Медицина/
Ryabuh N.M.,
Kovalenko E.V., Kpe Petit A.
SO «Luhansk state medical
university»
STATISTICAL
ESTIMATION OF INFLUANTION OF AGE PARAMETER BY THE MORTALITY RATE OF PATIENTS
WITH ISCHEMIC HEART DISEASES
The purpose of the
present work is estimation of mortality rates of patients by ischemic illness
of heart with the count of age parameters.
Difference of
mortality rates among men and women was conducted.
It explored a problem of a
mortality among patients suffering from ischemic heart disease, within the
first year after the diagnosis was detect. On the basis of a radiological
clinical survey of 585 patients, with their subsequent observation (first
half-year - once per month, second – ones per three months) was carried out.
Patients were assorted to the following indications: procedure of treatment,
gender, occupation, a place of residence, etc. We shall consider two sets of
patients separated by gender(male and female). In the first set collected
information about 370 men of which 134 deaths were registered. In the second
set collected information about 215 women of which 57 deaths were registered. Age difference around 45 years( from 35y.o. up to
80y.o.). In the able-bodied age around 338 people and 247 pensioners.
The distribution by age parameter shown in fig.1(men) and fig.2 (women).
Fig. 1. Men with ischemic
heart disease Fig.
2. Women with ischemic heart disease
The results of estimation by 
criterion shown in the Table 1.
Table 1.
|
Age groups |
men |
women |
|
|
||||
|
with disease |
deaths |
Mortality
% |
with disease |
deaths |
Mortality
% |
χ |
|
|
|
35-40 |
15 |
5 |
0,33333 |
9 |
1 |
0,11111 |
1,4815 |
|
|
41-45 |
57 |
19 |
0,33333 |
9 |
2 |
0,22222 |
0,4423 |
|
|
46-50 |
54 |
15 |
0,27778 |
12 |
4 |
0,33333 |
0,1478 |
|
|
51-55 |
69 |
24 |
0,34783 |
25 |
3 |
0,12 |
4,6525 |
|
|
56-60 |
63 |
26 |
0,4127 |
28 |
8 |
0,28571 |
1,3356 |
|
|
61-65 |
43 |
14 |
0,32558 |
35 |
9 |
0,25714 |
0,4347 |
|
|
66-70 |
42 |
19 |
0,45238 |
39 |
11 |
0,28205 |
2,5159 |
|
|
71-75 |
18 |
5 |
0,27778 |
27 |
9 |
0,33333 |
0,1555 |
|
|
>75 |
9 |
7 |
0,77778 |
31 |
10 |
0,32258 |
5,9141 |
|
|
summ |
370 |
134 |
3,53849 |
215 |
57 |
2,26749 |
17,08 |
|
Calculated value of χ2
equals to 17.08. The critical value for detected degree of freedom k=9
and significance level α: χ2кр=16.92 for α =0.05;
χ2кр=21.7 for α =0.01. Thus, the barrier of significance level α
=0.05 surpassed the difference between mortality rates of in the sets of
men and women, it is necessary to count statistical significance.
The results of estimation by
Wilckokson criterion shown in the Table 2.
|
Men with disease |
Men deaths |
Rank |
Women with disease |
Momen deaths |
Rank |
|
|
15 |
5 |
5,5 |
9 |
1 |
1 |
|
|
57 |
19 |
15,5 |
9 |
2 |
2 |
|
|
54 |
15 |
14 |
12 |
4 |
4 |
|
|
69 |
24 |
17 |
25 |
3 |
3 |
|
|
63 |
26 |
18 |
28 |
8 |
8 |
|
|
43 |
14 |
13 |
35 |
9 |
9,5 |
|
|
42 |
19 |
15,5 |
39 |
11 |
12 |
|
|
18 |
5 |
5,5 |
27 |
9 |
9,5 |
|
|
9 |
7 |
7 |
31 |
10 |
11 |
|
|
370 |
134 |
111 |
215 |
57 |
60 |
|
Calculated U parameter is
equals to 15. Critical values by significance level 0.05 equals to 17. Us
result a hypothesis H0 is rejected so difference between mortality rates of men
and women was proved.
From the solution carried out above
typical statistical problems - problems of checkout of a hypothesis about
difference of rate of mortality with the count of age parameters for two sets it is possible to
draw a deduction on expediency of the organization of works on critical
analysis of practice of statistical data processing developed in medico-biological
examinations and on introduction of the accumulated arsenal of methods of an
applied statistician. Wide introduction is deserved and, in particular, with
methods of a multivariate statistical analysis, quiescent analysis of the data
of the non-numerical nature.