Education, income, and functional limitation transitions among American adults: Contrasting onset and progression
Zimmer,Zachary; House,James S.
International Journal of Epidemiology 32(6): 1089-1097
Publication date: 2003
Although a robust association between socioeconomicstatus and health has been shown in past research, the processesthat explain the connection are not well understood. This paperseeks to advance such understanding in two ways, first by attendingto the distinction between onset of a functional health problemand its progression, and second by addressing whether and howeducation and income relate differently to the onset versusprogression of functional health problems.
Data come from the Americans' Changing Lives survey(n = 3617). The baseline was conducted in 1986 and outcome statusmeasured in 1994. Activity limitations are categorized intonone, mild, moderate, severe. Onset is defined as having nolimitation at origin and a limitation at outcome. Progressionis defined as limitation of a particular severity at originand improving, staying the same, or getting worse with respectto the severity. Multinomial regressions determine transitionprobabilities related to onset and progression.
Those with higher income and education are less likelyto experience an onset. Only income associates with progression.Those with the highest income are most likely to improve andleast likely to get worse in comparison to those with the lowestincome.
Education, being determined early in life and influencingpsychosocial mechanisms throughout life, may have a greaterimpact on prevention of activity and functional disorders. Income'srole may be both as a prevention factor and as a mechanism formanagement of health problems.