Working Too Little, Working Too Much – Both Are Risky

Two studies have delineated the benefits of a steady job – not too little, not too much work.  The first examines the relationship between unemployment and premature mortality.  It’s from Canada, and it’s published in the online journal Social Science & Medicine.

McGill scientists extracted data from 42 studies in a meta-analysis of 235 risk estimates covering more than 20 million persons.  Unemployment carried, on average, a 1.63-times greater risk of mortality; the risk was greater for men than for women (78% vs. 37%).  People under 50 are particularly at risk.  Further analyses showed that pre-existing health conditions played no role, emphasizing that the unemployment-mortality relationship is quite likely a causal one.  Stress and a lower socio-economical status are probable intermediate factors, leading to poorer health and higher mortality.

The second study examines the relationship between long working hours and the risk for coronary heart disease. It was published in the Annals of Internal Medicine, and employed 7,095 adults (2,109 women and 4,986 men) aged 39 to 62 years working full-time; they were without coronary heart disease at baseline.  The participants, who were civil servants (i.e. government employees) taking part in the Whitehall II Study, had their working hours recorded at baseline.  They were followed for an average of 12.3 years, during which time coronary death and non-fatal heart attacks were obtained from medical screenings every 5 years, hospital records, and so on.

There were 192 subjects who had a coronary heart disease incident during follow-up.  Working 10 hours a day was not associated with a significantly increased risk of heart attack than those who worked less.  But working 11 or more hours a day led to a 67% increase in the risk of having a heart attack or dying from one. 

Of course, this study doesn’t show if such a long working day causes the increased risk, or if it’s simply a ‘marker’ indicating someone who’s at increased risk for some other reason.  (That’s the disadvantage of such retrospective studies – they often show only associations, not cause and effect.)  It’s not as if we need this sort of information to explain something we know instinctively – a steady occupation has health benefits, whereas no work or too much work is clearly detrimental.