An analysis of suspected urinary tract infections in older adults: Time to stop the dip!!

Abstract

Background: Urinary Tract Infections (UTI) is the most commonly diagnosed infection in older adults. Despite this however studies show it is a diagnosis which is often made excessively and inappropriately. Clinicians often suspect a UTI due to vague non-specific symptoms, such as change in mental status, without sufficient local urinary tract symptoms i.e.dysuria, increased frequency or urgency. This is compounded by high rates of asymptomatic bacteriuria in older adults. This means that in an older adult, if urine testing is unnecessarily ordered, bacteria can be detected as an incidental finding even if no UTI is present. High rates of asymptomatic bacteriuria and inappropriately testing for bacteriuria, without sufficient clinical signs and symptoms can be problematic. It may result in clinicians frequently misdiagnosing UTI or inappropriately attributing a nonspecific finding such as fever or confusion to a UTI. This can promote inappropriate antibiotic prescribing which may promote antibiotic resistant bacteria and unnecessarily expose older adults to side effects of these medications. Incorrectly attributing a patient’s presenting complaint to a UTI can hinder the patient's care as it delays discovering the most appropriate cause of the patient's condition. In September 2021, HSE Antimicrobial Resistance and Infection Control (AMRIC) issued a position statement where they clearly outlined that in the absence of signs of symptoms of UTI, use of dipstick analysis should be avoided. This included those patients presenting with altered mental status and behavioural changes without urinary symptoms. They also state that dipstick analysis should not be used in those over 65 to assess UTI.. Strategy: The aim of the project was: To determine and quantify if dipstick urinalysis is conducted in those over 65 years old to assess UTI in contradiction to HSE guidance; To assess the relationship between clinical presentation and the diagnosis of a UTI; To assess if UTI are diagnosed in individuals in absence of clinical features of UTI; To characterise population of older adults diagnosed with a UTI in the hospital. The population reviewed was adult in-patients aged over 65 years old in the Mercy University Hospital (MUH) between January 2019 to June 2022 who had urine culture (MSU) sent to the microbiology laboratory. We audited a samples using a stratified random sampling strategy to get a spread of cases over the period. All selected cases had a retrospective chart review to determine the signs and symptoms when the MSU was ordered & to examine whether there were other indications of infection or systemic inflammatory response (SIRS). The patients co-morbidities, relevant laboratory results and relevant medication were recorded. The prescription sheet was examined to determine whether antibiotics were prescribed. The medical and nursing records were reviewed to clarify whether a urine dipstick was used in the assessment of possible UTI. For each case it was recorded whether a UTI was diagnosed by the primary team. For each case a determination was made based on recorded signs, symptoms, and laboratory results whether a) there was evidence of infection, & b) whether there was evidence to support a UTI as the diagnosis. The appropriateness of doing dipstick urinalysis was assessed using the AMRIC position statement 2021 as the standard. Results: There was a high use of dipstick urinalysis with 73.8% of cases having a urinary dipstick analysis performed as part of the assessment of possible UTI. In 25% of cases a UTI was “diagnosed” by the primary team. However, only 16.7% had any of the primary symptoms of UTI such as increased frequency, urgency or dysuria. Urine dipstick and MSU were frequently requested for patients with falls (20.2% of cases) and acute altered mental health state (22.6% of cases). The AMRIC statement specifically highlights that altered mental state should not trigger the use of urine dipstick. There was a statistically significant relationship between dipstick urinalysis being conducted and a UTI being “diagnosed”, even when accounting for LUTS as a confounding variable.(p=0.01). Falls, acute AMS and new urinary incontinence were not associated with the diagnosis of a UTI. Haematuria, flank pain, pungent urine and suprapubic pain alone without dysuria was not associated with diagnosis of a UTI. Retrospective accurate diagnosis of UTI is difficult but our project would be in keeping with previous studies showing a high level of incorrect UTI diagnosis and inappropriate antimicrobial therapy (Silver 2009). There is a significant cost to the Mercy University Hospital is inappropriately requested MSU. There was a total of 12,357 MSU over the 42 month period assessed in this project. That equates to nearly 300 samples in the microbiology laboratory each month. Only 16.7% of our cases had potential UTI symptoms. Therefore, potentially up to 250 MSU samples a month maybe inappropriate. Conclusions: Dipstick urinalysis is conducted at high rates in older adults in the Mercy University Hospital despite HSE guidance to the contrary. This is associated with increased likelihood of UTI being diagnosed inappropriately. Urinalysis testing was not associated with any specific clinical presentation suggesting it is conducted broadly in a more routine fashion rather than for specific indications. A very high level of MSU samples are requested with a low level of UTI diagnosis. It is unclear but likely that urinalysis results are driving MSU samples. There is cost saving by improving the use of appropriate dipstick urinalysis and more focused MSU samples. There is a need for more education on diagnosis of UTI in older people and the appropriate use of urine dipstick testing in hospital. References: Silver SA, Baillie L, Simor AE. Positive urine cultures: A major cause of inappropriate antimicrobial use in hospitals? .Can J Infect Dis Med Microbiol. 2009;20(4):107-111. doi:10.1155/2009/702545. Position Statements: Use of Dipstick Urinalysis for assessing evidence of Urinary Tract Infection In Adults, Antimicrobial Resistance and Infection Prevention and Control (AMRIC) clinical programme. v1. August 2021