Increasing Immunization Rates Among Inner-City, African American Children: A Randomized Trial of Case Management
Dec 31, 1997
Inner-city populations often lack access to important preventive health services, such as well-child care and immunizations. In recent years, many policymakers have embraced case management as a promising means of better serving these populations and of increasing their access to needed health care services. Previous research has indicated that, under some circumstances, case management can be a highly effective means of improving health outcomes. To determine whether case management would be similarly effective at increasing immunization rates and access to well-child care among high-risk populations, RAND performed a prospective, randomized controlled trial of a case management intervention among African-American families living in a low-income community in south central Los Angeles.
During the year-long study, the case managers conducted an initial, in-depth assessment of each child at home, then performed subsequent home visits two weeks prior to each well-child care visit at which an immunization was due. (On average, they visited each home four times during the course of the year.) After each scheduled well-child care visit, the case managers telephoned or visited the home to ascertain whether the family kept the appointment and whether the child had received the immunization.
As part of the intervention, the case managers also provided education about the importance of immunization, attempted to dispel misconceptions about contraindications to immunization, and encouraged the families to proactively request immunizations from their health care provider. In addition, they tried to overcome any barriers to receiving well-child care, such as lapses in Medicaid insurance or problems with transportation.
Overall, the case management intervention produced a disappointingly small effect, given the time, effort, and resources involved (total intervention costs exceeded $230,000). Case management had essentially no impact on well-child care visits: The average number of visits for the intervention group remained statistically indistinguishable from that for the control group. Neither did it affect the frequency of "missed opportunities to vaccinate," or "MOs," which occurred at approximately half of all health care visits among both the intervention and control groups.
Although case management did increase immunization rates by 13 percentage points (from 51 percent in the control group to 64 percent in the intervention group), it was not a cost-effective method of doing so: The intervention cost almost $1,600 per child, or the equivalent of approximately $12,000 per additional child immunized.
This study illustrates that it is possible to invest significant amounts of time and money in a well-designed intervention and still not achieve the desired outcome. Low immunization rates and lack of access to health care result from a complex interaction of factors, some of which are more amenable to change than others. In part, the modest immunization rates observed in this study can be attributed to factors somewhat beyond the case managers' direct control, such as whether health care providers actually administered immunizations during the participants' visits.
Limitations on external resources may have also hampered the intervention. The case managers were able to do some troubleshooting on behalf of their clients, such as contacting agencies to ensure continuity of insurance coverage. However, they generally lacked access to resources that could directly facilitate the receipt of well-child care and immunizations, such as taxi vouchers for families with transportation difficulties or the assistance of health care providers willing to administer immunizations in the participants' homes.
In retrospect, the type of home-based case management used in this study may be better suited to interventions that are directly tied to the living environment. For instance, the study may have had dramatically different outcomes if the objective had been injury prevention and the case managers were teaching parents how to childproof their home.
Future interventions aimed at increasing immunization rates may be better served by targeting provider behavior. For example, the majority of missed opportunities to vaccinate in this study occurred during acute illness visits, rather than during well-child visits. Previous research indicates that health care providers often mistakenly believe minor illness to be a contraindication to immunization. Since a single immunization can often spell the difference between being up-to-date or falling behind schedule, an intervention designed to encourage health care providers to administer immunizations to mildly ill children, as well as to healthy ones, could have a significant impact on immunization rates in high-risk communities like south central Los Angeles.