The survival time of chocolates on hospital wards: covert observational study

Parag R Gajendragadkar, Daniel J Moualed, Phillip L R Nicolson, Felicia D Adjei, Holly E Cakebread, Rudolf M Duehmke, Claire A Martin

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)f7198
Publication statusPublished - 14 Dec 2013


  • Cacao
  • Candy/statistics & numerical data
  • Feeding Behavior
  • Hospital Departments/statistics & numerical data
  • Humans
  • Inpatients/statistics & numerical data
  • Personnel, Hospital/statistics & numerical data
  • Prospective Studies
  • Time Factors


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