We tested a CM intervention targeting multifactor cardiovascular risk reduction for persons at elevated risk of CVD events in a low-income, predominantly ethnic minority, largely diabetic population in a county healthcare system. The intervention significantly lowered global cardiovascular risk score, compared with usual care. The intervention effect on global risk score was similar for all subgroups by sex and ethnicity. While not always statistically significant, CM yielded favorable outcomes for individual cardiovascular risk factors with reduced BP the leading driver of reduced aggregate cardiovascular risk score.
The intervention provided high intensity contact time with highly trained nurse and dietitian care managers, with mean face-to-face contact time of 11.2 hours per participant over an average 16 months follow-up (about 45 minutes per month). Due to gaps in SMMC administrative records we could not determine how the intervention affected time spent with primary care or specialty providers. Given the population’s social marginalization, substantial mobility between housing locations, travel in and out of the United States, and need to prioritize survival issues over preventive health care, participant retention was an acknowledged challenge. Nonetheless, participant retention was 81% over a mean follow-up of 16 months. A high rate of retention (91% over 12 months) also was observed in our previous study using the same CM model in a similarly low-income, multiethnic population of patients.9
This smaller (n=148), predecessor intervention focused on indigent patients without primary care providers seen in free clinics. The current study extended the care model of our previous study, including integrating CM and physician activities, and allowing CMs to initiate and titrate some medications. Our previous study reported significant improvements in BP, lipids, and blood glucose for CM, relative to usual care. Similarly, other studies evaluating multifactor cardiovascular risk reduction approaches also have demonstrated success in recruiting and retaining medically underserved, ethnic minority patients and achieving clinically meaningful changes in biologic risk factors.8-11
CM can enhance chronic disease care by facilitating guideline-concordant, patient-centered interventions that improve outcomes through intensive, individualized, longitudinal care.6, 7
Evidence supporting the utility of CM for multifactor cardiovascular risk reduction, however, is derived primarily from studies in patient populations with good access to health care. Our study adds to a growing body of evidence8-11
demonstrating the feasibility and efficacy of multifactor cardiovascular risk CM in medically underserved populations. Our success in modifying cardiovascular risk factors in HTH was less than expected based on recent clinical trials of multifactor risk reduction interventions among patients at varying levels of CVD risk.7-9
Levels of LDL-C and TC at baseline were normal or borderline in a majority of our participants, which likely reduced our ability to effect more pronounced improvements in FRS. Also, the high prevalence of diabetes (63%) presented special challenges. Furthermore, several factors specific to a multiethnic, low-income population may have led to less favorable results. These include cultural/language barriers, increased emotional stress due to low SES, financial barriers to medications, focus on survival issues without a long-term perspective, and limited resources to facilitate lifestyle changes. However, such populations might particularly benefit from multifactor cardiovascular risk management: most current care focuses on acute care needs, so that baseline prevention services may be particularly lacking. Further, gaps between guideline and actual risk factor parameters are wider in these populations despite their adverse cardiovascular risk factor profiles4
– the so-called “inverse care law” whereby medical care is most lacking for patients in greatest need.30
Research also shows that, to maximize benefits of multifactor cardiovascular risk management for low-income, ethnic minority patients, strategies that address known social, cultural, and financial barriers to optimal health care for disadvantaged populations are needed.8
Clinical prevention services, including clinical CM, will fall short of their promise if provided in isolation from a patient’s living environment.31
It may be unrealistic to expect patients to implement advice given in medical settings without a complimentary strategy focused on their home and neighborhood environments.32
In HTH, case managers did coordinate access to community resources (e.g., smoking cessation programs and pharmacy support programs), but all direct CM services were provided within health centers. Previous research has shown that outreach by community health workers can improve CVD prevention.8
Our recruitment process yielded participants who were a high-risk subset of the SMMC population. As a population requiring more intensive outpatient services, they form an important group in which to assess the effectiveness of CM. While use of point-of-care laboratory testing provided immediate feedback, this strategy introduced additional measurement variation and may have hampered detection of outcome differences. The Framingham risk functions13
integrate the risk factors that account for most of CVD burden.2
Consistent findings when other risk functions (including those specific to patient with diabetes and existing CVD)23, 26-28
were applied suggests out result’s robustness. We acknowledge that these models were not developed for persons with established CVD,13, 23
who accounted for 19% of our sample. In addition, application of any risk function developed in a single cohort to populations with differing background risk can be associated with misclassifications and might ideally require recalibration or consideration of other risk factors to improve prediction.22
These concerns are mitigated by using the FRS as a composite measure of change in modifiable risk factors, not as a predictor of risk.
Our CM approach to multifactor cardiovascular risk reduction was efficacious. These findings suggest that a multifactor risk reduction approach can foster improved cardiovascular care and outcomes for high-risk patients in low-income, ethnic minority populations.