Urinary Tract Infection RCE Final


Does this woman have an acute uncomplicated urinary tract infection?

Original Citation:

Bent S, Brahmajee KN, Simel DS, Fihn SD, Saint S. Does This Woman Have an Acute Uncomplicated Urinary Tract Infection? JAMA. 2002; 287(20): 2701-2710.

Bottom Line:

The following recommendations are based on uncomplicated UTIs in women.

· Positive dipstick combined with other positive findings is highly suggestive of UTI, while negative dipstick does not rule out UTI.

· Even a mostly negative history, physical and dipstick findings can NOT reliably rule out a UTI in women without a history of vaginal discharge or irritation

· Patients with recurrent infection may be able to accurately self-diagnose UTI.

SORT Grade of Recommendation: [A-] Systematic Review of moderately high quality studies

Prevalence:Of asymptomatic bacteriuria in women of reproductive age = 5%. A woman who presents with one or more symptoms of UTI has a pre-test probability of infection of almost 50%.

Accuracy of Exam:

Symptoms

+LR* (95%CI)

- LR*(95%CI)

Dysuria

1.5 (1.2-2.0)

0.5 (0.3-0.7)

Frequency

1.8 (1.1-3.0)

0.6 (0.4-1.0)

Hematuria

2.0 (1.3-2.9)

0.9 (0.9-1.0)

Fever

1.6 (1.0-2.6)

0.9 (0.9-1.0)

Flank Pain

1.1 (0.9-1.4)

0.9 (0.8-1.1)

Lower Abdominal Pain

1.1 (0.9-1.4)

0.9 (0.8-1.1)

Vaginal Discharge

0.3 (0.1-0.9)

3.1 (1.0-9.3)

Vaginal Irritation

0.2 (0.1-0.9)

2.7 (0.9-8.5)

Back Pain

1.6 (1.2-2.1)

0.8 (0.7-0.9)

Self-diagnosis

4.0 (2.9-5.5)

0.0 (0.0-0.1)

*LRs represent summary measures calculated from the original raw data

Signs/Labs

+LR* (95%CI)

-LR*(95%CI)

Vaginal Discharge

0.7 (0.5-0.9)

1.1 (1.0-1.2)

CVA Tenderness

1.7 (1.1-2.5)

0.9 (0.8-1.0)

Dipstick Urinanalysis†

4.2

0.3

† A positive result was defined as leukocyte esterase positive or nitrite positive; a negative result was defined as both negative. From systematic review Hurlburt T, Littendberg B. The diagnostic accuracy of rapid dipstick tests to predict urinary tract infection. Am J Clin Pathol. 1991:96:582-88


Symptom Combinations

Summary LR*

Dysuria present, frequency present, vaginal

Discharge absent, vaginal irritation absent

22.6

Dysuria absent, vaginal discharge or

Vaginal irritation present

0.1-0.2

Dysuria or frequency present, vaginal discharge or vaginal irritation present

0.3-0.5

*Calculated by multiplying the summary LRs for each of the symptom findings given in the included studies

Definitions:

Uncomplicated UTI- defined as occurring in individuals with a normal urinary tract system

Complicated UTI- defined as occurring in individuals with a functional or anatomical abnormality of the urinary tract. or recent urinary tract instrumentation

Description of physical examinations:

Neither suprapubic nor costovertebral angle tenderness was described.

Precision:

No studies described the precision of the history or physical examination in the diagnosis of UTI

Comments:

Three well-established risk factors for acute UTI in young women are recent sexual intercourse, use of spermicide (on condoms or with diaphragms) and history of UTI. While studies were not able to calculate LRs these factors should be considered in the diagnosis of UTI.

The article gives a proposed algorithm for women with UTI symptoms.

Studies Description:

Inclusion criteria- Studies with original data on accuracy and precision of the history and or physical in diagnosing acute uncomplicated UTI in healthy females. Also included were data from a systematic review that evaluated the diagnostic accuracy of the dipstick urinalysis. Studies were excluded if they evaluated infants, children, adolescents, pregnant females, nursing home patients, or patients with a complicated UTI(as described above).

Search dates- 1966-September 2001. 464 studies found; 9 met inclusion criteria

Quality- Five of the nine included studies were “Level I” quality; one study was “Level III”; two studies were “Level IV”; one study was “Level V.” The largest study was not well done (Level IV) therefore the authors performed a sensitivity analysis to determine if this study had substantial effect on the pooled LRs. Excluding this study did not cause major changes in the LRs. The largest change involved vaginal discharge where with the absence of discharge the LR changed from 3.1 to 1.7 and with the presence of discharge the LR changed from 0.3 to 0.6.

Limitations- Only one study describes the role of CVA tenderness and back pain in diagnosing UTI, and it was a retrospective chart review. Only one study investigated the ability of women to self diagnose recurrent UTIs.

Gold Standards- Urine culture was the gold standardin all but Level IV, V studies.

Update:

Search Date- 2/23/05

Findings- Lammers RL et al. Comparison of Test Characteristics of Urine Dipstick and Urinalysis at Various Test Cutoff Points. Annals of Emergency Medicine. 2001;38(5): 505-512.

A prospective, observational study of 343 adult women presenting to 1 of 2 community hospital EDs or an intermediate care center with dysuria, urgency, or urinary frequency on history, or suprapubic or costovertebral angle tenderness on examination. Dipstick and urinalysis results were compared with the urine culture results,. A UTI was defined as 100,000 or more colonies of one or two species per mL of urine.

Test

+LR*

-LR*

Dipstick†

1.81

0.28

Urinalysis‡

1.8

.28

† Dipstick was positive if LE>trace or Nitrite+

‡ Urinalysis was positive if WBC>10 orRBC>5

* LRs calculated from the stated sensitivities and specificities of positive dipstick and UA as described above

This study's results are very similar to the systematic review given in the article.

.

Reviewed by: Tommy Day MD, M. Lee Chambliss MD Date: 2/23/05


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