Voluntary CDSS for antibiotic stewardship does not compromise clinical outcomes

Voluntary use of computerized decision support system (CDSS) for antibiotic stewardship did not compromise appropriate indication of antibiotics and clinical outcomes compared with compulsory implementation of CDSS, a local study has shown.

“CDSS provides guidance on antibiotic use and infection management based on hospital guidelines,” said the researchers led by Dr Ng Tat Ming from Tan Tock Seng Hospital, Singapore. CDSS was activated at the point of antibiotic ordering in the electronic medical record.

“Theoretically, compulsory CDSS may improve the timeliness of appropriate antibiotic and clinical outcomes such as mortality, but doctors may find it cumbersome and intrusive, preferring on-demand CDSS use,” they explained.

In the real-world cluster randomized crossover trial, patients were assigned 1:1 to either voluntary (n=641) or compulsory CDSS (n=616) for the use of the broad-spectrum antibiotics piperacillin-tazobactam or carbapenem. For the voluntary cluster, CDSS was used at the demand of the doctor, as opposed to compulsory use in the other cluster. [Open Forum Infect Dis 2020;doi:10.1093/ofid/ofaa254]

Both arms were carried out on a background of another antimicrobial stewardship strategy, prospective review and feedback (PRF) of antibiotic prescriptions. While PRF has been shown to improve clinical response of patients and reduced adverse effects, this strategy is labour-intensive.

“Antibiotic CDSS has been used to facilitate these processes to circumvent the lack of manpower,” Ng and co-authors added.

The researchers found that voluntary use of CDSS did not increase the primary outcome of 30-day mortality compared with compulsory use (hazard ratio [HR], 0.87, 95 percent confidence interval [CI], 0.67–1.12).

Similarly, other outcomes such as antibiotic duration, re-infection and re-admission rates, duration of hospital stay, or hospitalization cost were comparable between the two groups.

There was also no significant difference in the proportion of patients requiring recommendations from PRF with voluntary vs compulsory CDSS (10 percent vs 13 percent; p=0.05). 

Importantly, appropriate indication of antibiotics remained high in both groups, regardless of whether the use of CDSS was voluntary or compulsory (78 percent vs 74 percent; p=0.18).

“In the setting of high appropriate antibiotic use and PRF, it is likely that compulsory CDSS may not have clinical benefits and may inconvenience doctors by causing delay, distraction, or irritation,” said Ng and co-authors.

“However, benefits may be magnified in settings with lower appropriateness of antibiotic use and when CDSS is implemented as a new system,” they noted. 

Among the subgroup of patients in geriatric medicine — in whom antibiotic appropriateness was <50 percent, the length of hospital stay (14 vs 19 days; p=0.03) and hospitalization cost (S$10,444 vs S$13,945; p=0.02) were reduced when prescription via CDSS was compulsory rather than voluntary.

“Voluntary broad-spectrum antibiotics with PRF via CDSS did not result in differing clinical outcomes, antibiotic duration, or length of stay,” the researchers concluded. “However, in the setting of low antibiotic appropriateness, compulsory CDSS may be beneficial.”

Based on their observation, the most commonly accepted CDSS recommendations involved optimization of antibiotic spectrum and dose. 

“It is important that these factors be correct early in the treatment of infection,” advised Ng and co-authors.