Accuracy of comparing bone quality to chocolate bars for patient information purposes : observational study

Objective To test whether standard information for patients using Crunchie and Aero chocolate bars to explain bone health and risk of fracture is robust. Design Observational study. Setting Domestic kitchen in rural west Wales. Participants 10 Crunchie bars and 10 Aero bars. Main outcome measure Fracture after falls from varying heights. Results Both Crunchie and Aero bars exhibited the same T and Z scores for bone density. Crunchie bars had a lower chocolate mass index than the Aero bars. Crunchie bars are more liable to fracture. Conclusions Using Crunchie and Aero chocolate bars to explain bone structure to patients may be visually attractive but oversimplifies the situation. IntroductIon It is important that information provided to patients as part of their treatment should be comprehensive and accurate. Within our area of practice relating to osteoporosis and fragility fracture we have noticed a tendency to compare normal, healthy bone to the finely honeycombed structure of a Crunchie (Cadbury Trebor Bassett; Bournville, Birmingham) chocolate bar and to compare abnormal, osteoporotic bone to the coarser structure of an Aero (Nestle UK; York) bar (fig 1).1 2 Although this explanation is readily appreciated by patients and clinicians it struck us that the comparison may not be completely valid as no work has been published on the fracture potential of each bar. This might mean that with best intentions we are advising patients to aspire to a bone structure that is actually more liable to fracture. To enable us to provide accurate data to our patients we studied the fracture risk for each chocolate bar. Methods We randomly purchased 20 chocolate bars (10 Crunchie and 10 Aero) from a reputable high street confectioner; the number of bars was limited by research funds and our rural environment. Each bar was measured to provide information on height Bronglais General Hospital, Aberystwyth SY23 1ER Correspondence to: P Jones [email protected]. nhs.uk bMJ 2007;335:1285-7 doi:10.1136/bmj.39413.798472.BE (defined as the longest dimension of the bar, in metres) and mass (determined in kilograms). The composition of the bar was determined through reference to the packaging. We could ascertain no data on other fracture risks. The tests were completed in a controlled environment and the flooring was standard 33×33 cm ceramic kitchen floor tiles with average grouting. This environment was chosen as being representative of the home environment, where many fractures occur. The end point of the study was fracture. Firstly, we allowed each bar to topple from its standing height in the centre of a tile. We then dropped each bar horizontally on to the centre of the tile from increasing heights until fracture, defined as a break in the cortex; Accuracy of comparing bone quality to chocolate bars for patient information purposes: observational study Phil Jones, Sarah Jones, Debbie Stone For the full versions of these articles see bmj.com MIxed MessAges BMJ | 22-29 DECEMBER 2007 | VoluME 335 1285 Fig 1 | Cross section of Crunchie (top) and Aero (bottom) chocolate bars on 15 August 2008 bmj.com Downloaded from