Alternative sampling methods for collection of urine specimens

Diagnostic technology: alternative sampling methods for collection of urine specimens in older adults

AuthorsLatour, Katrien; Plüddemann, Annette; Thompson, Matthew; Catry, Boudewijn; Price, Christopher P; Heneghan, Carl; Buntinx, Frank.

Clinical Question: Which sampling methods other than in-andout catheterization or suprapubic aspiration can be used to collect valid uncontaminated urine
specimens for microbiological culture in older adults?

Background, Current Practice and Advantages over Existing Technology: Urinary tract infections (UTIs) are one of the most common bacterial infections in older populations. Despite increasing research into this infectious disease, substantial uncertainty still surrounds its diagnosis. Symptoms tend to be less specific in frail elderly and difficulties with cognition or communication can further impair clinical evaluation. Consequently, physicians often resort to urinary analysis to support the diagnosis.

Urine samples should be collected by a protocol that minimizes contamination from the genital mucosa and perineal skin. Guidelines recommend the collection of a midstream
specimen in adults. However, obtaining such samples from older persons may be difficult, as they can be cognitively impaired, have physical constraints and/or suffer from
incontinence. In persons unable to control voiding or cooperate, in-and-out catheterization and suprapubic aspiration have therefore become standard methods for urine collection. These techniques can, however, cause pain or discomfort and induce a small risk of infection[4]. Moreover, they are also difficult to perform and more time- and resource-consuming.  To overcome these disadvantages there is a need for alternative urine collection methods in older adults.

Details of Technology: Several alternative methods for collecting urine specimens have been used in elderly individuals, depending on gender.
● In men, the use of condom catheters to obtain a urine specimen for culture is most promising. They are already frequently used as continence care products for men.
● As an alternative to the external catheter in men, external urine collection devices have been developed for urine sampling in adult women. These funnel-like devices need to be held near the vulva. When the person urinates, the urine runs into a small container connected to the funnel.
● Urine culture collection from disposable nappies has been used for urine collection in children. This technique has now been applied to geriatric care where it can be used with incontinence pads and adult diapers.
● Finally, urine sampling via simple clean catch technique into a (disinfected) bed pan,disposable hat/bowel or urinal has also been explored, without midstream being required.

A literature search was conducted to determine the validity of these alternative sampling methods compared to in and-out catheterization and suprapubic aspiration, the current reference methods (gold standards) in the elderly. The test performance results, i.e. sensitivity (Se), specificity (Sp), positive and negative likelihood ratios (LR+ and LR-) and positive and negative predictive values (PPV and NPV), are reported with their 95% confidence intervals (95% CI).

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Source: Family Medicine and Community Health, Volume 1, Number 2, June 2013, pp. 43-49(7)

Publisher: Compuscript