An Adult Immunization Best Practices Learning Collaborative: Impact, Scale Up, and Spread

The research objective was to rapidly scale up and spread a proven learning collaborative approach (intervention) for adult vaccination rates for influenza and pneumococcal disease from 7 to 39 US health care organizations and to examine improvement in adult immunization rates after scale-up. Comparative analyses were conducted between intervention and nonintervention propensity score-matched providers on vaccination rates using a difference-in-differences approach. Qualitative data, collected during site visits and in-person and virtual meetings, were used to enhance understanding of quantitative results. In 2017–2018, an analysis of a subset of sites (n = 9) from 2 intervention cohorts (∼20 sites each) demonstrated greater improvement than their matched providers in pneumococcal vaccinations (PV) for patients ages ≥65 years (treatment effect range: 1.4%-3.7%, P < 0.01) and PV for high-risk patients (eg, with immunocompromising conditions) aged 19–64 years (0.8%-1.6%, P < 0.01). Significant effects were observed in one of the study cohorts for PV for at-risk patients (eg, with diabetes) aged 19–64 years (1.7%, P < 0.01), and influenza vaccination rates (2.4%, P < 0.001). Individual health systems demonstrated even greater improvements across all 4 vaccinations: 9.5% influenza; 8.7% PV ages ≥65 years; 11.8% PV high-risk; 16.3% PV at-risk (all P < 0.01). Results demonstrated that a 7-site pilot could be successfully scaled to 39 additional sites, with similar improvements in vaccination rates. Between 2014 and 2018, vaccination improvements among all 46 groups (7 pilot, 39 in subsequent cohorts) resulted in an estimated 5.5 million adult vaccinations administered or documented in 27 states.