Which presenteeism measures are more sensitive to depression and anxiety?

Abstract

Background

Lost productivity from attending work when unwell, or “presenteeism”, is a largely hidden cost of mental disorders in the workplace. Sensitive measures are needed for clinical and policy applications, however there is no consensus on the optimal self-report measure to use. This paper examines the sensitivity of four alternative measures of presenteeism to depression and anxiety in an Australian employed cohort.

Methods

A prospective single-group study in ten call centres examined the association of presenteeism (presenteeism days, inefficiency days, Work Limitations Questionnaire, Stanford Presenteeism Scale) with Patient Health Questionnaire depression and anxiety syndromes.

Results

At baseline, all presenteeism measures were sensitive to differences between those with (N = 69) and without (N = 363) depression/anxiety. Only the Work Limitations Questionnaire consistently showed worse productivity as depression severity increased, and sensitivity to remission and onset of depression/anxiety over the 6-month follow-up (N = 231). There was some evidence of individual depressive symptoms having a differential association with different types of job demands.

Limitations

The study findings may not generalise to other occupational settings with different job demands. We were unable to compare responders with non-responders at baseline due to anonymity.

Conclusions

In this community sample the Work Limitations Questionnaire offered additional sensitivity to depression severity, change over time, and individual symptoms. The comprehensive assessment of work performance offers significant advantages in demonstrating both the individual and economic burden of common mental disorders, and the potential gains from early intervention and treatment.

Introduction

Presenteeism is broadly understood to reflect the phenomenon of attending work when sick (Aronsson et al., 2000), or “working through illness” (McKevitt et al., 1997). Presenteeism has been estimated to account for a majority of the economic cost of lost productivity from depression (Collins et al., 2005), as much as 86% (Stewart et al., 2003). This hidden cost of mental disorders in the workplace adds an extra dimension to estimating the individual and societal burden of mental disorders, and the potential gains from effective intervention or prevention.

In contrast to absenteeism which is readily validated against administrative records (Ferrie et al., 2005), presenteeism is usually assessed by generic, self-report measures that are applicable to any job. Measures vary in complexity from single items assessing the number of days in a given period in which the person attended work when unwell (Aronsson et al., 2000), to adjusting time at work for perceptions of productivity in relation to self and/or colleagues (Brouwer et al., 1999, Kessler et al., 2003, Stewart et al., 2003, Wang et al., 2003), to domain-based measures that assess health-related limitations in specific job demands (Koopman et al., 2002, Lerner et al., 2004a).

It has recently been suggested that measuring presenteeism per se may be more important than the specific type of presenteeism measure used (Collins et al., 2005). To date, there is insufficient research to support the equivalency of different measures or to help researchers and practitioners choose a measure that is most appropriate for their purposes. Head-to-head comparative studies of more than two presenteeism measures are rare. Most studies have only investigated whether measures are sensitive to differences between those with and without symptoms, so little is known about comparative sensitivity to symptom severity and change over time. Most epidemiologic research on presenteeism has used a non-standard measure of mental health (Sanderson and Andrews, 2006).

The aims of the study were to compare four presenteeism measures on their detection of clinically meaningful differences in depression and anxiety status as measured by the Patient Health Questionnaire (Kroenke et al., 2001). Presenteeism measures included the number of days attending work unwell, the equivalent number of days after adjusting for self-perceived productivity, and two domain-based measures that were developed specifically to include the cognitive/social aspects of work which may be more sensitive to mental health symptoms: the Work Limitations Questionnaire (WLQ, Lerner et al., 2004a) and the Stanford Presenteeism Scale (SPS-6, Koopman et al., 2002). We compared measures on their sensitivity to presence versus absence of depression and anxiety, symptom severity, and change in depression and anxiety over 6 months follow-up. We hypothesized that the more detailed, domain-based measures (WLQ, SPS-6) would show greater sensitivity in all cross-sectional and prospective comparisons than the other presenteeism measures and absenteeism. There has also been one study suggesting the WLQ subscales may be able to discriminate at the level of different types of depressive symptoms (Lerner et al., 2004a). We extended this in a secondary analysis by examining whether there was a differential association between the nine individual symptoms of depression and interference in different types of job demands as measured by the WLQ. We hypothesized that physical symptoms would be associated more strongly with physical work demands and cognitive/affective symptoms with mental work demands. This study builds on previous research by investigating whether more detailed presenteeism measures offer any additional information over briefer alternatives, both for cross-sectional comparisons and a naturalistic observation of change over time, and by using a standardised measure of depression and anxiety in a routine workplace setting.