Correlation of long-term care facility vaccination practices between seasons and resident types

Influenza vaccination varies widely across long-term care facilities (LTCFs) due to staff behaviors, LTCF practices, and patient factors. It is unclear how seasonal LTCF vaccination varies between cohabitating but distinct short-stay and long-stay residents. Thus, we assessed the correlation of LTCF vaccination between these populations and across seasons. The study design is a national retrospective cohort using Medicare and Minimum Data Set (MDS) data. Participants include U.S. LTCFs. Short-stay and long-stay Medicare-enrolled residents age ≥ 65 in U.S. LTCFs from a source population of residents during October 1 -March 31 in 2013-2014 (3,042,881 residents; 15,683 LTCFs) and 2014-2015 (3,143,174, residents; 15,667 LTCFs). MDS-assessed influenza vaccination was the outcome. Pearson correlation coefficients were estimated to assess seasonal correlations between short-stay and long-stay resident vaccination within LTCFs. The median proportion of short-stay residents vaccinated across LTCFs was 70.4% (IQR, 50.0-82.7%) in 2013-2014 and 69.6% (IQR, 50.0-81.6%) in 2014-2015. The median proportion of long-stay residents vaccinated across LTCFs was 85.5% (IQR, 78.0-90.9%) in 2013-2014 and 84.6% (IQR, 76.6-90.3%) in 2014-2015. Within LTCFs, there was a moderate correlation between short-stay and long-stay vaccination in 2013-2014 (r = 0.50, 95%CI: 0.49-0.51) and 2014-2015 (r = 0.53, 95%CI: 0.51-0.54). Across seasons, there was a moderate correlation for LTCFs with short-stay residents (r = 0.54, 95%CI: 0.53-0.55) and a strong correlation for those with long-stay residents (r = 0.68, 95%CI: 0.67-0.69). In LTCFs with inconsistent influenza vaccination across seasons or between populations, targeted vaccination protocols for all residents, regardless of stay type, may improve successful vaccination in this vulnerable patient population.