Effect of a multimorbidity intervention on health care utilization and costs in Ontario: randomized controlled trial and propensity-matched analyses

Background: Patients with multimorbidity require coordinated and patient-centred care. Telemedicine IMPACT Plus provides such care for complex patients in Toronto, Ontario. We conducted a randomized controlled trial (RCT) comparing health care utilization and costs at 1-year postintervention for an intervention group and 2 control groups (RCT and propensity matched).

Methods: Data for 82 RCT intervention and 74 RCT control participants were linked with health administrative data. We created a second control group using health administrative data-derived propensity scores to match (1:5) intervention participants with comparators. We evaluated 5 outcomes: acute hospital admissions, emergency department visits, costs of all insured health care, 30-day hospital readmissions and 7-day family physician follow-up after hospital discharge using generalized linear models for RCT controls and generalized estimating equations for propensity-matched controls.

Results: There were no significant differences between intervention participants and either control group. For hospital admissions, emergency department visits, costs and readmissions, the relative differences ranged from 1.00 (95% confidence interval [CI] 0.39-2.60) to 1.67 (95% CI 0.82-3.38) with intervention costs at about Can$20 000, RCT controls costs at around Can$15 000 and propensity controls costs at around Can$17 000. There was a higher rate of follow-up with a family physician for the intervention participants compared with the RCT controls (53.13 v. 21.43 per 100 hospital discharges; relative difference 2.48 [95% CI 0.98-6.29]) and propensity-matched controls (49.94 v. 28.21 per 100 hospital discharges; relative difference 1.81 [95% CI 0.99-3.30]).

Interpretation: Despite a complex patient-centred intervention, there was no significant improvement in health care utilization or cost. Future research requires larger sample sizes and should include outcomes important to patients and the health care system, and longer follow-up periods.

Ontario: ClinicalTrials.gov : 104191.