Evaluation of population frequency for age-dependent multifactorial disorders

Abstract

Aim. Description of the method to calculate the population incidence of age- and sex-dependent multifactorial diseases. Methods. For the analysis, we used statistical material of psychiatric hospitals in the Kharkiv region for 2016. Calculation of the population frequency was carrying out according to the methodology used in demographic studies. Results. In medical genetics, population frequency is mainly used for prognostic purposes to assess the genetic load of a population or to calculate the probability to inherit a disease. Evaluation of the population frequency of multifactorial disease is complicated by varying age of onset, differential survival, different thresholds of hereditary predisposition for men and women. Prevalence, which is often used instead population frequency, is not a gene pool characteristic and is not useful for genetic analysis and risk assessment. The population frequency, calculated for affective disorders by the proposed method (0.184%), is 1.33 times higher than the prevalence rate (0.138%), that is, a third of cases when using the prevalence turns out to be lost that distorts the derived genetic indicators. Conclusions. For the correct evaluation of the population frequency, the age-specific incidence for two sexes separately must be estimated, followed by the calculation of the cumulative frequencies.

Keywords: multifactorial diseases, prevalence, morbidity, population frequency.