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Biomedical subjects

A R Feinstein

Publications and source records attributed to A R Feinstein.

At least 73 records · Page 4Linked to original sources
PubMed1994

Variability in radiologists' interpretations of mammograms.

BACKGROUND: Despite the proved value of mammography in screening for breast cancer, its efficacy depends on radiologists' interpretations. The variability in such interpretations is not well understood. METHODS: Using a technique of stratified random sampling, we selected 150 mammograms obtained in 1987: 27 from women with histopathologically confirmed breast cancer and 123 from women with no evidence of breast cancer after three years of follow-up examinations. Ten radiologists, who were unaware of the diagnoses and research hypothesis, each interpreted the 150 mammograms. Disagreement was analyzed within pairs of the 10 radiologists, as well as for the group of 150 women as a whole. RESULTS: The diagnostic consistency between pairs of radiologists was moderate, with a median weighted percentage of agreement of 78 percent (weighted kappa, 0.47). The frequency of the radiologists' recommendations for an immediate workup ranged from 74 to 96 percent for mammograms from the women with cancer and from 11 to 65 percent for films from the women without cancer. A substantial disagreement in management recommendations--in which one radiologist recommended routine follow-up and another recommended a biopsy for the same patient--occurred in 3 percent of the pairwise comparisons but in 25 percent of the comparisons for the group of women as a whole. When two or more radiologists recommended a biopsy for the same patient, a disagreement in the stated location (right or left breast) occurred in 2 percent of the pairwise comparisons among the radiologists but in 9 percent of comparisons for the group of women as a whole. Because some disagreement was likely, given that 10 radiologists read each film, the pairwise comparison is a more conservative estimate of disagreement. CONCLUSIONS: Although mammography is of value in screening women for breast cancer, radiologists can differ, sometimes substantially, in their interpretations of mammograms and in their recommendations for management. Efforts to improve accuracy and reduce variability in interpretation may increase the effectiveness of mammography in detecting early breast cancers.

Breast Diseases↗
PubMed1994

Joseph Goldberger: an unsung hero of American clinical epidemiology.

Pellagra, a disease rarely seen in developed countries today, was common during the first half of this century in the United States. The disease was initially believed to be infectious, and severe "pellagraphobia" left many victims and their families ostracized. This paper calls attention to Joseph Goldberger, an American physician whose remarkable research helped correct the erroneous belief in an infectious cause for pellagra and led to the elimination of pellagra epidemics in the United States.

Epidemiology↗
PubMed1994

"Clinical Judgment" revisited: the distraction of quantitative models.

More than 25 years ago, in a book called Clinical Judgment, each act of patient care was described as having an experimental structure. The "experiments" needed substantial scientific improvement, however, in quality of basic data, taxonomic classification of phenomena, and specifications of clinical reasoning. During the past 2 decades, these improvements have not occurred as extensively as expected because many investigators working in clinical forms of clinical research have not addressed these basic scientific challenges in data, taxonomy, and reasoning. Instead, the investigators have applied quantitative "models," derived from non-clinical domains, that focus on hard data, randomized trials, Bayes theorem, quantitative decision analysis, and psychometric strategies for clinimetric measurement. Consequently, the main challenges of clinical judgment still remain generally available for basic scientific research by investigative clinicians.

Clinical Competence↗
PubMed1994

New clinical severity staging system for cancer of the larynx. Five-year survival rates.

Although statistics for cancer of the larynx are reported according to the tumor, node, metastasis (TNM) morphological staging system, functional clinical distinctions can identify major prognostic differences within the same morphological stage. This study was done to improve the staging system by incorporating pertinent clinical variables. In 193 patients with cancer of the larynx first treated between 1973 and 1985, the total 5-year survival was 66% (127/193). By TNM stage it was I, 78% (60/77); II, 67% (32/48); III, 60% (27/45); and IV, 35% (8/23). In three new functional severity stages that combined symptom severity and comorbidity, the corresponding rates were alpha, 83% (89/107); beta, 58% (34/59); and gamma, 15% (4/27). The functional severity stages could be combined with TNM stages to create a powerful new clinical severity staging system, in which the survival results were A, 88% (53/60); B, 80% (24/30); C, 63% (38/60); and D, 28% (12/43). These results demonstrate that inclusion of clinical variables in a formal staging system can strikingly improve prognostic estimations and classification of patients.

Aged↗
PubMed1994

Prognostic value of clinical variables in invasive cervical cancer.

OBJECTIVE: To test the hypothesis that clinical variables, such as patients' symptoms, symptom severity, and co-morbidity, affect the survival rate of patients with invasive cervical cancer. METHODS: From the medical records of 251 cases of invasive cervical cancer treated at Yale-New Haven Hospital between 1984 and 1988, information was extracted for patients' demographic characteristics, symptoms, symptom severity, comorbidity, physical findings, laboratory data, treatment, and subsequent course. RESULTS: Three-year survival data were available for 250 (99%) of the 251 cases. For a composite clinical predictive system based on symptom status and co-morbidity, the 3-year survival rates were as follows: 85% (64 of 75) for the patients who were asymptomatic without co-morbidity; 63% (58 of 92) for the group that was either symptomatic or co-morbid, but not both; and 40% (33 of 83) for symptomatic patients with co-morbidity or patients with systemic, metastatic, or severe symptoms (P < .0001, chi 2 for linear trend). When entered into a Cox proportional hazards model along with other variables that might affect prognosis, including International Federation of Gynecology and Obstetrics stage, the composite symptom-co-morbidity stage remained statistically significant. CONCLUSIONS: Our findings demonstrate the importance of clinical variables, such as symptoms and co-morbidity, in estimating prognosis in cervical cancer, even after stage and other factors are controlled. Unless the clinical variables are suitably analyzed, prognostic estimates based on morphology alone will be imprecise and therapeutic evaluations may be misleading.

Cohort Studies↗
PubMed1994

Ask patients what they want. Evaluation of individual complaints before total hip replacement.

We aimed to assess individual differences in complaints in patients just before total hip replacement (THR) and the importance attached to the relief of each of them. In a pilot study, using open-ended interviews, we identified 16 main complaints, four of which (night pain, unequal leg length and discomfort during sexual and recreational activities) were not included in any of the six hip-rating scales in general use. Each of the 16 complaints was then assessed in 72 patients and rated for severity and the relative importance of relief. From this we calculated a severity-importance rating for each complaint and a patient-specific score for all complaints. The 72 patients had a mean age of 64 years (17 to 92) and 51% were men. The most important reasons for wanting a THR were day pain and walking difficulty, but the complaints mentioned above and not included in standard hip scores were also important. Greater attention to the individual requirements of patients might improve evaluation of the outcome of orthopaedic treatments.

Activities of Daily Living↗
PubMed1993

The risk of determining risk with multivariable models.

PURPOSE: To review the principles of multivariable analysis and to examine the application of multivariable statistical methods in general medical literature. DATA SOURCES: A computer-assisted search of articles in The Lancet and The New England Journal of Medicine identified 451 publications containing multivariable methods from 1985 through 1989. A random sample of 60 articles that used the two most common methods--logistic regression or proportional hazards analysis--was selected for more intensive review. DATA EXTRACTION: During review of the 60 randomly selected articles, the focus was on generally accepted methodologic guidelines that can prevent problems affecting the accuracy and interpretation of multivariable analytic results. RESULTS: From 1985 to 1989, the relative frequency of multivariable statistical methods increased annually from about 10% to 18% among all articles in the two journals. In 44 (73%) of 60 articles using logistic or proportional hazards regression, risk estimates were quantified for individual variables ("risk factors"). Violations and omissions of methodologic guidelines in these 44 articles included overfitting of data; no test of conformity of variables to a linear gradient; no mention of pertinent checks for proportional hazards; no report of testing for interactions between independent variables; and unspecified coding or selection of independent variables. These problems would make the reported results potentially inaccurate, misleading, or difficult to interpret. CONCLUSIONS: The findings suggest a need for improvement in the reporting and perhaps conducting of multivariable analyses in medical research.

Humans↗
PubMed1993

A new clinical prognostic staging system for acute pancreatitis.

PURPOSE: (1) To test the hypothesis that the clinical features of patients with acute pancreatitis could be used to construct a new prognostic staging system, and (2) to compare the new system with the results of the existing Ranson system based on age and laboratory data. PATIENTS AND METHODS: We obtained an inception cohort of 162 persons with 176 episodes of acute pancreatitis admitted to Yale-New Haven Hospital from January 1, 1987, to March 31, 1989. RESULTS: The main adverse outcome events, death and/or complications, occurred in 22% of episodes. Acute pancreatitis severity was classified in three stages, reflecting the presence of only primary features (no ileus or peritonitis), or the occurrence of secondary features that could be mild (mild ileus) or severe (severe ileus and/or peritonitis). In these 3 stages, the respective rates for outcome events were 13% (17 of 133), 43% (13 of 30), and 62% (8 of 13). The severity of comorbidity was classified according to Charlson's comorbidity index. For the 3 comorbidity stages, the outcome event rates were: minimal: 13% (12 of 92); intermediate: 22% (11 of 49); and severe: 43% (15 of 35). When the acute pancreatitis severity stages and comorbidity stages were conjoined to form the composite staging system, the corresponding outcome event rates were stage I: 8 of 107 (7%); stage II: 24 of 60 (40%); and stage III: 6 of 9 (67%). The composite staging system produced sharper gradients for the outcome events than Ranson's system, and was more readily applicable to all patients, particularly when the requisite special laboratory tests had not been ordered. CONCLUSIONS: The clinical and comorbid features of patients with acute pancreatitis can be used to construct a clinically "sensible" composite staging system. The stages are easy to use, require no additional or special laboratory tests, and predict more accurately than Ranson's system.

Acute Disease↗
PubMed1993

The impact of symptoms and comorbidity on prognosis in stage IB cervical cancer.

OBJECTIVE: Like other gynecologic malignancies, cervical cancer is classified by the anatomic location and extent of the tumor. Because clinical variables such as patients' symptoms, symptom severity, and comorbidity may indicate a cancer's biologic virulence and the host-tumor interaction, this study was performed to test the hypothesis that clinical variables will also affect survival of patients with stage IB cervical cancer. STUDY DESIGN: From medical records of 251 cases of invasive cervical cancer treated at Yale-New Haven Hospital between 1984 and 1988, information was extracted for patients' demographic characteristics, symptoms, symptom severity, comorbidity, physical findings, laboratory data, treatment, and subsequent course. RESULTS: In the 122 available cases of stage IB cervical cancer the overall 3-year survival rate was 79%. For a composite clinical predictive system on the basis of symptom status and comorbidity, the 3-year survival rates were as follows: symptomatic patients with comorbidity 58% (seven of 12), either symptomatic or comorbid but not both 77% (46/60), and asymptomatic patients without comorbidity 86% (43/50) (p = 0.02 for linear trend chi 2). When entered into a Cox proportional-hazard model along with other variables that might have an impact on prognosis, the composite symptom-comorbidity stage was the only variable that remained statistically significant. CONCLUSION: These findings demonstrate the importance of clinical variables in estimating prognosis in stage IB cervical cancer. Unless these variables are suitably analyzed, prognostic estimates based only on morphologic studies will be imprecise and therapeutic evaluations may be misleading.

Adenocarcinoma↗
PubMed1993

Graphical display of categorical data.

Categorical data are usually displayed in medical publications with pie graphs and bar graphs. We here consider some of the problems that occur in displaying the rank, magnitude, width, and spacing of categorical data. A solution to some of these problems is offered by the dot chart, which has been used in other scientific literature, but not in medical publications. The dot chart can be a preferred alternative to pie graphs and offers a useful alternative to bar graphs. Dot charts can also be helpful in displaying categorical data for two groups.

Data Display↗
PubMed1993

Clinical reasoning and the new "non-" nosology.

Although seemingly odd, the designations prefixed with "non-" have become a familiar feature of clinical terminology. A common structure of these designations is the partition of a single clinical category into two contrasting ones. Despite the similar "non-" designations, the partitions can have four different functions: dividing one disease into two, aggregating multiple diseases, distinguishing etiologic uncertainty, and negating "legitimate" disease. The "non-" terminology may seem peculiar, but it is based on clinically pertinent distinctions and similarities in disease, reflecting prudent clinical reasoning.

Disease↗
PubMed1992

Spectrum bias in the evaluation of diagnostic tests: lessons from the rapid dipstick test for urinary tract infection.

OBJECTIVE: To determine if the leukocyte esterase and bacterial nitrite rapid dipstick test for urinary tract infection (UTI) is susceptible to spectrum bias (when a diagnostic test has different sensitivities or specificities in patients with different clinical manifestations of the disease for which the test is intended). DESIGN: Cross-sectional study. PATIENTS: A total of 366 consecutive adult patients in whom clinicians performed urinalysis to diagnose or exclude UTI. SETTING: An urban emergency department and walk-in clinic. MEASUREMENTS: After the patient encounter, but before dipstick test or culture was done, clinicians recorded the signs and symptoms that were the basis for suspecting UTI and for performing a urinalysis and an estimate of the probability of UTI based on the clinical evaluation. For all patients who received urinalysis, dipstick tests and culture were done in the clinical microbiology laboratory by medical technologists blinded to clinical evaluation. Sensitivity for the dipstick was calculated using a positive result in either leukocyte esterase or bacterial nitrite, or both, as the criterion for a positive dipstick, and greater than 10(5) CFU/mL for a positive culture. RESULTS: In the 107 patients with a high (greater than 50%) prior probability of UTI, who had many characteristic UTI symptoms, the sensitivity of the test was excellent (0.92; 95% CI, 0.82 to 0.98). In the 259 patients with a low (less than or equal to 50%) prior probability of UTI, the sensitivity of the test was poor (0.56; CI, 0.03 to 0.79). CONCLUSIONS: The leukocyte esterase and bacterial nitrite dipstick test for UTI is susceptible to spectrum bias, which may be responsible for differences in the test's sensitivity reported in previous studies. As a more general principle, diagnostic tests may have different sensitivities or specificities in different parts of the clinical spectrum of the disease they purport to identify or exclude, but studies evaluating such tests rarely report sensitivity and specificity in subgroups defined by clinical symptoms. When diagnostic tests are evaluated, information about symptoms in the patients recruited for study should be included, and analyses should be done within appropriate clinical subgroups so that clinicians may decide if reported sensitivities and specificities are applicable to their patients.

Adolescent↗