Sputum color: potential implications for clinical practice.
BACKGROUND
Respiratory infections with sputum production are a major reason for physician visits, diagnostic testing, and antibiotic prescription in the United States. We sought to determine whether the simple characteristic of sputum color provides information that impacts resource utilization such as laboratory testing and prescription of antibiotics.


METHODS
Out-patient sputum samples submitted to the microbiology laboratory for routine analysis were assigned to one of 8 color categories (green, yellow-green, rust, yellow, red, cream, white, and clear), based on a key made from paint chip color samples. Subsequent Gram stain and culture results were compared to sputum color.


RESULTS
Of 289 consecutive samples, 144 (50%) met standard Gram-stain criteria for being acceptable lower-respiratory-tract specimens. In the acceptable Gram-stain group, 60 samples had a predominant organism on Gram stain, and the culture yielded a consistent result in 42 samples (15% of the 289 total specimens). Yield at each level of analysis differed greatly by color. The yield from sputum colors green, yellow-green, yellow, and rust was much higher than the yield from cream, white, or clear.


CONCLUSIONS
If out-patient sputum is cream, white, or clear, the yield from bacteriologic analysis is extremely low. This information can reduce laboratory processing costs and help minimize unnecessary antibiotic prescription.
Johnson
Allen L
AL
The Polyclinic, Seattle, WA, USA.
Hampson
David F
DF
Hampson
Neil B
NB
D000553:Ambulatory Care; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D003116:Color; D046508:Culture Techniques; D005840:Gentian Violet; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis; D006296:Health Services / Q000706:statistics & numerical data; D006801:Humans; D010619:Phenazines; D012141:Respiratory Tract Infections / Q000503:physiopathology*; D013183:Sputum / Q000378:metabolism* / Q000502:physiology
D000900:Anti-Bacterial Agents; C035863:Gram's stain; D010619:Phenazines; D005840:Gentian Violet