Patients with complex chronic conditions: Health care use and clinical events associated with access to a patient portal

BACKGROUND: For patients with diabetes, many with multiple complex chronic conditions, using a patient portal can support self-management and coordination of health care services, and may impact the frequency of in-person health care visits. OBJECTIVE: To examine the impact of portal access on the number of outpatient visits, emergency visits, and preventable hospitalizations. DESIGN: Observational study comparing patients’ visit rates with and without portal access, using marginal structural modeling with inverse probability weighting estimates to account for potential bias due to confounding and attrition. SETTING: Large integrated delivery system which implemented a patient portal (2006–2007). PATIENTS: We examined 165,447 patients with diabetes defined using clinical registries. Our study included both patients with diabetes-only and patients with multiple complex chronic conditions (diabetes plus asthma, congestive artery disease, congestive heart failure, or hypertension). MEASUREMENTS: We examined rates of outpatient office visits, emergency room visits, and preventable hospitalizations (for ambulatory care sensitive conditions). RESULTS: Access to a patient portal was associated with significantly higher rates of outpatient office visits, in both patients with diabetes only and in patients with multiple complex conditions (p<0.05). In patients with multiple complex chronic conditions, portal use was also associated with significantly fewer emergency room visits (3.9 fewer per 1,000 patients per month, p<0.05) and preventable hospital stays (0.8 fewer per 1,000 patients per month, p<0.05). In patients with only diabetes, the results were directionally consistent but not statistically significantly associated with emergency room visits and preventable hospital stays. LIMITATIONS: Observational study in an integrated delivery system. CONCLUSION: Access to a patient portal can increase engagement in outpatient visits, potentially addressing unmet clinical needs, and reduce downstream health events that lead to emergency and hospital care, particularly among patients with multiple complex conditions.