What is the proper method for collecting a urine sample?

Proper Collection of Urine Sample

The proper method for collecting a urine sample is a midstream clean-catch technique, which is recommended to minimize contamination and ensure accurate diagnostic results. 1

General Collection Principles

For Adults:

1. Midstream collection with cleansing is the recommended approach for both men and women 1

   • This involves passing the first part of urine into the toilet, collecting the middle portion in a sterile container, and discarding the final portion
   • The container should be clean, leak-proof, urine pH-range resistant, and not shed plastic particles 1

2. Timing considerations:

   • Record the time between the last uncollected and collected void
   • Note whether it's a random/spot sample, first or second morning urine 1
   • Process samples within 8 hours of collection (maximum) 1
   • Store at 4°C maximum until processing to avoid microbial growth 1

Specific Instructions by Population:

For Women:

1. Wash hands thoroughly with soap and water
2. Cleanse the perineal area with antiseptic wipes (front to back)
3. Separate the labia during urination
4. Void the first portion of urine into the toilet
5. Collect the midstream portion in a sterile container without touching the inside
6. Discard the final portion of urine

For Men:

1. Wash hands thoroughly
2. Retract foreskin (if uncircumcised)
3. Cleanse the glans penis with antiseptic wipes
4. Void the first portion of urine into the toilet
5. Collect the midstream portion in a sterile container
6. Discard the final portion of urine

For Children:

1. Midstream collection with cleansing is recommended when possible 1
2. For non-toilet-trained children, sterile urine bags or catheterization may be necessary

Common Pitfalls and Considerations

• Contamination risk: Despite widespread use, contamination rates remain high even with proper technique. Studies show contamination rates of 29-32% regardless of collection method in women 2
• Illustrated instructions: Providing visual instructions can reduce contamination rates from 40% to 25% 3
• Quality control: Use of dipstick for preliminary assessment (pH, protein level) is recommended to exclude deviating samples (blood, microbes) 1
• Volume considerations: Record the exact volume collected in milliliters 1
• Storage: Samples should be refrigerated promptly (4°C) if not processed immediately 1

Evidence Considerations

While midstream clean-catch is the standard recommendation, some research challenges its superiority:

• A systematic review found no consistent evidence that midstream samples with or without cleansing are better than random void samples in women 4
• Some studies suggest that specimens collected at any time during voiding in unsterile disposable cups may yield reliable results 5

However, the highest quality guidelines still recommend the midstream clean-catch technique as the standard approach to minimize contamination and ensure diagnostic accuracy 1.

Practical Implementation Tips

• Use sterile containers specifically designed for urine collection
• Label specimens immediately with patient information and collection time
• Transport specimens to the laboratory promptly
• Consider using illustrated instructions to improve patient compliance and reduce contamination 3
• For research purposes or when higher accuracy is required, more detailed collection protocols may be necessary 1