Behavior model targets message to correct stage
CDC, NIH are studying groups using the model
Researchers studying behavior change among HIV-infected populations and people at risk for infection increasingly are interested in the transtheoretical model of health behavior change.
The model is based on a premise that people change their health behavior after progressing through five or six stages of behavior change. The theory holds that if clinicians understand the stages and know which stage their patients are in, they can gear their education and monitoring efforts according to that stage. For example, in early stages, physicians might spend time raising patients’ awareness of risks and options but not waste time urging them to change their behavior.
"The basic point of the whole model is to make intervention messages or counseling messages or media messages most effective by targeting the stage a person is in," says Christine Galavotti, PhD, research behavioral scientist and chief of the behavioral research unit of the Division of Reproductive Health at the Centers for Disease Control and Prevention in Atlanta.
The model’s chief developers are James O. Prochaska, PhD, a professor at the University of Rhode Island and a director of the Cancer Pre ven tion Research Center, both in Kingston; Carlo DiClemente, PhD, a professor at the University of Maryland in Baltimore; and Wayne Velicer, PhD, co-director of the Cancer Prevention Research Center and a professor in the department of psychology at the University of Rhode Island.
The CDC was so impressed with how the model worked in helping people quit smoking that the agency’s HIV group started using the model in a $5 million community project, called the AIDS Community Demonstration Project (ACDP), in 1989, Galavotti says.
ACDP researchers developed an intervention program that was used in Denver, Long Beach, CA, New York City, and Seattle, targeting one or more members of the following population groups: street-recruited injecting-drug users; female sex partners of male injecting-drug users; women who trade sex for money or drugs; men who have sex with men but do not call themselves homosexuals; and street youths. The program also was held in Dallas, where it targeted people living in two separate census tracts that had high rates of injecting-drug use and sexually transmitted diseases. The project goals were to increase consistent condom use among the targeted populations and to increase the use of bleach to clean needles among drug users.1
The program included a control group and a group that was counseled about HIV based on the stages-of-change model. The ACDP study found that condom use among a couple of groups targeted in the project was higher in the intervention group than in the control group. For example, among people who had vaginal intercourse with nonmain partners, 41.3% of the people who had been exposed to the intervention reported consistent condom use. Of those who received no intervention, 27.1% reported consistent condom use. In the group who had anal intercourse with nonmain partners, the difference was more striking: 58% of people who were exposed to the project reported consistent condom use, compared with 27% of people who were not exposed to the intervention.
The study protocol consisted of the use of behavior-change models; research within the project communities before beginning the intervention; development of brochures and other materials that had role-model stories of people who had changed their HIV-risk behavior; distribution of the brochures, condoms, and bleach kits; and an evaluation protocol to measure implementation and outcome.
The intervention was designed based on the stages-of-change model and other behavioral theories, such as the Health Belief Model, the Theory of Reasoned Action, and the Social Cognitive Theory. The CDC used the first five stages of the stages-of-change model. The stages-of-change scale for condom use reads as follows:
1. Precontemplation — has little or no intention to always use condoms in the future;
2. Contemplation — does not use condoms but intends to begin using them every time in the future;
3. Preparation — almost always or sometimes uses condoms and intends to use condoms every time in the future;
4. Action — has used condoms every time for less than six months;
5. Maintenance — has used condoms every time for six or more months.2 (See stages of change chart, p. 54.)
The study measured behavioral outcomes for each person according to the stages-of-change continuum. The four behaviors studied were: consistent condom use for vaginal intercourse with a main partner; consistent condom use for vaginal intercourse with nonmain partners; consistent condom use for anal intercourse with nonmain partners; and consistent use of bleach to clean injection equipment.
The study found that for each of the four behaviors, the mean stages-of-change value among the study participants exposed to intervention was greater than the mean stages-of-change value among those who did not receive intervention.
The CDC later used the stages-of-change model, focusing on women at risk, such as commercial sex workers and women who lived in areas where there was a high rate of drug use.
Prevention efforts included role models
"We had outreach workers who did a quick assessment of where someone was in respect to condom use," Galavotti says. "They would tailor street outreach to the stage, using material such as role-model stories in which a commercial sex worker would talk about where she was, saying, I don’t use condoms all the time, but I’ve been thinking about how this might affect my kids.’"
In 1993, the CDC developed a manual for training peer prevention workers in counseling. It was used at homeless shelters, drug treatment centers, and housing development health clinics. Peer prevention workers were recruited from the ranks of women who had HIV. Project coordinators taught them about the stages-of-change model and called them peer worker advocates. Women were offered six months of services, including health care and counseling that included messages based on the stages-of-change model. The advocates counseled women on condom use, contraceptives, reproductive decision-making, and other life goals.
"Our goal was to make sure women went through a thoughtful process of what they wanted to do, and we’d support whatever decision they made and try to make sure they didn’t have an unintended pregnancy," Galavotti says.
Researchers evaluated whether the women moved up along the stages-of-change continuum toward different outcomes.
"First we looked at condom use with their main partner, and in the HIV-positive sample, the women who received the stage-based intervention had significantly better results than the women who didn’t," Galavotti says.
These results were all the more remarkable because the women who did not receive the stage-based interventions still received the full reproductive health services of a complete gynecological exam and Pap smear, meeting with a reproductive health specialist, and contraceptive counseling.
The women who were randomly assigned to the enhanced services group received all of those services plus counseling with specially trained advocates. "We found that women who received that counseling were more than twice as likely to progress one or more stages or to have stayed in maintenance for condom use at the six-month follow-up period," Galavotti says. "And they were less likely to have relapses."
At the baseline, both groups in the HIV-positive sample reported about 43% consistent condom use. By the study’s end, the control group’s condom use was unchanged, but the enhanced group had increased condom use to 65%, Galavotti says.
"We were pleased with the HIV-infected sample," Galavotti says. "And we were extremely pleased that the peer professionals loved this; they thought it made tremendous sense and was intuitively very appealing, and they reported that clients loved it as well."
There was no turnover of staff during the study, which ran from 1993 to April 1997.
The results weren’t as promising with the non-HIV group of women at risk for infection. This was expected because the at-risk group was mainly in the precontemplation stage of change, with 59% in this stage at baseline, Galavotti says.
"Not everybody accepted the services," she explains. "Only 75% of the women in the at-risk sample wanted to meet with the advocate."
Despite the generally favorable results, the CDC will continue to evaluate the stages-of-change model before promoting it publicly for use with HIV-positive and at-risk populations, Galavotti says.
"I would like to see it incorporated in the HIV counseling guidelines, but to date it has not been," she adds. "What has been incorporated is the client-centered kind of approach and some of the elements of a stage-based approach."
References
1. Guenther-Grey CA, Johnson WD, Higgins DL, et al. Community-level prevention of human immunodeficiency virus infection among high-risk populations: The AIDS community demonstration projects. MMWR 1996; 44(RR-6):1-24.
2. Wolitski RJ, et al. Community-level HIV intervention in 5 cities: Final outcome data from the CDC AIDS community demonstration projects. Am J Public Health 1999; 89:336-345.
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