5.2  Absenteeism (labour force participants)

5.2.1  Methods

One of the most visible impacts of ill health for those participating is lost output owing to days absent from work. Research in other countries estimates the cost of absenteeism using the data from administrative sources on employee absence or the results of surveys that directly ask people about the number of sick days they have taken (see Goetzel et al., 2004; Davis et al., 2005; DeVol and Bedroussian, 2007). The number of days away from work owing to illness is not asked in SoFIE. Further, there are limited sources of information of this nature in a New Zealand context. As a result, estimates of absenteeism have to be based on other questions asked in SoFIE and assumptions about the responses to these. As such, absenteeism has two components:

• Component 1 – Assume that all those who are participating and who have ill health-related hospital inpatient appointments in the reference period have taken time off work to attend hospital. The hours lost per affected person are estimated using average daily hours usually worked multiplied by the length of the hospital appointment in days.[31]
• Component 2 – Assume that those who are participating and who answer yes to the question: “(Other than anything that resulted from an injury) In the last 12 months, did an illness or health problem stop you doing your usual activities for more than a week?” have taken at least one week off work. The hours lost per affected person are estimated using average weekly hours usually worked.[32]

The total number of hours estimated to be lost owing to absenteeism is simply the sum of these two components. The formula, when these components are evaluated at the average hourly full-time rate, can be found in Figure D1 in Appendix D.

There are a number of limitations of using this method to estimate lost hours from being absent from work. Firstly, it is not known what days of the week a person works. Even if they are employed at the time of the hospital appointment, they may arrange the hospital appointment to be for a day on which they do not work, therefore resulting in no hours of work being lost. Averaging the annual hours over the number of days in a year (including weekends), makes the assumption that an “average” day's hours are lost for each day of the hospital appointment. For some who are able to work flexibly and therefore rearrange the hospital appointment to avoid clashes with work, this may be an overestimate; however, for most people, who do not work on every day of the year, this will be an underestimate, thus, to some degree, balancing each other out.

A second issue is that, while hospital inpatient appointments are known to last more than three hours, the amount of work time lost for those hospital inpatient appointments where the number of overnight stays is zero, is hard to ascertain. However, taking into account waiting and transportation time, it is reasonable to assume that at least one day's average hours are lost for this group.

Another issue is the limitation of the assumption made in Component 2. Those reporting that an illness has stopped them doing their usual activities for more than a week may or may not have taken a week off work. This will depend on the nature of their illness and of their work. In contrast, a person reporting that an illness has stopped them doing their usual activities for more than a week may have taken much more time than a week off work. Using these methods, only illnesses that result in absence for more than a week can be estimated (other than hospital inpatient appointments that are less than a week that are included). Many people will be away from work owing to illness for less than a week at a time. In fact it is known from other sources that the majority of employees take less than one week off work in total each year. So this methodology potentially misses a large group of people who take off only a small number of days as well as underestimating absenteeism for those who take off more than a week at a time. This limitation should be remembered when interpreting the results.

A further limitation is that some of those reporting an illness or health problem lasting more than a week may in fact be referring to the hospital appointment being accounted for in Component 1 of the absenteeism estimate. In this analysis both these costs were included for two reasons. Firstly, the absenteeism costs owing to hospital appointments do not account for additional days sick leave required after the hospital appointment as it cannot be ascertained where this would be needed. This inclusion of the crossover allows for this to occur. Secondly, the absenteeism owing to illness or health problems is a week or more; a known lower bound. Therefore the inclusion of this crossover, that is quantified in the next section, allows for affected activity that is more than one week in length.

A broader issue is that it is not known if the respondent took annual leave to attend hospital or when they were sick. If an employee takes annual leave, in theory, hours are not lost. However, as the majority of employees have been with an employer for more than six months they will be entitled to at least five days sick leave so it is sensible to assume they will use this and thus output will be lost.[33]

This research could be developed further in future with different assumptions being made about the amount of time a person, reporting their activity to have been stopped owing to illness, has had off work.