Dipstick Chemical Urinalysis: An Accurate Cost-Effective Screening Test

Abstract

In a double-blind prospective study of 200 sequential urine specimens the sediment count of leukocytes in the centrifuged urine (white blood cells per high power field) was compared to a chamber count of leukocytes in uncentrifuged urine (white blood cells per microliter.). There was good correlation (coefficient of correlation 0.783, sensitivity 91.9 per cent, specificity 97.6 per cent and efficiency 96.6 per cent) between the more precise chamber count and the more commonly performed sediment count if the methodology of the sediment count was standardized. In a double-blind prospective study the results of the sediment count for leukocytes and erythrocytes were compared to the leukocyte esterase and hemoglobin dipstick results of urine specimens from 1,346 adults who underwent multiphasic screening. The dipsticks were found to be sensitive to physiologic limits for leukocytes and erythrocytes, with only 0.9 per cent false negative results for each. Formed elements in the urine not detectable by dipstick, such as casts and crystals, were present in 3 per cent of the specimens. Among patients who had significant pyuria, hematuria or formed elements not detectable by dipstick chemical urinalysis, no significant pathological condition was detected upon retrospective review. Because the chemical dipstick is not quantitative and because the sensitivity of the dipsticks resulted in many false positive findings compared to the sediment count (red and white blood cells 16.4 and 13.2 per cent, respectively) a protocol is offered in which results of screening urine specimens that are positive on dipstick culture would be confirmed by a properly performed microscopic urinalysis. This protocol as applied to an adult screening population would be an accurate, cost-effective method of urine testing.

Rapid dipstick urinalysis in the internal medicine clinic: what is missed?

“…Pels et al [4] recommended urinary culture in at least pregnant, diabetic, and elderly patients, as well as institutionalized patients. On the other hand, Oneson et al [2] and Mariani et al [1] found a much lower incidence of false negative results and therefore recommended the dipstick as a cost-effective test. The selection of patients was not given in detail in either of these studies.…”

“…In ambulatory patients of general practice medicine, this has proven to be reliable enough, since false negative results are rare in the general population [1,2]. For economical reasons, a dipstick screening without the microscopical evaluation is often performed also in hospitalized patients.…”

Is Asymptomatic Microscopic Hematuria Using a Dipstick Reliable?

“…The inclusion criteria in our study was a thorough examination within 2 years with no abnormal findings and no urogenital symptoms. Other studies 8,[14][15][16][17] included participant regardless of medical history, urological examinations and symptoms.…”

H�maturie beim Harnblasenkarzinom

“…Wegen der hohen Sensitivität etablierter Teststreifen [9,10] sind sie insbesondere zum Mikrohämaturiescreening geeignet. Nachteilig ist lediglich die interindividuelle Schwankungungsbreite von bis zu…”

“…Der Normalwert der Sediment-Gesichtsfeld-Methode weist nach Literaturangaben eine Spannweite von 1-8 Erythrozyten/Gesichtsfeld (Ery/GF) auf (⊡ Tabelle 2), [1,3,12,13,14,15,16]. Die aktuelle amerikanische Leitlinie definiert Hämaturie ab 3 Ery/GF in 2 von 3 Proben -relativiert diesen Grenzwert aber bereits wieder für Patienten mit Risikofaktoren für eine signifikante Erkrankung (s.⊡ Tabelle 1): Wegen der fehlenden unteren Sicherheitsgrenze (no safer lower limit) wird in diesen Fällen empfohlen, bereits ab 1 Ery/GF die Abklärung zu erwägen und bei einer einmaligen Hämaturie ab 3 Ery/GF durchzuführen [1].…”