The Use of Joinpoint Regression Analysis in the Mortality Study of Developmental Age Population in the Podlaskie Voivodeship, 2003–2012

Abstract

The youngest population in society is recognized as that at the healthiest stage of life but is burdened by the occurrence of premature death that should be avoidable. There is a need to use adequate statistical methods in assessing the health status of the population of developmental age. The aim of the study was to analyze trends of mortality in children and adolescents by age and gender in the Podlaskie Voivodeship in the years 2003-2012 by joinpoint regression and to identify the causes of mortality. The mortality rate was analysed according to gender and the age groups: 0, 1-4, 5-9, 10-14 and 15-19 years in the Podlaskie Voivodeship. The data were obtained from the Central Statistical Office for the period 2003-2012. Differences in mortality levels between age and gender subgroups were obtained by the Wilcoxon signed-rank test. Join- point regression was used to analyze the trends in mortality. The nomenclature of ICD-10 was used to assess the causes of mortality of children and adolescents. In the Podlaskie Voivodeship in the years 2003-2012 in the 0-19-year-old age group, the highest proportion of deaths (42.4%) occurred during the first year of life. There were differences in mortality rates between boys (8.0/104) and girls (3.1/104) in the 15-19-year-old age group (p < 0.01), and also between the 1-14-year-old and 15-19-year-old age groups (p < 0.01), both among boys (2.1/104 vs. 8.0/104) and girls (1.5/104 vs. 3.1/104). Monotonous trends were shown regarding total mortality rates in infants. There was a drop in the mortality rate of infant girls (AAPC = 5.3%, p < 0.05) and boys (AAPC = 4.7%, p < 0.05). Changes in the direction of the total mortality rate trend were visible in the population of boys aged 1-14 years, in which, between 2003 and 2010, a significant reduction in mortality (AAPC = 9.5%) was observed, while in the years 2010-2012 the trend was not significant. No statistical evidence was found that mortality changed among girls in the 1-14-year-old and 15-19-year-old age groups. Deaths in infancy were due to perinatal conditions and congenital mal- formations. The main causes of mortality in the 1-19-year-old age group were external causes, mainly traffic accidents and intentional self-harm. Joinpoint regression indicated a uniform decrease of mortality in the years 2003-2012 except for boys from 1-14 years old, for whom the decreasing trend was for the years 2003-2010 with subsequent stabilization. The main problems are still infant deaths due to perinatal conditions, traffic accidents and intentional self-harm in boys in the 15-19-year-old age group.