151
|
Wahl RL, Hawkins RA, Larson SM, Hendee WR, Coleman RE, Holden RW, Frick MP, Gatsonis C, Brown GS, Shtern F. Proceedings of a National Cancer Institute workshop: PET in oncology--a clinical research agenda. Radiology 1994; 193:604-6. [PMID: 7972793 DOI: 10.1148/radiology.193.3.7972793] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
152
|
Kovacs M, Gatsonis C, Pollock M, Parrone PL. A controlled prospective study of DSM-III adjustment disorder in childhood. Short-term prognosis and long-term predictive validity. ARCHIVES OF GENERAL PSYCHIATRY 1994; 51:535-41. [PMID: 8031226 DOI: 10.1001/archpsyc.1994.03950070027007] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVES Using DSM-III criteria for adjustment disorder (AD), further operationalized by requiring at least three clinically significant symptoms, we sought to characterize this diagnosis in terms of presenting features, recovery, and predictive validity among juveniles. DESIGN The samples included clinically referred, 8- to 13-year-old patients with the research diagnosis of AD (N = 30) and a high rate of comorbid disorders and age-and comorbid disorder-matched psychopathologic controls (N = 26). As part of a naturalistic, longitudinal, nosologic study, patients were repeatedly examined during an average follow-up interval of 7 to 8 years. RESULTS Adjustment disorder was associated with six symptoms, on average, and 60% of the patients had other, specific psychiatric disorders. Adjustment disorder had a median episode length of 7 months and a 97% recovery rate. Comorbidity had no appreciable effect on recovery. Patients with adjustment disorder and controls had similar rates of new psychiatric disorders and other dysfunctional outcomes during the follow-up. CONCLUSIONS Among psychiatrically referred youths, the diagnosis of AD has clinical information value and identifies a syndromatic presentation that can be the focus of concern or treatment. It has a reasonably good short-term prognosis, in spite of the fact that patients with this diagnosis typically present with comorbid specific psychiatric disorders. Controlling for the effects of comorbidity, AD does not predict later dysfunction. To achieve a convergence of findings from research and clinical practice, it would be important to ensure a uniform application of specific, operational diagnostic criteria for AD.
Collapse
|
153
|
Abstract
Using a psychiatrically referred, depressed, school-age sample, we sought to cross-validate the clinically pertinent epidemiologic finding that the distribution of age at onset of first episode of major depressive disorder (MDD) is subject to birth-cohort and period effects. Demographic and historical variables also were considered in attempting to explain the variability in age-at-onset. The results indicated a birth-cohort effect, but no discernable period effect on age at onset of MDD; successive birth cohorts were younger when they first developed MDD even after stringent analyses were conducted that corrected for structural sampling biases in the sample. In view of the relatively small size and clinical nature of the sample and the restricted birth-year span that characterizes children, the results are presented to stimulate further discussion of this topical area.
Collapse
|
154
|
Kovacs M, Akiskal HS, Gatsonis C, Parrone PL. Childhood-onset dysthymic disorder. Clinical features and prospective naturalistic outcome. ARCHIVES OF GENERAL PSYCHIATRY 1994; 51:365-74. [PMID: 8179460 DOI: 10.1001/archpsyc.1994.03950050025003] [Citation(s) in RCA: 235] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVES To characterize the clinical presentation, course, and outcome of childhood-onset dysthymic disorder and assess the predictive validity of this diagnosis. DESIGN As part of a longitudinal prospective study, school-age, clinically referred youngsters (n = 55) whose first depression was dysthymic disorder and a comparison group of youngsters (n = 60) whose first affective episode was major depressive disorder (MDD) were repeatedly examined during a 3- to 12-year interval. The diagnoses were based on DSM-III criteria. RESULTS Dysthymic disorder was associated with earlier age at onset than MDD, similarly frequent symptoms of affective dysregulation, but low rates of anhedonia and neurovegetative symptoms and greater overall risk of any subsequent affective disorder. The affective disorders that dysthymic children developed, including first-episode MDD (76%) and bipolar disorder (13%), far outnumbered nonaffective conditions. After the first episode of MDD, the clinical course of the initially dysthymic youths was similar to the course of the comparison patients with regard to rates of recurrent major depression, bipolar disorder, and certain nonaffective disorders. CONCLUSIONS Childhood-onset dysthymic disorder is an early marker of recurrent affective illness. Although on long-term follow-up, dysthymic disorder and MDD are associated with similar rates of certain outcomes, there exist sufficient differences to warrant diagnosis of each disorder. Dysthymic children who have subsequent mood disorders are most likely first to have an episode of MDD, and that episode appears to be the "gateway" to recurrent affective illness. The interval between the onset of dysthymia and the first major depression provides a window of opportunity for intervention and possible prevention of later episodes.
Collapse
|
155
|
Irwig L, Tosteson AN, Gatsonis C, Lau J, Colditz G, Chalmers TC, Mosteller F. Guidelines for meta-analyses evaluating diagnostic tests. Ann Intern Med 1994; 120:667-76. [PMID: 8135452 DOI: 10.7326/0003-4819-120-8-199404150-00008] [Citation(s) in RCA: 543] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES To introduce guidelines for the conduct, reporting, and critical appraisal of meta-analyses evaluating diagnostic tests and to apply these guidelines to recently published meta-analyses of diagnostic tests. DATA SOURCES Based on current concepts of how to assess diagnostic tests and conduct meta-analyses. They are applied to all meta-analyses evaluating diagnostic tests published in English-language journals from January 1990 through December 1991, identified through MEDLINE searching and by experts in the field. STUDY SELECTION Meta-analyses were included if at least two of three independent readers regarded their main purpose as the evaluation of diagnostic tests against a concurrent reference standard. DATA EXTRACTION By three independent readers on the extent to which meta-analyses fulfilled each guideline, with consensus defined as agreement by at least two readers. DATA SYNTHESIS The guidelines are concerned with determining the objective of the meta-analysis, identifying the relevant literature and extracting the data, estimating diagnostic accuracy, and identifying the extent to which variability is explained by study design characteristics and characteristics of the patients and diagnostic test. In general, the guidelines were only partially fulfilled. CONCLUSION Meta-analysis is potentially important in the assessment of diagnostic tests. Those reading meta-analyses evaluating diagnostic tests should critically appraise them; those doing meta-analyses should apply recently developed methods. The conduct and reporting of primary studies on which meta-analyses are based require improvement.
Collapse
|
156
|
Ellis JH, Tempany C, Sarin MS, Gatsonis C, Rifkin MD, McNeil BJ. MR imaging and sonography of early prostatic cancer: pathologic and imaging features that influence identification and diagnosis. AJR Am J Roentgenol 1994; 162:865-72. [PMID: 8141009 DOI: 10.2214/ajr.162.4.8141009] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE The purpose of this study was to correlate findings at MR imaging and transrectal sonography with histopathologic findings after surgery in patients with prostatic cancer, to identify the pathologic characteristics of prostatic cancer that improved detection with MR imaging and transrectal sonography, and to identify the imaging characteristics that correlated with detection of true cancers. MATERIALS AND METHODS Data from MR imaging in 320 patients and from transrectal sonography in 343 patients who were enrolled in the Radiological Diagnostic Oncology Group multiinstitutional study of imaging in prostatic cancer were correlated with results of radical prostatectomy. Only cancers 5 mm or greater in at least one dimension were evaluated pathologically. The locations of lesions and the linear dimensions and volumes of individual lesions and the prostate gland were evaluated pathologically and with imaging studies. The appearance of lesion margins on images and the degree of differentiation of lesions seen on pathologic examination were also studied. Univariate and multivariate analysis were performed to determine the pathologic findings associated with imaging detection and the imaging characteristics associated with prostatic cancer. RESULTS MR imaging and transrectal sonography showed 62% and 64% of cancers, respectively, each with a positive predictive value of 68%. Cancers that were larger, moderately or poorly differentiated, or located in the posterior half of the outer gland were easier to detect (p < .0001). The overall size of the prostate did not effect lesion detection. However, abnormalities identified in the posterior half of the outer gland were more likely to be cancers. On transrectal sonograms, larger abnormalities also were more likely to be malignant tumors. The sharpness of the margins of the imaged abnormalities did not predict pathologic status. CONCLUSION Detection of prostatic cancer with MR imaging or transrectal sonography is affected by cancer size, differentiation, and location; the odds of an imaged lesion's being malignant are related to location and, for transrectal sonography, size. Knowledge of anatomic/pathologic features that enhance lesion detection may help when using imaging tests to detect prostatic carcinoma. That certain imaging characteristics of lesions are associated with true cancers may assist in the interpretation of MR images and transrectal sonograms of the prostate.
Collapse
|
157
|
Webb WR, Sarin M, Zerhouni EA, Heelan RT, Glazer GM, Gatsonis C. Interobserver variability in CT and MR staging of lung cancer. J Comput Assist Tomogr 1993; 17:841-6. [PMID: 8227566 DOI: 10.1097/00004728-199311000-00001] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Our goal was to assess the interobserver variability in staging non-small cell lung cancer using CT and MRI. MATERIALS AND METHODS As part of the Radiologic Diagnostic Oncology Group (RDOG) study of lung cancer staging, the CT and MR examinations of 40 patients suspected of having non-small cell bronchogenic carcinoma were blindly interpreted by four expert observers. The primary tumor and lymph node stages in the 40 study subjects were similar to the final proportions reported in the RDOG study. Assessed abnormalities included the presence of a lung nodule, chest wall invasion, mediastinal invasion, bronchial involvement, lymph node metastasis in specific node stations, and T and N classifications. Percent agreement and kappa-values were calculated for each of these determinations. RESULTS Depending on the finding assessed and the method of analysis, average agreement rates ranged from 58 to 90% for CT and from 61 to 96% for MRI. Average kappa-values were largely between 0.40 and 0.60 when dichotomous analysis was used; weighted kappa-values were similar. With a single exception, no significant differences were found for kappa-values calculated for CT and MRI. CONCLUSION Although interobserver agreement rates are good for determining T and N classification in patients with lung cancer, variability in image interpretation is frequent, even among experienced observers.
Collapse
|
158
|
Cleary PD, Fowler FJ, Weissman J, Massagli MP, Wilson I, Seage GR, Gatsonis C, Epstein A. Health-related quality of life in persons with acquired immune deficiency syndrome. Med Care 1993; 31:569-80. [PMID: 8326772 DOI: 10.1097/00005650-199307000-00001] [Citation(s) in RCA: 140] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Assessing health-related quality of life in persons infected with human immunodeficiency virus (HIV) is extremely important, but most available scales are too long, contain items that are not relevant for such persons, or do not assess important signs and symptoms of HIV infection. This study presents a new set of scales for assessing the symptoms and functioning of persons infected with HIV and reports data on their reliability and validity collected in face-to-face interviews with 189 patients receiving primary care. This study also assesses the associations among systems, functional impairment, and global health assessments. The scales are easy to administer, are reliable, and serve as valid measures of quality of life. Fatigue, functional status, and average severity of all symptoms were the best predictors of overall perceived health status. Psychological well-being and perceived health status were the best predictors of overall perceived health status. Psychological well-being and perceived health status were the strongest correlates of life satisfaction. When assessing the health-related quality of life of persons infected with HIV, this study recommends utilizing a comprehensive set of measures that allows one to examine both discrete symptoms and the more diffuse impact of illness on functioning, mental health, and quality of life.
Collapse
|
159
|
Sideridou-Karayannidou I, Gatsonis C, Orfanou O, Stalidis G, Varvoglis A. [Hydroxy(tosyloxy)iodo]benzene as Thermal initiator for the Radical Polymerization of Methyl Methacrylate. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 1993. [DOI: 10.1080/10601329308009418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
160
|
Haas JS, Weissman JS, Cleary PD, Goldberg J, Gatsonis C, Seage GR, Fowler FJ, Massagli MP, Makadon HJ, Epstein AM. Discussion of preferences for life-sustaining care by persons with AIDS. Predictors of failure in patient-physician communication. ARCHIVES OF INTERNAL MEDICINE 1993; 153:1241-8. [PMID: 8494476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES To assess the determinants of communication about resuscitation between persons with acquired immunodeficiency syndrome (AIDS) and their physician. DESIGN AND SETTING Structured patient interview at a staff-model health maintenance organization (HMO), an internal medicine group practice at a private teaching hospital, and an AIDS clinic at a public hospital. PATIENTS 289 persons with AIDS. MAIN RESULTS Only 38% of patients had discussed their preferences for resuscitation with their physician. Using logistic regression, we found that patients were less likely to have discussed resuscitation with their physician if they were nonwhite (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.24 to 0.99), had never been hospitalized (OR, 0.52; 95% CI, 0.27 to 0.99), or were cared for in the HMO (OR, 0.44 relative to the private teaching hospital; 95% CI, 0.23 to 0.82). Patients were more likely to have discussed their preferences if they were not currently taking zidovudine (OR, 1.76; 95% CI, 1.02 to 3.03) and if they had decided to defer life-sustaining therapy (OR, 2.30; 95% CI, 1.35 to 3.91). Among nonwhites, those with a nonwhite physician were more likely to have discussed resuscitation (OR, 4.38; 95% CI, 1.13 to 16.93). Of patients who had not discussed their preferences for life-sustaining care, 72% wanted to do so. Patient desire for discussion of this issue did not vary by race, severity of illness, hospitalization status, use of zidovudine, or site of care. CONCLUSIONS A majority of persons with AIDS in this study had not discussed their preferences for life-sustaining care with their physician, despite the desire to do so. Interventions to improve patient-physician communication about resuscitation for nonwhites and other groups at risk of inadequate discussion might lead to clinical decisions that are more consistent with patient preferences.
Collapse
|
161
|
Gatsonis C, Normand SL, Liu C, Morris C. Geographic variation of procedure utilization. A hierarchical model approach. Med Care 1993; 31:YS54-9. [PMID: 8492586 DOI: 10.1097/00005650-199305001-00008] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In this study, an abbreviated introduction to hierarchical statistical models for quantifying and explaining variations in the utilization of medical care is presented. The illustrative example was derived from an analysis of interstate variation in coronary angiography utilization for Medicare patients with a recent acute myocardial infarction. The hierarchical model distinguished within-from between-states variation: the former was modeled via a separate logistic regression for each state, with age and sex as the independent variables, while the latter was modeled via a multivariate normal distribution for the coefficients of the state-specific logistic models. Alternative computation approaches were compared and model fit was assessed. Estimates of the distribution of state rates of angiography for an average patient and for age-by-sex strata were obtained. The results showed substantial interstate variation in angiography utilization, but only moderate interstate variation in the effects of age and sex on the decision to perform angiography. This analytic approach allows substantially more detailed results than those by standardization, and accounts for sample size differences between units of aggregation. The next major step in the analysis would be to derive smoothed estimates of the individual state logistic models by pooling data across states. The analysis can also be extended to incorporate other patient characteristics, such as race and comorbidity, and state characteristics, such as geographic location and availability of the procedure.
Collapse
|
162
|
Sidtis JJ, Gatsonis C, Price RW, Singer EJ, Collier AC, Richman DD, Hirsch MS, Schaerf FW, Fischl MA, Kieburtz K. Zidovudine treatment of the AIDS dementia complex: results of a placebo-controlled trial. AIDS Clinical Trials Group. Ann Neurol 1993; 33:343-9. [PMID: 8489204 DOI: 10.1002/ana.410330403] [Citation(s) in RCA: 193] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The efficacy of two doses of zidovudine was examined for the treatment of the acquired immunodeficiency syndrome (AIDS) dementia complex in a randomized, double-blinded, placebo-controlled trial conducted at nine study centers. For the initial 16 weeks, 40 subjects with mild to moderate AIDS dementia complex were randomized to one of three treatment arms: 400 mg of zidovudine five times daily, 200 mg of zidovudine five times daily, or placebo five times daily. After week 16, patients initially randomized to the placebo group were rerandomized to one of the two zidovudine treatment arms. The primary efficacy end point was improvement in performance on a battery of seven neuropsychological tests; the secondary end point was improvement on a protocol neurological evaluation directed at the cardinal features of the AIDS dementia complex. For the initial 16-week period, average z scores based on the neuropsychological test battery revealed a significant improvement in the combined treatment groups compared to the placebo group; however, when the two treatment groups were compared separately to the placebo group, only the group receiving the higher zidovudine dose exhibited significant improvement. After rerandomization of the placebo patients to one of the two treatment arms at week 16, this group also showed significant improvement in the average neuropsychological z score by week 32. These results extend previous observations that indicate a therapeutic benefit of zidovudine for the treatment of AIDS dementia complex.
Collapse
|
163
|
Kovacs M, Goldston D, Gatsonis C. Suicidal behaviors and childhood-onset depressive disorders: a longitudinal investigation. J Am Acad Child Adolesc Psychiatry 1993; 32:8-20. [PMID: 8428888 DOI: 10.1097/00004583-199301000-00003] [Citation(s) in RCA: 204] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In this longitudinal study, the rates and correlates of suicidal ideation and suicide attempts were determined among outpatient youths with depressive disorders and youths with other psychiatric disorders. At study entry, about 66% of the subjects evidenced suicidal ideation and 9% already attempted suicide. The rate of ideation remained fairly stable over time, whereas the rate of attempts reached 24% by the average age of 17 years. Major depressive and dysthymic disorders were associated with significantly higher rates of suicidal behaviors than were adjustment disorder with depressed mood and nondepressive disorders. In the presence of affective disorders, comorbid conduct and/or substance use disorders further increased the risk of suicide attempts.
Collapse
|
164
|
Udvarhelyi IS, Gatsonis C, Epstein AM, Pashos CL, Newhouse JP, McNeil BJ. Acute myocardial infarction in the Medicare population. Process of care and clinical outcomes. JAMA 1992; 268:2530-6. [PMID: 1404820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To describe the process of care and clinical outcomes associated with acute myocardial infarction (AMI) in the Medicare population, and to examine differences in process of care and outcome of care as a function of patient age, gender, and race. DESIGN Retrospective cohort study using a longitudinal database created from Medicare utilization and administrative files. PATIENT POPULATIONS: A cohort of AMI patients covered by Medicare in 1987 and a random sample of Medicare patients without AMI. MAIN PROCESS AND OUTCOME MEASUREMENTS: (1) The use of coronary angiography, coronary artery bypass graft surgery, and percutaneous transluminal coronary angioplasty during the first 90 days after a new AMI; (2) mortality at 30 days, 1 year, and 2 years; (3) reinfarction rates; and (4) reoperation rates for coronary artery bypass graft surgery and percutaneous transluminal coronary angioplasty. MAIN RESULTS Mortality rates were high: 26% at 30 days, 40% at 1 year, and 47% at 2 years. They varied greatly by age, less so by gender and race, and were high even among patients who survived the first 30 days. Compared with mortality, reinfarction was uncommon, occurring in 7.3% of patients. During the first 90 days, 23% of all patients underwent angiography and 13% underwent coronary revascularization (coronary artery bypass graft surgery, 8%; percutaneous transluminal coronary angioplasty, 5%). The use of all three procedures decreased with age and was less common among women and blacks than among men and whites. Differential use by age and race was greater for angiography than for revascularization procedures. CONCLUSIONS The prognosis following AMI in patients aged 65 years and above is much worse than is commonly realized. Procedure use in these patients varies as a function of gender and race, even though mortality does not. Further research is needed to reduce the mortality of elderly patients with AMI and to understand the significance of differences in procedure use on the basis of sociodemographic characteristics.
Collapse
|
165
|
Weissman JS, Gatsonis C, Epstein AM. Rates of avoidable hospitalization by insurance status in Massachusetts and Maryland. JAMA 1992; 268:2388-94. [PMID: 1404795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To determine whether uninsured and Medicaid patients have higher rates of avoidable hospitalizations than do insured patients. DESIGN We used 1987 computerized hospital discharge data to select a cross-sectional sample of hospitalized patients. Population estimates from the Current Population Survey were used to estimate rates of admission, standardized for age and sex. SETTING Nonfederal acute care hospitals in Massachusetts and Maryland. PATIENTS All patients under 65 years of age who were uninsured, privately insured, or insured by Medicaid. Hospitalizations for obstetric and psychiatric conditions were excluded. MAIN OUTCOME MEASURES Relative risk of admission for 12 avoidable hospital conditions (AHCs) identified by a physician panel. RESULTS Uninsured and Medicaid patients were more likely than insured patients to be hospitalized for AHCs. Rates for uninsured patients were significantly greater than for privately insured patients in Massachusetts for 10 of 12 individual AHCs, and in Maryland for five of 12 AHCs. After adjustment for baseline utilization, the results were statistically significant for 10 of 12 AHCs in Massachusetts and seven of 12 AHCs in Maryland. For Medicaid patients, rates were significantly greater than for privately insured patients for all AHCs in each state before adjustment, and for nine of 12 and seven of 12 AHCs in each state, respectively, after adjustment for baseline utilization. CONCLUSION Our findings suggest that patients who are uninsured or who have Medicaid coverage have higher rates of hospitalization for conditions that can often be treated out of hospital or avoided altogether. Our approach is potentially useful for routine monitoring of access and quality of care for selected groups of patients.
Collapse
|
166
|
Filderman AE, Silvestri GA, Gatsonis C, Luthringer DJ, Honig J, Flynn SD. Prognostic significance of tumor proliferative fraction and DNA content in stage I non-small cell lung cancer. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1992; 146:707-10. [PMID: 1325749 DOI: 10.1164/ajrccm/146.3.707] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Analyses of tumor DNA content and proliferative fraction by flow cytometry have been useful as prognostic determinants in a variety of solid tumors. The significance of this analysis in Stage I (T1N0M0 and T2N0M0) non-small cell lung carcinoma (NSCC) is unestablished. We determined DNA content (ploidy) and proliferative fraction (percentage S phase) on 44 surgically resected Stage I NSCC specimens obtained between 1977 and 1982. All cases had a minimum follow-up of 5 yr. Of the 44 cases, 27 were adenocarcinomas, 15 squamous cell carcinomas, and 2 large cell carcinomas. Of these, 32 (73%) had T1N0M0 lesions and 12 (27%) had T2N0M0 lesions. Overall 5-yr survival was 70%. All patients surviving 5 yr were free of detectable tumor. Patients with T1N0M0 lesions had an 81% 5-yr survival, but those with T2N0M0 lesions had a 42% 5-yr survival (p = 0.009). Analysis of tumor DNA content revealed 35 diploid tumors (79%) and 9 aneuploid tumors (21%). The 5-yr survival for diploid tumors was 77% compared with a 44% 5-yr survival in aneuploid lesions (p = 0.048). The median proliferative fraction was 6%. All patients with a percentage S phase less than 6% survived 5 yr, and 41% (9 of 22) of those greater than 6% survived 5 yr (p less than 0.001). When 8% S phase was used as a cutoff, 93% (28 of 30) below the cutoff survived 5 yr but only 21% (3 of 14) above the cutoff survived 5 yr (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
167
|
Abstract
Phase I clinical trials are conducted to determine the dose-response curve of a new drug with respect to toxic side effects and, in particular, to estimate the maximum tolerated dose (MTD). In this paper we take a Bayesian approach to the problem of making inferences about the MTD. Working with broad classes of priors, we obtain the posterior distribution of the MTD and study its properties. We also address the question of providing updated assessments of the risk of toxicity for new patients entering the study at a specific dose level. These assessments would be useful in deciding issues of study management and ethics. Our analysis pays particular attention to the sensitivity of the inferences and risk assessments to the choice of prior and the choice of model for the dose-response relationship.
Collapse
|
168
|
Jacob RG, Shapiro AP, O'Hara P, Portser S, Kruger A, Gatsonis C, Ding Y. Relaxation therapy for hypertension: setting-specific effects. Psychosom Med 1992; 54:87-101. [PMID: 1553404 DOI: 10.1097/00006842-199201000-00011] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We determined the effect of relaxation therapy for hypertension in patients whose blood pressure remained elevated despite the use of antihypertensive medication. The effect was assessed in multiple settings, including the relaxation therapist's office, the Hypertension Clinic, and the patient's natural environment, the latter using 24-hour automated ambulatory blood pressure measures. Nineteen patients were randomized either to temperature biofeedback-assisted relaxation or to an attention control, "stress education." Antihypertensive medication was kept constant. In the behavioral therapist's office, blood pressure decreased in equivalent amounts with both treatments. Hypertension Clinic nurse blood pressure remained stable or increased with both treatments, but again there was no difference between treatments. Ambulatory blood pressure increased with relaxation therapy and decreased with stress education, the effect being significant for diastolic pressure. The effects on ambulatory blood pressure were limited to the waking hours. The only variable that showed superior effects for relaxation therapy was physician-determined blood pressure. These results call into question the generalizability of the effects of relaxation therapy from one setting to another.
Collapse
|
169
|
Webb WR, Gatsonis C, Zerhouni EA, Heelan RT, Glazer GM, Francis IR, McNeil BJ. CT and MR imaging in staging non-small cell bronchogenic carcinoma: report of the Radiologic Diagnostic Oncology Group. Radiology 1991; 178:705-13. [PMID: 1847239 DOI: 10.1148/radiology.178.3.1847239] [Citation(s) in RCA: 321] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The accuracies of magnetic resonance (MR) imaging and computed tomography (CT) in determining tumor classification and assessing mediastinal node metastases were compared in a prospective cooperative study of 170 patients with non-small cell bronchogenic carcinoma. The sensitivity of CT in distinguishing T3-T4 tumors from T0-T2 tumors was 63%; specificity was 84%. These values for MR imaging were not significantly different (56% and 80%). With receiver operating characteristic (ROC) analysis, no difference existed between the accuracies of CT and MR imaging in diagnosis of bronchial involvement or chest wall invasion, but MR imaging was significantly more accurate than CT (P = .047) in diagnosis of mediastinal invasion. Lymph node sampling was performed in 155 patients (642 node stations). Cancerous nodes were found in 14% of stations in 21% of patients. There was no significant difference between the accuracies of CT and MR imaging in detecting mediastinal node metastases (N2 or N3); the sensitivities were 52% and 48%, respectively, and specificities were 69% and 64%. ROC analysis also showed no difference between CT and MR imaging.
Collapse
|
170
|
Byar DP, Schoenfeld DA, Green SB, Amato DA, Davis R, De Gruttola V, Finkelstein DM, Gatsonis C, Gelber RD, Lagakos S. Design considerations for AIDS trials. N Engl J Med 1990; 323:1343-8. [PMID: 2215622 DOI: 10.1056/nejm199011083231912] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
171
|
Gatsonis C, McNeil BJ. Collaborative evaluations of diagnostic tests: experience of the Radiology Diagnostic Oncology Group. Radiology 1990; 175:571-5. [PMID: 2183290 DOI: 10.1148/radiology.175.2.2183290] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Multicenter, collaborative studies offer an effective way to meet the growing need for timely and generalizable clinical evaluations of imaging technologies. This article discusses issues of study design, statistical analysis, organization, and day-to-day group operation for collaborative prospective clinical evaluations. It draws significantly on the authors' experience with the Radiology Diagnostic Oncology Group, a cooperative group funded by the National Cancer Institute, which conducts comparative studies of the ability of diagnostic imaging modalities to enable the staging of various types of cancer including that of the prostate gland, lung, pancreas, colon, and rectum. The results from 2 1/2 years of the experience of this group hold promise for the importance of this approach to the future growth of radiologic research.
Collapse
|
172
|
Gatsonis C. The long debate on the sixth guaiac test: time to move on to new grounds. JOURNAL OF HEALTH ECONOMICS 1990; 9:495-497. [PMID: 10109993 DOI: 10.1016/0167-6296(90)90009-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
173
|
Kaplan JR, Manuck SB, Gatsonis C. Heart rate and social status among male cynomolgus monkeys (Macaca fascicularis) housed in disrupted social groupings. Am J Primatol 1990; 21:175-187. [DOI: 10.1002/ajp.1350210302] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/1989] [Revised: 03/02/1990] [Indexed: 11/08/2022]
|
174
|
Abstract
This article discusses power and sample size calculations for observational studies in which the values of the independent variables cannot be fixed in advance but are themselves outcomes of the study. It reviews the mathematical framework applicable when a multivariate normal distribution can be assumed and describes a method for calculating exact power and sample sizes using a series expansion for the distribution of the multiple correlation coefficient. A table of exact sample sizes for level .05 tests is provided. Approximations to the exact power are discussed, most notably those of Cohen (1977). A rigorous justification of Cohen's approximations is given. Comparisons with exact answers show that the approximations are quite accurate in many situations of practical interest. More extensive tables and a computer program for exact calculations can be obtained from the authors.
Collapse
|
175
|
Kovacs M, Gatsonis C, Paulauskas SL, Richards C. Depressive disorders in childhood. IV. A longitudinal study of comorbidity with and risk for anxiety disorders. ARCHIVES OF GENERAL PSYCHIATRY 1989; 46:776-82. [PMID: 2774847 DOI: 10.1001/archpsyc.1989.01810090018003] [Citation(s) in RCA: 273] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
As part of a longitudinal nosologic study of major depressive disorder (MDD), dysthymic disorder (DD), and adjustment disorder with depressed mood (ADDM) in a school-age cohort, we examined the prevalence and clinical consequences of comorbid anxiety disorders. We also estimated the risk of a first anxiety disorder and examined its predictors. Of 104 cases, 41% had anxiety disorders in conjunction with their index depression, which was more likely with MDD and DD than with ADDM. The age-corrected risk of a first anxiety disorder was 0.47 up to age 18 years. Separation-anxiety disorder was the most frequent diagnosis of anxiety, followed by overanxious disorder of childhood. Among the MDD cases with comorbidity, the anxiety disorder preceded the depression about two thirds of the time and often persisted after the depression remitted. The effect of comorbid anxiety disorder on the length of index MDD depended on the presence of other clinical features, but it did not seem to affect the risk of subsequent MDD or the course of DD or ADDM. Concurrent maternal psychopathology and poor physical health increased the risk of anxiety disorder in the children, but a history of prior separation from parental figures did not seem to have an effect.
Collapse
|
176
|
|
177
|
Cohen A, Gatsonis C, Marden JI. Hypothesis Testing for Marginal Probabilities in a 2 × 2 × 2 Contingency Table with Conditional Independence. J Am Stat Assoc 1983. [DOI: 10.1080/01621459.1983.10477041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
178
|
Cohen A, Gatsonis C, Marden JI. Hypothesis Testing for Marginal Probabilities in a 2 × 2 × 2 Contingency Table With Conditional Independence. J Am Stat Assoc 1983. [DOI: 10.2307/2288205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|