Increased SCOC has not had any negative effects on quality of care. Indeed, in many cases, increased SCOC heightens patient satisfaction, decreases hospitalizations and emergency department visits, and improves receipt of preventive services. The positive effect of SCOC on health care use has been well documented for patients with chronic conditions. Although our search strategy and exclusion criteria differed from a previous review by Dietrich et al, we report similar conclusions regarding SCOC and patient satisfaction.16
We observed that the association between SCOC and quality of care appears most consistent for patients with chronic conditions, and we think there are several reasons for this relationship. Improved care should evolve throughout the course of a long-term relationship. The time frame of most studies in our analysis was limited, with the longest being only 2 years. It is possible that the benefits of SCOC do not become manifest until a much longer time period or after many visits with the same primary care provider.
However, patients with chronic disease are more likely to use outpatient, emergency department, and hospital services than are otherwise healthy persons. The increased number of outpatient visits by a patient with chronic disease may establish SCOC more quickly in a relationship, compared with patients who have fewer outpatient visits in general. The increased frequency of emergency department use and hospitalizations for patients with chronic disease may also magnify the effects and benefits of SCOC. As a result, it may be easier to detect the positive effects of SCOC for patients with chronic disease.
Finally, low SCOC may simply be a marker for other factors (associated with the patient or health care system) that are linked to decreased quality of care or increased costs.
Because this review included only published articles, it is susceptible to publication bias.40 We included only studies that looked at the effect of SCOC on quality of care, and excluded studies that considered SCOC as part of a larger intervention. It is not clear if this under- or overestimates the effect of SCOC. However, by including only such studies, we are underreporting the overall evidence base of the effect of SCOC on quality of care.
Benefits of SCOC may occur if a patient develops a consistent relationship with a specific clinic or practice site. Since we limited our analysis to the provider-level, our results might not reflect the benefits of SCOC in broader contexts.
Although SCOC has many positive effects on quality of care, absolute or complete SCOC may not necessarily be ideal. There may be tradeoffs between SCOC and patient access to care. One study suggested that in certain scenarios (ie, “minor problems”), convenience was more important than SCOC; however for chronic issues, SCOC was more valued.39 Although this analysis suggests that SCOC is associated with improved quality of care, it is beyond the scope of this study to suggest the ideal level of SCOC in relation to other factors such as access. The published studies in this analysis were not designed to address these issues.
Finally, patient satisfaction may not be an appropriate measure for quality in this particular analysis. Patients who are dissatisfied with care may be more likely to change physicians and thus have less continuity. However, in this analysis we examined quality-of-care endpoints separately from other endpoints.
Implications and future research
Based on our study criteria, our analysis suggests an association between SCOC and patient satisfaction, as well as improved process of care and patient outcomes.
Other areas remain to be investigated. We found few studies, for example, that examined the impact of SCOC on cost of care. Programs that attempt to maximize SCOC may require significant administrative resources and costs (ie, to improve scheduling or provider availability). In an era of limited resources, promoting increased investment in this area may necessitate a demonstration of the long-term financial effects of SCOC and the absence of any unintended consequences (eg, delays in diagnosis). Although there are specific expenditures associated with promoting SCOC, such changes should theoretically lower health care costs overall by decreasing avoidable hospitalizations or emergency department visits.
Future research should investigate which populations benefit most from SCOC. A significant portion of the evidence for the positive effects of SCOC on quality of care includes patients with chronic disease, such as asthma and diabetes. Programs or clinics with limited resources to promote SCOC may be able to maximize impact by focusing on such populations.
Presented in part at the Pediatric Academic Societies Annual Meeting, Seattle, Wash. May 6, 2003. Support (SHJ) provided by the National Institute of Child Health and Human Development T32 HD07534-03. The authors would like to thank Ms. Lucy M. Schiller and Ms. Kathryn L. Wheeler for their assistance in data collection, as well Ms. Kathryn Slish for her editorial assistance.
Michael D. Cabana, MD, MPH, 6-D-19 NIB, Box 0456, 300 North Ingalls Street, Ann Arbor, MI 48109-0456. E-mail: [email protected]