Occup. Med. 1992; 42: 188-192
Relationship between occupational health care and absenteeism P. Hamers, P. Kamphuis and J. van Poppel Institute for Social Research, University of Tilburg, The Netherlands
THE EXPERIMENT The experiment took place in three areas: Doetinchem, Eindhoven and Tilburg. A total of 333 schools (83 per cent of the schools in the three areas) with approximately 8500 teaching personnel participated. It thus concerns a large-scale experiment. The most significant thing about it, however, was the fact that it made use of an unusual model for occupational health care. Innumerable publications1"4 suggest that longterm absenteeism in education is primarily of a psychological nature. The ratio between psychological and non-psychological illness in education is approximately 60 to 40 per cent. Occupational health care has built up a certain tradition in trade and industry. In the industrial field physical illness is far more frequent. The same goes for the public sector. On the basis of the industrial disability figures, one can suggest that the ratio between psychological and non-psychological illness in the civil service is approximately 40 to 60 per cent (van Poppel et al? and the annual reports of the National Civil Pension Fund [ABP]). Most occupational health care units (BGZs) are aimed mainly at these non-psychological problems. The IVA (Institute for Social Research, University of Correspondence and reprint requests to: Dr P. Hamers, Institute for Social Research, Post Box 90153, NL-5000 Le Tilburg, The Netherlands.
© 1992 Butterworth-Heinemann for SOM 0962-7480/92/040188-05
Tilburg, The Netherlands) has therefore developed an occupational health care model for teaching personnel which is geared specifically to the problems occurring in education. This model emphasizes the integration of medical, psychological and social provisions within a single occupational health care unit for teaching personnel. Those involved in the occupational health care unit are the school doctor, who is a trained and qualified occupational health physician, the school psychologist and the school welfare worker. This special unit is part of an existing occupational health care unit. The advantage is that in a team interdisciplinary work is possible, there can be a clear division of tasks, and the channels of communication are kept extremely short. This makes for clarity towards the personnel concerned: there is a single 'unit' which can be called upon to provide all the relevant services. The psychologist will concern himself primarily with the relationship between the problems of organization and work. His tasks include carrying out studies, writing reports and recommendations and guiding organization processes. The task of the welfare worker covers individual and group guidance as regards problems related to work, the aim here being to throw light on problems in the psycho-social sphere. One of the concrete tasks of the welfare worker is, for example, to supervise the return to school of personnel who have been absent for a considerable length of time.
Downloaded from http://occmed.oxfordjournals.org/ at Cambridge University on July 14, 2015
A connection is generally assumed between occupational health care (in Dutch 'bedrijfsgezondheidszorg', or BGZ) and a reduction in absenteeism. In the Dutch literature various authors and researchers make great claims for the effect of occupational health care in reducing absenteeism. As yet, however, they have not concerned themselves very much with providing proof for the validity of their position. They speculate as to the positive influence of occupational health care on the health and welfare of employees and assume a direct connection between it and the reduction of absenteeism, but they do not have at their disposal empirical research results to support their speculations. So far as we know solid research of an experimental or quasi-experimental design into the relationship between occupational health care and absenteeism has never been carried out. Recently, however, an experiment with occupational health care for teaching personnel (in Dutch: Experiment met BGZ voor Onderwijspersoneel, or EBO) did take place, providing the opportunity to determine the influence of occupational health care on absenteeism in a quasi-experimental setting. Unfortunately, the results of the experiment indicate that the relationship between occupational health care and absenteeism is more complex than is generally assumed. In the course of the experiment, and in particular during the final year, the level of absence in the experimental group rose considerably, while in the control group it fell slightly. That rise was mainly due to the increase in the number of persons who were sick for a long period of time (at least 6 months).
P. Hamers et a/.: Relationship between occupational health care and absenteeism
Other occupational health care activities which were carried out during the course of the experiment were the registration of absence due to illness, an occupational health care 'surgery', periodical occupational health examinations, therapeutic work, group guidance, school health examinations, and the provision of Health Information and Education. DESIGN OF THE STUDY AND RESULTS
OlXeO2 O3 Xc O4 where: 01 and O3 relate to the absence due to illness before the start of the experiment, Ol is that of the experimental group, and O3 is that of the control group; O2 and O4 relate to the absence due to illness during the final year of the experiment, O2 is that of the experimental group and O4 is that of the control group; Xe is the experimental variable: occupational health care for teaching personnel; Xc relates to the control group. Xc thus indicates that nothing happened in this group. The effect of the experimental variable (Xe — Xc) can now be calculated using the following formula: Xe - Xc = (02 - Ol) - (O4 - O3). The model presented here is only part of the story. We will now proceed to deal only with the effect during the final year. The effect can be viewed as an end effect of the experiment with occupational health care for teaching personnel. In the intervening period the absenteeism was also registered. Those results will not be considered at the moment. This type of study is based on the assumption that the changes (those relevant to absenteeism) which can take place in the experimental group and in the control group during the course of the whole experiment are the same. In order to facilitate measurement of the effect, the control group consisted of the national sample with which the Work and Welfare Study Group at the University of Leiden measures absenteeism in the teaching profession. The cases selected from the national sample were those that had no access to occupational health care. Since the areas covered by the experiment differ considerably from the control group as regards a number of variables, a multivariate analysis (MANOVA)
was carried out before the above formulae were applied to calculate the effect of the experiment with occupational health care for teaching personnel ('EBO effect'), with the most important differences in school and personnel characteristics between the 'EBO group' and the national control group (in so far as these are relevant to the nature of the absenteeism) being allowed for. One of the differences which had already been allowed for right at the beginning was the composition according to school type. A weighting factor was introduced in order to make the composition according to school type in the national control group exactly equal to that of the EBO group. A variation analysis was also used to correct for: composition according to the level of urbanization of the communities in which the schools were situated; composition according to the religious denomination of the schools (roman-catholic, protestant, other denomination or non-denominational); the average age of the school team; . the male/female distribution of the school team; the proportion of part-timers in the school team; the average number of years that personnel had been employed at the school; the type of school (because of possible interaction with the other features); the possible interaction between the above-mentioned characteristics. The figures for absence due to illness which were finally entered in the formula were the corrected values resulting from a MANOVA, making use of an MCA (multiple classification analysis). These analyses were carried out by the Work and Welfare Study Group in Leiden. Cook and Campbell6 drew attention to two important disruptive factors in this design: selection and regression. The application of a multivariate analysis already solves the problem of the selection. Regression to the average is mainly a problem when the experimental group and/or the control group are made up of groups with extreme scores on the dependent variable. Since this was not the case, it is not likely that the effect measured was disturbed by regression to the average.
RESULTS Table 1 brings together the most significant data from the study. The Table contains not the raw data but with absenteeism figures which have been corrected to allow for the factors relevant to absenteeism. Determining the occupational health care effect is however a matter of the relative differences between the measurements. A negative result of the formula for measuring the effect indicates that in the areas covered by the experiment absenteeism in the relative sense fell, while a positive result indicates a relative increase within the areas covered by the experiment. If the absenteeism percentage figures are compared
Downloaded from http://occmed.oxfordjournals.org/ at Cambridge University on July 14, 2015
Absence due to illness was registered by the Work and Welfare Study Group (Werkgroep A & W) at the University of Leiden (The Netherlands) throughout the course of the whole experiment and during the year previous to it. It is obvious that data on absenteeism are needed to determine changes in it. In order to determine effects, a suitable design is required. Therefore a variant of the non-equivalent control group has been used: The Untreated Control Group Design with Pretest and Posttest6. In broad outline, this design is as follows:
189
190
Occup. Med. 1992, Vol. 42, No 4
Table 1. Corrected levels of absence due to illness for the experimental areas during the preliminary measurements and in the final year of the experiment Experimental areas
Control group national sample
Absenteeism percentage* Preliminary Experimental Difference
7.45 8.19 0.74
7.98 7.85 -0.13
Frequency of absenteeism! Preliminary Experimental Difference
152 147 -5
166 156 -10
13.0 14.4 1.40
15.3 14.2 -1.10
Frequency of long-term absence! Preliminary Experimental Difference
Difference
p
Relationship between occupational health care and absenteeism P. Hamers, P. Kamphuis and J. van Poppel Institute for Social Research, University of Tilburg, The Netherlands
THE EXPERIMENT The experiment took place in three areas: Doetinchem, Eindhoven and Tilburg. A total of 333 schools (83 per cent of the schools in the three areas) with approximately 8500 teaching personnel participated. It thus concerns a large-scale experiment. The most significant thing about it, however, was the fact that it made use of an unusual model for occupational health care. Innumerable publications1"4 suggest that longterm absenteeism in education is primarily of a psychological nature. The ratio between psychological and non-psychological illness in education is approximately 60 to 40 per cent. Occupational health care has built up a certain tradition in trade and industry. In the industrial field physical illness is far more frequent. The same goes for the public sector. On the basis of the industrial disability figures, one can suggest that the ratio between psychological and non-psychological illness in the civil service is approximately 40 to 60 per cent (van Poppel et al? and the annual reports of the National Civil Pension Fund [ABP]). Most occupational health care units (BGZs) are aimed mainly at these non-psychological problems. The IVA (Institute for Social Research, University of Correspondence and reprint requests to: Dr P. Hamers, Institute for Social Research, Post Box 90153, NL-5000 Le Tilburg, The Netherlands.
© 1992 Butterworth-Heinemann for SOM 0962-7480/92/040188-05
Tilburg, The Netherlands) has therefore developed an occupational health care model for teaching personnel which is geared specifically to the problems occurring in education. This model emphasizes the integration of medical, psychological and social provisions within a single occupational health care unit for teaching personnel. Those involved in the occupational health care unit are the school doctor, who is a trained and qualified occupational health physician, the school psychologist and the school welfare worker. This special unit is part of an existing occupational health care unit. The advantage is that in a team interdisciplinary work is possible, there can be a clear division of tasks, and the channels of communication are kept extremely short. This makes for clarity towards the personnel concerned: there is a single 'unit' which can be called upon to provide all the relevant services. The psychologist will concern himself primarily with the relationship between the problems of organization and work. His tasks include carrying out studies, writing reports and recommendations and guiding organization processes. The task of the welfare worker covers individual and group guidance as regards problems related to work, the aim here being to throw light on problems in the psycho-social sphere. One of the concrete tasks of the welfare worker is, for example, to supervise the return to school of personnel who have been absent for a considerable length of time.
Downloaded from http://occmed.oxfordjournals.org/ at Cambridge University on July 14, 2015
A connection is generally assumed between occupational health care (in Dutch 'bedrijfsgezondheidszorg', or BGZ) and a reduction in absenteeism. In the Dutch literature various authors and researchers make great claims for the effect of occupational health care in reducing absenteeism. As yet, however, they have not concerned themselves very much with providing proof for the validity of their position. They speculate as to the positive influence of occupational health care on the health and welfare of employees and assume a direct connection between it and the reduction of absenteeism, but they do not have at their disposal empirical research results to support their speculations. So far as we know solid research of an experimental or quasi-experimental design into the relationship between occupational health care and absenteeism has never been carried out. Recently, however, an experiment with occupational health care for teaching personnel (in Dutch: Experiment met BGZ voor Onderwijspersoneel, or EBO) did take place, providing the opportunity to determine the influence of occupational health care on absenteeism in a quasi-experimental setting. Unfortunately, the results of the experiment indicate that the relationship between occupational health care and absenteeism is more complex than is generally assumed. In the course of the experiment, and in particular during the final year, the level of absence in the experimental group rose considerably, while in the control group it fell slightly. That rise was mainly due to the increase in the number of persons who were sick for a long period of time (at least 6 months).
P. Hamers et a/.: Relationship between occupational health care and absenteeism
Other occupational health care activities which were carried out during the course of the experiment were the registration of absence due to illness, an occupational health care 'surgery', periodical occupational health examinations, therapeutic work, group guidance, school health examinations, and the provision of Health Information and Education. DESIGN OF THE STUDY AND RESULTS
OlXeO2 O3 Xc O4 where: 01 and O3 relate to the absence due to illness before the start of the experiment, Ol is that of the experimental group, and O3 is that of the control group; O2 and O4 relate to the absence due to illness during the final year of the experiment, O2 is that of the experimental group and O4 is that of the control group; Xe is the experimental variable: occupational health care for teaching personnel; Xc relates to the control group. Xc thus indicates that nothing happened in this group. The effect of the experimental variable (Xe — Xc) can now be calculated using the following formula: Xe - Xc = (02 - Ol) - (O4 - O3). The model presented here is only part of the story. We will now proceed to deal only with the effect during the final year. The effect can be viewed as an end effect of the experiment with occupational health care for teaching personnel. In the intervening period the absenteeism was also registered. Those results will not be considered at the moment. This type of study is based on the assumption that the changes (those relevant to absenteeism) which can take place in the experimental group and in the control group during the course of the whole experiment are the same. In order to facilitate measurement of the effect, the control group consisted of the national sample with which the Work and Welfare Study Group at the University of Leiden measures absenteeism in the teaching profession. The cases selected from the national sample were those that had no access to occupational health care. Since the areas covered by the experiment differ considerably from the control group as regards a number of variables, a multivariate analysis (MANOVA)
was carried out before the above formulae were applied to calculate the effect of the experiment with occupational health care for teaching personnel ('EBO effect'), with the most important differences in school and personnel characteristics between the 'EBO group' and the national control group (in so far as these are relevant to the nature of the absenteeism) being allowed for. One of the differences which had already been allowed for right at the beginning was the composition according to school type. A weighting factor was introduced in order to make the composition according to school type in the national control group exactly equal to that of the EBO group. A variation analysis was also used to correct for: composition according to the level of urbanization of the communities in which the schools were situated; composition according to the religious denomination of the schools (roman-catholic, protestant, other denomination or non-denominational); the average age of the school team; . the male/female distribution of the school team; the proportion of part-timers in the school team; the average number of years that personnel had been employed at the school; the type of school (because of possible interaction with the other features); the possible interaction between the above-mentioned characteristics. The figures for absence due to illness which were finally entered in the formula were the corrected values resulting from a MANOVA, making use of an MCA (multiple classification analysis). These analyses were carried out by the Work and Welfare Study Group in Leiden. Cook and Campbell6 drew attention to two important disruptive factors in this design: selection and regression. The application of a multivariate analysis already solves the problem of the selection. Regression to the average is mainly a problem when the experimental group and/or the control group are made up of groups with extreme scores on the dependent variable. Since this was not the case, it is not likely that the effect measured was disturbed by regression to the average.
RESULTS Table 1 brings together the most significant data from the study. The Table contains not the raw data but with absenteeism figures which have been corrected to allow for the factors relevant to absenteeism. Determining the occupational health care effect is however a matter of the relative differences between the measurements. A negative result of the formula for measuring the effect indicates that in the areas covered by the experiment absenteeism in the relative sense fell, while a positive result indicates a relative increase within the areas covered by the experiment. If the absenteeism percentage figures are compared
Downloaded from http://occmed.oxfordjournals.org/ at Cambridge University on July 14, 2015
Absence due to illness was registered by the Work and Welfare Study Group (Werkgroep A & W) at the University of Leiden (The Netherlands) throughout the course of the whole experiment and during the year previous to it. It is obvious that data on absenteeism are needed to determine changes in it. In order to determine effects, a suitable design is required. Therefore a variant of the non-equivalent control group has been used: The Untreated Control Group Design with Pretest and Posttest6. In broad outline, this design is as follows:
189
190
Occup. Med. 1992, Vol. 42, No 4
Table 1. Corrected levels of absence due to illness for the experimental areas during the preliminary measurements and in the final year of the experiment Experimental areas
Control group national sample
Absenteeism percentage* Preliminary Experimental Difference
7.45 8.19 0.74
7.98 7.85 -0.13
Frequency of absenteeism! Preliminary Experimental Difference
152 147 -5
166 156 -10
13.0 14.4 1.40
15.3 14.2 -1.10
Frequency of long-term absence! Preliminary Experimental Difference
Difference
p
