A mixed method approach into disease-specific and generic predictors of paid work in older individuals with depression, osteoarthritis and cardiovascular disease

Introduction
With the rising age of the working population and prevalence of chronic disorders with age, maintaining and improving labour force participation of older individuals with chronic disorders deserves attention. The prevalence of chronic morbidity may be high, but the prevalence of specific disorders may be low. When different disorders have similar predictors, forces can be joined to develop and implement interventions to improve labour force participation.
The aim of this study was to distinguish disease-specific and generic predictors of paid work in individuals of 55 years and up. To include a large variety of different chronic disorders, we focussed on depression (D), osteoarthritis (O) or cardiovascular disease (C).

Methods
A mixed method approach was applied by combining quantitative data from the Longitudinal Aging Study Amsterdam 2002-2003 (LASA), with qualitative data from 12 in-depth interviews with patients with D, O or C aged 55-62 years. Potential predictors in 2002-2003 of participation in paid work in 2005-2006 were: health, functional limitations, personality characteristics, work characteristics, and demographics. All interviews were analysed using thematic content analysis.

Results
The quantitative results show that all predictors included in this study appeared to be generic rather than disease-specific predictors. Male sex, lower age, higher education, paid work in 2002-2003, better perceived health, comorbidity, less neuroticism and more mastery were significantly associated with paid work in 2005-2006. The results of the qualitative study will be available at the end of 2011 and will be presented.

Discussion
All predictors examined in the quantitative part of this study were generic for the different disorders, although not all were significantly associated with paid work. It is expected that the qualitative part will add information on generic and specific predictors of paid work. Insight in generic predictors of paid work may be used to develop interventions for groups of individuals with different chronic disorders.