https://acpinternist.org/weekly/archives/2019/03/05/4.htm

Delayed antibiotics in older adults with UTI associated with bloodstream infections, death

An editorial noted that the relationships found in the study may not be causal and advised clinicians to offer prompt treatment to patients at the highest risk of bloodstream infections: older patients, men, and those living in areas of greater socioeconomic deprivation.


Antibiotic prescribing in primary care was the focus of two studies published online on Feb. 27 by The BMJ. While one study showed that delaying antibiotics in older adults with urinary tract infection (UTI) was associated with serious adverse outcomes, another showed that the duration of many antibiotic courses prescribed by primary care practices in England exceed guideline recommendations.

The first study assessed the association between antibiotic treatment for UTI and severe adverse outcomes in a cohort of older adults in England. Researchers used the Clinical Practice Research Datalink to assess primary care records of 157,264 adults ages 65 years and older who had at least one diagnosis of suspected or confirmed lower UTI from November 2007 to May 2015. The main outcomes were bloodstream infection, hospital admission, and all-cause mortality within 60 days after index UTI diagnosis. Overall, the cohort had a total of 312,896 UTI episodes. Of these, 7.2% (n=22,534) had no record of antibiotics being prescribed and 6.2% (n=19,292) had a delay in antibiotic prescribing.

Bloodstream infection within 60 days of UTI was recorded in 1,539 UTI cases (0.5%). Compared to patients who initially received an antibiotic prescription, the rate of bloodstream infection was significantly higher in patients who were not prescribed an antibiotic (0.2% vs. 2.9%), as well as in those who revisited the primary care clinician within seven days of the initial presentation for an antibiotic prescription (0.2% vs. 2.2%; P<0.001). Patients in the deferred antibiotics and no antibiotics groups were significantly more likely to have a bloodstream infection within 60 days of UTI compared with those who immediately received antibiotics (adjusted odds ratios, 7.12 [95% CI, 6.22 to 8.14] and 8.08 [95% CI, 7.12 to 9.16], respectively). Compared with the immediate antibiotics group, the number needed to harm for occurrence of bloodstream infection was 37 in the no antibiotics group and 51 in the deferred antibiotics group.

The rate of hospital admissions was 27.0% in the no antibiotics group, 26.8% in the deferred antibiotics group, and 14.8% in the immediate antibiotics group (P=0.001). The risk of all-cause mortality in the 60 days of follow-up was also higher with deferred antibiotics and no antibiotics than with immediate antibiotics (adjusted hazard ratios, 1.16 [95% CI, 1.06 to 1.27] and 2.18 [95% CI, 2.04 to 2.33], respectively). In subgroup analyses, men older than age 85 years were at particularly high risk for both bloodstream infection and all-cause mortality within 60 days of presentation.

The study authors noted limitations, such as the observational design and the potential for unmeasured and residual confounders, as well as inconsistencies in coding between practices and over time.

An editorial pointed out that the relationships found in this study may not be causal and “are likely to be more nuanced than primary care doctors risking the health of older adults to meet targets for antimicrobial stewardship.” In practice, clinicians should offer prompt treatment to patients at the highest risk of bloodstream infections: older patients, men, and those living in areas of greater socioeconomic deprivation, according to the editorial.

In the second study, researchers assessed 931,015 visits at general practices in England between 2013 and 2015 that resulted in an antibiotic prescription for various indications. The most common reasons for antibiotics were acute cough and bronchitis (41.6%), acute sore throat (25.7%), acute otitis media (8.9%), and acute sinusitis (8.2%). Antibiotic therapy for upper respiratory tract indications and acute cough and bronchitis accounted for more than two-thirds of all prescriptions, and 80% or more of these courses exceeded guideline recommendations. Overall, about 1.3 million antibiotic days were beyond guideline-recommended durations.

“Both clinicians and patients may need convincing to abandon longer courses of antibiotics. … [W]hen antibiotics are needed, shorter courses are sufficient to kill bacteria and less harmful than longer courses,” the accompanying editorial said of this study.