Role of Post-Acute Care in Readmissions for Preexisting Healthcare-Associated Infections

Abstract

Objectives: Although preventable, healthcare-associated infections (HAIs) are commonly observed in post-acute care settings for at-risk older adults and are a leading cause of hospital readmissions. However, whether HAIs resulting in avoidable readmissions for preexisting HAIs (the same HAI as at the index admission) are more common for patients discharged to post-acute care as opposed to home is unknown. We examined the risk of preexisting HAI readmissions according to patient discharge disposition and comorbidity level.

Design: We used 2013-2014 national hospital discharge data to estimate the likelihood of readmissions for preexisting HAIs according to patients' discharge disposition and whether the likelihood varies according to patient comorbidity level, across four common types of HAIs (not including respiratory infections).

Participants: A total of 702 304 hospital discharges for Medicare beneficiaries 65 years or older.

Measurements: Our outcome was a 30-day preexisting, or "linked," HAI readmission (readmission involving the same HAI diagnosis as at the index admission). Patient discharge disposition was skilled nursing facility (SNF), home health care, and home care without home health care ("home").

Results: Of 702 304 index admissions involving HAI treatment, 353 073 (50%) were discharged to a SNF, 179 490 (26%) to home health care, and 169 872 (24%) to home. Overall, 17 523 (2.5%) of preexisting HAIs resulted in linked HAI readmissions, which were more common for Clostridioides difficile infections (4.0%) and urinary tract infections (2.4%) than surgical site infections (1.1%; P < .001). Being discharged to a SNF compared to home or to home health care was associated with a 1.15 percentage point (95% confidence interval = -1.29 to -1.00), or 38%, lower risk of a linked HAI readmission. This risk difference was observed to increase with greater patient comorbidity.

Conclusions: SNF discharges were associated with fewer avoidable readmissions for preexisting HAIs compared with home discharges. Further research to identify modifiable mechanisms that improve posthospital infection care at home is needed. J Am Geriatr Soc 68:370-378, 2020.

Keywords: comorbidity; infections; post-acute care; readmissions; skilled nursing.

Figure 1.

Survey weights were used to estimate the number of individuals readmitted and the percentage that were readmitted with a linked HAI. A linked HAI readmission is an unplanned readmission for the same HAI observed at the index admission. For instance, a patient who is discharged from the index (first) hospitalization with an SSI and who is then readmitted with an SSI would have a linked SSI readmission; if that same patient were readmitted with a CLABSI infection but not an SSI, then the patient would not have any linked HAI readmission. The percent difference is how different SNF and home health linked HAI readmission rates are, respectively, compared to routine home discharge linked HAI readmission rates. Differences in linked HAI readmission rates were statistically significantly different across discharge dispositions when considering any HAI or the specific HAIs C. Diff., and UTIs (p<0.001), but not for SSIs (p=0.06) and CLABSI (p=0.23). SNF = Skilled nursing facility (which in this analysis additionally includes intermediate care facilities); SSI – Surgical site infection; C. Diff. = Clostroides difficile; UTI = Urinary tract infection; CLABSI = Central-line associated bloodstream infection.

Figure 2.

Risk differences in linked HAIs were estimated using predicted probabilities obtained from logistic regression models that were adjusted for patient age, sex, income (quartile of median household income of the patient’s zip code), Elixhauser comorbidity index, and clinical cohort and length of stay at the index admission. A bootstrapping procedure with 1,000 replications was used to obtain 95% bias-corrected confidence intervals for the risk differences. SSI = surgical site infection; UTI = urinary tract infection; CLABSI = central line-associated blood stream infection; C. Diff. = Clostroides difficile.

Figure 3.

Predicted risks of linked HAIs were estimated using predicted probabilities obtained from logistic regression models that were adjusted for patient age, sex, income (quartile of median household income of the patient’s zip code), Elixhauser (weighted) comorbidity index, and clinical cohort and length of stay at the index admission. A bootstrapping procedure with 1,000 replications was used to obtain 95% bias-corrected confidence intervals for the risk differences.