One in three sick days fall on a Monday and more working days are lost in January than any other month, according to new research.
An analysis of sickness absence records for 11,000 employees, by consulting firm Mercer, revealed that the first month of the year was the worst for sick leave, averaging half a day per person.
During the whole of 2008, 13 of the 20 most popular days for sickness absence occurred in January, and six of these were taken between 2 and 9 January.
Nearly 5% of the total employee population was off sick on the 3 and 4 January.
Other findings showed that more than one-third of sick leave was taken on a Monday, while Friday was the least likely day for staff to call in ill.
Phiroze Bilimoria, a client manager at Mercer, said 'Monday sickness' and frequent short-term absences could be a symptom of low employee engagement and morale within certain department teams.
He said: "Companies with high absence rates carry an extra burden of costs that often drains organisational effectiveness and profitability. Direct costs can be measured through overtime payments and temporary contracts, but hidden costs, reflected in reduced productivity, missed deadlines and litigation, are generally much higher."
Musculoskeletal conditions were found to be the main cause of absence, with strain or injury to bones, muscles and joints accounting for nearly a quarter of all days lost. Other common causes were stress-related illness and cold, flu and other viral infections.
The findings also revealed that 24% more days were taken off by female workers compared to their male counterparts.
Absence rates among women were more than twice as high for men in instances of stress-related illness, exhaustion and depression. By contrast, muscle sprains, fractures and other physical injuries sustained by men accounted for at least double the absence rate of women.
In August, Personnel Today reported how a number of NHS workers were falling victim to 'presenteeism' - working when they felt unwell - which could significantly affect the level of sickness absence and labour productivity ac