Novokuznetsk State Institute of Postgraduate Medicine,

Novokuznetsk, Russia

 

The health of working population is the complex social hygienic and economic index, which integrates some biological, demographic and social processes in the human society. It reflects the level of economic and cultural development, state of medicine and it is influenced by traditions, historical, ethnographic and natural climatic conditions of the society.  

One of the actual objectives of Russian health care is protection and promotion of health of working age people. The basis of state social politics is provision of priority for maintenance and promotion of health of working people as the important social productive forces defining national safety of the state and its economic development. Development and realization of the social program for protection of workers’ health are especially important at the background of the problems, which appeared in 90s in the previous century and in the beginning of the present century in Russian Federation in conditions of the social economic reforms [1].     

Kemerovo region is the district of developed chemical and coal mining industry. Novokuznetsk city and its suburbs include multiple coal mines and two large metal industry enterprises: Western Siberian Iron & Steel Works and Novokuznetsk Iron & Steel Works (the united enterprise now). Also there are aluminum, chemical factories etc. Most employees work at the above mentioned enterprises of heavy industry and, as result, the issue of health preservation is fairly actual and it requires additional investigation.

Objective – to identify the main trends and patterns of health status in the working population of a large industrial city in Siberia (on the example of Novokuznetsk).

 

MATERIALS AND METHODS

The analysis was based on the data from the automatic information system Health Status of Employees and the normative-reference fund of Kustovoy Medical Information Analytic Center, Novokuznetsk. We developed the system as a component of social hygienic monitoring of environment and health status of population in Novokuznetsk [2]. The system is maintained in Kustovoy Medical Information Analytic Center. The database of the estimate indicators of health status of employees [3, 4] is based on the personalized information from the databases: Incidence, Health Assessment, Mortality, Disability, Hospital, Temporary Work Incapacity (the forms 025, 030, 028, 024, 066, 016 correspondingly), which are registered in the Scientific technical center Informregister (state registration from July, 19, 2007). The article describes the algorithm of integration of indicators in use for the automatic information system of social hygienic monitoring [5].         

The information about structural characteristics of the population of Novokuznetsk (2008-2013) was taken from the territorial department of federal statistics.

For statistical analysis the data of health status of the employees in Novokuznetsk (2008-2014) was converted into IBM SPSS Statistics 19.0. IBM SPSS Statistics 19.0 and Biostat 4.03 were used for calculation of statistical criteria χ² for analysis of qualitative signs in several independent groups, z-criterion for analysis of sequential signs in two non-coherent groups, Spearman rank correlation for examination of sequential signs, Kendall's tau test for examination of significance of trends of signs over time, Wilcoxon test for comparison of mean age of death among working men and women, and descriptive statistics. Annual average values (M) are given with standard deviation (σ).

 

RESULTS

During the studied period the population of Novokuznetsk decreased by 2.3 % from 562,200 to 549,200.             

The amount of working age population decreased by 8.1 % (from 360,400 to 331,800). The proportion of working age population was 64.1 % in 2008 and it decreased to 60.4 % in 2013. The number of the working age men decreased from 178,100 to 166,200 (6.7 %). Decrease in the number of the working age women was even higher – from 182,300 to 165,600 (9.2 %).

Before 2012 the number of working age women was above the number of working age men. In 2013 the number of working age women (165,600) was lower than the number of working age men (166,200).

According to the department of state statistics of Kemerovo city, the number of the employees in Novokuznetsk decreased by 14.3 thousand people in comparison with 2009, and it consists 248,290 employees in 2013. Moreover, during 2011-2013 the number of working individuals increased by 3,900 persons.

The health of working individuals in Novokuznetsk is estimated by means of the integral index – health index (HI), which includes the values of general incidence (polyclinic and hospital), temporary disability, health examination, disability and mortality among working individuals; also it includes the indexes of demographic load to working population.  

The correspondence of health indexes to linguistic variables of health state in working population: [0.75 – 1.00] – acceptable level of health, [0.51 – 0.74] – satisfactory one, [0.26 – 0.50] – low level, [0.00 – 0.25] – extremely low level.

Health index in the working population of Novokuznetsk (2014) decreased from the acceptable to satisfactory level (0.696). It is the most unfavorable index during 7 years.     

Hereafter we describe the actual and integral values of health in the working population during 2008-2014 which present the main components of health index.

The values of demographic load to the working population.

The percentage of the working population increased to 87.8 % in Novokuznetsk in 2014. This is the highest index for the last seven years. The index is 0.92 that corresponds to the acceptable level according to the linguistic scale.  

In 2014 the non-working population (with children) load to one worker decreased from 1.01 in 2011 to 0.91 (i.e. 91 non-working individuals per 100 employable persons in 2014). The index improved from 0.89 (2009) to 0.99 (2014), and it corresponds to acceptable level according to the linguistic scale.  

The load, which the non-working population applied to one worker including children, decreased from 1.01 (2011) to 0.91 (i.e. 91 non-working individuals among 100 working persons in 2014). The index increased from 0.89 (2009) to 0.99 (2014). It corresponds to acceptable level according to the linguistic scale.

Hereafter we consider the values of health state in working individuals: morbidity according to addressing to medical facilities, morbidity with temporary work incapacity, values of health examination for chronic diseases, hospital mortality, disability and mortality

In 2008-2014 we observed increase in the indices of morbidity among the working population according to addressing to medical facilities. Beginning from 2010 one could observe increasing morbidity and injury rates among the working population. The positive factor is associated with decreasing rate of chronical diseases (table 1).  

Table 1
The main rates of morbidity among working persons in Novokuznetsk

Within the last 4 years the increasing values of morbidity and traumatic accidents have been identified. At the background of two year decrease in severity of pathologic process, the increase in primary morbidity should not be related to exclusively negative moments, because it testifies timely addressing to medical facilities (Fig. 1). In 2013-2014 the rates of chronic morbidity per 1,000 working individuals was significantly lower than the values of primary morbidity (z = 14.6 in 2013, z = 18.5 in 2014, ð < 0.001).

Figure 1

The general and chronic morbidity in workers of Novokuznetsk

Medical specialist attendance. In 2014 the total amount of visits was 1,056,600. It is 0.8 % lower than in 2013. The highest percentage of medical specialist attendance was related to therapeutists (34.3 %), gynecologists (13.9 %) and surgeons (9.7 %).

Significance of visit trends in 2008-2014 was tested with Kendall's tau test. The results are presented in the table 2.

Table 2
Significance of changes in number of referral to medical specialists in Novokuznetsk in 2008-2014

Beginning from 2008 one could observe the decreasing rates of medical attendance except for surgeons (Fig. 2). In 2014 (in comparison with the previous years) the greatest decrease was registered for ophthalmologists (growth rate -21.0), endocrinologists (-11.3), neurologists (-7.6). In 2008-2014 neurologist attendance decreased from 102,000 to 72,100 visits (by 29.3 %).

Figure 2

The amount of visits to specialists (the absolute number, thousands of visits) in 2008-2014 

 

The health care managers should consider some issues of availability of medical specialists for the city population including working individuals.

The dynamic trends (2008-2014) of the main indices of temporary disability of Novokuznetsk workers and significance of the trends according to Kendall's tau criterion are presented in the table 3.

Table 3
Dynamics of the main values of temporary work incapacity in Novokuznetsk for 2008-2014

The number of registered working individuals with chronic diseases decreased by 357 persons in 2014 in comparison with 2013 (growth rate -1.06). It included 33,397 persons. The index is 1.00 that corresponds to acceptable level. All values of the composite index were close to the optimal level except for the percentage of the working individuals examined by urologists. It is 0.61 (satisfactory level). The value did not alter in comparison with the previous year.

In Novokuznetsk most working persons with registered chronic diseases are observed by therapeutists (69.8 ± 2 %), gynecologists (14.7 ± 1.4 %), endocrinologists (3.3 ± 0.2 %).     

Over time the absolute number and percentage of persons with chronic diseases increased for ophthalmologists (τ = 0.8, ð = 0.017), and decreased for surgeons (τ = -0.9, ð = 0.023) and endocrinologists (τ = -0.8, ð = 0.015).   

One could observe some increasing relative values of health examination from 103.3 in 2008 to 116.0 in 2014; the changes are statistically significant: z = 2.9; p = 0.003. The annual variations do not allow identifying any significant time trends: τ = 0.52, ð = 0.099.   

During comparison of morbidity rates in the working individuals and the rates of health examination in the working individuals with chronic diseases one can make some conclusions:

-          The index of healh examination is persistent despite of the increasing rate of surgeon attendance from 63,700 to 102,700 people. The relationship between the indices is reversely related, statistically significant; Spearman correlation test: r = -1.0, p <0.001.

-          The rate of health examination in individuals with chronic diseases reliably increases with decreasing ophthalmologist attendance from 57,000 to 38,800 people in 2008-2014. The relationship between the indices is reversely related and statistically significant: r = -0.9, p = 0.003.

-          For the examined period one could observe the decreasing rate of gynecologist attendance among employed women. The health care managers have received a recommendation about investigation of availability of gynecologists. In 2013 the increasing rate of monitored patients with chronic gynecologic diseases was registered. Again it confirms the importance of timely treatment.           

147,600 patients were admitted to the hospitals of Novokuznetsk, i.e. 7,000 lower than in 2013. 56,027 cases (32.3 %) are the cases of admission in the working population among all admitted patients in 2008. In 2014 this value decreased to 40,566 cases (27.5 %). For the last 5 years the trends showed decreasing admission rate for both the whole population and the working individuals.

The proportion of the working individuals who were discharged in state of recovery increased from 41.2 % in 2011 to 48.3 % in 2014.

Up to 2014 the percentage of the admitted working individuals who were referred from outpatient clinics was decreasing: from 42.7 % in 2008 to 30.1 % in 2013. In 2013 one could observe the lowest generalized index among all health indexes in the working individuals of Novokuznetsk (0.38). In 2014 the index increased up to 36 %.

The statistically significant trends of decreasing for some values of admission were found in the working individuals in Novokuznetsk in 2008-2014.     

The mean duration of hospital stay decreased from 11.2 to 10.4 days. Among the working individuals the percentage of emergent admission decreased from 64.6 % in 2008 to 54.8 % in 2014. The trend was positive, but the value is still high.  

Therefore, one may make some  conclusions about decreasing quantiative values of admission. However some qualitative values worsen, for example, the percentage of admissions according to polyclinic referrals, with the persistent trend up to 2013. Some indicators showed the positive trends: the increasing percent of discharged patients with recovery, the decreasing proportion of emergent patients and recurrent admission, and the decreasing rate of patients with worsening state.     

Within 2008-2014 the examination of disability status covered 2,635 ± 668 working persons each year; among them 2,582 ± 665 were recognized as disabled persons each year.

Over time the actual indices of disability had been decreasing significantly, except for the item acknowledged as disabled persons. The most severe category of disability was assigned to 135 persons in 2008 (3.6 % of the persons who were acknowledged as disabled), 217 persons in 2013 (10.5 %), 235 in 2011 (9.3 %), with decreasing up to 157 persons in 2014 (8.6 %) (Fig. 3).  

Figure 3

The percent of disability of category I among the working persons in Novokuznetsk in 2008-2014

  

The table 4 shows the main indices of disability and distribution of the working individuals according to the disability categories for 7 years.

Table 4
The values of disability among working persons in Novokuznetsk for 2008-2014

The value of general disability (per 10,000 working individuals) was 61.4 % in 2014, with decreasing for the last 7 years (127.0 ‰0 in 2008). According to the linguistic scale the index (1.00) is at acceptable level. 

The index of primary disability (per 10,000) decreased from 59.0 ‰0 in 2008 to 33.4 ‰0 in 2014.   

The significant increase in the percent level in 2014 was observed in the first group of consideration (from 3.6 % in 2008 to 8.6 %). It indicates the statistically significant worsening of disability among the working individuals: z = 7.8, p < 0.001. The decreasing from 10.5 % to 8.6 % was in 2014 in comparison with 2013. But over time the increase in the trend was statistically significant: τ = 0.7, ð = 0.024.

More than a half of the examined working individuals (60.5 ± 5.9 % for 7 years) rceived the third group of disability. During 2009-2014 the value increased from 51.7 to 69.3 %: z = 12.3; p < 0.001. The trend is statistically significant: τ = 0.7, ð = 0.024.

The disabled persons of the second group are 30.1 ± 8.5 %. The working individuals with the second group of disability demonstrated the statistically significant decrease in the values from 43.1 to 18.1 %: z = 18.1;  ð < 0.001.      

Therefore, the significant decrease of the proportion of disabled persons with the second group of disability and the significant increase in the proportion of disability of the first group (the most severe group) testify worsening disability among the working individuals in Novokuznetsk.

The integrated index of the second and third groups of disability was at acceptable level according to the linguistic scale. The index was low according to the first group (0.47). 

The main cause of disability was a general disease. According to this cause, 92.4 ± 2.1 % of the working individuals were recognized as disabled persons according to the results of medical expert commission. About 0.6 ± 0.4 % of disability cases as result of professional diseases are registered each year. In 1.8 ± 0.7 % cases a category of disability is given as result of an industrial injury. The average annual ratio of severity of disability is 1.4 ± 0.05 %, with stable dynamics.       

Therefore, at the background of positive trends of decrease in some values of disability among working individuals in Novokuznetsk, the anxiety is associated with increase in absolute and relative number of disabled persons in 2008-2013.

A total of 359 working individuals (288 men [80.2 %] and 71 [19.8 %] women died. In 2008-2014 the mortality rate decreased from 636 cases in 2008 to 359 in 2014, but the trend was unfavorable in 2010-2013. It is also evident according to distribution of the deceased persons according to gender (better values in 2014).

The figure 4 demonstrates the gender correlation in the deceased working individuals for 2008-2014.    

Figure 4

The gender ratio in deceased persons for 2008-2014

Therefore, 10 deceased employed women fall on 33-44 deceased employed men.

Annually 207 ± 61.3 working individuals die due to diseases, 184 ± 33.2 – from injuries and poisoning, 23 ± 6.6 – from indistrial accidents, 32 ± 6.4 – from suicide.   

As for the causes of death, the first place is taken by blood circulation system diseases (114 ± 25.8 working individuals each year), followed by ischemic heart disease (68 ± 10.2) and malignant tumors (63 ± 14.1).   

The figure 5 demonstrates the general mortality among the working individuals (per 1,000) in Novokuznetsk in 2008-2014.

Figure 5

The general mortality in the working persons in Novokuznetsk (per 1,000 persons) for 2008-2014

After comparison of the years 2008 and 2014 the statistically significant decrease in general mortality was found: from 2.15 to 1.25 per 1,000 working persons: z = 16.9, p < 0.001.

The positive statistically significant trends were found for the mortality as result of respiratory diseases: τ = -0.7, ð = 0.039; lethal outcomes after industrial accidents: τ = -0.7, ð = 0.033; mean age of died employed women: τ = 0.8, ð = 0.011.

The mean age of the deceased working persons is 46.0 ± 0.9 for the examined period. The mean age of the deceased men is 45.2 ± 0.9, the deceased women – 48.8 ± 1.7. Therefore, the working men die at yonger age in comparison with women. Wilcoxon’s test was used for determing the differences in mean age of death in the working men and women in 2008-2014. The statistically significant difference was found: z = -2.4; p = 0.018.       

The most unfavorable values among the generalized values of mortality are associated with the mean age of the deceased men (0.84) and the mean age of the deceased working individuals (0.85).

Generally, the lowest levels of the generalized indices of health in the working persons in Novokuznetsk (2014) are related to the values, which are presented in the figure 6.  

Figure 6

The generalized indexes of health requiring specific control among the working persons for 2014

 

The lowest generalized indices of health (0.45) are related to the rate of admission of the working persons according to polyclinic referrals; 0.47 – the percent of disabled persons of the first group. The unfavorable indices are the percentage of the working individuals registered at urologist (0.60), morbidity per 1,000 working individuals (0.64), the mean age of deceased men (0.84).   

The correlation analysis of the main health indices in the working individuals of Novokuznetsk in 2008-2014 was conducted with Spearman correlation test that identified the direct strong relationship between the index of health examination per 1,000 working individuals and the percentage of disability of the first group among the examined working individuals: r = 0.9, p = 0.003 (the increasing trend).

The strong reverse relationships were between the percentage of the disability of the first group and the following signs: the amount of cases of work incapacity per 100 working individuals, the values of general and primary disability (r = -0.8, p = 0.023), the percentage of referrals from outpatient polyclinic services (r = -0.7, p = 0.036).  

The strong reverse correlation was found between the number of available beds and the rate of hospital mortality: Spearman correlation test, r = -0.81; p = 0.008. Therefore, the decreasing number of hospital beds was related to increasing hospital mortality.

The strong reverse relationship was between labor conditions and the proportion of the first group of disability (the most severe one) in the working individuals: Spearman correlation, r = -1.0; p < 0.001. Therefore, the worse labor conditions, the higher proportion of disabled persons of the first group among the working individuals.       

 

CONCLUSION

During 2008-2014 one could observe the decreasing values of temporary work incapacity, disability and mortality in Novokuznetsk. At the same time we found the increasing values of morbidity with increasing rates of adressing to the medical facilities, from 2010 – increasing morbidity and injury rates, increasing relative value of health examination according to chronical disease, the increasing proportion of disability of the first group (the most severe one), the increasing number of recurrent admission, the very low percent of admissions with referrals from outpatient clinical services, the high percent of suicides.

According to the results of the study one may make some conclusions about some natural relationships between health of working individuals, labor conditions and some values of health care activity. Therefore, some complex measures at federal, regional and municipal level are necessary.   

 

THE RECOMMENDATIONS

1. Full information about morbidity in the working individuals of Novokuznetsk city requires data transfer to Kustovoy Medical Information Analytic Center not only from municipal medical facilities, but also from private medical organizations according to orders by city administration.
2. For increasing reliability of information we need to correct and specify some standards of integrated values of health with use of the automatized system, for example, percentage of surgeon attendance.
3. The relative values of disability should be calculated per 10,000 working individuals, but not per 1,000.
4. It is necessary to increase control of working conditions and conduction of timely and complete preventive medical examinations for decreasing chronical course of diseases, pathologic processes and disability among employed persons.       

 

The author gives thanks to V.A. Makhov, MD, the director of Kustovoy Medical Information Analytic Center, for presenting the output data from the automatic center Health Status of Working Individuals (2014), the actual and integrated values of health in the working individuals in Novokuznetsk.