Measuring sick leave: a comparison of self-reported data on sick leave and data from company records

The objective of this study was to compare sick leave data obtained from questionnaires with data from company records. During a period of 12 months, questionnaires were completed monthly for 6 months and then at 9 and 12 months. The sensitivity and specificity of questionnaires for detecting an episode of sick leave were determined, using the company records as a reference standard. In addition, the duration of sick leave episodes reported in the two data sets was compared. In this analysis, company records were not assumed to be superior, and agreement was assessed with intraclass correlation coefficients (ICCs). The sensitivity of questionnaires for detecting an episode of sick leave was 55% (95% CI = 0.50-0.60) and the specificity 83% (95% CI = 0.72-0.94). The ICC for all episodes was 0.58 (95% CI = 0.47-0.67). The only satisfactory ICC (0.87; 95% CI = 0.74-0.93) was found for the questionnaires at 9 and 12 months. No large systematic differences were found between the duration of episodes reported in the two data sets. In conclusion, in our study, the sensitivity of questionnaires for detecting an episode of sick leave was very low. Furthermore, when episodes were recalled, there was little agreement on the duration of the episode between questionnaire data and data in the company records. Based on these results and considering the risk of missing questionnaires, data on sick leave gathered from company records are clearly preferable as an outcome measure in research.     

Job stress and depression symptoms in middle-aged workers--prospective results from the Belstress study

OBJECTIVE: The aim of this study was to explore the prospective relation between job stress and symptoms of depression within a cohort study. METHODS: Altogether 2821 workers were involved in the longitudinal Belstress study (Belgian job stress study); there were two measurements with a mean follow-up time of 6.6 years. Job stress was assessed by the Job Content Questionnaire. Depression symptoms were assessed by the Iowa form of the Center for Epidemiological Studies-Depression Scale. Baseline and repeated exposures to job stress were related to the development of high levels of depression symptoms through logistic regression analysis. RESULTS: Within a population free of high depression scores at baseline, job stress increased the risk of developing high levels of depression symptoms after a mean follow-up time of 6.6 years. Independent associations were found for low decision latitude, high job strain, and isolated strain among women, but not among men. The adjusted association with high job strain among men was borderline significant. Repeated high job strain was associated with a more elevated risk of developing high levels of depression symptoms among both the women and the men. CONCLUSIONS: The results of this study confirm that job stress is a risk factor for developing symptoms of depression. Stronger associations were found for women. The impact of high job strain among both men and women was more harmful when there was repeated exposure.     

Job strain and sick leave among Japanese employees: a longitudinal study

Objectives: The present study is an investigation of the association between job stress, determined on the basis of a demand–control model or worksite social support at the baseline, and absence due to illness among employed Japanese males and females. Methods: We analyzed 448 male and 81 female subjects who had taken no sick leave in the year preceding the baseline (1997) and observed them all until 1999. A self-administered questionnaire was the source information collected. It consisted of questions on socio-demographic variables, occupations, health-related behavior, a Japanese version of the Job Content Questionnaire, and the number of absences in the year preceding both the baseline and follow-up. Logistic regression analyses were used to determine how the characteristics of a job at the baseline affected sickness absence of 5 days or longer per year; controls were established for the gender, age, level of education completed, occupation, number of cigarettes smoked daily, and the amount of alcohol consumed weekly. Results: Compared to the lowest tertile of the ratio of demand to control (job strain), the highest tertile was significantly associated with an increased risk of sickness absence of 5 days or longer per year (odds ratio 3.02; 95%CI 1.00–9.16) at follow-up. The dose–response relationship was supported (p for trend <0.05). However, individual variables of job demand, job control, and worksite social support were not significantly associated with the risk of absence from illness. Conclusions: The study provided prospective evidence that job strain leads to an increased risk of sick leave among Japanese employees.     

Validation of sick leave measures: self-reported sick leave and sickness benefit data from a Danish national register compared to multiple workplace-registered sick leave spells in a Danish municipality

ABSTRACT: BACKGROUND: Previous validation studies of sick leave measures have focused on self-reports. Register-based sick leave data are considered to be valid; however methodological problems may be associated with such data. A Danish national register on sickness benefit (DREAM) has been widely used in sick leave research. On the basis of sick leave records from 3,554 and 2,311 eldercare workers in 14 different workplaces, the aim of this study was to: 1) validate registered sickness benefit data from DREAM against workplace-registered sick leave spells of at least 15 days; 2) validate self-reported sick leave days during one year against workplace-registered sick leave. METHODS: Agreement between workplace-registered sick leave and DREAM-registered sickness benefit was reported as sensitivities, specificities and positive predictive values. A receiver-operating characteristic curve and a Bland-Altman plot were used to study the concordance with sick leave duration of the first spell. By means of an analysis of agreement between self-reported and workplace-registered sick leave sensitivity and specificity was calculated. Ninety-five percent confidence intervals (95% CI) were used. RESULTS: The probability that registered DREAM data on sickness benefit agrees with workplace-registered sick leave of at least 15 days was 96.7% (95% CI: 95.6-97.6). Specificity was close to 100% (95% CI: 98.3-100). The registered DREAM data on sickness benefit overestimated the duration of sick leave spells by an average of 1.4 (SD: 3.9) weeks. Separate analysis on pregnancy-related sick leave revealed a maximum sensitivity of 20% (95% CI: 4.3-48.1).The sensitivity of self-reporting at least one or at least 56 sick leave day/s was 94.5 (95% CI: 93.4 -- 95.5) % and 58.5 (95% CI: 51.1 -- 65.6) % respectively. The corresponding specificities were 85.3 (95% CI: 81.4 -- 88.6) % and 98.9 (95% CI: 98.3 -- 99.3) %. CONCLUSIONS: The DREAM register offered valid measures of sick leave spells of at least 15 days among eldercare employees. Pregnancy-related sick leave should be excluded in studies planning to use DREAM data on sickness benefit. Self-reported sick leave became more imprecise when number of absence days increased, but the sensitivity and specificity were acceptable for lengths not exceeding one week.     

Age-, sex-, and diagnosis-specific incidence rate of medically certified long-term sick leave among private sector employees: The Japan Epidemiology Collaboration on Occupational Health (J-ECOH) study

Background

Long-term sick-leave is a major public health problem, but data on its incidence in Japan are scarce. We aimed to present reference data for long-term sick-leave among private sector employees in Japan.

Predictors of changes in sick leave in workers with asthma: a follow-up study

Objective: The aim of this prospective study was to investigate predictors of 1-year changes in sick leave in workers with asthma. Methods: The initial cohort consisted of 111 workers with asthma. One-hundred and one participants completed the follow-up after 1 year. Self-reported sick leave over the past 12 months was reported at baseline and at follow-up. At the start of this study, all participants completed questionnaires on adaptation to functional limitations, psychosocial variables, working conditions, lung function characteristics, disease history characteristics, health complaints and functional limitations, and person characteristics (‘potential predictors’). Three multivariate logistic regression models were calculated, with an increase in sick leave, a decrease in sick leave, and stable high sick leave as dependent (outcome) variables, and the potential predictors as independent (explanatory) variables. Results: An increase in sick leave was predicted by a lower level of education and perceiving more functional limitations in activities of daily life. A decrease in sick leave was predicted by spending all energy at work less often and perceiving fewer health complaints in social activities (adaptation criteria 4 and 5). Stable high sick leave was predicted by less job satisfaction, perceiving more support from the employer and perceiving more health complaints in social activities (adaptation criterion 5). Lung function characteristics, or disease history characteristics were not predictive for changes in sick leave in any of the groups. Conclusion: We conclude that adaptation to functional limitations played a major role in changes in sick leave in workers with asthma. Lung function characteristics hardly played a role.     

Experiences within the process of sick leave

The aim of this study was to explore what individuals who have been on sick leave experienced as important in the process of returning to work, moving to long-term sick leave, or receiving a disability pension. Grounded Theory was used for interpreting interviews with 15 people who had been on sick leave four years previously. In the results four ideal types were crystallized which are presented in the form of vignettes. The ideal types were discussed focusing on occupational life using the Model of Human Occupation and the theories of Sense of Coherence and Status Passage. The study provided a deeper understanding of people's experiences during the process of their sick leave. Valuable predictors for re-entry into work or disability retirement were: individual mental resources; clear or unclear diagnosis; how long had been spent in the sick-leave process; and personal belief in an ability to work in the future. The interventions and support given by professionals and the social environment, the balance and sense of coherence in life, and participation in the sick leave process were also important. The idealtypes found could be helpful to professionals working in this field in deepening their understanding of the clients.     

Experiences within the process of sick leave

The aim of this study was to explore what individuals who have been on sick leave experienced as important in the process of returning to work, moving to long-term sick leave, or receiving a disability pension. Grounded Theory was used for interpreting interviews with 15 people who had been on sick leave four years previously. In the results four ideal types were crystallized which are presented in the form of vignettes. The ideal types were discussed focusing on occupational life using the Model of Human Occupation and the theories of Sense of Coherence and Status Passage. The study provided a deeper understanding of people's experiences during the process of their sick leave. Valuable predictors for re-entry into work or disability retirement were: individual mental resources; clear or unclear diagnosis; how long had been spent in the sick-leave process; and personal belief in an ability to work in the future. The interventions and support given by professionals and the social environment, the balance and sense of coherence in life, and participation in the sick leave process were also important. The idealtypes found could be helpful to professionals working in this field in deepening their understanding of the clients.     

Diabetes mellitus in middle-aged people is associated with increased sick leave: the BELSTRESS study

In a prospective study of the association between self-reported diabetes mellitus and sick leave from work, 21,149 men and women, aged 35-59 years, participated. Prevalence of diabetes was obtained by questionnaire. Sick leave was prospectively obtained from departments of human resources in the year after the baseline survey. Outcome variables related to duration of sick leave, repetitive absences, and long absences of at least seven consecutive days. In gender-specific multivariate analyses the relation between diabetes and sick leave was studied independent of age, body mass index, physical activity, alcohol intake, education, job title, and smoking habit. Prevalence rates of self reported diabetes were 2.8% and 2.2% in men and women, respectively. For each outcome variable a significant association between diabetes and sick leave was observed. Significant associations were found between diabetes and duration of sick leave and repetitive absences in men. In women a similar trend was observed for duration, and a significant association was found for repetitive absences.     

School environment as predictor of teacher sick leave: data-linked prospective cohort study

ABSTRACT: BACKGROUND: Poor indoor air quality (IAQ) and psychosocial problems are common in schools worldwide, yet longitudinal research on the issue is scarce. We examined whether the level of or a change in pupil-reported school environment (IAQ, school satisfaction, and bullying) predicts recorded sick leaves among teachers. METHODS: Changes in the school environment were assessed using pupil surveys at two time points (2001/02 and 2004/05) in 92 secondary schools in Finland. Variables indicating change were based on median values at baseline. We linked these data to individual-level records of teachers' (n = 1678) sick leaves in 2001--02 and in 2004--05. RESULTS: Multilevel multinomial logistic regression models adjusted for baseline sick leave and covariates showed a decreased risk for short-term (one to three days) sick leaves among teachers working in schools with good perceived IAQ at both times (OR = 0.6, 95% CI: 0.5-0.9), and for those with a positive change in IAQ (OR = 0.6, 95% CI: 0.4-0.9), compared to teachers in schools where IAQ was constantly poor. Negative changes in pupil school satisfaction (OR = 1.8, 95% CI: 1.1-2.8) and bullying (OR = 1.5, 95% CI: 1.0-2.3) increased the risk for short-term leaves among teachers when compared to teachers in schools where the level of satisfaction and bullying had remained stable. School environment factors were not associated with long-term sick leaves. CONCLUSIONS: Good and improved IAQ are associated with decreased teacher absenteeism. While pupil-related psychosocial factors also contribute to sick leaves, no effect modification or mediation of psychosocial factors on the association between IAQ and sick leave was observed.     

The cost of sickness: On the effect of the duration of sick leave on post-sick leave earnings

Studies analysing the effect of the duration of sick leave on subsequent labour market outcomes do not consider the potential endogenous relationship between duration and labour market outcomes. This paper deals with this shortcoming by using a consistent estimator attained through Instrumental Variables methods for estimating the effect of the duration of a sick leave spell on post-sick leave earnings. I use Danish administrative data and a major 2001 reform of the sick leave system as the instrument for duration. I find that the duration of a sick leave spell has both short and long term effects on post-sick leave earnings.     

A study of indoor carbon dioxide levels and sick leave among office workers

Background  

A previous observational study detected a strong positive relationship between sick leave absences and carbon dioxide (CO₂) concentrations in office buildings in the Boston area. The authors speculated that the observed association was due to a causal effect associated with low dilution ventilation, perhaps increased airborne transmission of respiratory infections. This study was undertaken to explore this association.     

Risk factors for sick leave due to low back pain: a prospective study

The objectives of this prospective study were to identify predictive factors for sick leave of 8 days or more due to low back pain (LBSL) and to compare them with predictive factors for low back pain with no or shorter sick leave (LB) in a cohort of French workers. The predictive factors for LBSL were a past history of low back pain (odds ratio [OR], 7.2; 95% confidence interval [CI], 4.1 to 13), a low employment grade (OR, 4.3; 95% CI, 1.7 to 11), heavy smoking (OR, 5.5; 95% CI, 2.3 to 13), a pain score different from zero (OR, 4.9; 95% CI, 2.5 to 9.7), required bending backward or forward at work every day repetitively (OR, 7.4; 95% CI, 2.3 to 23), overall social integration (OR, 2.0; 95% CI, 1.3 to 3.3), and low social support at work (OR, 3.4; 95% CI, 1.6 to 7.3). Low social support at work and bending backward or forward at work were more strongly associated with LBSL than with LB (P = 0.02 and P < 0.01, respectively). The implications of the results of this prospective study are that both the level of biomechanical exposure and the psychosocial work environment, especially social support, represents important dimensions to consider in the reduction of work absenteeism.     

Physical leisure-time activities and long-term sick leave: a 15-month prospective study of nurses' aides

The objective of the study was to determine the relationship between physical leisure-time activities and the occurrence of long-term sick leaves in nurses' aides. Of 5563 Norwegian nurses' aides who were not on sick leave when they completed a questionnaire in 1999, 4744 (85.3%) completed a second questionnaire 15 months later. Brisk walks (odds ratio [OR], 0.78; 95% confidence interval [CI], 0.63 to 0.98), aerobics or gymnastics (OR, 0.71; 95% CI, 0.49 to 1.02), and other physical leisure activities (OR, 0.81; 95% CI, 0.66 to 1.00) for 20 minutes or more at least once a week predicted fewer long-term sick leaves (> 14 days), after adjustments for baseline health complaints, demographic and familial characteristics, former and current smoking, and work factors. In conclusion, regular physical leisure-time activity may be associated with a reduced risk of long-term sickness absence in nurses' aides.     

Reducing sick leave by minimal postal intervention: a randomised, controlled intervention study

Background

The lack of efficient medical interventions for combating increasing sickness absence rates has lead to the introduction of alternative measures initiated by the Norwegian National Insurance Service or at workplaces.

Aim

To determine whether minimal postal intervention had any effect on the length of sick leave.

Methods

Randomised, controlled trial with a one year follow up in Northern Norway in 1997 and 1998; 990 consecutive newly sick‐listed persons with musculoskeletal or mental disorders were studied. Within the intervention group, 495 eligible sick‐listed persons received a general information letter and a questionnaire as their sick leave passed 14 days. Possible intervention effects were analysed by survival analysis of the probability of returning to work within one year, and logistic regressions with benefits at one year as the dependent variable.

Results

The overall reduction of 8.3 (95% CI −22.5 to 6.0) calendar days in mean length of sick leaves in the intervention group compared to controls, was not statistically significant. However, intervention significantly reduced length of sick leaves in subgroups with mental disorders, and with rheumatic disorders and arthritis, and overall for sick leaves lasting 12 weeks or more. Young people with low back pain showed an adverse effect to intervention. The overall relative risk of receiving benefits due to sickness after one year in the intervention group was 0.69 (95% CI 0.51 to 0.93) compared to controls.

Conclusion

The results should encourage employers, insurance institutions, and authorities to initiate challenges as questions on the length of sick leave and possible modified work measures, during the first few weeks of sick leave, for at least some groups of sick‐listed persons.