Improving the health and well-being of people with depression following a cardiac event

Background: Depression is highly prevalent in cardiac populations. While depression can lead to a range of clinical and psychological impairments, its impact on vocational, mental and physical health functioning remains under-researched in this population. Also unclear is whether targeted treatment can improve these outcomes. Combining depression management with a Coronary Heart Disease (CHD) secondary prevention program using a flexible mode of delivery could facilitate access to treatment, improving these patient outcomes and minimising the burden of this co-morbidity. The purpose of this thesis was to assess the impact of depression on mental, physical and vocational functioning in those with cardiovascular disease (CVD), and determine whether targeted treatment can improve these outcomes. Methods: Australian population-based data were used to assess the burden of, and interaction between, major depressive disorder (MDD) and CVD on vocational and health related quality of life (HRQOL) outcomes. Further, a novel systematic review was conducted to determine the predictive role of depression on return to work (RTW) after a cardiac event. In order to determine the effectiveness of depression treatment on mental and physical HRQOL outcomes of cardiac patients, a meta-analysis was conducted. Finally, data from a two-arm, 24-week randomised feasibility trial, with 6-month evaluation outcomes, were used to assess the effectiveness of a telephone-delivered, depression and lifestyle management program (‘MoodCare’) on mental and physical HRQOL and vocational functioning of depressed Acute Coronary Syndrome patients. Results: First, Australians with co-morbid MDD and CVD were least likely to be participating in the workforce (adj. Odds Ratio (OR): 0.4, 95% CI:0.3-0.6), and most likely to experience work functioning impairments (adj. OR:8.1, 95% CI:3.8-17.3) and absenteeism (adj. OR:3.0, 95% CI:1.4-6.6) when compared with individuals with one or neither condition. Second, depression predicted RTW after a cardiac event in over half of the 12 studies reviewed. Third, Australians with co-morbid MDD and CVD reported the greatest deficits in Assessment of Quality of Life (AQOL) utility scores (adj. Coefficient:-0.32, 95% CI:-0.40,-0.23) when compared with those with one or neither condition. Fourth, a meta-analysis demonstrated that depression treatment administered after a cardiac event significantly improved both mental and physical health functioning. Effect sizes were greatest for mental (standardised mean difference [SMD]=-0.29, 95% CI:-0.38,-0.20) versus physical HRQOL (SMD:-0.14, 95% CI:-0.24,-0.04). Finally, the MoodCare program yielded significant improvements in physical health functioning after 6-months (SF-12 mean difference=6.7; 95% CI:1.1, 12.3), compared with a control condition. Significant improvements in mental health functioning were also observed for those with a history of MDD. No intervention effects were observed for vocational outcomes. Conclusions: These findings confirm co-morbid depression and CVD as a significant public health issue. The benefits of treating depression in this population can go beyond psychological outcomes to improve HRQOL. These findings provide support for the use of a combined depression management and lifestyle program which is delivered over the telephone to improve key functioning outcomes of cardiac patients. Further research is required to determine the most effective way to impact vocational outcomes. Several clinically- and policy-relevant recommendations are discussed in light of these findings.