The similarity in risk of readmission between vaccinated and unvaccinated surgical inpatients should encourage influenza immunization in this group, claimed researchers of a recent study.
Study participants were individuals aged ≥6 months who were scheduled to undergo inpatient surgery between 1 September and 31 March in 2010-2013 (influenza seasons). From a cohort of 42,777 surgeries, there were 6,420 influenza vaccines administered in-hospital, 78 percent of which were administered on day of discharge.
There were no differences between the groups in terms of risk of inpatient visits (rate ratio [RR], 1.12, 95 percent CI, 0.96-1.32; p=0.162) or emergency department (ED) visits (RR, 1.07, 95 percent CI, 0.96-1.20; p=0.22) 7 days postdischarge. There was also no difference detected for postdischarge fever (RR, 1.00, 95 percent CI, 0.76-1.31; p=0.99) or clinical evaluation for infection (RR, 1.06, 95 percent CI, 0.99-1.13; p=0.099) between the groups. [Ann Intern Med 2016;doi:10.7326/M15-1667]
There was, however, a slightly higher risk of outpatient visits in the vaccinated group (RR, 1.05, 95 percent CI, 1.00-1.10; p=0.032). Study authors felt that this minor increased risk should be weighed against the benefits of vaccination.
“Our data support the rationale for increasing vaccination rates among surgical inpatients,” said the authors, who stated that approximately 34 percent of the study population did not receive an influenza vaccination despite being eligible.
“The concern among providers is that vaccine-associated adverse events could lead to unnecessary evaluations and would influence postsurgical care,” said the authors. However, previous studies have shown that the safety of influenza vaccines is similar in hospitalized and ambulatory patients.