NICE, FRANCE — Male gender, advanced age, and a history of several office visits in the past year were among the risk factors for a complicated urinary tract infection in a retrospective cohort study of older primary care patients with type 2 diabetes mellitus.
The findings were used to create a clinical prediction rule that could improve management of UTIs in patients aged 45 years and older, Leonie Muller said at the 16th European Congress of Clinical Microbiology and Infectious Diseases. Patients with type 2 diabetes are known to be at greater risk for urinary tract infections. But little is known about predictors of a complicated course.
Although the rule still needs to be validated in other populations, the idea is to use it to identify patients at high risk for serious UTI and educate them about the signs and risk factors for complicated infection, she said.
In a second retrospective cohort study, Ms. Muller and colleagues at the University Medical Center Utrecht, the Netherlands, created a similar rule for predicting complicated lower respiratory tract infections, which also are common in older patients with diabetes.
Using data from the Second Dutch National Survey of General Practice, the investigators conducted a 12-month, prospective cohort study that identified 6,343 patients, 45 years or older, with type 2 diabetes. The primary outcome was a complicated course UTI, defined as an episode of acute pyelonephritis or prostatitis, and recurrent cystitis. The mean age was 67 years, 46% were male, and 45% had recurrent cystitis.
Multivariate logistic regression analysis was used to develop a clinical prediction rule.
There were 179 (2.8%) complicated UTIs, 1 per 100 patient-years in females and 2 per 100 patient-years in males. Independent predictors were increasing age (odds ratio 1.7), male gender (OR 1.8), 12 or more office visits in the previous year (OR 11.5), urinary incontinence (OR 2.4), cerebrovascular disease or dementia (OR 2.14), and renal disease (OR 5.6).
Using a cut-off score of 4 points or more on a 12- point scale, 60% of patients would be selected for tailored care, and 8% of patients with a complicated course of UTI would be missed.
An example of how the rule might be applied in a diagnostic setting would be that a 75-year-old (1 point) male (1 point) patient with diabetes and renal disease (3 points) would be considered high risk, whereas his 73-year-old (1 point) wife with diabetes and urinary incontinence (2 points) would not. Ms. Muller, a doctoral student at the university, acknowledged that the model has the potential to identify a large percentage of high-risk patients, adding that future studies should focus on the cost-effectiveness of the rule.
In the second study, the investigators evaluated 20 predictors of death and/or 30-day hospitalization following an episode of lower respiratory tract infection in a subgroup of 1,693 patients, aged 65 years and older, with diabetes, from the same database. Among 445 episodes of lower respiratory tract infections including acute bronchitis, exacerbation of chronic obstructive pulmonary disease, asthma, or pneumonia, 13 were fatal and 55 required hospitalization.
Positive predictors of death and/or hospitalization were pneumonia (adjusted odds ratio 5.3), age greater than 80 years (OR 2.2), presence of heart failure (OR 2.1), and prednisone use (OR 2.4). The hospitalization/death rate was 5.2% among patients found to be at low risk and 36.6% among high-risk patients, Ms. Muller reported.