Evaluating the Follow-up of Post-discharge Positive Sterile Site Cultures and the Impact on Infection-Related Complications

Introduction: Numerous patients have cultures pending at discharge which, if not addressed, may delay diagnosis and initiation of appropriate antimicrobials. The purpose of the study is to evaluate the appropriateness of discharge antimicrobial therapy and result documentation in patients with positive cultures finalized post-discharge.

Methods: This was a cross-sectional cohort study of patients admitted from July 1 to December 31, 2019 with positive sterile-site microbiologic cultures finalized post-discharge. Pertinent inclusion and exclusion factors were admission ≥ 48 h and non-sterile sites, respectively. The primary objective was to determine the frequency of discharged patients warranting antimicrobial changes based on finalized cultures. Secondary objectives included prevalence and timeliness of result documentation and rates of 30-day readmission, among intervention warranted versus not warranted. Chi-squared or Fisher's exact tests were used as appropriate. Binary multivariable logistic regression was completed for 30-day readmission stratified by infectious disease (ID) involvement due to the potential for effect modification.

Results: A total of 208 of 768 patients screened were included. Most patients were discharged from a surgical service (45.7%); deep tissue and blood were the most common culture sites (29.3%). Change in discharge antimicrobial was warranted in 36.5% of patients (n = 76). Result documentation was overall low (35.5%). Time to documentation was significantly shorter in patients warranting antimicrobial intervention (4 days vs. 9 days, P = 0.039), although rates of hospital readmission were higher in this group (32.9% vs. 22.7%, P = 0.109). Finally, in patients not being followed by ID, documentation of finalized results was associated with decreased odds of 30-day readmission (aOR 0.19; 95% CI 0.07-0.53).

Conclusions: A significant number of patients with cultures finalized post-discharge warranted antimicrobial intervention. Acknowledgment of finalized culture results may decrease the risk of 30-day hospital readmission, particularly in patients not followed by ID. Quality improvement efforts should focus on methods to improve documentation and action on pending cultures to positively impact patient outcomes.