Blood pressure in essential hypertension before and after treatment

Patients	Blood pressure		Difference	Rank difference	The sum of the ranks "+"	The sum of the ranks "-"
	Before treatment	After treatment
В.	210	175	-35	6,5	6,5	-
D.	180	180	0	-	-	-
К.	185	140	-35	6,5	6,5	-
Р.	160	185	+25	4	-	4
Н.	175	145	-30	5	5	-
Р.	190	150	-40	8	8	-
А.	155	160	+5	1	-	1
С.	180	160	-20	3	3	-
U.	200	155	-45	9	9	-
Т.	170	155	-15	2	2	-
					T=40	T=5

Determined by the difference in the pairs of observation between the upper and lower levels of blood pressure.

 

X-ray results on the margin between the rates without considering the direction of change. Results without the dynamics are excluded from further evaluation. If two results have the same absolute value changes, then their ranks are referred to as the floor amount of sequence numbers.

 

Counting the sum of the ranks of single-valued (positive and negative).

Rated at the sum of the ranks is by comparing a specific t-tests with the tabulated value at the respective pairs of observations.

 

Wilcoxon's test T = 5 does not exceed the tabulated value for a given number of observations n= 9, T0, 05 = 6. However, we can conclude about the nature (statistical probability), the dynamics of blood pressure in patients after treatment. another group of non-parametric criteria - criteria that are used in the comparison of independent populations. These typical examples of their practical use is to compare the study and control groups of patients, the result of two groups of observations that apply to different diseases or severity of pathology.

For comparison, independent sets are used:

1. The serial test;

2. Criterion Uaita;

3. The criterion of Van der Vard.

METHOD OF KOLMOGOROV-SMIRNOV

Table 38

Change in radioactivity of the blood of irradiated animals that received (A) treatment and did not receive (V) treatment (arbitrary units)

Variations on a number of X and Y	Frequency options for groups		Cumulative frequencies for groups		Accumulated part by groups of		Difference │(Sx / nx)- -(Sy/ ny)│
	Px	Py	Sx	Sigh	Sx / nx	Sy/ ny
24	2	0	2	0	0,22	0	0,22
26	3	0	5	0	0,56	0	0,56
28	1	2	6	2	0,67	0,25	0,42
30	1	1	7	3	0,78	0,38	0,40
32	1	0	8	3	0,89	0,38	0,51
34	1	1	9	4	1	0,50	0,50
36	0	1	9	5	1	0,63	0,37
38	0	1	9	6	1	0,75	0,25
40	0	2	9	8	1	1	0
	Nx=9	Ny=8

 

1. The numerical values of two variation series combined into a single variation series, versions of which are placed in ascending order.

2. Determine the frequencies of variants for both groups of observations.

3. Determine the frequencies obtained for both groups.

4. Determine the received parts, for which the accumulated frequency divided by the number of observations for each group.

5. Calculated as the difference obtained by the frequency of groups X and Y without signs.

6. Determine the maximum difference - D = 0.51

7. Determine the criteria (λ²) by the formula

8. Comparative result with the limit values of the Kolmogorov-Smirnov test.

If λ² more limiting value, the difference between the two groups is significant.

For this task, λ² = 1,10. Comparing this result with borderline value λ^²_0.05 = 1.84 and λ²_{0, 01} = 2.65, we conclude that no significant difference between the comparison groups.

 

CRITERIA PEARSON:

 

F-is reality frequency;                                                                            

F₁- is theoretical frequency

THEME 6

DYNAMIC ROW. STANDARDIZATION

Features of the theme

In practical work doctors must analyze some processes in time. If the analysis is difficult we use standardized coefficients that help to eliminate the difference.

Aims of studies

To teach students the method of finding indices dynamic row and carrying out the analysis of direct method of index standardization and practical using.

Topic contents

Dynamic row is a row of heterogeneous statistical values showing alteration of a definite phenomenon within temporal and spatial limits. Figures constituting dynamic row are its levels (absolute, relative or average values).

Simple dynamic row and its indices consist of absolute values.

Derived dynamic row - consist of relative or average values.

Instant dynamic row – values are given in a definite time instant, for example, the number of physicians by the end of the year.

Interval dynamic row – values are given for a definite time period (month, quarter).

Basic indices characterizing dynamic row:

1. Absolute increase (decrease) – difference between succeeding and preceding levels.

2. Rate of increase (decrease) – proportion of absolute increase in preceding level.

3. Value of 1% (decrease) – proportion of absolute increase to increase rates.

4. Rate of growth – proportion of succeeding level to preceding one.

I. Dynamic row

II. Method to smooth out dynamic row:

a) Consolidation interval

b) Smooth out row: - find grouping average

- find sliding average

Standardization

Comparison of parameters in sets which differ in structure, demands their standardization, it means the amendment, provided that the structure of sets will be shown to the uniform standard. Doctors and scientific workers often compare the statistical indices according to groups. In these cases, methods of standard indices are applied to eliminate differences in different groups.

Methods of standardization:

 1.Direct

 2. Indirect

 3. Approximate.

Here we apply the direct method of standardization.

Direct method of index standardization is conducted in five stages:

Stage I. Calculation of intensive indices in compared groups. (Sickness rate, for example, city and village population).

Stage II. Choice and calculation of standard

Stage III. The calculation of “expected” figures in every group of standard.

Stage IV. Calculation of standardized indices.

Stage V. Comparative of simple intensive and standardized indices, conclusion.

Table 39