Interventions on health care providers to improve seasonal influenza vaccination rates among patients: a systematic review and meta-analysis of the evidence since 2000

BACKGROUND: Seasonal influenza vaccination (SIV) rates remain suboptimal in many populations, even in those with universal SIV. OBJECTIVE: To summarize the evidence on interventions on health care providers (physicians/nurses/pharmacists) to increase SIV rates. METHODS: We systematically searched/selected full-text English publications from January 2000 to July 2019 (PROSPERO-CRD42019147199). Our outcome was the difference in SIV rates between patients in intervention and non-intervention groups. We calculated pooled difference using an inverse variance, random-effects model. RESULTS: We included 39 studies from 8370 retrieved citations. Compared with no intervention, team-based training/education of physicians significantly increased SIV rates in adult patients: 20.1% [7.5–32.7%; I(2) = 0%; two randomized controlled trials (RCTs)] and 13.4% [8.6–18.1%; I(2) = 0%; two non-randomized intervention studies (NRS)]. A smaller increase was observed in paediatric patients: 7% (0.1–14%; I(2) = 0%; two NRS), and in adult patients with team-based training/education of physicians and nurses together: 0.9% (0.2–1.5%; I(2) = 30.6%; four NRS). One-off provision of guidelines/information to physicians, and to both physicians and nurses, increased SIV rates in adult patients: 23.8% (15.7–31.8%; I(2) = 45.8%; three NRS) and paediatric patients: 24% (8.1–39.9%; I(2) = 0%; two NRS), respectively. Use of reminders (prompts) by physicians and nurses slightly increased SIV rates in paediatric patients: 2.3% (0.5–4.2%; I(2) = 0%; two RCTs). A larger increase was observed in adult patients: 18.5% (14.8–22.1%; I(2) = 0%; two NRS). Evidence from both RCTs and NRS showed significant increases in SIV rates with varied combinations of interventions. CONCLUSIONS: Limited evidence suggests various forms of physicians’ and nurses’ education and use of reminders may be effective for increasing SIV rates among patients.