Occupational musculoskeletal and mental disorders as the most frequent associations to worker’s sickness absence: A 10-year cohort study

Absenteeism or sickness absence (SA) is a worldwide concern due to the economic consequences for the employer, for government or profitable institutions, and for the workers themselves. A broad spectrum of factors influences SA, including demographics, health systems, health status, and preventative occupational actions. By promoting prompt detection mechanisms, workers at risk can be readily identified and treated [1–3].

Epidemiological patterns of absenteeism have recently shifted, showing an increase in psychosocial disorders in contrast to a decreasing, but still frequent, incidence of musculoskeletal and connective tissue diseases, especially in countries of the European Union. This shift in the epidemiological profile of SA raises concern for public and private institutions, since SA significantly impacts budgets and contributes to the deterioration of employee health [3–9]. Besides of its established evidence - recognized mostly in European countries, this shift was not recognized or studied in Brazil.

Among the expected benefits of a recent Brazilian federal law, employees have the right to leave work for health reasons that is determined necessary by a medical expert, without prejudice regarding their entitled wages [10]. Correlation of variables such as age, gender, job function, and disease (ICD10 - World Health Organization, 1998) [11] sets the parameters to evaluate the causes of absences, and whether or not these causes are characterized as occupational diseases. Federal law stipulates that disability retirement must be preceded by a medical leave of absence for a period not exceeding 24 months. Workers must retire if their licenses expire or if they are unable to return to their original jobs and cannot be reassigned to a new position [10].

In this study we evaluated causes of absenteeism within a population of workers based at a federal university and focused our analysis on assessments provided by the workers’ health division (WHD), which granted sick-leave requests upon the recommendation of a medical expert. The study focus in the recognition of a Brazilian “primer” regarding to SA motivations and its epidemiological profile. This research is an initiative that could encourage a rationale for an evidence-based national agenda [12], which is relevant for policy-makers, physicians and workers.

The aim of this study was not only to determine the main diseases that cause SA, but also to construct an epidemiological profile of these workers, recognize the relationship between SA and job function and the outcome of medical examinations performed over the 10-year period of the study.

The goal of this study was to verify the diagnoses that lead to the absenteeism of workers, to calculate the average time of SA according to ICD10 (appendix 1and 2), and to determine the correlation of SA with gender and professional activities. We have grouped the data according to professional activities.

For categorical variables, descriptive statistics were used with absolute and relative frequencies to delineate the sample. For numerical variables, continuous, descriptive statistics were applied to show the distribution by utilizing measures of central tendency and dispersion, with alpha at 0.05. When choosing the group of statistical test that would be used for statistical inference, we applied the Kolmogorov-Smirnov normality test with the purpose of checking the normal distribution of the data. We found that our data were normally distributed. We used the t-test for the comparison of means with significance levels of 95%. We used SAS software for statistical analysis.

Because our data came from a population based at a university that specializes in the health sciences, such as medicine, nursing, and biomedical sciences, we presumed that we would find a high number of medical workers developing SA. Regarding the causes of SA, our results correspond well with those of previous studies [13–18], which identified musculoskeletal and connective tissue disorders and mental illness as the main causes of absenteeism [18, 19].

The Brazilian law system stipulates a maximum length of 2 years for sickness absence; after this period of time the worker should be relocated or retired. Implementing a clear time period for insurance support possibly avoids insurance misuse. In this regard Brazil differs from more socially focused insurance systems, such as the Swedish system, in which it is possible that the excessive protection of SA workers threatens the welfare state [19, 20].

Apart from the limitations on sick leave imposed by the Brazilian government, few comprehensive studies of absenteeism in Brazil have been performed [14–16, 18, 21, 22], and most of these studies targeted specific professional groups or sectors [23]. Our data suggest that the pattern of disease associated with absenteeism resembles that in other countries where comprehensive data are available [19, 24–26]. Our large sample group, comprised of 5000 workers, and the wide scope of our data due to the diversity of workers’ skills, strengthen this conclusion. However, we must consider certain limitations of our study, especially regarding the nature of our data collection and study design. We analyzed a specific population (university personnel/São Paulo Metropolitan area) and part of the data was obtained retrospectively.

Our research is important since it reveals some aspects of Brazilian’s worker health and our society. Musculoskeletal conditions – mostly occupational - and psychological disorders emerged as the most relevant causes incurring at Sickness absence in our population and we believe that our sample most likely reflects the general Brazilian working population because we included a great variety of working categories and we included data from a large (representative) sample. This fact is relevant, since besides the differences among different country’s, culture and population income, we believe that working diseases might have a more universal characteristic, which sounds similar to worldwide studies.

We believe that facing these conditions and proposing preventative programs for dealing with these conditions is a cornerstone action. This panorama has led us to the development of a robust research agenda, which is focused in the recognition of avoidable risk factors and clinical studies for determining the effectiveness of alternative interventional actions.

The main outcomes of WHD expert reports on workers granted sick leave included retirement (30.4%), return to original activities (60.7%), and death (5.7%). Our results regarding the length of SA are also consistent with findings of this previous study, in which tumors were the main diagnosis leading to a long period of SA [27].

Musculoskeletal and connective tissue disorders and mental and behavioral diseases were the most frequent cause of sickness absence. Men had an increased frequency of SA, and neoplasms and infectious disorders were associated with longer absences. Mostly, these are occupational disorders. A preventative research-focused agenda is desirable for a more accurate depiction of this population in the scope of policy-making. Our results for SA in Brazilian workers correspond with those of other studies worldwide.

F32.2 Severe depressive episode without psychotic symptoms

I10 Essential (primary) hypertension

Z54.0 Convalescence following surgery

M75 Shoulder Lesions

F32.1 Moderate Depressive episode

M54 Dorsalgia

F43.2 Adaptation Reaction

I25 Chronic ischaemic heart disease

F32 Depressive Episode

F33.2 Recurrent depressive disorder, current episode severe without psychotic symptoms