Sick at work and future sickness absence: a prospective study of two measures of sickness presence

Abstract
Background
Sickness presence (SP), or going to work despite being ill, is a common way of practicing sickness absence (SA). However, its consequences for long-term SA are poorly understood, and there is no consensus on how to measure SP. This study aims to examine the consequences of SP on long-term sickness absence (>14 days) using two different measures.

Methods
Data from a Danish public human service organization were analyzed, with approximately 2400 employees answering questionnaires in November 2019, yielding a response rate of 50%. Information on SA, work environment, self-reported health, SP episodes, and sociodemographic information were included in negative binomial regression models. The outcome variable was prospective episodes of SA (>14 days) taken from the SA register of the organization. Two different ways of measuring SP were used: a traditional measure of overall SP frequency and a measure of going to work with specific symptoms (fever, cold, headache, musculoskeletal pain).

Results
Participants who reported SP frequency of more than 10 times during the last 6 months had a two-fold risk of long-term SA (IRR: 2.19 (95%CI 1.09-4.58)) in the follow-up period. This risk remained significant even after adjusting for work environment factors, sociodemographic factors, self-rated health, and spells of sickness absence in the previous year. Going to work with fever (IR: 1.43) or cold (IR: 1.48) was also associated with long-term SA in the follow-up period.

Conclusions
SP may negatively impact employees’ health status and increase long-term sickness absence. Health professionals should be aware of the negative consequences of focusing solely on reducing short-term sickness absence especially if they inadvertently encourage employees to substitute sickness presence for sickness absence.

Key messages
• Going to work despite having ill health is common but may have adverse health consequences and lead to long-term sickness absence.

• Focusing narrowly on reducing short-term sickness absence might be a bad idea for public health. Employees might feel encouraged to go ill to work which could increase future sick leave.