When people go to work, more is contributed to the economy through taxation. Similarly, when people do not work, less is contributed to the economy through taxation.
Less time off work sick due to illness (absenteeism) means statutory sick pay does not have to be paid by the employer. Absence from work costs £15 billion per year in the UK.
If individuals can return to work sooner (e.g. children going to day care) they can contribute more to the economy through taxation.
Individuals being able to manage their health and feel well means greater productivity when they are at work.
Better management of individuals when they are at work (e.g. support with motivation or stress) boosts their productivity.