THE NEW ZEALAND MEDICAL JOURNAL Journal of the New Zealand Medical Association

Sickness presenteeism in a New Zealand hospital Lisa M Bracewell, Duncan I Campbell, Palmira R Faure, Emily R Giblin, Tessa A Morris, Liyana B Satterthwaite, Cameron D A Simmers, Caroline M Ulrich, John D Holmes Abstract Aims The aim of this study was to assess the attitudes of hospital clinical staff to acute personal illness. Methods A self-reported questionnaire was developed. Four hundred clinical staff employed by the district health board (DHB) who met the inclusion criteria who were randomly selected. Data were collected and analysed using SPSS software. Ethical approval was obtained from the Lower South Regional Ethics Committee and from the DHB Health Research Office. Results Doctors were more likely to exhibit sickness presenteeism (SP)—i.e. working despite being sick—than any other occupational group at the DHB. Two main reasons were given for not taking sick leave: staff did not believe they were unwell enough to justify taking leave and they did not want to increase the workload of others. The majority of study participants would not contact anyone for advice about whether to take leave. Conclusion This study provides evidence that SP, especially in doctors, is prevalent in the DHB and is similar to findings from elsewhere. Low rates of clinical staff contacting someone for advice on coming to work whilst ill could be targeted to improve infection control.

This study was carried out to explore attitudes of Otago District Health Board (ODHB) staff to acute personal illness. The perceived need for such a study was heightened with the outbreak of norovirus in the ODHB hospitals in August 2008. During a 4-week period more than 2300 scheduled appointments were postponed, including outpatient clinics, elective surgery and planned admissions.1 In total, 383 staff and 143 patients were affected at Dunedin and Wakari Hospitals. 2 Norovirus (or Norwalk virus) is recognised as the major cause of non-bacterial gastroenteritis in the world. 3,4 The virus is highly contagious, with an infective dose of between 10 and 100 particles. 3 It is estimated that ingestion of one virus particle will lead to a 21% probability of infection in a susceptible individual. 5 Norovirus is spread via the faecal-oral route and through contact with vomitus, as well as through person- to-person contact, aerosolisation of virus particles, or contact with infected surfaces and food. 3,4 In the recent outbreak at Dunedin and Wakari Hospitals, more staff were affected by norovirus than patients. It is therefore reasonable to consider this population as a possible method of transmission and reservoir of the virus. Staff could contract norovirus while at work by interaction with patients and other staff, or could become infected in the community, and bring the virus into the hospital.

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Sickness presenteeism (SP) is a term that was coined in the 1990s to “designate the phenomenon of people, despite complaints and ill-health that should prompt rest and absence from work, still turning up at their jobs”.6 It is of particular interest in the hospital setting as this represents a high-risk population for the transmission of illness. The hospital inpatient population is already unwell, and are thus more likely to be relatively immunocompromised and experience a more complicated clinical course of illness. This results in greater levels of morbidity and the potential for higher mortality rates. SP places a significant burden on the general workforce, by severely decreasing productivity and making it costly for employers and society. 7 One study of the Danish workforce found that more than 70% of the core workforce goes to work ill at least once during a 12-month period. 7 Workers in education, care and welfare situations have significantly higher rates of SP when compared with other professions. 6 Many reasons have been proposed for why people may continue to work despite illness, including work-related factors, personal circumstances and attitudes. Work- related factors may include lack of resources, lack of control over work tasks, relationships with colleagues and employment conditions. Employees who do not have a suitable replacement or fill-in available to cover their workload if they take a sick day have higher levels of SP than those who feel that they will not face a backlog of tasks when they return to work. 7 This time pressure was the single most influential factor impacting on an employee’s decision whether or not to go to work when sick. 7 Hansen and Andersen also found that those with a supervisory role, those with less control over their work tasks and those who work shift work have increased rates of SP. 7 A New Zealand study looking at SP in healthcare workers found that SP was part of a professional identity, with staff feeling that it was part of their job to continue to work while unwell, and due to a sense of loyalty to their colleagues. 8 M āori workers interviewed spoke of a cultural ethic of staying at work until a job is finished, and that “we don’t like things to fall down because if they do fall down we are part of that thing falling down too”. 8 Taking sick leave on one occasion is thought to make a person more reluctant to do so on subsequent occasions, leading to SP. 7,9 Of all occupational groups, healthcare workers and education workers form a sector of the workforce with the highest rates SP and lowest rates of sickness absenteeism (SA). 6 There is little evidence looking at specific risk factors for SP in this group, although it is recognised that doctors have lower rates of SA than other healthcare workers. 9 Proposed reasons for these differences in SA include unwillingness to burden colleagues and difficulty adopting a patient role. 9 The aims of this study were to survey Otago District Health Board clinical staff, at Dunedin Public Hospital (DPH) and Wakari Hospital regarding attitudes to personal infectious illness. The primary aim was to estimate how many clinical staff had continued to work despite personal illness in the last 12 months. Methods Study group—This study was a cross-sectional survey of 400 clinical staff members working for the ODHB, carried out between 13 March and 9 April 2009.

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Questionnaire design—The questionnaire was developed by the study group with a small number of questions adapted from previous studies. 8,9 During development, the questionnaire was reviewed by senior staff in the Department of Preventive and Social Medicine, as well as ODHB staff in the areas of Infection Prevention and Control and Staff Occupational Health. The questionnaire contained five main sections. Section 1 asked participants to state the job description which was most applicable to them, then went on to ask basic demographic questions such as age and gender. Participants were also asked how frequently they had received the influenza vaccination in the last five years. Section 2 was titled ‘Personal Illness’, and consisted of the main body of questions regarding staff attitudes to acute personal illness. Participants were asked to describe the number and nature of any acute infectious illnesses experienced since April 2008. For any such illness, they were asked to state the numbers of days leave taken from work due to this illness. If they had not taken leave on any occasion, they were then asked to elaborate on the reasons for this. Participants were also asked to state which, if any, DHB services were utilised for advice on working whilst ill. Section 3 followed a similar format to section one, but attempted to establish staff attitudes towards taking leave from work whilst family members were affected by an infectious illness. Sections 4 and 5 included both personal and work-related demographic questions. Participants were also asked about job satisfaction and the increased burden on their workload following a sick day. A section for comments was included at the end of the questionnaire. Sample—A sample size of 300 participants would be required to provide sufficient numbers to detect significant statistical differences. Assuming a 75% response rate (similar to response rates for similar studies), 400 staff members were asked to participate. Four hundred participants were randomly selected by the Human Resources Department from a database of 2000 DHB employees who met the inclusion criteria. Inclusion criteria were that the participant had face-to-face patient contact in the normal requirements of their job, was on the staff database, was currently in employment, and worked full- or part-time. Subcontracted staff (cleaners and orderlies) were excluded from participation as they were not employed by the ODHB and are therefore difficult to contact reliably. Potential participants were sent a cover letter and a confidential questionnaire to their internal mail address explaining the purpose of the survey, and inviting participation. Replies were to be returned via the internal mail using an enclosed reply envelope. Participants were given one week to return the questionnaire. A reminder letter and duplicate questionnaire were posted one week after the first mail- out. No questionnaires received after Thursday 2 April 2008 were included in this analysis, and any received after this date were counted as non-respondents. All questionnaires (including ones sent with a reminder letter) were numbered to ensure we did not record data from the same participant more than once, and any duplicate questionnaire received was excluded. Ethical approval—This project was given ethical approval by the Lower South Regional Ethics Committee and ODHB approval through the Health Research Office. Statistical analysis. All responses to the questionnaire were entered onto a spreadsheet using SPSS (Version 14, 2006). Data were analysed with SPSS software using Chi-squared tests. Results Of the 400 randomly selected DHB staff invited to participate in this study, 224 completed the questionnaire. Two questionnaires were returned unopened after being sent to staff who were no longer employed by the DHB. This gave a total number of questionnaires which could potentially be returned of 398, and a response rate of 56%. Seven duplicate questionnaires were returned and these were excluded from the analysis. Where possible, comparisons were made between the demographic characteristics of the study group and those in the pool of all clinical staff from which our sample was drawn. Men were slightly under-represented in our sample compared to the sample

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pool (19% vs 24%). The distribution of staff across different occupational groups in our study population was comparable to the total study pool in most categories, although doctors were under-represented and social workers proportionately over- represented. Baseline demographic data of the study population are shown in Table 1.

Table 1. Baseline job information of study participants

Variables Number (%) Occupation Doctor 30 (13.4) Nurse 110 (49.1) Physiotherapist 4 (1.8) OT 3 (1.3) SW 9 (4.0) Psychologist 6 (2.7) Midwife 3 (1.3) Other 57 (25.4) Not stated 2 (0.9) Years at ODHB <1 year 27 (12.1) 1–2 years 30 (13.4) 3–4 years 21 (9.4) >4 years 144 (64.3) Not stated 2 (0.9) Years since graduation <1 year 11 (4.9) 1–2 years 16 (7.1) 3–4 years 13 (5.8) >4 years 166 (74.1) Not stated 18 (8.0) Hours worked per week <10 2 (0.9) 10–19 5 (2.2) 20–29 31 (13.8) 30–39 56 (25) 40–49 102 (45.5) 50–59 15 (6.7) 60–69 6 (2.7) ≥70 3 (1.3) Not stated 4 (1.8) Job satisfaction Very satisfied 64 (28.6) Fairly satisfied 118 (52.7) Neither satisfied nor dissatisfied 22 (9.8) Fairly dissatisfied 17 (7.6) Very dissatisfied 0 (0) Not stated 3 (1.3) Proportion of work left undone after work absence None, or a small proportion 114 (50.9) Less than half 23 (10.3) More than half 31 (13.8) All 49 (21.9) Don’t know 6 (2.7) Not stated 1 (0.4) OT=Occupational therapist; SW=Social Worker.

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The results show that the DHB has a reasonably stable and experienced workforce, with 64.3% having worked for the DHB for greater than 4 years, and 74.1% having been qualified for more than 4 years. The majority (81.3%) of the respondents are very or fairly satisfied with their job. Almost 70% of participants had had at least one episode of acute infectious illness in the past 12 months (Table 2).

Table 2. Incidence of personal infectious illness in the past 12 months by occupation, age, sex, nature of illness

Variables Incidence (%) Had infectious illness in past 12 months (#) 1 156 (69.6) 2 75 (33.5) 3 30 (13.4) 4 or more 15 (6.7) By occupation (%) Doctor 26 (86.7) Nurse 68 (64.8) Physiotherapist 3 (100.0) OT 3 (100.0) SW 7 (77.8) Psychologist 5 (83.3) Midwife 3 (100.0) Other 39 (68.4) p-value* 0.045 By age (years) < 25 7 (77.8) 25-34 33 (82.5) 35-44 38 (79.2) 45-54 50 (69.4) ≥ 55 25 (54.3) p-value for trend 0.003 By sex Male 31 (75.6) Female 120 (70.2) p-value 0.638 By self-reported health status Excellent 43 (58.1) Very good 82 (78.8) Good 24 (77.4) Fair or Poor 5 (83.3) p-value for trend 0.009 Nature of illness Influenza 34 (21.8) Vomiting 42 (26.9) Diarrhoea 59 (37.9) Common Cold 122 (78.2) Other 16 (10.3) OT=Occupational Therapist; SW=Social Worker; *p-value for occupation indicates the difference between incidences of personal infectious illness in doctors and all other occupations.

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There was a statistically significant trend of increasing prevalence of personal infectious illness in the past 12 months with poorer self-reported health status (p=0.009). Age also showed a significant trend with younger age being associated with increased likelihood of infectious illness in the past 12 months (p=0.003). Doctors were significantly more likely than all other occupation groups to have had a personal infectious illness in the past 12 months (p=0.045). The common cold was the most common infectious illness to have been experienced by the study participants in the last 12 months; 78.2% of people reported having had a common cold versus 21.8% having influenza. Nearly 50% of participants who were sick with an infectious illness at any point in the previous 12 months did not take leave whilst ill (sickness presenteeism). The most frequent reason given for working with a personal infectious illness was that the participant did not want to increase the workload of others (53.5%). Other reasons noted frequently included that there would not have been a replacement available (31.0%), that there would have been an increased burden of work once returned to work (31.0%), that they did not feel they were sick enough (26.8%) and that there was pressure from work (22.5%) (Table 3).

Table 3. Reasons why leave was not taken despite the presence of infectious illness

Reason for not taking leave Personal illness (%) Did not want to increase workload of others 38 (53.5) There would not have been a replacement available 22 (31.0) Felt that there would have been an increased burden of work once returned 22 (31.0) Not sick enough 19 (26.8) Pressure from work 16 (22.5) Did not want to cancel clinics 14 (19.7) Unwell during days off 10 (14.1) Could not cancel clinics 6 (8.5) Money/financial stressors 3 (4.2) Sick leave had been used up/no more sick days 2 (2.8) No reasons given 2 (2.8) Concerns about job security 1 (1.4) Other 5 (7.0)

When participants were asked to state the main reason why they did not take sick leave when they had an infectious illness, the most common reason was that they did not feel they were unwell enough to justify taking sick leave (Figure 1).

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Figure 1. Main reasons given for working with a personal infectious illness

45 40.9 40

Percent (%) Percent 15.2 15 12.1

10 7.6 6.1 4.5 4.5 4.5 5 3 1.5 0

s k s rs r ble r ic e so h ila Wo in s Other a Cl e Ot tr ll Enough f om e t Av r Returned S n F e ad o e ial lo r Cancel c k eme Reason Given u c o s o or a N T inan Not Unw W Unwell On Days Off l res oad Onc F p P l nt se ney/ a t Wa o re A Re c M n o I Been Did No T e reased Work v c ant In W t Ha ot No N ld u Did

ere Wo h T

The only variable which was found to have statistically significant differences between those who took leave for personal infectious illness and those who did not across a category was occupation; 76.9% of doctors continued to work whilst unwell and when compared to all other occupations this was significantly higher (p=0.004) (Table 4). The majority of participants indicated that they would not contact anyone, should they become unwell, for advice on whether or not they should come to work. This was indicated by 59.1% of doctors, possibly because they felt their clinical experience negated the need for external advice. Participants who did not contact anyone for advice when they were ill were significantly more likely to have had an infectious illness in the past 12 months that those who did contact someone for advice (p=0.025).

Table 4. Percentages of individuals who took and did not take leave for personal infectious illness by work-related factors, dependents, age, gender and self-reported health status

Variables Took leave (%) Did not take leave (%) Employment Conditions Proportion of work left undone after absence None, or a small proportion 41 (53.9) 35 (46.1) Less than half 9 (52.9) 8 (47.1) More than half 11 (47.8) 12 (52.2) All 15 (44.1) 19 (55.9) p-value for trend* 0.321 Hours worked 10-19 2 (50) 2 (50) 20-29 11 (55) 9 (45) 30-39 21 (55.2) 17 (44.8) 40-49 35 (49.3) 36 (50.7) ≥50 11 (55.0) 9 (45.0) p-value for trend* 0.815 Job satisfaction Very satisfied 22 (52.4) 20 (47.6) Fairly satisfied 44 (53.0) 39 (47.0) Neither satisfied nor dissatisfied 5 (29.4) 12 (70.6) Fairly or very dissatisfied 8 (61.5) 5 (38.5) p-value for trend* 0.775 Occupation Doctor 6 (23.1) 20 (76.9) Nurse 36 (53.0) 32 (47.0) Physiotherapist 1 (33.3) 2 (66.7) OT 0.0 (0) 3 (100) SW 5 (71.4) 2 (28.6) Psychologist 2 (40.0) 3 (60.0) Midwife 2 (66.7) 1 (33.3) Other 26 (66.7) 13 (33.3) p-value* # 0.004 Dependents 0 51 (50.5) 50 (49.5) 1 15 (62.5) 9 (37.5) 2 7 (36.8) 12 (63.2) 3 or more 4 (44.5) 5 (55.5) p-value for trend* 0.506 Age < 25 4 (57.1) 3 (42.9) 25-34 16 (48.5) 17 (51.5) 35-44 18 (47.4) 20 (52.6) 45-54 24 (48.0) 26 (52.0) ≥55 16 (64.0) 9 (36.0) p-value for trend* 0.474 Gender Male 12 (48.7) 19 (61.3) Female 64 (53.3) 56 (46.7) p-value* 0.211 Self-reported health status Excellent 23 (53.5) 20 (46.5) Very good 46 (56.1) 36 (43.9) Good 9 (37.5) 15 (62.5) Fair or Poor 1 (20.0) 4 (80.0) p-value for trend* 0.113 OT=Occupational therapist; SW=Social Worker; * p-values indicate difference between those who took leave and those who did not across a category—e.g. age; #p-value for occupation indicates the difference between those who took leave and those who did not for doctors and all other occupations.

Discussion The results of this study confirm that amongst ODHB employees, doctors are significantly more likely to continue to work despite having an infectious illness than all other occupational groups (76.9%; p=0.004), consistent with research by McKevitt et al.9 Overall, sickness presenteeism occurred in 48.7% of respondents, and the main reason for not taking leave was that they felt they were not unwell enough. It was also demonstrated in our results that the majority of participants would not contact anyone for advice, and that these participants were significantly more likely to have had an infectious illness in the previous 12 months. Almost 70% of participants had at least one episode of acute infectious illness in the past 12 months, and there were statistically significant trends for increased personal infectious illness in those respondents who had poorer self-reported health status or were in a younger age group. A study of this nature has not been carried out before in Dunedin, and it attracted much interest from departments such as Infection Prevention and Control, Human Resources, Management as well as other hospitals. The questionnaire is an original document, designed by the study group based on results from previous studies. Several validated questionnaires were referenced by similar studies however we were unable to gain access to these studies. Limitations of the study include that it is a self-reported and retrospective study which will inevitably contain recall bias. To limit this we limited recall time to 12 months. To assist in recall and to avoid misreporting we stated and defined the illnesses of interest for participants to select from. Time was the biggest limitation of this study. An imposed departmental deadline meant that the project was limited to six weeks, and all data had to be collected, entered and analysed by the end of the fifth week. Our study population excluded staff sub-contracted by the hospital, such as cleaners and orderlies, who are not employed by the DHB. This was due to perceived difficulties contacting and accessing information from these groups in the short time frame we had available. However, they are an important group who have a significant role to play in infection control in hospitals. Our sample size was 400 which was a manageable number for data entry and analysis in 5 weeks and also prevented over- sampling of a population which is already regularly surveyed. Our response rate was not as high as expected and it is possible that the 56% of respondents may be those who are strong-minded regarding the issues of infection control. Our questionnaire design was also a limitation of this study. A number of questionnaires were returned incomplete. This may be for a variety of reasons including confidentiality, unclear questions, and participants not reading the questionnaire carefully. Along with incomplete questionnaires, some questions were misinterpreted. The data collected from this study is comparable with much larger overseas studies. One of the main reasons for sickness presenteeism in the overall population was found to be “not wanting to increase the workload of others”. This concurs with Dew et al 8, who noted a professional identity among healthcare workers, and echoed by

Hansen and Andersen, who found that employee relationships with colleagues was associated with sickness presenteeism 7. The results have outlined a number of areas which can be improved upon to support staff requiring leave from work when unwell with an infectious illness. One of the difficulties encountered by staff was the number of days sick leave allocated annually. Staff who had already reached their allocated sick leave felt unable to take leave when unwell with an infectious illness because no sick leave remained. According to current DHB policy, once the allocated sick leave has been used, sick days may be deducted from annual leave, advance sick leave may be given, unpaid leave may be taken or compassionate sick leave may be allowed. There is not currently a consistent policy across all departments. Implementation of a hospital-wide policy on sickness leave may help to introduce consistency. Lynn et al, assessed two separate Norovirus outbreaks at Princess Margaret Hospital in Christchurch.10 Between outbreaks they introduced a policy to grant extra paid sick leave without financial penalty to staff members affected by Norovirus and to emphasise that staff must remain off work for the recommended 48 hours following the resolution of symptoms. They found that staff who took leave had a longer period of time away from work during the second outbreak. This resulted in the Norovirus outbreak being contained. During the second outbreak, fewer staff reported norovirus infection, fewer patients in total were affected, and as a result the ward was closed for a shorter period than during the previous outbreak. Obviously, both the health and financial cost of paying for extended sick leave by the ODHB would be substantially less than the cost of an extended Norovirus outbreak. The low rates of staff contacting someone for advice regarding whether to take leave for an acute personal illness highlights the need for a single consistent source of advice available to staff. An infection control ‘helpline’ would provide staff members with consistent, unbiased advice from colleagues who would not pressure them into working despite being unwell. Although the ODHB has developed a set of guidelines 11 addressing staff advice for infectious illness and sick leave, they are only available onsite via the hospital based website. Offsite web access for ODHB employees would be simple and cost-effective to implement. In this study, a major finding was that staff perceived themselves as “not unwell enough” to stay home when sick. This highlights the need to educate staff regarding the importance of taking time off in order to decrease the risk of passing the infection onto patients and other staff members. Further research looking at sickness presenteeism and its prevalence amongst healthcare workers is important in order to attempt elucidate ways in which sickness presenteeism can be reduced, especially in light of the recent emergence of the H1N1 influenza pandemic. A larger sample size and a longer time frame would likely yield a greater response rate thus allowing more reliable conclusions about the sickness behaviour of hospital staff to be made. Questionnaires used in future research should be more focused and look at reasons behind individual illness episodes as opposed to general illness as in our questionnaire to avoid misinterpretation of questions asked. . It is assumed that most people with

diarrhoea and vomiting would not present at work but the way our questionnaire was structured, we were unable to relate reasons for presenteeism with type of illness. By individualising each episode of personal infectious illness this will enable researchers to analyse data without including episodes of the common cold which may in turn over-estimate the amount of sickness presenteeism. Future research therefore needs to determine reasons for sickness presenteeism and hence propose ways to reduce it and in turn reduce both the health and financial toll on both employees and health systems. Conclusions Doctors were more likely to exhibit sickness presenteeism than any other clinical group surveyed. In addition, the most common reason behind sickness presenteeism was that respondents “did not feel sick enough” to stay away from work. Statistically significant results for the reasons behind sickness presenteeism were not found in this study but results did highlight the prevalence of sickness presenteeism, its potential effects on both the economic and health costs of presenteeism as well as the need for further research. Competing interests: None known. Author information: Lisa Bracewell, Duncan Campbell, Palmira Faure, Emily Giblin, Tessa Morris, Liyana Satterthwaite, Cameron Simmers, Caroline Ulrich, 6th-year Medical Students, Dunedin School of Medicine, University of Otago, Dunedin; John Holmes, Clinical Senior Lecturer, Dunedin School of Medicine, University of Otago, Dunedin (and Medical Officer of Health, Otago District Health Board). Acknowledgements: We thank the following individuals and organisations for their assistance in this study: Dr Hilda Firth; A/Prof Peter Herbison; Human Resources Department, ODHB; Infection Prevention and Control Department, ODHB; and Administration staff, Department of Preventive and Social Medicine, University of Otago Correspondence: Dr John Holmes, Medical Officer of Health, Public Health South, PO Box 5144, Moray Place, Dunedin 9058, New Zealand. Fax: +64 (0)3 476 9858; email: [email protected] References: 1. McLean E. Both hospitals back to normal today. Otago Daily Times. 2008 Aug 25. http://www.odt.co.nz/news/dunedin/19318/both-hospitals-back-normal-today 2. Holmes J. Personal commentary. Medical Officer of Health, Otago District Health Board. 2009 Mar 26. 3. Norovirus fact sheet (information for staff). Otago District Health Board. 2008. Downloaded from MIDAS document system (ODHB Intranet). 4. Fauci AS, Braunwald E, Kasper DL, et al (eds). Harrison’s Principals of Internal Medicine 17th Ed. Parashar UD, Glass RI. Chapter 183. Viral Gastroenteritis. [Online]. 2009 Mar 2. http://online.statref.com/document.aspx?fxid=55&docid=1562 5. Simmons G, Foster M, McLean M, et al. Guidelines for the management of Norovirus outbreaks in hospitals and elderly care institutions. New Zealand Ministry of Health; 2008. http://www.moh.govt.nz/moh.nsf/pagesmh/8727/$File/guidelines-management-norovirus.pdf

6. Aronsson G, Gustafsson K, Dallner M. Sick but yet at work. An empirical study of sickness presenteeism. J Epidemiol Community Health 2000;54:502–9. 7. Hansen C, Andersen J. Going ill to work – what personal circumstances, attitudes and work- related factors are associated with sickness presenteeism? Soc Sci Med 2008;67:956–64. 8. Dew K, Keefe B, Small K. ‘Choosing’ to work when sick: workplace presenteeism. Soc Sci Med 2005;60:2273–82. 9. McKevitt C, Morgan M, Dundas R, Holland WW. Sickness absence and ‘working through’ illness: a comparison of two professional groups. J Public Health Med 1997;19(3):295–300. 10. Lynn S, Toop J, Hanger C, Millar N. Norovirus outbreaks in a hospital setting: the role of infection control. N Z Med J 2004 Feb 20;117(1189). http://www.nzmj.com/journal/117- 1189/771/content.pdf 11. Guidelines for the management of staff with communicable diseases. Otago District Health Board. 2007. [Online]. Downloaded from MIDAS document system (ODHB Intranet).