The American Journal of Managed Care April 2007
A Review of Methods to Measure Health-related Productivity Loss
Background: Annual US health-related productivity losses are estimated to reach some $260 billion, attributable not only to absenteeism but also to presenteeism (being present at work but working at a reduced capacity). The search for remedies has been hampered by the lack of accurate estimates of the loss of productivity and its true costs. To date, little effort has been made to assess the availability of measurement instruments or the validity and reliability of those that exist.
Objectives: To systematically review the instruments used to measure productivity loss and its costs and to assess limitations in current research.
Design: A systematic search was conducted of the published and gray-market research literature from 1995 through 2005 on methods for estimating productivity loss and monetizing that loss.
Results: Twenty survey instruments were identified that assess the effect of health problems on absenteeism or presenteeism by attempting to quantify self-perceived or comparative impairment or by measuring unproductive work time. Some of the methods have been validated. The challenges of measuring presenteeism far exceed those of measuring absenteeism primarily because many jobs do not have easily measurable output. Methods to estimate the cost of lost productivity were also identified; however, none have been validated, to our knowledge.
Conclusions: The greatest impediment to estimating the cost of productivity lost to illness is the lack of established and validated methods for monetization. The issues raised in this review are intended to stimulate future research to validate and improve such methods.
(Am J Manag Care. 2007;13:211-217)
This article reviews available methods to measure and monitor health-related productivity loss, a major concern to employers and policy makers as productivity losses may cost $260 billion annually and may exceed direct medical costs:
- We identified 20 instruments that capture absenteeism and presenteeism based on employee self-reporting. Many have been validated and used in research and operations.
- Several methods to estimate the effect of productivity loss on cost have been developed, but none of them have been firmly established and validated to our knowledge.
Approximately $260 billion in output is lost each year in the United States because of health-related problems, according to the Commonwealth Fund.1 Seemingly harmless conditions such as back pain are suspected to translate into substantial losses because of their high prevalence. Stewart and coauthors2 estimated the productivity loss attributable to common pain conditions at $61.2 billion annually. Such revelations, particularly at a time when competition has employers searching for ways to cut costs, have sparked the interest of employers, policy makers, and others interested in this issue.
Findings from studies3-5 suggest that the cost of lost productivity may be several times greater than the direct medical costs; furthermore, presenteeism (being present at work but working at a reduced capacity) may account for a larger proportion of losses than absenteeism (being absent from work). For example, in a meta-analysis4 of 7 studies that estimated productivity losses, the overall cost of presenteeism was found to account for one fifth to three fifths of the total US dollars lost to 10 costly conditions (which also included absenteeism costs and direct medical costs). Another study5 found that days lost because of presenteeism were 7.5 times the number of days lost due to absenteeism when 17 common conditions were considered.
Awareness of the magnitude of these losses has driven employers and policy makers to search for remedies. Employers believe that better management of chronic conditions might help decrease their costs substantially. For some employers, such data have triggered a paradigm shift in that they have begun to regard their employees as critical assets, with the health-related benefits their organizations provide (such as group health insurance, wellness programs, and disability insurance) as an investment in those assets rather than just costly benefits. Policy makers are intrigued by the opportunity to align the social welfare objective of improving care for chronic conditions with the need to make the business case for quality improvement.
To pursue those opportunities, instruments that measure the effect of health on productivity and estimate its financial effect with reasonable accuracy are needed. To date, little effort has been made to assess the availability, validity, or reliability of instruments for productivity measurement. This article summarizes the findings of a systematic review of such instruments and interviews with eminent researchers in the field. Our aim was to inform the debate by describing the existing types of instruments and monetary conversion methods and by highlighting limitations and trends in current research. This information can help readers understand what is behind the numbers reported on health-related productivity losses and put such estimates into perspective. The review should also contribute to focusing the research agenda in this important and growing field.
We identified instruments for measuring the effect of ill health on productivity because of absence from work (absenteeism) or because of reduced performance while at work (presenteeism) through searches of the published and unpublished literature and governmental and corporate communications from 1995 through 2005 using the following search terms: absenteeism, presenteeism, workplace, employment, productivity, questionnaires, instruments, measurement, and cost of illness. We contacted experts and searched the references of identified articles for additional leads. We retrieved supporting material, such as information on assessment of reliability and validity, for each identified instrument. Finally, we reviewed methods to derive monetary estimates of productivity loss from those instruments and conducted interviews with 5 recognized experts in the field of estimating cost of lost productivity to help put the findings into perspective and to shed light on current research trends.
We identified 17 survey instruments that assess the effect of respondents' health problems on absenteeism or presenteeism (Table). One instrument, the Stanford Presenteeism Scale, exclusively addresses presenteeism, but it is commonly combined with questions on absenteeism. The instruments vary substantially in length (range, 3-44 questions) and scope. Some address only specific conditions, some address a range of conditions, and others address all conditions. We identified several methods for estimating the cost of lost work time. The challenges involved in measuring presenteeism and its costs are far greater than those involved in measuring absenteeism because reduced performance on the job is less tangible than absence. Therefore, most of the findings we report herein pertain to measuring presenteeism.
Absenteeism is measured by asking respondents how much time they missed from work because of ill health. The recall periods range from 1 week to 3 months. Because such self-reported data have been found to be reliable and valid when the recall periods are short (ie, 1-2 weeks), they can serve as a reasonable substitute for lost time data, which most companies do not routinely collect.23 Results derived based on longer recall periods should be viewed with caution.
Measuring presenteeism is complex. Some attempts have been made to measure presenteeism directly (eg, by telephone call volume per employee in a call center).19 However, generating objective data for other types of work would require developing methods to suit the particular characteristics of a given firm, workplace, and profession or job description and collecting data on a regular basis. Furthermore, developing such methods for knowledge-based occupations might be impossible because such workers often produce no easily quantifiable output.
To overcome these obstacles, researchers have developed instruments that can be applied to various professions and employers.24,25 These instruments focus on the following 3 modes of conceiving presenteeism: (1) assessment of perceived impairment, (2) comparative productivity, performance, and efficiency (with those of others and with one's norm), and (3) estimation of unproductive time while at work.
Assessment of Perceived Impairment. The most common approach to measuring presenteeism is assessment of perceived impairment, accomplished by asking employees how much their illnesses hinder them in performing common mental, physical, and interpersonal activities and in meeting job demands. Tools that use this approach include the Health and Productivity Questionnaire, Health and Work Questionnaire, Stanford Presenteeism Scale, Work Limitations Questionnaire, and Work Productivity and Activity Impairment Questionnaire.
Questions about perceived impairment can range from the general to the specific. The following example of a general question is found in the Stanford Presenteeism Scale: "Despite having my [health problem], I felt energetic enough to complete all my work," to which the employee is invited to respond using a 5-point scale of responses ranging from "strongly disagree" to "strongly agree." An example of a specific question in the Work Limitations Questionnaire requires a respondent to rank on a 5-point scale the difficulty he or she had in using the "upper body to operate tools or equipment."
Comparative Productivity, Performance, and Efficiency. Measuring comparative productivity, performance, and efficiency is another way to capture presenteeism. This method, which is used by the Health and Productivity Questionnaire and the Health and Work Questionnaire, seeks to understand how an employee's performance differs from that of others or from his or her usual performance.
On a 10-point scale that ranges from "worst ever" to "best possible," the Health and Work Questionnaire asks respondents to rate the overall quality and amount of work produced in the preceding week and how efficiently it was performed. Using a 10-point scale that ranges from "worst performance" to "best performance," the Health and Productivity Questionnaire asks respondents to rate the job performance of workers in similar positions, their usual performance in "the past year or two," and their overall performance during the recall period (4 weeks). The Health and Productivity Questionnaire and the Health and Work Questionnaire include these comparative performance questions in addition to questions about perceived impairments.
Compared with measures of perceived impairment, measures of self-reported performance have 3 main advantages for expressing presenteeism as a single meaningful number. First, the attempt to benchmark one's perceived performance provides a reference against which loss can be measured. Questions about perceived impairment do not include any conception of what is a standard or usual level of impairment. Second, when based on a 10-point performance scale or a percentage scale, the results can more easily be incorporated into a monetization formula than agreements or disagreements with statements about perceived impairment. Third, attempts have been made to validate employees' self-reported performance evaluation by comparing them with their supervisors' assessments.25
Estimation of Unproductive Time While at Work. Estimation of unproductive time to assess presenteeism (ie, asking employees to estimate lost time, as is done for absenteeism) is attempted by only a small number of instruments. For example, the Work Productivity Short Inventory asks employees to estimate how many unproductive hours they spent at work during the recall period. Although this approach would lead to the easiest monetization, no study (to our knowledge) has shown that employees can accurately transform their perceived impairments into a temporal measure.
Validation Studies for Presenteeism Measures
The validity of productivity survey instruments is difficult to establish. While it is conceptually straightforward to validate self-reported measures of absenteeism against factual data of workplace presence or absence, validating presenteeism poses significant challenges because of the nature of the data being collected. For certain types of employment and occupation, such as call centers, employee activity logs are maintained. However, for most jobs there is no true account of productivity with which to assess an employee's performance. Nevertheless, researchers have attempted to validate presenteeism instruments. A detailed summary of published validation studies can be found in the online Appendix (available at www.ajmc.com.).