Background:Using available communication technologies, clinicians may offer timely support to family caregivers in managing symptoms in patients with advanced cancer at home.Aim:To assess the effects of an online symptom reporting system on caregiver preparedness, physical burden, and negative mood.Design:A pooled analysis of two randomized trials (NCT00214162 and NCT00365963) was conducted to compare caregiver outcomes at 6 and 12 months after intervention between two randomized, unblinded groups using General Linear Mixed Modeling. Caregivers in one group (Comprehensive Health Enhancement Support System-Only) were given access to an interactive cancer communication system, the Comprehensive Health Enhancement Support System. Those in the other group (Comprehensive Health Enhancement Support System + Clinician Report) received access to Comprehensive Health Enhancement Support System plus an online symptom reporting system called the Clinician Report. Clinicians of patients in the Comprehensive Health Enhancement Support System + Clinician Report group received e-mail alerts notifying them when a symptom distress was reported over a predetermined threshold.Setting/participants:Dyads (n = 235) of advanced-stage lung, breast, and prostate cancer patients and their adult caregivers were recruited at five outpatient oncology clinics in the United States.Results:Caregivers in the Comprehensive Health Enhancement Support System + Clinician Report group reported less negative mood than those in the Comprehensive Health Enhancement Support System-Only group at both 6 months (p = 0.009) and 12 months (p = 0.004). Groups were not significantly different on caregiver preparedness or physical burden at either time point.Conclusions:This study provides new evidence that by using an online symptom reporting system, caregivers may experience less emotional distress due to the Clinician Report's timely communication of caregiving needs in symptom management to clinicians.