This dissertation consists of four papers aimed at understanding the complex relationship between employment and health. One paper is a systematic review of the return to work literature, while the other three papers used secondary data from three cohorts of people with HIV to examine the association between employment and health-related quality of life. The systematic review looked at longitudinal studies that reported health outcomes associated with return to work in relation to other employment trajectories. This review supported the beneficial effect of return to work on health in a variety of populations, times, and settings, and also found evidence that poor health interferes with the prospects of returning to work. Two other papers looked at the association between employment and health-related quality of life in people with HIV; one paper used a cross-sectional sample of people with HIV, while the other paper used a longitudinal sample of men who have sex with men. These two studies found evidence to support the association between employment and both physical and mental health-related quality of life. They also found that employment had a stronger relationship with physical than mental health, suggesting an adaptation process to the experience of unemployment. Finally, another paper examined the cross-sectional association between job security and quality of life in men and women living with HIV. This study found that job security offered additional mental health quality of life benefits, over and above participation in employment alone, for men living with HIV. On the other hand, women benefited from the availability of work, but the perception of job security failed to offer additional health benefits. The current level of evidence on the relationship between work and health in HIV needs to be strengthened by further research to develop and support practical clinical and policy recommendations.

This dissertation consists of four papers aimed at understanding the complex relationship between employment and health. One paper is a systematic review of the return to work literature, while the other three papers used secondary data from three cohorts of people with HIV to examine the association between employment and health-related quality of life. The systematic review looked at longitudinal studies that reported health outcomes associated with return to work in relation to other employment trajectories. This review supported the beneficial effect of return to work on health in a variety of populations, times, and settings, and also found evidence that poor health interferes with the prospects of returning to work. Two other papers looked at the association between employment and health-related quality of life in people with HIV; one paper used a cross-sectional sample of people with HIV, while the other paper used a longitudinal sample of men who have sex with men. These two studies found evidence to support the association between employment and both physical and mental health-related quality of life. They also found that employment had a stronger relationship with physical than mental health, suggesting an adaptation process to the experience of unemployment. Finally, another paper examined the cross-sectional association between job security and quality of life in men and women living with HIV. This study found that job security offered additional mental health quality of life benefits, over and above participation in employment alone, for men living with HIV. On the other hand, women benefited from the availability of work, but the perception of job security failed to offer additional health benefits. The current level of evidence on the relationship between work and health in HIV needs to be strengthened by further research to develop and support practical clinical and policy recommendations.

Reprint from: Allergology International 54(4), 2005, p.589-599

Research on health related Quality of Life (QoL) is valuable in developing health policy, assessing medical treatment outcomes and social sciences. Different QoL measurement instruments reflect different facets, and some QoL assessment tools are culturally insensitive. This study examines the existing WHOQOL-BREF (World Health Organisation Quality of Life) 26-item instrument for its suitability for use in New Zealand studies. It focuses on seeking facets of QoL of particular importance to New Zealand culture upon which New Zealand national items may be constructed and included when using the WHOQOL-BREF in studies in New Zealand. In order to achieve this goal, the project involved four sub-studies: verifying the existing WHOQOL response scale descriptors; conducting focus groups to elicit new areas or facets of QoL peculiar and particular to New Zealanders; examining the stability of the WHOQOL-BREF importance scale test-retest reliability; and conducting a national survey to assess what facets of QoL are most important to New Zealanders upon which national items may be developed and the national importance survey. The verification of response scale showed good correspondence with the standard English WHOQOL version. A total of 46 candidate importance items were generated from 12 focus groups’ discussions. Test/retest reliability revealed that the existing WHOQOL-Importance questionnaire items were more stable over a three week period, better than several of the new candidate importance items. Two thousand questionnaires asking what is important to New Zealand were sent out to the NZ general population and 585 returned. Results revealed that what is important varies across age, gender and health states. Twenty-four national items were developed from the national importance data. The study confirmed that what is considered as important facets of QoL varies within New Zealand and that there are facets that are important to New Zealanders not in the existing WHOQOL-BREF.

In chronic illnesses, such as prostate cancer, multiple health outcomes need to be considered. This project focused on two types of health outcomes: health-related quality of life (HRQoL) and cognitive function. The first aim was to investigate cognitive effects of pharmacological androgen-suppressing treatment. Numerous studies have shown cognitive performance to be associated with sex hormones. One of the main groups of drugs used for hormonal ablation in men with prostate cancer, the luteinising hormone releasing hormone (LHRH) agonists, has been associated with adverse cognitive effects in controlled studies in women and in case reports of female and male patients. However, there have been no published studies on the effect of LHRH agonists and other androgen-suppressing treatments on cognitive functioning in male patients. The second aim was to investigate the effect of treatments on HRQoL in men with prostate cancer. There are few randomised treatment studies of HRQoL in these patients. The third aim was to study additional predictors of HRQoL, examining stress and coping theory as a theoretical basis for understanding individual differences in HRQoL. The fourth aim was to examine patients’ subjective experiences of prostate cancer. To investigate these questions, 82 men with non-localised prostate cancer were randomly assigned to receive leuprorelin (LHRH agonist), goserelin (LHRH agonist), cyproterone (steroidal antiandrogen), or close clinical monitoring. These patients and 20 community volunteers matched for age, marital status, and general health undertook medical, psychosocial, and cognitive assessments before treatment and after 6 and 12 months of treatment. The main question for statistical analysis was whether dependent variables would show Group x Time interactions in the predicted directions. Compared with baseline assessments, men administered androgen suppression monotherapy performed worse in 3/12 tests of attention, memory, and executive function. Twenty-six percent of men randomised to active treatment demonstrated clinically significant decline in one or more cognitive tests at 6 months compared with baseline performance. By contrast, no community volunteers or patients randomised to close monitoring showed decline in test performance. Men on hormonal treatments reported impaired sexual function on treatment compared with baseline assessments. Men assigned to close monitoring and cyproterone treatment reported increased emotional distress over time. Groups did not differ in change in existential satisfaction, subjective cognitive function, physical symptoms, or social and role functioning. For individuals, hormonal treatments were more frequently associated with decreased physical, sexual, social and role functioning, but were also associated with improved HRQoL for some individuals. In hierarchical regression analysis, HRQoL was lower for men who had more comorbid illnesses, a history of neurological dysfunction, higher threat appraisals, or higher use of emotion-focused coping strategies. Coping strategies also showed some longitudinal associations with HRQoL, even when earlier levels of HRQoL had been taken into account. Subjective reports demonstrated that many patients viewed prostate cancer as a relatively manageable problem. Several patients said that other health problems affected them more than prostate cancer, whereas no patient said that prostate cancer was worse than other problems. Comments about the seriousness of prostate cancer were equally divided between patients who reported it as very serious (14.3% of patients) and those who saw it as a relatively minor problem (14.3%). Other patient observations were grouped into categories of personal responses to prostate cancer, health, and health research; life circumstances that were not directly associated with health; attributions about medication; and function prior to the study. The results demonstrated that pharmacological androgen suppression therapy was associated with impaired memory, attention, and executive function in male patients. Hormonal treatments and close monitoring had differential effects on patients’ HRQoL, particularly in terms of sexual function and emotional distress. HRQoL was also associated with appraisal and coping, to a greater extent than it was associated with medical variables, supporting the applicability of stress and coping theory for these patients. Observations from participants placed these findings in the context of participants’ concerns, demonstrating that issues such as cognitive and sexual function were relevant for these patients. These findings suggest that cognitive function should be given increased attention as a health outcome, not only in “neurological” disorders but also in other “non-neurological” conditions such as prostate cancer. They also support continued efforts to understand both beneficial and adverse effects of treatments for chronic illness on HRQoL and individual factors that affect health outcomes.

Thesis (Ph. D.)--Virginia Commonwealth University, 2007. / Prepared for: School of Nursing. Bibliography: leaves 120-145. Also available online.

Thesis (M. Nurs.)--University of Hong Kong, 2007.

Thesis (Ph. D.)--University of Washington, 1988. / Vita. Bibliography: leaves [352]-358.

Thesis (Ph. D.)--Virginia Commonwealth University, 2006. / Prepared for: School of Nursing. Bibliography: leaves 117-143. Also available online via the Internet.

Thesis (M. P. H.)--University of Hong Kong, 2006. / Also available in print.