Measuring gain in the evaluation of medical technology. The probability of a better outcome.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to F Mosteller.
Explore the source record for details and available documents.
The 1988 edition of the Uniform Requirements for Manuscripts Submitted to Biomedical Journals includes guidelines for presenting statistical aspects of scientific research. The guidelines are intended to aid authors in reporting the statistical aspects of their work in ways that are clear and helpful to readers. We examine these guidelines for statistics using 15 numbered statements. Although the information presented relates to manuscript preparation, it will also help investigators in earlier stages make critical decisions about research approaches and protocols.
Quality of life measurements can lead to legislative programs for health, new policies for the health care system, and possibly new attitudes in the courts. Clinical decisions, public health evaluations, and advice for legislatures and courts require diverse measures. We illustrate potential use of such measures with reimbursement problems, programs like Head Start, mainstreaming the handicapped, day care and prenatal care, terminal care for the elderly, monitoring programs, and chronic disabilities. The many treatment policies discussed at the Portugal Conference show the need for quality of life measures in clinical trials. The courts, although considering quality of life, do not seem to consider quality of life measures. If scientists and medical experts wish to establish or change the positions of the courts, consensus conferences appear more effective than regulation or new legislation. To contribute more than they now do to policy, workers measuring quality of life need to develop a variety of measures and methods. They, then, must apply them to medical and health problems, build up a substantial literature, and set priorities for the research needs of the field.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Qualitative expressions of probability, such as "likely," have different numerical meanings to different people, which can lead to misunderstanding among physicians and between physicians and patients. In a study conducted through a nationwide interactive computer network based at Massachusetts General Hospital, we gathered information on the meaning of common expressions of probability. Three groups of medical professionals assigned percentage values to 12 expressions of the probability that a given symptom would appear in a patient with an unspecified disease. The median values assigned to these expressions by physicians, medical students, and other professionals were almost the same. Comparisons of the means for 7 of these 12 expressions with those found in an earlier study by other investigators showed that they were quantified in the same order, although they had not been assigned the same numerical values. This degree of agreement among professionals and between studies is encouraging for the future prospects of codifying the meaning of such expressions. The variation among five studies in the mean values assigned to 37 expressions in the medical literature and the variation among individual opinions show that such codification is necessary. In the meantime, the average numerical values presented here for various qualitative expressions of probability could well be used to enhance communication among medical professionals.
At the request of Congress, a Working Group of the National Institutes of Health prepared radioepidemiologic tables which estimate the likelihood that cancer victims previously exposed to a dose of radiation developed their cancer as a result of this exposure. The ultimate purpose of the tables is to provide a scientific basis for determining compensation for such victims, and their use would represent a marked departure from the current tort system for deciding compensation. The preparation of radioepidemiologic tables requires extensive mathematical modeling because matters such as sex, size of dose, age at exposure, type of cancer, and age at diagnosis must be taken into account. The limited data require many assumptions about the quantitative relationship between radiation dose and the age-specific incidence rate of cancer. After partitioning a population into reference sets based on age at exposure, size of dose, type of cancer, etc., an assigned share is computed for each reference set and then assigned to all of its members. The assigned share represents the fraction of the cancer cases in the reference set that are attributed to the radiation dose. Because the population can be partitioned in many ways, each individual's assigned share depends on the partition used and will change with different partitions. Options for modeling and limitations in epidemiologic data lead to considerable uncertainties in estimates of assigned shares that have been scientifically evaluated for the Working Group's tables. In contrast, the uncertainties associated with the current approach for determining the likelihood that a claimant's cancer was caused by radiation have not been appraised, but are likely to be even greater than those associated with the Working Group's tables. One issue is how to use such tables to compensate victims. Some among many possibilities are: to use them together with a compensation formula to determine the fraction of a standard award to be given; to use them as a starting value for the fraction, to be modified by an authority on the basis of additional information supplied by the claimant and defendant; and to use them as input to the present compensation system.
Explore the source record for details and available documents.
Readers need information about the design and analysis of a clinical trial to evaluate and interpret its findings. We reviewed 84 therapeutic trials appearing in six general surgical journals from July 1981 through June 1982 and assessed the reporting of 11 important aspects of design and analysis. Overall, 59% of the 11 items were clearly reported, 5% were ambiguously discussed, and 36% were not reported. The frequency of reporting in general surgical journals is thus similar to the 56% found by others for four general medical journals. Reporting was best for random allocation (89%), loss to follow-up (86%), and statistical analyses (85%). Reporting was most deficient for the method used to generate the treatment assignment (27%) and for the power of the investigation to detect treatment differences (5%). We recommend that clinical journals provide a list of important items to be included in reports on clinical trials.
A clinical trial cannot be adequately interpreted without information about the methods used in the design of the study and the analysis of the results. To determine the frequency of reporting what we consider 11 important aspects of design and analysis, we surveyed all 67 clinical trials published in the New England Journal of Medicine, the Lancet, and the British Medical Journal from July through December 1979 and in the Journal of the American Medical Association from July 1979 through June 1980. Of all 11 items in the 67 trials published in all four journals, 56 per cent were clearly reported, 10 per cent were ambiguously mentioned, and 34 per cent were not reported at all. At least 80 per cent of the 67 trials reported information about statistical analyses, statistical methods used, and random allocation of subjects, yet only 19 per cent reported the method of randomization. Loss to follow-up was discussed in 79 per cent of the articles, treatment complications in 64 per cent, and admission of subjects before allocation in 57 per cent, but eligibility criteria for admission to the trial appeared in only 37 per cent. Although information about whether patients were blind to treatment was given in 55 per cent, information about whether there was blind assessment of outcome was reported in only 30 per cent. The statistical power of the trial to detect treatment effects was discussed in only 12 per cent of the articles. The clinical trials published in The New England Journal of Medicine reported 71 per cent of the 11 items, those in the Journal of the American Medical Association 63 per cent, those in the British Medical Journal 52 per cent, and those in the Lancet 46 per cent. These rates are significantly different (P less than 0.001). We recommend that editors improve the reporting of clinical trials by giving authors a list of the important items to be reported.
Explore the source record for details and available documents.
Social, medical, and technological innovations are discussed, first with reference to historical examples and then with modern studies. I show the need for evaluating both the innovations themselves and the research processes leading to them. I suggest some kinds of research that need to be carried out if we are to continue to have a vigorous program of scientific and technological innovation. Finally, I explain the new initiative by the AAAS in science and engineering education.
Unexpected findings in a mouse study in which the safety of FD&C No. 40 (Red 40) was examined led to additional experimentation and to new statistical analyses and models. The possibility of acceleration of tumors raised questions about an operational definition of acceleration and of appropriate statistical methods for assessing acceleration, especially in the face of data dredging. The evaluation of Red 40 was further complicated by cage and litter effects and the multigenerational design. In this report the investigations of these studies are reviewed and are used to illustrate how new scientific work can emerge through the regulatory process. A number of issues in animal experimentation that need to be examind are indicated.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.