According to the current study’s national estimates, just over 30 million US adults reported an out-of-pocket expenditure for at least one CAM service in 2007. The current study found that 7.4 million US adults were heavy CAM spenders () with a mean annual expenditure of $1385 compared to just $45 for the lowest CAM expenditure quartile.
The Characteristics of US Adults that Used Complementary and Alternative Medicine Services by Out-of-pocket
The total amount spent on all US CAM services was $13.9 billion: (1) 60% of expenditures on manipulative and body-based therapies, (2) 24% on mind-body therapies, (3) 10% on alternative medical systems, and (4 and 5) 6.4% on biologically-based therapies and energy healing therapy.
Concentration of Expenditures
The research team found spending on CAM to be concentrated (). The highest expenditure quartile accounted for 72% of the nation’s out-of-pocket expenditures on CAM ($10 billion of the $13.9 billion spent on CAM), while the lowest CAM expenditure quartile accounted for only 2.5%. Examining the distribution of CAM spending more closely, the research team found that the top 10% of CAM spenders accounted for nearly half of all CAM expenditures ($6.6 billion of $13.9 billion) and had a mean annual expenditure of $2392 on CAM. The bottom 50% of CAM spenders accounted for only 10% of CAM expenditures ($1.4 billion of $13.9 billion) and had a mean annual expenditure of $92 on CAM.
The Concentration of Out-of-pocket Expenditures on Complementary and Alternative Medicine (CAM)
Spending Patterns by Expenditure Quartile
The highest quartile spent $10 billion while the lowest spent $348 million on CAM services (). Across all quartiles, over 50% of expenditures were on manipulative and body-based therapies ($8.3 billion out of $13.9 billion) with virtually all expenditures being on chiropractic or osteopathic manipulation and massage therapy, while biologically-based therapies comprised only 1% to 6% of CAM expenditures across quartiles. The highest quartile spent significantly more on mind-body therapies, with 29% of expenditures in the highest quartile devoted to mind-body therapies compared to only 6% to 11% in the other three quartiles.
Out-of-pocket Expenditures on Specific Complementary and Alternative Medicine (CAM) Modalities by Expenditure Quartile
The lowest quartile spent $283 million on manipulative- and body-based therapies, $31.4 million on mind-body therapies, $21.4 million on alternative medical systems, $10.2 million on biologically-based therapies, and only $2.8 million on energy healing therapy. The highest quartile spent $5.2 billion on manipulative and body-based therapies, $2.9 billion on mind-body therapies, $1.1 billion on alternative medical systems, $576 million on biologically-based therapies, and $224 million on energy healing therapy ( and ). Expenditures on all specific CAM modalities increased from Quartile 1 to Quartile 4, except for special diets, biofeedback, and hypnosis, which decreased from Quartile 1 (lowest) to Quartile 2.
Out-of-pocket Expenditures on Complementary and Alternative Medicine Domains by Expenditure Quartile
Characteristics of CAM Users by Quartile
Adults in the highest quartile were more likely to reside in the Northeast or the West and less likely to reside in the Midwest as compared to those in the other three quartiles, P-value < .01 (). Those in the highest quartile were more likely to be older, female, non-Hispanic white, unmarried, and more educated. The research team did not find statistically significant differences in employment status or health insurance across quartiles.
The team found little difference in health status and behavior measures across quartiles; for instance, 10.2% of the highest quartile reported a fair or poor health status compared to 11.6% in the lowest quartile (P-value = .42). Similarly, the research team found little difference in obesity status, in number of individuals with limitations, and in smoking status when comparing lowest and highest quartiles as well; however, those in the highest quartile were more likely to report consuming alcohol (P-value = .01).
In the team’s multiple linear regression model, self-reported health status was not associated with CAM spending (
= 1.00 (95% CI, 0.8–1.2) after adjustment for age, gender, education, marital status, and race/ethnicity.