This study was a quantitative synthesis of 23 CDSMP studies to determine the effectiveness of CDSMP on health behaviors, physical and psychological health status, and health care utilization in both short-term and longer-term follow-up. The small English-speaking group delivery mode produced moderate improvements in self-efficacy and small and moderate improvements in psychological health and some health behaviors; many improvements were maintained for at least 12 months. Changes in physical health status were less consistent, and we found few significant changes in health care utilization. Our analysis is reasonably consistent with an analysis of lay-led self-management interventions (12
); the differences between the analyses may have resulted from our analysis of CDSMP in isolation rather than in combination with other interventions and our inclusion of both RCTs and longitudinal evaluations. Our results are also consistent with small-group CDSMP studies conducted in Shanghai (31
), Hong Kong (3
), and Japan (33
), although a Dutch study found no significant improvements from CDSMP (4
). Our study also examined whether delivery mode influenced intervention effectiveness; our exploratory analysis suggested that alternative delivery modes are promising, although most alternative modes had fewer significant improvements than the small English-speaking group mode.
The benefits of CDSMP observed in this study have meaningful, wide-ranging, and complementary implications for chronic disease self-management and for primary and tertiary prevention of chronic disease. Analysis of the small English-speaking group delivery mode demonstrated consistent and sustained improvements in self-efficacy. Not only is self-efficacy the hypothesized mechanism of action for CDSMP (34
) but it is also directly associated with such health behaviors as physical activity, healthful eating, pain-coping strategies, and medication adherence (35
) and changes in pain, function, and depression (36
). Although the ES was small, our study found direct changes in physical activity, an essential ingredient in primary and tertiary prevention of many chronic diseases (eg, arthritis, diabetes, heart disease) and crucial for general health and well-being (38
). Interventions that increase physical activity among people who have chronic diseases are important tertiary prevention strategies. Reductions in health distress and depression are important benefits for people who have chronic diseases because depression is a common comorbidity (39
) that complicates management of chronic diseases (40
) and produces greater somatic symptoms and activity limitations (41
). Interventions that improve these psychological outcomes can be useful adjuncts to clinical treatment.
The inconsistent changes in physical health status measures such as pain, fatigue, shortness of breath, and physical function may not be surprising. Because CDSMP is designed for people with various chronic health conditions, the presence and severity of symptoms like pain and shortness of breath varies among participants. Participants who rate symptoms as minimal at baseline have little room for improvement at follow-up. Changes in symptoms could be evaluated by segmenting participants’ symptom severity at baseline, but these data were not available in the reports we studied. However, a post-hoc subgroup analysis of a CDSMP RCT found that participants who reported lower self-efficacy, energy, and health-related quality of life at baseline reported greater benefits from CDSMP participation (43
). Significant changes in pain and shortness of breath at 9 to 12 months that were not evident at 4 to 6 months may indicate a delay in improvement of some symptoms; however, energy and fatigue, which both improved in the short term, were no longer significantly improved in longer-term follow up. The improvements in social role limitations at both follow-up points may be a function of improvements in psychological distress; a study reported an association between psychological distress and limitations in people who have chronic diseases (42
That we found only 1 small improvement in health care utilization may be due to several factors. First, CDSMP may not be sufficiently potent to produce decreases in an outcome as complex and multifactorial as health care utilization. Second, a healthy-participant bias may have affected our results: perhaps before attending CDSMP, participants had limited use of health care services, so little change was possible. Third, perhaps participants became more appropriate users of health care services (eg, those who were not seeking health care attention at advantageous times began to). Fourth, all measures of health care utilization used in these studies were based on self-report and may be insufficiently sensitive to identify changes. Using administrative claims data or contemporaneous reporting of utilization could provide more robust assessments of CDSMP effects on health care utilization.
This meta-analysis had several limitations. First, the unit of analysis was the study, not the individual. Factors such as comorbidity or symptom severity may confound estimates of intervention effectiveness at the study level. Second, for each outcome, the number of studies available for analysis varied, and some estimates were based on small sample sizes. We recommend caution when interpreting estimates based on small numbers of studies. The analysis by delivery mode at 4 to 6 months was exploratory because we examined only 7 studies that had delivery modes other than small English-speaking group. Finally, because our analysis focused on studies conducted in English-speaking countries and limited data were available on men and nonwhite racial/ethnic groups, our results may not be generalizable to other populations.
This study also had several strengths. First, it is the only meta-analysis to examine the Stanford CDSMP alone and not in combination with other self-management or self-management education programs. Second, whereas most meta-analytic studies have examined only 2 to 4 outcomes per disease, we examined 20 outcomes. Third, the analyses examined data at 2 points postintervention to determine whether effects were maintained at longer-term follow-up. Finally, this is the first examination of the statistical validity of combining RCTs and longitudinal evaluations in analyses. We identified no heterogeneity by study design and determined that combining data from the 2 kinds of studies was appropriate; the combined analysis increases the generalizability of findings to populations most likely to enroll in CDSMP when it is offered in nonresearch settings.
This study identifies several areas for further research. Studies that differentiate among subpopulations would determine whether CDSMP is more effective in some populations than in others or whether contextual or implementation factors influence effectiveness. Additional studies are necessary to determine whether alternative delivery modes are as effective as the small English-speaking group mode. Direct measurement of health care utilization would provide more definitive data on CDSMP’s effect on health care utilization. A comparison of the effectiveness of CDSMP implemented alone and in combination with other self-management activities would also be useful. Finally, cost-effectiveness and cost-benefit analyses would help clarify the financial and quality-of-life return on investment of CDSMP.
The robust findings of small and moderate improvements in self-efficacy, psychological health, and select health behaviors that were maintained through 12 months suggest that the small English-speaking group CDSMP creates health benefits for program participants. The combined evidence from RCTs (with strong internal validity) and longitudinal program evaluations (with strong external validity) increases confidence that benefits will occur as programs are delivered in practice (44
). Although some of the ESs obtained in this meta-analysis are modest, they have public health significance because of the cumulative effect of small changes in a large population — 141 million people in the United States have at least 1 chronic disease (45
). CDSMP could have a considerable public health effect because of its potential scalability, low implementation cost, wide applicability across various settings and audiences, and capacity to reach large numbers of people.
CDSMP provides people who have chronic diseases with opportunities to develop the skills and confidence to self-manage their diseases and disease-related problems and improve their quality of life. On the basis of our meta-analysis, health care systems and community organizations can adopt CDSMP as part of their comprehensive chronic disease management strategy to increase their constituents’ psychological health status, physical activity, and confidence in their ability to manage their chronic conditions, and health care providers can confidently recommend CDSMP to achieve these same benefits in their patients with chronic disease. The self-management supports that communities and health systems provide, such as CDSMP, are essential components of patient-centered medical homes (1
) and the chronic-care model (46
) that is reshaping how care is delivered to people who have chronic health conditions.