MINI CASE 15.3
In 2011, the UK National Health Service published an article with the stunning headline 'Half of the UK obese by 2030'. The article paints a grim picture and, based on a number of contemporary studies, suggested that if current trends continue, up to 48 per cent of men and 43 per cent of women in the UK could be obese by 2030, adding an additional £2 billion per year in medical costs for obesity-related diseases.
Many of the studies are based on regression analysis models and use past trends to forecast the future. One such study used obesity prevalence in children (aged 2-11) and adolescents (aged 11-18) over the years 1995 to 2007, to forecast likely obesity levels in 2015.
The report of this study provides details of the data and the regression models used for forecasting:
? The data was based on randomly selected participants of the annually administered Health Survey for England.
? The prevalence predictions to 2015 were based on linear and non-linear (power or exponential) regression models.
Overall, the estimated 2015 prevalence was higher than the 2007 levels for all boys and for girls in manual social classes, regardless of the forecasting method used.
The BIG question is will it happen? All forecasts will be based on a set of assumptions. In this case, unless there is a lifestyle change, more of us will be obese. If the report is successful in making us think about lifestyle and sufficient numbers make lifestyle changes, the forecast could be wrong for the right reasons. In many ways a forecast is a scenario of the future. The argument being that if current trends continue (and we use good forecasting practice) then this is what you can expect if nothing else happens.
Source: 'Time trends in childhood and adolescent obesity in England from 1995 to 2007 and projections of prevalence to 2015', Journal of Epidemiology and Community Health 64, 2 (2010); authors: E. Stamatakis, P. Zaninotto, E. Falaschetti, J. Mindell and J. Head, Joint Health Surveys Unit (National Centre for Social Research and Department of Epidemiology and Public Health at the Royal Free and University College Medical School). www.ic.nhs.uk Statistics on obesity, physical activity and diet: England, 2011 Office for National Statistics licensed under the Open Government Licence v.1.0.