BackgroundMental Workload (MWL) is a widely studied concept within the human factors and patient safety fields. MWL is measured to identify how busy employees are, the complexity of tasks being carried out and whether additional tasks can be added to their current workload without reducing task performance or safety.  To date, the MWL of community pharmacists (CPs) practising in the United Kingdom (UK) has not been measured. This study aimed to measure CPs’ MWL throughout a day in their usual practice. MethodFollowing receipt of university ethics approval a convenience sample of 104 CPs who had participated in an earlier study were invited to participate. The 104 CPs were strategically recruited through superintendent pharmacists and social media to be demographically representative of UK CPs. Fifty CPs expressed interest in this follow-up study and were posted a diary containing questions on demographics, the enhanced and locally commissioned services offered and seven copies of the NASA Task Load Index (TLX). The NASA-TLX is a self-report measure of MWL that measures six facets of MWL (time pressure, mental effort, mental demand, physical demand, task frustration and performance concern), each rated on an 11 point scale (0-10). The mean of the scores on the six items provides an overall MWL score. Participants were asked to complete between two and seven MWL ratings over one day and received a £5 highstreet voucher for their participation. MWL ratings were plotted against time of day. Bivariate correlations were produced between overall MWL and the demographic characteristics of participants. Potentially significant relationships were explored further with an independent t-test. ResultsForty CPs (19 men) returned their diaries (response rate of 38%) and a total of 186 MWL ratings were made across the diaries, providing sufficient power to carry out the planned analyses. MWL ratings were plotted against time of day. Peaks in overall MWL were seen at 11 o’clock in the morning and five o’clock in the afternoon. Time pressure, mental and physical demand were the highest rated facets of MWL. Bivariate correlations revealed no relationship between participant sex, age, pharmacy experience, or the type of community pharmacy CPs worked in and overall MWL. However, the correlations indicated a relationship between overall MWL and whether the CP worked full time (> 35 hours a week) or part-time (48 ratings were from part-time CPs). An independent t-test showed that part-time CPs reported significantly lower overall MWL (mean = 4.39) compared to full-time CPs (mean = 5.14) (t (184) =2.29, p < .05, r= .17).Discussion and ConclusionsThese results suggest that MWL peaks for many CPs at specific times of the day and that part-time CPs experience significantly less MWL compared to their full-time colleagues. However, the effect size of this difference was small. The diary ratings also suggest that time pressure, mental and physical demands are the primary sources of MWL that CPs experience. This initial study highlights the impact working patterns have on MWL and has implications for the times of day that safety critical tasks are carried out by CPs.
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