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D G Seigel

Publications and source records attributed to D G Seigel.

At least 19 recordsLinked to original sources
PubMed1992

Acceptable values of kappa for comparison of two groups.

A model was developed for a simple clinical trial in which graders had defined probabilities of misclassifying pathologic material to disease present or absent. The authors compared Kappa between graders, and efficiency and bias in the clinical trial in the presence of misclassification. Though related to bias and efficiency, Kappa did not predict these two statistics well. These results pertain generally to evaluation of systems for encoding medical information, and the relevance of Kappa in determining whether such systems are ready for use in comparative studies. The authors conclude that, by itself, Kappa is not informative enough to evaluate the appropriateness of a grading scheme for comparative studies. Additional, and perhaps difficult, questions must be addressed for such evaluation.

Bias↗
PubMed1989

Factors associated with visual outcome after photocoagulation for diabetic retinopathy. Diabetic Retinopathy Study Report #13.

Six risk factors for severe visual loss despite panretinal (scatter) photocoagulation were identified by analyzing data collected during the first 5 years after randomization in the Diabetic Retinopathy Study. Proportional hazards regression revealed NVD (neovascularization on/around the optic disc) to be the most important risk factor. The risk of severe visual loss rose with increasing NVD, hemorrhages/microaneurysms, retinal elevation, proteinuria, and hyperglycemia and fell with increasing "treatment density." These results are similar to previous DRS findings on untreated eyes. The importance of "treatment density" as an independent predictor of visual outcome is a new finding and lends support to the common clinical practice of repeating photocoagulation if initial treatment does not reduce or stabilize retinal neovascularization.

Aged↗
PubMed1978

A fetal-infant life table based on single births in Norway, 1967--1973.

The study is based on 440,452 single births occurring in Norway, 1967--1973, with known gestational age. The information was collected through a notification system known as "Medical Registration of Births," covering all births occurring in Norway, and the data are made available through the Medical Birth Registry of Norway, which allows for linkage between births and infant deaths. The life table describes the experience of women still pregnant at a gestational age of 16 completed weeks, and states for each subsequent week the number of pregnancy terminations, the outcome, and the number of women still pregnant. Seven outcomes of pregnancy are considered: fetal death prior to labor, fetal death during labor, death within 24 hours, death 1--6 days, death 7--27 days, death 28 days--1 year, and survival of one year or more. The data in the life table provide information on the probability of pregnancy termination in each week of gestation (after 16 completed weeks), and the probabilities of the various outcomes. The fetal-infant life table is considered as an extension of descriptive perinatal statistics and is of value in monitoring health changes and in comparing perinatal mortality between populations. It also provides information on time of pregnancy termination and outcome, which has some clinical applications.

Adult↗