Evidence based processes to prevent readmissions: more is better, a ten-site observational study

30-day hospital readmissions are an indicator of quality of care; hospitals are financially penalized by Medicare for high rates. Numerous care transition processes reduce readmissions in clinical trials. The objective of this study was to examine the relationship between the number of evidence-based transitional care processes used and the risk standardized readmission rate (RSRR). Design: Mixed method, multi-stepped observational study. Data collection occurred 2014-2018 with data analyses completed in 2021. Ten VA hospitals, chosen for 5-year trend of improving or worsening RSRR prior to study start plus documented efforts to reduce readmissions. During five-day site visits, three observers conducted semi-structured interviews (n = 314) with staff responsible for care transition processes and observations of care transitions work (n = 105) in inpatient medicine, geriatrics, and primary care. Frequency of use of twenty recommended care transition processes, scored 0-3. Sites' individual process scores and cumulative total scores were tested for correlation with RSRR. best fit predicted RSRR for quarter of site visit based on the 21 months surrounding the site visits. Total scores: Mean 38.3 (range 24-47). No site performed all 20 processes. Two processes (pre-discharge patient education, medication reconciliation prior to discharge) were performed at all facilities. Five processes were performed at most facilities but inconsistently and the other 13 processes were more varied across facilities. Total care transition process score was correlated with RSRR (R = 0..61, p