Final Research Plan

Asymptomatic Bacteriuria in Adults: Screening

December 28, 2017

Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.

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Panel 1

The final Research Plan will be used to guide a systematic review of the evidence by researchers at an Evidence-based Practice Center. The resulting Evidence Review will form the basis of the USPSTF Recommendation Statement on this topic.

The draft Research Plan was available for comment from September 28 until October 25, 2017 at 5:00 p.m., ET.

Figure 1 is the analytic framework that depicts the four Key Questions to be addressed in the systematic review. The figure illustrates how screening asymptomatic pregnant and nonpregant adults may result in reducing the incidence of symptomatic urinary tract infection, kidney infection, and perinatal/maternal morbidity or mortality, as well as improving quality of life (KQ1). Once detected, the figure shows how treatment of asymptomatic bacteriuria may result in improved health outcomes (KQ3). Further, the figure illustrates whether screening for and treatment of asymptomatic bacteriuria are associated with any adverse events (KQ2, KQ4).

  1. Does screening for asymptomatic bacteriuria in adults, including pregnant women, improve health outcomes?
  2. What are the harms of screening for asymptomatic bacteriuria in adults, including pregnant women?
  3. Does treatment of screen-detected, asymptomatic bacteriuria improve health outcomes?
  4. What are the harms of treatment of screen-detected, asymptomatic bacteriuria?

Contextual questions will not be systematically reviewed and are not shown in the Analytic Framework.

  1. What is the accuracy of onsite clinical screening tests for asymptomatic bacteriuria?
  2. What is the optimal timing and frequency of screening for asymptomatic bacteriuria in pregnant women?
  3. What is the association between asymptomatic bacteriuria and health outcomes?

The Research Approach identifies the study characteristics and criteria that the Evidence-based Practice Center will use to search for publications and to determine whether identified studies should be included or excluded from the Evidence Review. Criteria are overarching as well as specific to each of the key questions (KQs).

  Included Excluded
Populations KQs 1, 2: Unselected, asymptomatic, community-dwelling adults age ≥18 years (including those residing in independent living facilities)

KQs 3, 4: Community-dwelling adults age ≥18 years with asymptomatic bacteriuria (including those residing in independent living facilities); unselected, asymptomatic pregnant women receiving routine prenatal care (any age)
  • Persons with symptoms of or suspected urinary tract infection (cystitis or pyelonephritis) or with a history of recurrent urinary tract infection
  • Persons who have a compromised immune system
  • Persons who have a catheter, urinary stent, or nephrostomy tube; recipients of a kidney or other organ transplant; patients on kidney dialysis
  • Pregnant women with sickle cell disease
  • Persons seen in specialty care for treatment or followup of conditions affecting the urinary tract (e.g., prostate cancer)
  • Persons being tested in preparation for urological procedures
  • Persons with spinal cord injuries
  • Studies conducted exclusively among persons who are institutionalized or hospitalized
Interventions KQs 1, 2: Screening with urine testing (e.g., urine culture, urinalysis with microscopy, dipstick, dipslide, screening with reflex urine culture)

KQs 3, 4: Treatment (e.g., antibiotics) or interventions to prevent urinary tract infection in patients with screen-detected, asymptomatic bacteriuria		 Interventions to prevent asymptomatic bacteriuria
Comparisons KQ 1: No screening

KQ 3: No treatment; treatment with a placebo		  
Outcomes KQs 1, 3:
General health outcomes:
  • Urinary tract infection, including cystitis and pyelonephritis
  • Kidney failure
  • Quality of life
  • Mortality
Pregnancy-specific health outcomes:
  • Complications of pregnancy associated with maternal or fetal morbidity: preterm birth (before 37 weeks’ gestation), low birth weight (<2,500 g), preeclampsia, eclampsia, HELLP syndrome, congenital malformations (birth defects)
  • Maternal and fetal/infant mortality
KQs 2, 4: All of the above health outcomes, with a focus on fetal anomalies, stillbirth, and adverse effects of treatment with antibiotics (e.g., recurrent and/or antimicrobial resistant infections, allergic reactions, secondary infections, and longer-term child health outcomes)		  
Setting Prenatal or primary care settings Studies conducted exclusively in populations living in special settings outside of the community (e.g., hospital, nursing or care home, rehabilitation center, or other long-term care facility), emergency departments, and other settings not generalizable to primary care
Study Design KQs 1, 3:
Nonpregnant adults: RCTs

Pregnant women*: RCTs, observational cohort studies with a comparator of no screening or no treatment

KQs 2, 4: RCTs, observational cohort studies with and without a comparison group, registry studies		 KQs 1, 3:
Nonpregnant adults: Study designs other than RCTs

Pregnant women*: Study designs other than RCTs or observational cohort studies with a comparator of no screening or no treatment

KQs 2, 4: Case control studies, case series and case reports, qualitative studies
Countries Nonpregnant adults: Studies conducted in countries categorized as “Very High” on the 2016 Human Development Index (as defined by the United Nations Development Programme)

Pregnant women*: Studies conducted in countries categorized as “Very High” and “High” on the 2016 Human Development Index		 Nonpregnant adults: Studies not conducted in countries categorized as “Very High” on the 2016 Human Development Index

Pregnant women*: Studies not conducted in countries categorized as “Very High” or “High” on the 2016 Human Development Index
Publication language English Languages other than English

*The inclusion criteria for studies of screening for and treatment of asymptomatic bacteriuria in pregnant women are more broad because prior evidence from trials and ensuing recommendations have established a standard practice of screening and treatment.

Abbreviations: HELLP=hemolysis, elevated liver enzymes, low platelet count; RCT=randomized, controlled trial.

The draft Research Plan was posted for public comment on the USPSTF Web site from September 28, 2017 to October 25, 2017. In response, the USPSTF made minor changes to clarify the included population and relevant outcomes. Several comments suggested that screening for asymptomatic bacteriuria may be important for patients in long-term care institutional care settings or with indwelling catheters. The evidence review will focus on community-dwelling adults presenting in primary care settings rather than institutionalized populations, in accordance with the usual scope of USPSTF recommendations. Some comments expressed concern that antibiotic treatment of asymptomatic bacteriuria could contribute to the emergence of antibiotic-resistant infections; the USPSTF included this potential harm to the included outcomes for the evidence review.