depression may represent a modifiable risk factor in the development of CBP.     

Social relatedness and autism: current research, issues, directions

Social relatedness has recently become a primary focus of investigators in the field of autism. This shift to regarding disturbances in social relatedness as one of the defining manifestations of the disorder marks the movement of research on autistic disorder back to its origins, when Kanner first noted the "social and affective" symptoms of autism as pathognomonic. Currently, social impairment in autism is viewed as more pervasively characteristic of the disorder than any other single symptom. Further, there has been a recent proliferation of research designed to document the nature of social deficit in autism, and whether it is primarily affective, communicative, or cognitive in nature, or involves some combination of these three variables. This review summarizes recent research focusing on social relatedness in autism and discusses the implications of these findings.     

A clinical-severity staging system for patients with lung cancer

The prognostic staging of cancer in general, and lung cancer in particular, has customarily depended mainly on morphologic distinctions. The gross anatomic extensiveness of cancers is cited with TNM stages that describe the primary tumor (T), spread to regional lymph nodes (N), and metastatic dissemination (M) to distant sites. Microscopic characteristics are cited according to the cancer's cell type (e.g., adenocarcinoma, epidermoid carcinoma) and/or grade of differentiation (e.g., well differentiated, poorly differentiated, anaplastic). Although the clinical manifestations, functional effects, and associated co-morbidity of a cancer are universally recognized as having major prognostic importance, they have not been classified with a standard system of taxonomy. When considered at all, clinical phenomena have been cited with a surrogate index of "performance status" that ignores the underlying clinical dysfunctions while being greatly affected by non-clinical phenomena, such as the patient's psychic status, economic motivations, and system of social support. The current research was done to develop a standard system of taxonomy (or "staging") for the prognostic impact of clinical distinctions in patients with primary lung cancer. Appropriate data were obtained, computer-coded, and analyzed from medical records for the complete clinical course of an inception cohort of 1266 patients who were first treated at either the Yale-New Haven Hospital or the West Haven Veterans Administration Hospital during the interval January 1, 1953-December 31, 1964. The information under analysis included clinical phenomena as well as anatomic extensiveness (TNM stage), microscopic histology, the chronometric duration of the interval from the first symptom of lung cancer to zero time, the iatrotropic reason why the patient sought medical attention, the presence of anemia, the amount of customary cigarette use, and the conventional demographic data for age and gender. The main clinical phenomena were expressed in variables for symptom pattern severity, and co-morbidity. Symptom pattern referred to the existence of specific pulmonic symptoms (e.g., hemoptysis), systemic symptoms (e.g., complaint of weight loss), and metastatic symptoms that might be mediastinal (e.g., superior vena cava syndrome), regional (e.g., the Horner syndrome), or distantly metastatic (e.g., central nervous system). The symptom severity variable included the amount of weight loss, and the existence of severe dyspnea or particularly severe tumor effects (such as mental obtundation, rather than hemiparesis in patients with CNS metastasis). Prognostic co-morbidity was cited for coexisting diseases, such as recurrent myocardial infarctions, that might be more lethal than the lung cancer itself.(ABSTRACT TRUNCATED AT 400 WORDS)     

A comparison of multivariable mathematical methods for predicting survival--I. Introduction, rationale, and general strategy

This paper and the two following papers (Parts I-III) report an investigation of performance variability for four multivariable methods: discriminant function analysis, and linear, logistic, and Cox regression. Each method was examined for its performance in using the same independent variables to develop predictive models for survival of a large cohort of patients with lung cancer. The cogent biologic attributes of the patients had previously been divided into five ordinal stages having a strong prognostic gradient. With stratified random sampling, we prepared seven "generating" sets of data in which the five biologic stages were arranged in proportional, uniform, symmetrical unimodal, decreasing exponential, increasing exponential, U-shaped, or bi-modal distributions. Each of the multivariable methods was applied to each of the seven generating distributions, and the results were tested in a separate "challenge" set, which had not been included in any of the generating sets. The research was intended not merely to compare the performance of the multivariable methods, but also to see how their performance would be affected by different statistical distributions of the same cogent biologic attributes. The results, which are presented in the second and third papers, were compared for selection of independent variables and coefficients, and for accuracy in fitting the generating sets and the challenge set.     

High agreement but low kappa: II. Resolving the paradoxes

An omnibus index offers a single summary expression for a fourfold table of binary concordance among two observers. Among the available other omnibus indexes, none offers a satisfactory solution for the paradoxes that occur with p0 and kappa. The problem can be avoided only by using ppos and pneg as two separate indexes of proportionate agreement in the observers' positive and negative decisions. These two indexes, which are analogous to sensitivity and specificity for concordance in a diagnostic marker test, create the paradoxes formed when the chance correction in kappa is calculated as a product of the increment in the two indexes and the increment in marginal totals. If only a single omnibus index is used to compared different performances in observer variability, the paradoxes of kappa are desirable since they appropriately "penalize" inequalities in ppos and pneg. For better understanding of results and for planning improvements in the observers' performance, however, the omnibus value of kappa should always be accompanied by separate individual values of ppos and pneg.     

Classifying clinical severity to help solve problems of stage migration in nonconcurrent comparisons of lung cancer therapy

To compare the effects of stage migration in the "traditional" 3-stage TNM (tumor, node, metastasis) system with those in a new "expanded" 5-stage system, which has two additional stages for the poor prognostic groups, we used both systems to classify a cohort of 178 patients with primary lung cancer. To check for migrations, the stages in both systems were first assigned using only "old" technological information and were then reassigned using all the available "new" as well as old technological data. Although the 5-stage system had more migrations than the 3-stage system, survival rates were relatively unaffected for patients in the two new stages with poor prognosis. In both TNM staging patterns, the effects of stage migration on survival statistics were most impressive in the prognostically better (TNM I and II) stages. A solution to the migration problem is offered by the "clinical severity" (CS) staging system. Like the expanded TNM system, the CS system has 5 stages and a sharp prognostic gradient among stages. The CS system, however, had fewer technology-induced stage migrations than either TNM system, and the migrations had no substantial impact on stage-specific survival results. The excellent prognostic discrimination and secular stability of the CS system make it superior to the TNM system for comparing treatment results from different eras, especially for patients with stage I and II disease.     

Early postpartum discharges. Impact on distress and outpatient problems.

OBJECTIVE: To determine the impact of shortened postpartum hospital stays on common clinical phenomena in a sociodemographically diverse, unselected group of general maternity patients. DESIGN: Observational cohort study in which the preapproved hospital stay duration of either 1 or 2 nights was set by third-party payers before each mother's admission. SETTING: Yale-New Haven Hospital, New Haven, Conn, from June 19 through August 10, 1995. PATIENTS: Two hundred forty-four volunteers from among 400 eligible deliveries. MAIN OUTCOME MEASURES: Readmission within 1 month of hospital discharge, report of outpatient morbidity and use of outpatient health services within 1 week of discharge, status of breast-feeding during the first post-discharge week, and patient satisfaction. RESULTS: At discharge from the hospital, the hospital stay was regarded as "too short" by 80 (47%) of 171 mothers and 19 (26%) of 73 mothers in the 1- and 2-night groups, respectively (P = .002). Although readmission rates were similar (5% vs 3%, P = .48), the 1-night group reported significantly more morbidity in the newborns (31% vs 16%, P = .03) and averaged more pediatric visits (96 vs 54 per 100 newborns, P = .002). Mothers in the 1-night group also reported more fatigue (49% vs 29%, P = .001) and more worries about their newborns' health (24% vs 11%, P = .02). They were less likely to start breast-feeding (64% vs 77%, P = .06), and, if they started, were somewhat more likely to stop prematurely (14% vs 8%, P = .43). A series of disturbing events was reported only in the 1-night group. CONCLUSIONS: In a relatively unselected group, mothers who stayed 1 night after routine vaginal delivery reported more distress and more pediatric problems and had greater use of outpatient health services than mothers who stayed 2 nights.     

Ultrasound Densitometric Analysis: Comparison Between an Online Digital Acquisition Acoustic Program and an Offline Analog Program

Videodensitometric analysis of myocardial contrast echocardiography is traditionally performed off line. Recently, an online contrast ultrasound analysis system, Acoustic Densitometry (Hewlett-Packard), was introduced. We compared pixel intensities acquired with Acoustic Densitometry to pixel intensities derived from videodensitometry. A tissue phantom was imaged in phase I using three transducer frequencies (2.5, 3.5, and 5.0 MHz). In phase II, an in vitro flowing tube model with various concentrations of Albunex® was imaged at two flow rates, 0.6 and 1.2 m/sec, and at two transducer frequencies, 2.5 and 3.5 MHz. The relationship between pixel intensities yielded by the two systems for identical ultrasound signals was determined with linear regression. Intensities derived with Acoustic Densitometry strongly correlated with those derived from the offline videodensitometry system. The intensities were related by a predictive multiplicative factor based on display characteristics of the two systems. These results suggest that semiquantitative, online perfusion analysis with Acoustic Densitometry is as sensitive as analysis offline with videodensitometry.     

The Woodhaven short-term model reconsidered: a study of developmental growth and criteria for discharge

This article concerns the issues surrounding discharge of mentally retarded clients from a short-term, intensive residential service setting. The Temple University Woodhaven Center is designed as a two-year setting for about 270 clients. They require intensive assistance in acquiring behaviors necessary for independent functioning and in learning appropriate social behavior, so that they can adapt to and thrive in a less restrictive, more integrated setting. Woodhaven, however, serves clients at all levels of retardation. The question arises: How is it decided who is to be discharged and when? Upon entry to Woodhaven, a contract is written with the family and client, specifying what behavioral changes are expected as preconditions for discharge. In this approach, a client should be discharged upon attainment of contract goals. A second approach uses adaptive behavior skills as a criterion of progress, and attempts to determine the level of skills displayed by other, similar clients who are already living in the community. This second, criterion-referenced approach is important not only for discharge decisions from one facility, but for broad service system planning as well. The results of the present study supported the notion of a two-year intensive residential program.