First Longitudinal Analysis of Complementary Health Approach Use by U.S. Adults Identifies Factors That Predict New, Continued, and Discontinued Use

Researchers at the National Center for Complementary and Integrative Health (NCCIH) have completed the first analysis of the use of complementary health approaches in a nationally representative sample of adults over a long period of time. The analysis provides insights into the use of four common complementary approaches over nearly two decades and identifies specific factors that may predict new, continued, or discontinued use. The analysis, which was funded by NCCIH, was recently published in The Journal of Alternative and Complementary Medicine.

Previous studies have found that certain factors are associated with the use of complementary health approaches. For instance, people who use them are more likely to be female and younger than 65 years of age, have multiple chronic health conditions, and have a higher socioeconomic status than nonusers. However, past studies have not determined what factors are associated with use of complementary approaches over a long period of time and how they are related to starting, continuing, or stopping an approach.

In this analysis, researchers used multiple waves of data from the Midlife in the U.S. (MIDUS) survey, which has collected over 20 years of data on complementary health approach use by noninstitutionalized English-speaking 25- to 74-year-old adults living in the United States. The survey involved 6,325 individuals in the initial wave (1995–1996), 4,041 of whom participated in the second wave (2004–2005) and 2,717 in the third wave (2013–2014).

From wave 1 (1995–1996) to nearly two decades later in wave 3 (2013), each of the four complementary health approaches saw substantial increases in use:

• From 8.51 to 18.18 percent for massage therapy
• From 13.33 to 23.67 percent for meditation
• From 12 to 17.3 percent for chiropractic
• From 5.03 to 7.14 percent for herbal products

Only 24 to 41 percent of people continued use of an approach from one wave to the next. Also, only 2 to 9 percent of people who didn’t use an approach in one wave then reported use of the approach in the next wave.

Predisposing factors such as age, sex, and education were associated differently with new and continued use of complementary health approaches, with prior use of each approach having the most significant relationship with future use. Age, spiritual importance, and previous wave 1 use were significantly associated with new use across all four approaches. The authors reported key findings about each approach.

 

Massage Therapy

• Individuals with a high school diploma, GED, or associate's degree in wave 1 were less likely than those who held bachelor’s degrees to start massage therapy in wave 2.
• Individuals reporting spiritual importance in wave 2 were twice as likely to start massage therapy in wave 3.
• Compared to men, women who used massage therapy in wave 1 were more than twice as likely to continue its use in wave 2. Women were also more likely than men to start massage therapy in waves 2 and 3.
• Adults aged 25 to 44 were more likely than those aged 45 to 64 to start massage therapy in waves 2 and 3. Compared to adults aged 45 to 64, those aged 65 and older in wave 2 were more likely to discontinue massage therapy in wave 3.
• People using massage therapy in wave 1 were more than twice as likely to continue massage therapy from waves 2 to 3, and three times as likely to restart massage therapy nearly two decades later in wave 3.

 

Meditation

• White individuals were more likely to start meditation than others in wave 2.
• Individuals not reporting depression in wave 1 were slightly less likely to start meditation in wave 2.
• Adults aged 65 and older in wave 1 were the least likely to start meditation in waves 2 and 3.
• Compared to individuals with a bachelor’s degree, those with a high school diploma, GED, or associate’s degree in wave 1 were less likely to start meditation in waves 2 and 3, and if they were already using meditation in wave 1, they were more likely to stop meditation in wave 2.
• People reporting spiritual importance in wave 1 were nearly twice as likely to start meditation in waves 2 and 3.
• Being female, reporting spiritual importance, and previous meditation practice in wave 1 were all significantly associated with continued meditation use later.

 

Chiropractic

• White individuals in wave 1 were more likely to start chiropractic in wave 2 than others and were three times as likely to continue chiropractic use in wave 2 if they were already using it in wave 1.
• Individuals not depressed in wave 1 were less likely to start chiropractic in wave 2 than those who were depressed.
• Compared to adults aged 45 to 64, adults aged 25 to 44 were more likely to start chiropractic use in waves 2 and 3.
• Adults aged 65 and older were the least likely to start chiropractic in waves 2 and 3. The same age group in wave 2 was more likely than those aged 45 to 64 to discontinue chiropractic use in wave 3.
• Prior chiropractic use in wave 1 was a significant predictor for use in wave 3, with those using it in wave 1 more than twice as likely to continue use and three times as likely to use it again nearly two decades later in wave 3.
• People with an advanced degree (e.g., master’s degree or doctorate) in wave 2 were more likely to stop chiropractic use in wave 3 than those with a bachelor’s degree.

 

Herbal Products

• Compared to men, women were almost three times as likely to start using herbal products in wave 2 and two and a half times as likely to continue using herbal products in wave 2 if they were already using them in wave 1.
• Individuals with a high school diploma, GED, or associate’s degree were nearly half as likely to start using herbal products in wave 2 as those with a bachelor’s degree.
• Spiritual importance was associated with new herbal product use in waves 2 and 3.
• Prior herbal product use in wave 1 predicted new herbal product use in wave 3 and continued use from wave 2 to 3.
• No factors predicted the discontinued use of herbal products between any of the waves.

The authors say that additional research is needed to confirm their findings and to investigate other important populations, such as veterans, in which there are significant gender, race, and ethnicity differences among those who use complementary health. Additionally, the distinction between new and continued or discontinued use of complementary health approaches is especially important to consider when examining prevalence data, where it is challenging to identify these different users and trends. These analyses will serve as baseline knowledge for related education and outreach efforts to patients, providers, and health plans.