Does low alcohol use increase the risk of sickness absence? A discordant twin study

Do Differences in Drinking Attitudes and Alcohol-Related Problems Explain Differences in Sick Leave? A Multilevel Analysis of 95 Work Units Within 14 Companies From the WIRUS Study

Background

Systematic reviews have shown a strong relationship between alcohol consumption and sick leave. The effect of alcohol consumption on sick leave may, however, vary according to the work environment. While attitudes toward drinking may impact sick leave, there is little research on the contribution of drinking attitudes to sick leave. Moreover, alcohol-related problems and drinking attitudes may be influenced by the broader sociocultural contexts of the organizational units where people work.

Objectives

This study aimed to explore the relationship of alcohol-related problems and drinking attitudes with sick leave while considering the nesting of employees within working units within companies.

Method

Data from the WIRUS (Workplace Interventions preventing Risky alcohol Use and Sick leave) study were linked to company-registered sick leave data for 2,560 employees from 95 different work units in public (n = 9) and private companies (n = 5) in Norway. Three-level (employee, work unit, and company) negative binomial regression models were estimated to explore the 12-month prospective association of alcohol-related problems and drinking attitudes with four measures of sick leave (one-day, short-term, long-term, and overall sick leave days). Models were adjusted for gender, age, cohabitation status, educational attainment, work position, and employment sector.

Results

We observed higher variation of one-day, short-term, and overall sick leave days between companies than between work units within companies (15, 12, and 30% vs. 0, 5, and 8%, respectively). However, neither alcohol-related problems nor drinking attitudes were associated with sick leave and, thus, those variations in sick leave were not explained by alcohol-related problems or drinking attitudes.

Conclusion

Our findings suggest company-level differences are more important than within company differences when explaining differences in sick leave. While alcohol-related problems or drinking attitudes were not associated with sick leave, future studies may need to explore the role of company policies, practices, or social norms in variations in sick leave rates.

A systematic review and meta-analysis uncovering the relationship between alcohol consumption and sickness absence. When type of design, data, and sickness absence make a difference

AIM

Earlier research has revealed a strong relationship between alcohol use and sickness absence. The aim of this review was to explore and uncover this relationship by looking at differences in type of design (cross-sectional vs. longitudinal), type of data (self-reported vs. registered data), and type of sickness absence (long-term vs. short term).

METHOD

Six databases were searched through June 2020. Observational and experimental studies from 1980 to 2020, in English or Scandinavian languages reporting the results of the association between alcohol consumption and sickness absence among working population were included. Quality assessment, and statistical analysis focusing on differences in the likelihood of sickness absence on subgroup levels were performed on each association, not on each study. Differences in the likelihood of sickness absence were analyzed by means of meta-analysis. PROSPERO registration number: CRD42018112078.

RESULTS

Fifty-nine studies (58% longitudinal) including 439,209 employees (min. 43, max. 77,746) from 15 countries were included. Most associations indicating positive and statistically significant results were based on longitudinal data (70%) and confirmed the strong/causal relationship between alcohol use and sickness absence. The meta-analysis included eight studies (ten samples). The increased risk for sickness absence was likely to be found in cross-sectional studies (OR: 8.28, 95% CI: 6.33-10.81), studies using self-reported absence data (OR: 5.16, 95% CI: 3.16-8.45), and those reporting short-term sickness absence (OR: 4.84, 95% CI: 2.73-8.60).

CONCLUSION

This review supports, but also challenges earlier evidence on the association between alcohol use and sickness absence. Certain types of design, data, and types of sickness absence may produce large effects. Hence, to investigate the actual association between alcohol and sickness absence, research should produce and review longitudinal designed studies using registry data and do subgroup analyses that cover and explain variability of this association.

The role of alcohol use and cigarette smoking in sickness absence: Are there social inequalities?

BACKGROUND

While studies have found a social gradient in negative consequences of drinking and smoking, evidence is less clear for a gradient also in alcohol use and smoking's association with sickness absence. We investigate the association between alcohol use and cigarette smoking and general sickness absence, and examine the moderating role of socio-economic status for these associations when controlling for general health status.

METHOD

Questions on alcohol use, measured by the Alcohol Use Disorders Identification Test (AUDIT-C), smoking, general health and sickness absence were included in annual national cross-sectional telephone surveys on alcohol, tobacco and drug use (2015-18) amongst Norwegian adults aged 16-79-years (average response rate=59%). The analytic sample comprised 4719 full- and part-time employees aged 25-79 years (46.7% were female, mean age=44.3 years). Individual-level data on education were obtained from national registries.

RESULTS

In adjusted negative binomial regression analyses, current and former daily smoking were associated with a higher occurrence of sickness absence in groups with low educational attainment, but not in groups with high educational attainment. Alcohol use was negatively associated with sickness absence. While a significantly higher number of sickness days was reported by smokers in the low compared with the high education group, educational attainment did not moderate the alcohol use - sickness absence association.

CONCLUSION

Daily smoking is associated with sickness absence. A negative social gradient was found in the smoking - absence association. Reduced daily smoking might give a reduction in sickness absence.

Education differences in sickness absence and the role of health behaviors: a prospective twin study

BACKGROUND

Long-term sickness absences burden the economy in many industrialized countries. Both educational attainment and health behaviors are well-known predictors of sickness absence. It remains, however, unclear whether these associations are causal or due to confounding factors. The co-twin control method allows examining causal hypotheses by controlling for familial confounding (shared genes and environment). In this study, we applied this design to study the role of education and health behaviors in sickness absence, taking sex and cohort differences into account.

METHODS

Participants were two cohorts of in total 8806 Norwegian twins born 1948 to 1960 (older cohort, mean age at questionnaire = 40.3, 55.8% women), and 1967 to 1979 (younger cohort, mean age at questionnaire = 25.6, 58.9% women). Both cohorts had reported their health behaviors (smoking, physical activity and body mass index (BMI)) through a questionnaire during the 1990s. Data on the twins' educational attainment and long-term sickness absences between 2000 and 2014 were retrieved from Norwegian national registries. Random (individual-level) and fixed (within-twin pair) effects regression models were used to measure the associations between educational attainment, health behaviours and sickness absence and to test the effects of possible familial confounding.

RESULTS

Low education and poor health behaviors were associated with a higher proportion of sickness absence at the individual level. There were stronger effects of health behaviors on sickness absence in women, and in the older cohort, whereas the effect of educational attainment was similar across sex and cohorts. After adjustment for unobserved familial factors (genetic and environmental factors shared by twin pairs), the associations were strongly attenuated and non-significant, with the exception of health behaviors and sickness absence among men in the older cohort.

CONCLUSIONS

The associations between educational attainment, health behaviors, and sickness absence seem to be confounded by unobserved familial factors shared by co-twins. However, the association between health behaviors and sickness absence was consistent with a causal effect among men in the older cohort. Future studies should consider familial confounding, as well as sex and age/cohort differences, when assessing associations between education, health behaviors and sickness absence.

The relative impact of smoking, alcohol use and drug use on general sickness absence among Norwegian employees

BACKGROUND

It is well documented that tobacco, alcohol and drug use can be detrimental to health. However, little is known about the relative impact of these factors on sickness absence, and whether the association between use of these substances and sickness absence is different for women and men. The aim of this study was to examine the association between tobacco-, alcohol- and drug use, as well as polydrug use, and sickness absence among Norwegian employees.

METHODS

During 2011-2014, 1911 employees in Norway completed a questionnaire about their tobacco, alcohol and drug use habits, their total number of sickness absences during the last 12 months, and the length (no. of days) of their last sick leave. Samples of oral fluid were analysed for illegal and medicinal drugs.

RESULTS

Daily smoking and current use of medical drugs were significantly associated with sickness absence. Employees who were daily smokers also had an increased likelihood of having long and frequent sickness absence. Use of snus (Swedish moist snuff), binge drinking, current use of illegal drugs and polydrug use were not significantly associated with sickness absence. Women and young participants were more likely to report having had sickness absence the past 12 months. However, the associations between daily smoking and medical drug use and sickness absence, respectively, were only statistically significant for men.

CONCLUSION

According to this study, daily smoking and use of medical drugs are the substance use habits most closely associated with sickness absence. Implications for future research are discussed.

Sociodemographic Differences Between Alcohol Use and Sickness Absence: Pooled Analysis of Four Cohort Studies

Aims

We examined differences in sickness absence in relation to at-risk drinking and abstinence, taking into account potential changes in consumption.

Methods

We used individual-participant data (n = 46,514) from four prospective cohort studies from Finland, France and the UK. Participants responded to a survey on alcohol use at two time points 4-6 years apart, and were linked to records of sickness absence for an ~6-year follow-up after the latter survey. Abstainers were those reporting no alcohol use in either survey. At-risk drinkers at T1 were labelled as 'former', at-risk drinkers at T2 as 'current' and at-risk drinkers at both times as 'consistent' at-risk drinkers. The reference group was low-risk drinkers at both times. Study-specific analyses were stratified by sex and socioeconomic status (SES) and the estimates were pooled using meta-analysis.

Results

Among men (n = 17,285), abstainers (6%), former (5%), current (5%) and consistent (7%) at-risk drinkers had an increased risk of sickness absence compared with consistent low-risk drinkers (77%). Among women (n = 29,229), only abstainers (12%) had a higher risk of sickness absence compared to consistent low-risk drinkers (74%). After adjustment for lifestyle and health, abstaining from alcohol was associated with sickness absence among people with intermediate and high SES, but not among people with low SES.

Conclusions

The U-shaped alcohol use-sickness absence association is more consistent in men than women. Abstinence is a risk factor for sickness absence among people with higher rather than lower SES. Healthy worker effect and health selection may partly explain the observed differences.

Short summary

In a pooled analysis from four cohort studies from three European countries, we demonstrated a U-shaped association between alcohol use and sickness absence, particularly among men. Abstinence from alcohol was associated with increased sickness absenteeism among both sexes and across socioeconomic strata, except those with low SES.

Changes in drinking as predictors of changes in sickness absence: a case-crossover study

Background

We investigated whether changes in alcohol use predict changes in the risk of sickness absence in a case-crossover design.

Methods

Finnish public sector employees were surveyed in 2000, 2004 and 2008 on alcohol use and covariates. Heavy drinking was defined as either a weekly intake that exceeded recommendations (12 units for women; 23 for men) or having an extreme drinking session. The responses were linked to national sickness absence registers. We analysed the within-person relative risk of change in the risk of sickness absence in relation to change in drinking. Case period refers to being sickness absent within 1 year of the survey and control period refers to not being sickness absent within 1 year of the survey.

Results

Periods of heavy drinking were associated with increased odds of self-certified short-term (1–3 days) sickness absence (multivariable-adjusted OR 1.21, 95% CI 1.07 to 1.38 for all participants; 1.62, 95% CI 1.19 to 2.21 for men and 1.15, 95% CI 1.00 to 1.33 for women). A higher risk of short-term sickness absence was also observed after increase in drinking (OR=1.27, 95% CI 1.07 to 1.52) and a lower risk was observed after decrease in drinking (OR=0.83, 95% CI 0.69 to 1.00). Both increase (OR=1.38, 95% CI 1.21 to 1.57) and decrease (OR=1.27, 95% CI 1.19 to 1.43) in drinking were associated with increased risk of long-term (>9 days) medically certified all-cause sickness absence.

Conclusion

Increase in drinking was related to increases in short-term and long-term sickness absences. Men and employees with a low socioeconomic position in particular seemed to be at risk.