Variance estimation for medical decision analysis.

We have derived the variance of an expected utility for a probability tree in medical decision analysis based on a Taylor series approximation of the expected utility as a function of the probability and utility values used in the decision tree. The resulting variance estimate is an algebraic expression of the variances associated with the probability and utility estimates used. We also derive expressions for the case where the input parameter estimates are not independent. We discuss the choice of input parameters and their variance estimates and give an example that compares two protocols for the treatment of chlamydial infection.

[An analysis of the quality of the clinical diagnosis based on autopsy data]. / Analiz kachestva klinicheskoi diagnostiki po sektsionnym materialam.

The findings from 4359 autopsies made in 4 Moscow hospitals during 1986 were analyzed with two proposed tables. The primary materials were processes with a computer. Table 1 includes data on the total number of unrecognized cases by the main disease, major complications, concomitant and underlying diseases in terms of their category and cause of diagnosis discrepancy. The rate of the discrepancy between clinical and postmortem diagnoses averaged 21.6 +/- 4.7% by the main disease, that of unrecognized fatal complications and major concomitant and underlying diseases was found to be 7.6 and some 2%, respectively. By the categories, the analysis of diagnosis discrepancy indicated 35, 58.6, and 6.4% in Categories I, II, and III, respectively. Table 2 (combined correlational one) makes it possible to study the range of diagnostic errors in various diseases and to find typical mistakes made by clinicians. Analyzing the quality of clinical diagnosis according to the given pattern is of advantage in routine practice to obtain comparable consistent data, to make a thorough examination, and to generalized discrepancy cases of clinical and postmortem diagnoses.

Clinical analysis of a general practice in a West Indian town

A general private practice, with no midwifery or surgery, in a West Indian town is surveyed. 1,433 new cases were seen within six months. Children accounted for 10 per cent and old people for 9 per cent. There were almost twice as many female as male cases. Every third was a woman aged between 15 and 40 years. The complaints of 1,290 adults were analysed. One out of four came because of pain located in some region of the body; one out of seven was "feeling not well" in a vague way and one out of ten for a female complaint. All other complaints were met with in considerably smaller numbers. The diagnoses made in the same group of adults showed gynaecology to be the largest branch of medicine presented: it could claim every fifth patient and almost every third woman. Conditions mainly of an emotional kind, termed 'functional', were the principal findings in one out of every seven patients (about 14 percent). The group of patients with vague complaints furnished one-third of these cases. Backache was considered functional more often than headache. Malaria was not commonly met with (less that 2 per cent of the adult cases) and no other tropical diseases were diagnosed. The corelation between complaint and medical findings was lowest in regard to heart conditions. People coming from obvious trivialities and unjustified certificates were few. The variety of conditions seen in a general practice and the possible effects of the present day trend towards specialisation are remarked upon (AU)