The decision analysis approach used in this study requires presenteeism and absenteeism to be defined as mutually exclusive scenarios. Presenteeism, was therefore defined as the absence of absenteeism, consistent with previous approaches. In other words, no reported depression-specific, work and role-functioning disability days in response to the NSMHWB depression module item. Absenteeism, was the converse. Therefore, this analysis is based on two assumptions; a) all employed individuals with 12-month depression will experience impairment relevant to their work; and b) the categories of 12-month absenteeism and presenteeism are mutually exclusive. This method was selected as it provides a measure of depression-specific disability days and therefore removes the possible influence of co-morbid disorders of work attendance decisions. Two subsequent models determined whether outcomes differed for blue versus white-collar Shikonin workers. All models were identically structured and generated using Data TreeAge Pro software. Cohort simulation was deemed appropriate as it synthesises best available evidence to address difficult-toanswer questions, and is ideal when 25-Methoxyalisol-A experimental trials are not ethical or feasible. Cohort simulation is commonly used in health economics, and related clinical and epidemiological research, to model future costs and outcomes of patients, groups or populations under alternative scenarios such as different treatment options and is unique in that it is able to predict cross-sectional data and simulate life courses of people, providing longitudinal outcomes. A wide range of evidence is usually included, such as epidemiologic surveys, meta-analyses, and high-quality single studies in order to determine the benefits and costs beyond time horizon of existing data. A hypothetical cohort of employees occupied and moved between seven health states over time according to probabilities. A 3-month cycle length was chosen to reflect the natural history of depression, and the selected health states are clinically relevant and informed by related research.