Relevance. The problem of predicting the probability of re-onset schizophrenia in the early period is one of the most pressing in the process of treatment and secondary rehabilitation of patients. According to researchers [2.4], relapse is observed within the first two years after the end of the regular attack at least 70% of patients, and no less than 40% of patients within the first year. The highest probability of relapse is during the first year after the patient's discharge from hospital [6]. At the same time, along with clinical and biological factors that influence the occurrence of an attack, more research attention is paid to social and labor characteristics of patients [2]. It is unclear what factors affect the risk of recurrence, and what is their total contribution.

Aim. The aim of the study was to develop a system of clear criteria for individual predictors of recurrence, i.e., symptoms, the occurrence of which should serve as an indication of increased risk, and the signal for correction of therapy. For convenience in the practical use of such a combination of features it should be provided integrated assessment, reflecting the contribution of the total weight of each variable [3,5].

Materials and methods. On the basis of psycho-neurological clinic inpatient units patients with schizophrenia and schizophrenia-spectrum psychosis were examined. In order to collect patient information the "Questionnaire for the assessment of social functioning and quality of life of the mentally ill patients", developed at the Institute of Social and Clinical Psychiatry [2], used. Inclusion criteria were young, working age, the absence of disability. The study excluded patients with the presence of other mental or severe somatic pathology. There were 90 patients with schizophrenia and schizophrenia-spectrum psychosis under our supervision. The average age of patients was 24,6 ± 1,4 years, mean disease duration at the time of the survey was 1,7 ± 0,3 years. In 35% of the patients were psychotic episodes at the time of this admission. In 41 persons (46%) had been diagnosed with schizophrenia. The majority (30 people) course of the disease was defined as episodic-like progressive, the rest (11 patients) as a continuous. At 40 the state was classified as acute polymorphic psychotic disorder, that, mostly, reflected the desire to avoid the stigma of primary patients. 9 people diagnosed with schizoaffective psychosis. Data on patients were recorded using a special card that contained 3 pieces of information: the biological, clinical and socio-labor signs.

In the first stage processing of information the structure of medical and social characteristics of patients is studied. In the second stage from all attributes relevant to the likelihood of re-attack 16 variables were isolated. The expert information for rank evaluation of each characteristic value was collected through using the method of a priori ranking. When collecting a priori information experts (8 psychiatrists with experience from 3 to 20 years) were offered to fill in the questionnaire of 16 indicators, in their opinion, the most influence on the probability of re-onset schizophrenia. Indicators were ranked from 1 (the most significant sign) to 16 (least influencing sign). (Table 1)

According to the type of data logging variables were of two types. The first group included indicators reflecting a quantitative component, the signs with numerical score belonged to the second category. For each indicator scores system was designed from 1 to 5. Catamnesis all patients was followed for two years, or until the completion of the remission. Patients were divided into 3 groups depending on the disease type. At favorable type qualitative remission and absence of hospitalization were observed, at medium-progredient type there was single admission, and at poor course - hospitalization rate was more than twice during the study period.

Results. Consistency of expert opinions is confirmed by calculation coefficient of concordance, which amounted to 0.84, that proves  the hypothesis of experts consistency.

According to the ranking matrix the weight values w_i of the individual indicators [1.5], affecting the level of rehabilitation potential, were determined.

W_i was calculated by the formula:

,

where m - number of columns of the matrix (in this case - it is the number of experts),

n - the number of rows (number of parameters),

r_ij - assessment of the j-th expert.

Table 1 shows the rank sum and the weight factors for each studied trait.

Table 1. Estimates of experts, the sum of ranks and weights.

Indicator	Assessments of eight experts
	1	2	3	4	5	6	7	8	∑	wi
X1 (Heredity)	2	8	8	9	2	11	2	5	47	0,05062
X2 (Transferred episode)	1	9	1	1	3	1	1	4	21	0,06687
X3 (Rage)	9	10	9	2	9	8	6	6	59	0,04312
X4 (Maintenance therapy)	11	1	2	4	4	2	7	7	38	0,05625
X5 (Drug abuse)	10	2	10	5	8	4	8	16	63	0,04063
X6 (Acuteness of psychosis)	3	11	4	16	12	9	11	1	67	0,03813
X7 (Age)	4	12	11	15	16	10	14	13	96	0,02
X8 (Daily activity)	8	13	14	10	14	15	3	12	89	0,02438
X9 (Marital status)	5	14	12	8	10	12	9	11	81	0,02938
X10 (Relationship with relatives)	6	1	3	13	6	5	12	2	48	0,05
X11 (Disease duration)	12	15	13	3	13	13	4	14	87	0,02563
X12 (Work, study)	13	4	5	6	5	6	13	8	60	0,0425
X13 (Housing conditions)	16	16	16	12	16	16	15	15	122	0,00375
X14 (Effectiveness of treatment)	7	5	6	11	11	7	16	9	72	0,035
X15 (Alcohol Abuse)	14	6	15	7	1	3	5	10	61	0,04188
X16 (Education)	15	7	7	14	7	10	10	3	73	0,03438

 

Based on data from the table, the highest value in the assessment of recurrence risk of schizophrenia experts gave such biological signs as heredity and age. From clinical signs, most experts prefer the severity of psychosis, aggressive behavior, substance abuse. From the most significant social unit was the nature of the relationship with the family, education level, marital status.

Integral indicator (IP) of the probability of re-attack was defined as

where w_i - weight (importance) i-th index,

X_i - scoping the i-th index.

According to the results of calculations the integral index ranged from 1.3 to 1.7. (Tab. 2). Thus, quantification of the likelihood of re-attack can be written in the form of slots. In this case, the dependence of the integral index is inversely proportional to the probability of re-onset schizophrenia. That is, more favorable course of schizophrenia and a low probability of worsening are characterized by high indexes IP and the unfavorable currents and a high probability of relapse - by low indexes.

Table 2. Values of the integral index, and the likelihood of relapse.

The probability of an attack	High IP (low)	Average IP (average)	Low IP (high)
IP	1,7 - 1,63	1,64 - 1,41	1,40 - 1,30

 

In order to test the validity of the proposed integral index for all patients admitted for treatment during this period integral indicator of the probability of re-arrest was calculated. Quantitative assessment of the indicator was 1.3 to 1.7. Using the integral index as the product of joint influence of an attribute set on the occurrence of re-onset schizophrenia showed high accuracy. The total share of falsely classified objects did not exceed 26%. It is particularly important approach to clinical expert metrics in the group with a high risk of relapse occurrence where errors accounted for 6%.

Thus, with the help of the integral index of the probability of re-onset schizophrenia it is possible to predict the course of the disease and the possibility of recurrence with sufficient accuracy.

Conclusions. The signs, most influencing the ability of re-attack, is distinguished. A component that allows to carry out the complex estimation of the patient condition, apply the appropriate rehabilitation programs, and prevent relapse has been offered. For the convenience of the physician work the calculation of integral index may be implemented in a computer program.

 

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