1,721,086 research outputs found
Group sequential clinical trials with triangular continuation regions.
No full textIn this paper a new class of group sequential procedures for clinical trials is introduced, and the use of these procedures is illustrated by reference to a recently completed comparative study. In a group sequential trial the decision to stop or to continue is made at regular intervals throughout the trial, but not as frequently as after every patient response. This more practical formulation retains most of the advantages of sequential analysis, particularly the economy in sample size. Comparisons are made with group sequential designs derived from the repeated significance test.</p
Florence Nightingale diagrams of deaths in England & Wales
No full textWhen time-series data is plotted as a normal x-y plot with the time variable along the x axis it is difficult to identify seasonality or other factors that may influence the data.
Florence Nightingale used a form of radial plots to display data from the Crimean War and to demonstrate that better hygiene would reduce the death rate amongst soldiers could be reduced by better hygiene.
Plotting the weekly numbers of deaths using this radial form demonstrates the variability during the first months of the year – deaths from “Aussie flu” in the first weeks of 2018. The increase in the number of deaths from the first week in April 2020 can clearly be seen.
Radial plots are available in all the main stats packages (Radar plots in Excel, several procedures in R, proc gradar in SAS, RADAR in STATA)
The influence of method of contraception and cigarette smoking on menstrual patterns
No full textSummary. Self‐perceived menstrual patterns have been investigated in a sample of 2115 women aged 18–9 years using a postal questionnaire. Seven aspects of ‘abnormal’ menstruation were denned: prolonged periods, heavy periods, frequent periods, irregular periods, intermenstrual bleeding, painful periods and severe premenstrual syndrome. Women who used oral contraceptives were less likely than other women to report any of the seven menstrual abnormalities except for intermenstrual bleeding and severe premenstrual tension. Women who used an intrauterine contraceptive device (IUCD) reported prolonged, heavy, and frequent periods and intermenstrual bleeding more often than other women, but they did not report painful periods with undue frequency. Women who had had a tubal sterilization generally reported menstrual patterns similar to, or slightly less favourable than, women using no contraception or contraceptive methods other than the pill or the IUCD. There was a significant association between smoking habits and each of the abnormal menstrual patterns except for severe premenstrual tension. In every case, the effect of smoking was unfavourable and in almost every case, current smokers reported the worst experience, with ex‐smokers occupying an intermediate position. We believe that these data are of considerable clinical significance and that they offer a basis for a conservative approach to managing menstrual disorders in some women.</p
Rapid and simultaneous detection of multiple mutations by pooled and multiplex single nucleotide primer extension: Application to the study of insulin-responsive glucose transporter and insulin receptor mutations in non-insulindependent diabetes
No full textThe application of molecular scanning techniques to the detection of potentially pathogenic mutations in candidate genes in patients with non-insulin-dependent diabetes has revealed a number of molecular variants of uncertain pathophysiologic significance. The determination of the significance of such variants requires large-scale population studies of the prevalence of the mutant in affected and control groups. Herein, we describe two adaptations of the technique of single nucleotide primer extension (SNuPE) which allow the simultaneous examination of large numbers of alleles at multiple loci. The usefulness of these adaptations is illustrated by their application to the simultaneous detection of three point mutations, two in the tyrosine kinase domain of the insulin receptor and one in the insulin-responsive glucose transporter(GLUT4)in a highly insulin-resistant NIDDM population. By pooling genomic or amplified DNA and performing the SNuPE reactions with three primers of different length we could readily examine 300 alleles on a single 20 lane gel. Using pooled SNuPE, we also examined a large British Caucasian control population for the prevalence of GLUT4II e 383, a variant which has previously been reported only in NIDDM. GLUT4 II e 383 was detected in 2/42 of the highly insulin-resistant NIDDM subjects and 4/240 middleaged blood donors. Family studies and examination of the expressed mutant transporter will be necessary to establish whether this mutation is of functional significance. Pooled and multiplex SNuPE are powerful techniques with wide applicability to population genetic studies of specific mutaitions.</p
Survival analysis vs longitudinal modeling with multiple imputation—a false dichotomy—reply
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Breast cancer: views of general practitioners on its detection and treatment
No full textA considerable proportion of women with breast cancer in this country present for treatment in late stages of the disease; Britain's primary health-care system means that in most cases the possible diagnosis of breast cancer is first made in general practice. This offers ample opportunity for early diagnosis and a better understanding about the way the general practitioners perceive the problems associated with the disease. With that specific aim, the present article reports on a survey conducted simultaneously in Oxford and in Edinburgh. Results show that general practitioners in the survey are deeply concerned about breast cancer and see a definite role for themselves in its early detection and long-term management. They also see a need for more health education that includes the encourgement of breast self-examination programmes. Most are in favour of open-access breast clinics for women and, in general, they feel positive about self-education programmes
Should the term "diabetes resolved" ever be used? A perspective from retinopathy screening services
No full textThere is evidence that the term "diabetes resolved" is being used inappropriately by clinicians. This can result in people no longer being recalled for diabetes risk factor or complication screening even though they are at risk of such complications. We recommend that, where appropriate, the term "diabetes in remission" be used and that "diabetes resolved" is not used.</p
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