Validation of a subjective evaluation study using work sampling

A study to investigate how community pharmacists in Great Britain spent their time was previously performed.[1] This utilised the work study technique of subjective evaluation (estimation). However, to determine the validity of these results a further study utilising a different work study technique was conducted. Five trained observers made a total of 2 682 observations at two minute intervals. These were performed on three separate days over a six week period in five pharmacies. Observations were categorised into 16 previously used activity categories representing the work of a community pharmacist. The mean percentage times of the observed and estimated time values were compared and tested for significant differences. Only two of the sixteen categories were shown to be significantly different; waiting and personal time (category 13) and communication non-health related (category 11). It appears that subjective evaluation can be used as a tool to gain quantifiable measurements on how pharmacists spend their time. Furthermore it is a method by which large numbers of pharmacies can participate simultaneously to gain data on the working patterns of community pharmacists.