Associations of work ability with frequent and long-term sickness absence

Reduced work ability is related to long-term sickness absence. The relationship between work ability and frequent sickness absence has not previously been investigated. It is important to distinguish between frequent and long-term sickness absence as they are outcomes of different processes.

To investigate the associations of work ability with frequent short-term (three or more episodes lasting <2 weeks in the past year), long-term (one or more episodes lasting at least 2 weeks in the past year) and combined (frequent and long-term) sickness absence.

In 2010-12, we invited employees working in different economic sectors to complete a postal questionnaire measuring work ability using the work ability index (WAI). We compared the WAI scores in employees with frequent, long-term and combined sickness absence with the scores in employees without such sickness absence by multinomial regression analysis.

Of 6682 invited employees, 3660 (55%) completed the questionnaire. Mean (standard deviation) WAI scores were 41.2 (3.4), 39.4 (3.9), 37.2 (5.2) and 43.2 (2.7) in employees with frequent, long-term, combined sickness absence and neither frequent nor long-term sickness absence, respectively. WAI scores were negatively related to frequent (odds ratio [OR] = 0.85; 95% confidence interval [CI] 0.82-0.88), long-term (OR = 0.79; 95% CI 0.75-0.82) and combined sickness absence (OR = 0.74; 95% CI 0.71-0.77).

Self-reported reduced work ability is associated with both frequent and long-term sickness absence, suggesting that frequent sickness absence is not only driven by motivational processes.