Limits...
Dipstick Spot urine pH does not accurately represent 24 hour urine PH measured by an electrode.

Omar M, Sarkissian C, Jianbo L, Calle J, Monga M - Int Braz J Urol (2016 May-Jun)

Bottom Line: Higher pH was associated with lower accuracy (p<0.001).The overall accuracy is lower than 80% (p<0.001).Influence of diurnal variation was not significant (p=0.588).

View Article: PubMed Central - PubMed

Affiliation: Glickman Urological & Kidney Institute - Cleveland Clinic Foundation, Cleveland, OH, USA.

ABSTRACT

Objectives: To determine whether spot urine pH measured by dipstick is an accurate representation of 24 hours urine pH measured by an electrode.

Materials and methods: We retrospectively reviewed urine pH results of patients who presented to the urology stone clinic. For each patient we recorded the most recente pH result measured by dipstick from a spot urine sample that preceded the result of a 24-hour urine pH measured by the use of a pH electrode. Patients were excluded if there was a change in medications or dietary recommendations or if the two samples were more than 4 months apart. A difference of more than 0.5 pH was considered na inaccurate result.

Results: A total 600 patients were retrospectively reviewed for the pH results. The mean difference in pH between spot urine value and the 24 hours collection values was 0.52±0.45 pH. Higher pH was associated with lower accuracy (p<0.001). The accuracy of spot urine samples to predict 24-hour pH values of <5.5 was 68.9%, 68.2% for 5.5 to 6.5 and 35% for >6.5. Samples taken more than 75 days apart had only 49% the accuracy of more recent samples (p<0.002). The overall accuracy is lower than 80% (p<0.001). Influence of diurnal variation was not significant (p=0.588).

Conclusions: Spot urine pH by dipstick is not an accurate method for evaluation of the patients with urolithiasis. Patients with alkaline urine are more prone to error with reliance on spot urine pH.

No MeSH data available.


Related in: MedlinePlus

24 hours Urine pH.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4920573&req=5

f01: 24 hours Urine pH.

Mentions: The accuracy of spot urine samples to predict 24 hours pH values of <5.5 was 68.9% (71/103). The accuracy of spot urine samples to predict 24 hours pH values of 5.5-6.5 was 68.2% (232/340), while the accuracy of spot urines to detect 24 hours pH values >6.5 was only 35% (55/157). The >6.5 pH group had accuracy significantly lower than both the <5.5 pH and the 5.5-6.5 pH groups (both p’s <0.001) (Figure-1). The overall accuracy was 59.7% (358/600), which is significantly lower than an adequate accuracy of 80% (p<0.001).


Dipstick Spot urine pH does not accurately represent 24 hour urine PH measured by an electrode.

Omar M, Sarkissian C, Jianbo L, Calle J, Monga M - Int Braz J Urol (2016 May-Jun)

24 hours Urine pH.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4920573&req=5

f01: 24 hours Urine pH.
Mentions: The accuracy of spot urine samples to predict 24 hours pH values of <5.5 was 68.9% (71/103). The accuracy of spot urine samples to predict 24 hours pH values of 5.5-6.5 was 68.2% (232/340), while the accuracy of spot urines to detect 24 hours pH values >6.5 was only 35% (55/157). The >6.5 pH group had accuracy significantly lower than both the <5.5 pH and the 5.5-6.5 pH groups (both p’s <0.001) (Figure-1). The overall accuracy was 59.7% (358/600), which is significantly lower than an adequate accuracy of 80% (p<0.001).

Bottom Line: Higher pH was associated with lower accuracy (p<0.001).The overall accuracy is lower than 80% (p<0.001).Influence of diurnal variation was not significant (p=0.588).

View Article: PubMed Central - PubMed

Affiliation: Glickman Urological & Kidney Institute - Cleveland Clinic Foundation, Cleveland, OH, USA.

ABSTRACT

Objectives: To determine whether spot urine pH measured by dipstick is an accurate representation of 24 hours urine pH measured by an electrode.

Materials and methods: We retrospectively reviewed urine pH results of patients who presented to the urology stone clinic. For each patient we recorded the most recente pH result measured by dipstick from a spot urine sample that preceded the result of a 24-hour urine pH measured by the use of a pH electrode. Patients were excluded if there was a change in medications or dietary recommendations or if the two samples were more than 4 months apart. A difference of more than 0.5 pH was considered na inaccurate result.

Results: A total 600 patients were retrospectively reviewed for the pH results. The mean difference in pH between spot urine value and the 24 hours collection values was 0.52±0.45 pH. Higher pH was associated with lower accuracy (p<0.001). The accuracy of spot urine samples to predict 24-hour pH values of <5.5 was 68.9%, 68.2% for 5.5 to 6.5 and 35% for >6.5. Samples taken more than 75 days apart had only 49% the accuracy of more recent samples (p<0.002). The overall accuracy is lower than 80% (p<0.001). Influence of diurnal variation was not significant (p=0.588).

Conclusions: Spot urine pH by dipstick is not an accurate method for evaluation of the patients with urolithiasis. Patients with alkaline urine are more prone to error with reliance on spot urine pH.

No MeSH data available.


Related in: MedlinePlus