Self employment is good for productivity, except for farmers, who score badly on every measure of health and quality of life, research shows.

Finnish researchers used validated survey data to assess factors affecting productivity, as well as perceived health and quality of life among a sample of 5,000 adults aged between 30 and 64.

All the participants had already taken part in the National Health 2000 survey.

Of the 3,536 people who worked full time, around 90 per cent completed the questionnaires.

Of those working full time, almost 10 per cent were self-employed entrepreneurs of whom 3.5 per cent were farmers.

The farmers and entrepreneurs tended to be older than the salaried workers, and all the self-employed who were sole traders tended to have lower levels of educational success and incomes than their peers with staff and salaried workers.

Self-employed entrepreneurs with staff scored the highest on all the measures assessed, while farmers scored the lowest.

When productivity was assessed separately, more than a third of farmers achieved low or average scores.

This compares with 16 per cent of salaried workers and sole traders and 12 per cent of entrepreneurs with staff.

After taking account of a range of influential factors, such as age, long term conditions, and loving relationships, entrepreneurs with staff and salaried workers scored around the same.

But farmers still fared the worst, according to the study.

Previous research has suggested that the jobs which are best for health and wellbeing are those in which the worker has a good deal of control and support, irrespective of the demands made on him/her.

Self-employed people tend to have more control over their working lives, but their work tends to be more stressful, say the researchers.

They concluded that farmers, in particular, need more social and emotional support.

The study is published ahead of print in Occupational and Environmental Medicine.