Benefits gained, benefits lost: comparing baby boomers to other generations in a longitudinal cohort study of self-rated health.
POLICY POINTS: Despite beliefs that baby boomers are healthier than previous generations, we found no evidence that the health of baby boomers is substantially different from that of the previous or succeeding cohorts. The effects of increased education, higher income, and lower smoking rates on improving self-rated health were nearly counterbalanced by the adverse effect of increasing body mass index (BMI). Assumptions that baby boomers will require less health care as they age because of better education, more prosperity, and less propensity to smoke may not be realized because of increases in obesity.


BACKGROUND
Baby boomers are commonly believed to be healthier than the previous generation. Using self-rated health (SRH) as an indicator of health status, this study examines the effects of age, period, and birth cohort on the trajectory of health across 4 generations: World War II (born between 1935 and 1944), older baby boomers (born between 1945 and 1954), younger baby boomers (born between 1955 and 1964), and Generation X (born between 1965 and 1974).


METHODS
We analyzed Canada's longitudinal National Population Health Survey 1994-2010 (n = 8,570 at baseline), using multilevel growth models to estimate the age trajectory of SRH by cohort, accounting for period and incorporating the influence of changes in education, household income, smoking status, and body mass index (BMI) on SRH over time.


RESULTS
SRH worsened with increasing age in all cohorts. Cohort differences in SRH were modest (p = 0.034), but there was a significant period effect (p = 0.002). We found marked cohort effects for increasing education, income, and BMI, and decreasing smoking from the youngest to the oldest cohorts, which were much reduced (education and smoking) or removed (income and BMI) once period was taken into account. At the population level, multivariable analysis showed the benefits of increasing education and income and declines in smoking on the trajectory of improving SRH were almost counterbalanced by the effects of increasing BMI (obesity).


CONCLUSIONS
We found no evidence to support the expectation that baby boomers will age more or less healthily than previous cohorts did. We also found that increasing BMI has likely undermined improvements in health that might have otherwise occurred, with possible implications for the need for health care. Period effects had a more profound effect than birth cohort effects. This suggests that interventions to improve health, such as reducing obesity, can be targeted to the entire, or a major portion of the, population and need not single out particular birth cohorts.
Toronto Western Research Institute, University Health Network; Dalla Lana School of Public Health, University of Toronto.
Elizabeth M
EM
Badley
Mayilee
M
Canizares
Anthony V
AV
Perruccio
Sheilah
S
Hogg-Johnson
Monique A M
MA
Gignac
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000375:Aging; D015992:Body Mass Index; D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D007182:Income / Q000639:trends; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D055361:Multilevel Analysis; D009765:Obesity / Q000150:complications* / Q000453:epidemiology; D057566:Self Report; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D012922:Social Change; D012923:Social Class; D064890:Social Determinants of Health; D014933:Women's Rights / Q000639:trends; D055815:Young Adult
age-period-cohort; obesity; self-rated health; socioeconomic status