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

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.

Atrial arrhythmogenicity in aged Scn5a+/DeltaKPQ mice modeling long QT type 3 syndrome and its relationship to Na+ channel expression and cardiac conduction.

Recent studies have reported that human mutations in Nav1.5 predispose to early age onset atrial arrhythmia. The present experiments accordingly assess atrial arrhythmogenicity in aging Scn5a+/KPQ mice modeling long QT3 syndrome in relationship to cardiac Na(+) channel, Nav1.5, expression. Atrial electrophysiological properties in isolated Langendorff-perfused hearts from 3- and 12-month-old wild type (WT), and Scn5a+/KPQ mice were assessed using programmed electrical stimulation and their Nav1.5 expression assessed by Western blot. Cardiac conduction properties were assessed electrocardiographically in intact anesthetized animals. Monophasic action potential recordings demonstrated increased atrial arrhythmogenicity specifically in aged Scn5a+/DeltaKPQ hearts. These showed greater action potential duration/refractory period ratios but lower atrial Nav1.5 expression levels than aged WT mice. Atrial Nav1.5 levels were higher in young Scn5a+/DeltaKPQ than young WT. These levels increased with age in WT but not Scn5a+/DeltaKPQ. Both young and aged Scn5a+/DeltaKPQ mice showed lower heart rates and longer PR intervals than their WT counterparts. Young Scn5a+/DeltaKPQ mice showed longer QT and QTc intervals than young WT. Aged Scn5a+/DeltaKPQ showed longer QRS durations than aged WT. PR intervals were prolonged and QT intervals were shortened in young relative to aged WT. In contrast, ECG parameters were similar between young and aged Scn5a+/DeltaKPQ. Aged murine Scn5a+/DeltaKPQ hearts thus exhibit an increased atrial arrhythmogenicity. The differing Nav1.5 expression and electrocardiographic indicators of slowed cardiac conduction between Scn5a+/DeltaKPQ and WT, which show further variations associated with aging, may contribute toward atrial arrhythmia in aged Scn5a+/DeltaKPQ hearts.