Preston, 2014. Projecting the Effect of Changes in Smoking and Obesity on Future Life Expectancy in the United States
I thought it was very interesting to evaluate future life expectancy using projections of obesity and cohort smoking patterns. Effects on life expectancy were greater in males due to reductions in smoking, while in females this effect was offset by the rise in obesity expected by 2040. They mention that 10-year BMI transition matrices have been nearly constant for 8 years, and use this data with the assumption that it will remain constant in the future. I wonder if this will remain true, how likely it is to change and the impact it would have on the projections. Markov models seem appropriate but I wonder how much they rely on this assumption.
I am concerned about lung cancer mortality as a marker of the effects of smoking since although lung cancer is attributable mainly to smoking, not most smoking-related deaths are due to lung cancer. I would like to understand the generalizability of the results obtained in other studies that estimate the risk attributable to smoking for other smoking-related causes. The fact that both methods gave similar results is reassuring but it would be relevant to understand it.
These results contrast with others that projected negative survival effects of obesity would be greater than the advantages of reducing smoking.
Christensen, 2009. Ageing populations: the challenges ahead
This paper explores is increasing life expectancy in countries also translates into a postponement of functional limitations and disability. Low fertility and low mortality produced population aging, and health deterioration has been assessed through several indicators to capture these trends. Functional limitation measurement has improved. Disabilities in activities of the daily leaving have been declining, but national datasets have reported conflicting evidence especially of personal-care disability. They mention that considering differing wording, sampling strategies, and inclusion of institutional populations in four US health surveys, they found a general reduction of personal-care disability of 1·0–2·5% per year is evident. I wonder about the contradicting studies' design and the validity of their results.