Margaret A.WinkerMD, Senior EditorIndividualAuthorPhil B.FontanarosaMD, Senior EditorIndividualAuthor
To the Editor.—The article by Dr Lantz and colleagues1 concerning the apparent relationship between various socioeconomic lifestyle factors and differential population mortality rates seems to reinforce previous perceptions that a relationship exists between income and mortality.1 The authors do not offer the slightest evidence of what, if any, factors are involved in causing the apparent inverse relationship. What is the purpose of presenting an effect without a cause? Also, the use of a "sedentary lifestyle" parameter ignores the fact that a large segment of the population engages in few or no formal or semiformal exercise programs (and ergo is "sedentary") yet on average has a daily energy expenditure far exceeding that of the average individual described as having an "active" lifestyle. This segment comprises people employed in manual labor occupations such as waste handlers, freight handlers, construction workers, lumber workers, and factory workers.
Manning GC. Socioeconomic Factors and Determinants of Mortality. JAMA. 1998;280(20):1744-1745. doi:10-1001/pubs.JAMA-ISSN-0098-7484-280-20-jac80013