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The survival time of chocolates on hospital wards: covert observational study
Parag R Gajendragadkar1, Daniel J Moualed, Phillip L R Nicolson
1Department of Cardiology, Bedford Hospital, Bedford MK42 9DJ, UK.
Objective:
To quantify the consumption of chocolates in a hospital ward environment.
Design:
Multicentre, prospective, covert observational study.
Setting:
Four wards at three hospitals (where the authors worked) within the United Kingdom.
Participants:
Boxes of Quality Street (Nestlé) and Roses (Cadbury) on the ward and anyone eating these chocolates.
Intervention:
Observers covertly placed two 350 g boxes of Quality Street and Roses chocolates on each ward (eight boxes were used in the study containing a total of 258 individual chocolates). These boxes were kept under continuous covert surveillance, with the time recorded when each chocolate was eaten.
Main Outcome Measure:
Median survival time of a chocolate.
Results:
191 out of 258 (74%) chocolates were observed being eaten. The mean total observation period was 254 minutes (95% confidence interval 179 to 329). The median survival time of a chocolate was 51 minutes (39 to 63). The model of chocolate consumption was non-linear, with an initial rapid rate of consumption that slowed with time. An exponential decay model best fitted these findings (model R(2)=0.844, P<0.001), with a survival half life (time taken for 50% of the chocolates to be eaten) of 99 minutes. The mean time taken to open a box of chocolates from first appearance on the ward was 12 minutes (95% confidence interval 0 to 24). Quality Street chocolates survived longer than Roses chocolates (hazard ratio for survival of Roses v Quality Street 0.70, 95% confidence interval 0.53 to 0.93, P=0.014). The highest percentages of chocolates were consumed by healthcare assistants (28%) and nurses (28%), followed by doctors (15%).
Conclusions:
From our observational study, chocolate survival in a hospital ward was relatively short, and was modelled well by an exponential decay model. Roses chocolates were preferentially consumed to Quality Street chocolates in a ward setting. Chocolates were consumed primarily by healthcare assistants and nurses, followed by doctors. Further practical studies are needed.
