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Empiric Use of Antibiotics in Women With Symptoms of Urinary Tract Infection But Negative Dipstick Results

Three Part Question

In [ambulatory females with dysuria and frequency and negative urine dipstick test] does [empiric antibiotic therapy] [significantly reduce symptoms]?

Clinical Scenario

A 35 year-old non-pregnant female presents to the emergency departement with symptoms of dysuria and frequency. You suspect she has a UTI, however the urine dipstick is negative for both leukocyte esterase and nitrite. Will treating this patient with empiric antibiotics alleviate her symptoms?

Search Strategy

Medline 1966-04/06 using the OVID interface, Cochrane Library (2006), PubMed clinical queries.
[(exp urinary tract infections) AND (exp reagent strips OR reagent AND (exp anti-infective agents). LIMIT to human AND English.

Search Outcome

28 papers found of which 26 were irrelevant or of insufficient quality.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Richards D, Toop L, Chambers S, Fletcher L
2005 Jul 16
Women ages 16-50 years presenting to general practitioners with history of "dysuria and frequency" in whom dipstick test of midstream urine was negative for both nitrites and leucocytes. Excluded: allergy to TMP (Trimethoprim), recent UTI, pregnancy, complicated UTIDouble-blind randomized control trial in which females with UTI symptoms and negative urine dipsticks were randomized to 3 days TMP or placebo. Urine was cultured. Patient symptoms at days 3 and 7 were recorded.Resolution of dysuria at 3 and 7 days and median time to resolution of dysuria (based on symptom diaries or a structured telephone questionnaire).Among the 48 women (81%) who reported dysuria on day 1, fewer women in the trimethoprim group than in the placebo group still had dysuria on day 3 and day 7. Women in the trimethoprim group had a shorter median time to resolution of dysuria (3 vs 5 d, P = 0.002).Small sample size (66 women). Tested only an estimated one in every five eligible patients during the study duration. 90% of participants reported having previous, similar episodes. The sensitivity and negative predictive value of the dipstick urine test vary and may be higher than in the present study.
Secondary outcomes were resolution of other symptoms.Among the 22 women reporting feverishness or shivers at baseline, fewer women in the trimethoprim group had these symptoms at 3 days, but the groups did not differ at 7 days. women in the trimethoprim group had a shorter median time to resolution of feverishness or shivers (2 vs 6 d, P = 0.02). Among women reporting baseline symptoms of frequency, blood in urine, itching, abdominal pain, or low-back pain, the trimethoprim and placebo groups did not differ for continued presence of the specific symptom at 3 or 7 days or for median time to resolution of symptoms.
Grude N. Tveten Y. Jenkins A. Kristiansen BE.
June 2005
A total of 184 female patients between 15 and 65 years of age with symptoms of uncomplicated urinary tract infection.Prospective study of 184 female patients with UTI symptoms. Urine dipstick performed in office. Urine was sent to a lab for culture with sensitivities to certain antibiotics. Statistical values for nitrite and leukocyte esterase were compared to culture results. Patients were treated at the discression of the primary care physician.Significant bacteriuria found in 140 of 184 cases.Positive urnine nitrite accurately predicted culture-positive UTE, while positive leukocyte esterase did not.This study does not address the efficacy of empiric treatment based on urine dipstick results. It is unknown if the patients with LE false positives were given antibiotics, and if their response to treatment varried from those with culture positive results. Only 184 out of 3803 possible study participates were enrolled, leaving a high chance of selection bias.


The prevalence of urinary symptoms in women 40 to 60 years of age is about 30%, and the yearly incidence is 10%. To offer antibiotic treatment to a large proportion of symptomatic women regardless of urine findings would have staggering effects in terms of side effects and induction of resistance.

Clinical Bottom Line

Consider antibiotic treatment of suspected urinary tract infection in female patients with negative urine dipstick testing.


  1. Richards D, Toop L, Chambers S, Fletcher L Response to antibiotics of women with symptoms of urinary tract infection but negative dipstick urine test results: double blind randomised controlled trial. British Medical Journal BMJ. 2005 Jul 16;331(7509):143
  2. Grude N. Tveten Y. Jenkins A. Kristiansen BE. Uncomplicated urinary tract infections. Bacterial findings and efficacy of empirical antibacterial treatment. Scandinavian Journal of Primary Health Care 23(2):115-9, 2005 Jun.