Long QT-interval is one of most important predictors of risk of development of life threatening arrhythmias and sudden death. Correct measurement of QT-interval is essential for diagnosis of its prolongation. At present the Bazett formula for calculation of corrected QT (QT(c) = QT/ radical (RR)) is a standard method of QT estimation. However historically in Russia calculation of predicted QT (QT(k) = k radical (RR)) QT(k) has become an accepted technique. Furthermore many authors in this country apply criteria created for QT(c) for interpretation of QT(k) values. This results in hyperdiagnosis of QT prolongation in unaffected persons, erroneous conclusions on harmless nature of this condition, and underestimation of risk in patients with real long QT syndrome. Thus it is vital to proclaim calculation of QT(c) an obligatory standard and to use existing international criteria for its interpretation.
At the population level, the quantitative assessment of the impact of social-economic and medical-demographic factors on the dynamics of main mental health indicators (prevalence, incidence, level of suicide, disability) in the population of the Russian Federation in 1992-2010 years is presented. Regression models relating the key indicators of mental health with the health-demographic and social-economic factors have been developed. The interpretation of the dynamics of mental health in Russia according to the social changes and living conditions in the country during 1992-2010 years is suggested. Models have good predictive performance, which allows their use as a tool for real-time monitoring and planning of health and social services.
Correlation and regression analysis of tuberculosis morbidity among children in Udmurtiya covered the period from 1991 to 2007. It was shown that linear functions can be used to prognosticate the morbidity rate. It is expected to increase in the near future. The morbidity rate is influenced by such factors as the lack of adequate disinfection in the foci of tuberculous infection, unfavourable living conditions, irregular treatment of infection sources, concomitant chronic pathology, incomplete family, and poorly controlled preventive chemotherapy.
Correlations between neonatal mortality coefficient and a group of socioeconomic and ecological parameters are analyzed for some economic regions and districts of Russia. At the level of regions, the strongest correlations were observed between birth rates, maternal mortality, subsistence minimum, level of education, incidence of narcomania and toxicomania (including that among adolescents), release of hard harmful substances in the atmosphere and of chlorine and sulfates in surface water bodies (r = 0.4-0.8). Multifactorial model was derived by the step regression method. This model can be used for predicting the level of neonatal mortality in the nearest 5.6 years on the basis of the negative or positive shifts in the socioeconomic status of Russia. In addition, several unifactorial exponential models at a district level were obtained, reflecting the relationship between neonatal mortality and birth rates, unemployment and incidence of narcomania and toxicomania.
The paper considers some modes of designing regression and autoregression models for predicting morbidity rates, as well as methods for correlation and factorial analysis of medical statistics on the basis of the materials available on cancer morbidity in Udmurtia.
The trends and main factors influencing the fluctuations of the levels of tularemia and pseudotuberculosis morbidity in the Iaroslavl region were revealed by the methods of mathematical statistics (regress analysis, time-series analysis, etc.). Tularemia morbidity was 0.467 +/- 0.216 cases (1950-1997) and pseudotuberculosis morbidity was 0.979 +/- 0.297 cases (1979-1997) per 100,000 of the population. The multiple regression equations permitting the prognostication of tularemia and pseudotuberculosis morbidity in the Iaroslvl region were derived.