Health Affairs: Public health spending influences outcomes
Increased public health investments can produce measurable improvements in health, especially in low-resource communities. However, without improvements in public health practices, more money by itself is unlikely to generate significant and sustainable health gains, according to a study published online July 21 in Health Affairs.
“Very little attention has been paid to the value of investments in the public health system as a whole, leading to persistent questions about whether the nation’s current spending levels are worth the opportunity costs,” wrote Glen P. Mays, PhD, MPH, professor in and the chair of the department of health policy and management at the Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, in Little Rock; and Sharla A. Smith, MPH, research associate in the same department.
To estimate how changes in public health spending influence population health, Mays and Smith assembled a longitudinal database that included local government public health spending, population characteristics and community mortality rates. The 13-year study focused on local public health agencies, which implement, mobilize and coordinate public health activities in most communities and channel most federal, state and private philanthropic funding.
The researchers analyzed changes in spending patterns and mortality rates within the service areas of the nation’s nearly 3,000 local public health agencies. They measured mortality rates “that were expected to be sensitive to public health interventions,” including the age-adjusted all-cause mortality rate, infant mortality rate and age-adjusted mortality rates for heart disease, cancer, diabetes and influenza.
Spending data collected by the National Association of County and City Health Officials were used, along with organizational and operational characteristics of local public health agencies from census surveys conducted in 1993, 1997 and 2005. Key variables reflecting annual agency spending, service offerings and staffing levels were collected in each year of the survey.
Survey data were linked with county-level data on population characteristics and health resources from the Health Resources and Services Administration’s Area Resource File, a national county-level health resource information database. Federal and state spending estimates from the Census Bureau’s Consolidated Federal Funds Report and Census of Governments, and cause-specific mortality rates from the Centers for Disease Control and Prevention’s Compressed Mortality File, also were used.
“A general trend of growth in public health spending and reductions in certain mortality rates between 1993 and 2005 masked significant community-level differences,” stated Mays and Smith. For example, although local public health spending in the average community reached $40.84 per capita in 2005, up from $34.68 per capita in 1993, only 65 percent of agencies experienced positive growth in per capita public health spending during that period, while 35 percent experienced spending reductions.
“The degree of change in per capita spending varied widely across communities. The top 20 percent of agencies experienced growth of nearly 150 percent, while the bottom 20 percent of agencies experienced reductions of nearly 45 percent during the study period. Meanwhile, infant mortality and heart disease mortality rates declined moderately during the same period, continuing a longer-term secular trend downward, while cancer and diabetes mortality rose slightly.”
The rates of change also varied widely among communities: The top 20 percent of communities experienced a reduction in age-adjusted heart disease mortality of 104 deaths per 100,000 people, while the bottom 20 percent of communities saw mortality increase by 43 deaths per 100,000 people, stated the authors.
Overall, population size, educational attainment, physician availability and number of people above the federal poverty level increased in the average community during this period.
Nevertheless, “increases in public health spending were associated with statistically significant reductions in mortality for four of the six mortality rates we examined,” Mays and Smith wrote. “The strongest effects were found for infant mortality and cardiovascular disease mortality, indicating that mortality rates fell by 6.9 percent and 3.2 percent for each 10 percent increase in spending. Diabetes mortality fell by 1.4 percent and cancer mortality fell by 1.1 percent for each 10 percent increase in spending.”
Influenza mortality and total mortality changed in the expected direction, but did not reach statistical significance, they added.
The authors acknowledged several limitations of their research. “Although we used strong statistical controls to address possible sources of bias, it remains possible that factors distinct from, but closely correlated with, public health spending may explain some of the observed associations between spending and mortality,” they warned. “In addition, our analysis focused on selected mortality rates as measures of population health, not on other indicators of disease burden or quality of life.”
“Very little attention has been paid to the value of investments in the public health system as a whole, leading to persistent questions about whether the nation’s current spending levels are worth the opportunity costs,” wrote Glen P. Mays, PhD, MPH, professor in and the chair of the department of health policy and management at the Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, in Little Rock; and Sharla A. Smith, MPH, research associate in the same department.
To estimate how changes in public health spending influence population health, Mays and Smith assembled a longitudinal database that included local government public health spending, population characteristics and community mortality rates. The 13-year study focused on local public health agencies, which implement, mobilize and coordinate public health activities in most communities and channel most federal, state and private philanthropic funding.
The researchers analyzed changes in spending patterns and mortality rates within the service areas of the nation’s nearly 3,000 local public health agencies. They measured mortality rates “that were expected to be sensitive to public health interventions,” including the age-adjusted all-cause mortality rate, infant mortality rate and age-adjusted mortality rates for heart disease, cancer, diabetes and influenza.
Spending data collected by the National Association of County and City Health Officials were used, along with organizational and operational characteristics of local public health agencies from census surveys conducted in 1993, 1997 and 2005. Key variables reflecting annual agency spending, service offerings and staffing levels were collected in each year of the survey.
Survey data were linked with county-level data on population characteristics and health resources from the Health Resources and Services Administration’s Area Resource File, a national county-level health resource information database. Federal and state spending estimates from the Census Bureau’s Consolidated Federal Funds Report and Census of Governments, and cause-specific mortality rates from the Centers for Disease Control and Prevention’s Compressed Mortality File, also were used.
“A general trend of growth in public health spending and reductions in certain mortality rates between 1993 and 2005 masked significant community-level differences,” stated Mays and Smith. For example, although local public health spending in the average community reached $40.84 per capita in 2005, up from $34.68 per capita in 1993, only 65 percent of agencies experienced positive growth in per capita public health spending during that period, while 35 percent experienced spending reductions.
“The degree of change in per capita spending varied widely across communities. The top 20 percent of agencies experienced growth of nearly 150 percent, while the bottom 20 percent of agencies experienced reductions of nearly 45 percent during the study period. Meanwhile, infant mortality and heart disease mortality rates declined moderately during the same period, continuing a longer-term secular trend downward, while cancer and diabetes mortality rose slightly.”
The rates of change also varied widely among communities: The top 20 percent of communities experienced a reduction in age-adjusted heart disease mortality of 104 deaths per 100,000 people, while the bottom 20 percent of communities saw mortality increase by 43 deaths per 100,000 people, stated the authors.
Overall, population size, educational attainment, physician availability and number of people above the federal poverty level increased in the average community during this period.
Nevertheless, “increases in public health spending were associated with statistically significant reductions in mortality for four of the six mortality rates we examined,” Mays and Smith wrote. “The strongest effects were found for infant mortality and cardiovascular disease mortality, indicating that mortality rates fell by 6.9 percent and 3.2 percent for each 10 percent increase in spending. Diabetes mortality fell by 1.4 percent and cancer mortality fell by 1.1 percent for each 10 percent increase in spending.”
Influenza mortality and total mortality changed in the expected direction, but did not reach statistical significance, they added.
The authors acknowledged several limitations of their research. “Although we used strong statistical controls to address possible sources of bias, it remains possible that factors distinct from, but closely correlated with, public health spending may explain some of the observed associations between spending and mortality,” they warned. “In addition, our analysis focused on selected mortality rates as measures of population health, not on other indicators of disease burden or quality of life.”