No Need To Aim: Why Urine Collection May Be Easier Than We Thought

Date Submitted: 02/03/2025

Date Published: 07/13/2025

UTIs are one of the most common reasons people visit the doctor, yet traditional urine collection guidelines may be unnecessarily complicated. While physicians have in the past advocated for a more complicated procedure to collect urine, the evidence does not support any particular method over another. Rather, the biggest difference seen is that providing written education decreases contamination risk compared to verbally explaining the method. Looking ahead, more research is needed to definitively answer the question of “What is the best method of urine collection?”. Currently, we are making decisions based on imperfect methods from the 1900’s. Complicating the story, most research has been done on women without UTIs. We echo the researcher’s call to conduct research using modern and repeatable techniques.

Urinary tract infections, more commonly referred to as UTIs, are a common and unfortunately uncomfortable condition, particularly in women. This is due to their shorter urethras, which make it easier for the bacteria to travel to the bladder (1). UTIs occur when parts of the urinary tract, like the urethra, bladder, or kidneys, become infected. Common side effects of the infection are pain during urination, frequent urges to pee, and cloudy or strong-smelling urine (1). Though rare, UTIs could cause severe diseases,  like sepsis (3). While most UTIs are uncomplicated and affect otherwise healthy women, diagnosing them requires collecting urine samples. 

For non-pregnant women, several non-invasive collection methods are available: midstream clean-catch (MSCC), midstream urine (MSU without cleansing), and first-void urine (FVU). MSCC involves starting to urinate and then catching the middle portion of the urine stream in a new container. MSU involves only catching the middle portion of the urine stream. FVU involves collecting the very first portion of the urine stream. A recent study from 2023 evaluated these non-invasive methods to determine which provides the most reliable and least contaminated samples (2).  

Contamination, often caused by skin or fecal matter bacteria, can interfere with test results, making it harder to identify the actual infection. Therefore, researchers conducted a systematic review of 6 different papers on data on ~ 1010 women from the 1950s to the 2010s. This had a large sample size and was representative of women of all ages from the US, Europe, and Australia (2).  Surprisingly, traditional advice like using MSCC may not be the best option, challenging the long-held “gold standard” in healthcare (2). This research opens the door for simpler, patient-friendly collection methods.

The findings from these studies challenge the long-standing practice of midstream clean-catch (MCC) procedure. Despite historical recommendations favoring midstream samples, researchers found no significant difference in contamination rates when comparing clean-catch methods to simpler approaches, showing that simpler collection methods may be just as effective (2).

The main findings of the studies are summarized below:

• Morris 1979 (4)

  • 9% contamination in the MSU group 

  • 8% contamination in the MSCC group

• Bradbury 1988 (5)

  • 9.2% contamination in the MSU group

  • 8.6% contamination in the MSCC group 

• Baerheim study in 1990 (6)

  • 4.1% contamination for the home voided 

  • 9.6% contamination for the MSCC

• Lifshitz 2000 (7)

  • 28.6% contamination for no cleansing & no midstream

  • 32.1% for MSCC group with no use of a tampon 

  • 30.9% for MSCC with insertion of tampon before urine was collected 

• Eley 2016 (8)

  • 25% of samples were contaminated when patients received written instructions compared to 39.2% with verbal instructions alone

The main takeaway is that there is no real difference in contamination rate when comparing different methods. However, there is a huge difference when comparing different researchers to each other. This hints that there are non-standard methods being used, making comparisons difficult.

Continuing on this theme, Eley 2016 hits on the importance of instructional delivery methods for urine collection. In a pseudo-randomized trial, researchers compared two groups of women providing midstream clean-catch samples: one group received verbal instructions while the other got illustrated guides. The results showed that visual instructions significantly reduced contamination rates (8). 

That said,  the review also highlights a need for more research. Much of the evidence comes from older studies, and future investigations with modern techniques and larger populations would help confirm these observations. In sum, this review suggests that simplifying urine collection guidelines could potentially ease patient burden, reduce clinical workload, and maintain reliable UTI diagnosis.

In real-world healthcare settings, these findings can streamline and improve patient care. For one, providers may opt for straightforward collection techniques without worrying about compromising diagnostic accuracy. This simplifies instructions given to patients, reducing any anxiety they may experience about doing it wrong. 

In busy emergency departments, faster and simpler collection methods can free staff from having to meticulously explain or supervise the midstream procedure, ultimately saving time and resources. Moreover, elderly or disabled patients, who may find midstream collection physically challenging, could benefit substantially from less cumbersome methods. 

Despite these insights, the researchers emphasize the need for more high-quality studies to confirm these findings and ensure they apply across various patient populations and settings. Until more research is available, healthcare professionals are encouraged to prioritize the needs and comfort of their patients when choosing a urine collection method. Overall, adopting simpler collection protocols stands to make UTI testing more accessible, efficient, and patient-friendly, while still maintaining confidence in diagnostic outcomes.

In addition, showing the instructions for how to do MSCC sampling was better than telling the instructions for decreasing the rate of contamination. This was due to how there was a higher 39.2% contamination for telling but a much lower 25% contamination for showing (2). Although the test was not optimal, MSU collection was shown to be significantly more accurate than FVU sampling immediately after voiding when the results were compared with point of care tests (tests performed outside of the lab setting) as gold standard. However, the correlation between these rapid tests and urine culture is suboptimal (2).

Authors

• Kaito Dao: kaitodao753@gmail.com, University of California San Diego

• Riya Vijayapal: reezy2005@gmail.com, University of Michigan

• Jacqueline Wu: jacquelinewu33@gmail.com, Boston University

• Monica Zhu: monicazhu5818@gmail.com, University of North Carolina at Chapel Hill

References 

1. Mayo Clinic. Urinary Tract Infection (UTI) - Symptoms and Causes [Internet]. Mayo Clinic. 2022 [cited 2025 Feb 3]. Available from: https://www.mayoclinic.org/diseases-conditions/urinary-tract-infection/symptoms-causes/syc-20353447

2. Llor C, Moragas A, Aguilar-Sánchez M, García-Sangenís A, Monfà R, Morros R. Best methods for urine sample collection for diagnostic accuracy in women with urinary tract infection symptoms: a systematic review. Fam Pract. 2022 Jun 2;40(1).

3. Sepsis from UTIs [Internet]. Cleveland Clinic. 2024 [cited 2025 Feb 3]. Available from: https://my.clevelandclinic.org/health/diseases/25008-urosepsis

4. Morris RW, Watts MR, Reeves DS. Perineal cleansing before mid-stream urine, a necessary ritual. Lancet. 1979;2(8134):158–9. doi:10.1016/s0140-6736(79)90053-9.

5. Bradbury SM. Collection of urine specimens in general practice: to clean or not to clean? J R Coll Gen Pract. 1988;38(313):363–5.

6. Bærheim A, Lærum E. Home-voided urine specimens in women. Diagnostic agreement with clean-catch midstream specimens. Scand J Prim Health Care. 1990;8(4):207–11. doi:10.3109/02813439008994960.

7. Lifshitz E, Kramer L. Outpatient urine culture: does collection technique matter? Arch Intern Med. 2000;160(16):2537–40. doi:10.1001/archinte.160.16.2537.

8. Eley R, Judge C, Knight L, Dimeski G, Sinnott M. Illustrations reduce contamination of midstream urine samples in the emergency department. J Clin Pathol. 2016;69(10):921–5. doi:10.1136/jclinpath-2015-203504.