Although the relationship between continuity and quality of care was significant, it was also fairly weak (r = .148). Other barriers may have been more important than continuity in determining the quality of care provided to patients with type 2 diabetes. For example, to improve quality of care, clinicians must keep track of multiple indicators over long periods. Many current medical record systems offer inadequate support for this function. Because this structure may vary by clinic, we included clinic sites as dummy variables in the multiple regression model. Even after adjusting for clinic site, continuity was significantly associated with quality. However, 2 clinic sites had significantly higher mean quality of care scores than did the other sites. Upon closer examination, 1 clinic site had an electronic medical record with prompts for preventive services.
Several limitations to this study must be mentioned. Recall bias is a possibility; the continuity data were based on patient recall of physician office visits over a 12-month period. This is a nonrandom sample; we enrolled a consecutive sample of consenting patients from the clinic population. Thus, this sample may have been heavily weighted with frequent attenders. Patients who were visually impaired, had low literacy skills, or had very poor health status may have declined participation in the study. We were able to collect only performance data from the primary care providers’ charts. If a patient had a blood pressure measurement or a glycosylated hemoglobin measurement recorded at another physician’s office, then the primary care chart might not be adequate to document the overall quality of care received by the patient over the past 12 months. Another limitation is the predominant use of process indicators rather than outcome indicators, such as quality of life, morbidity, or mortality, as measures of quality of care.
The cross-sectional design of the study and the limitations of data collected create the possibility that an unmeasured confounder caused the relation between continuity and quality. It is possible that patients who were more aggressive about seeking care from their usual providers were also more likely to keep appointments for eye and foot examinations. It is also possible that patients who did not see their usual providers sought care only for acute illnesses and were willing to see any available provider. If so, the competing demands of patient care during the acute care visit may have prevented the provider from obtaining the necessary laboratory tests or referrals needed to improve the quality of diabetes care.21 The setting of the study, ie, residency clinics, might have limited the generalizability of these findings to other community family physician practices. With the help of their supervising physicians, residents might have overcome competing demands of practice to attend to preventive measures, leading us to underestimate the strength of the relation between continuity and quality.
Current changes in the financing and organization of health care create significant threats to a sustained relationship between a provider and a patient.22 In a recent report from the Community Tracking Survey, 1 of 6 consumers changed insurance plans in a 1-year period. Of those, 23% also changed their usual source of care.23 Understanding how the physician–patient relationship might influence quality of care and patient outcomes may facilitate successful organizational interventions within a health care delivery system. If continuity promotes improvements in quality of care, as suggested by the results of this study, policies that promote continuity should be considered in an effort to improve the overall quality of care delivered to adult patients with diabetes.