Table 3

Quality of case–control studies examining the effect of circumcision on urinary tract infection in male subjects

Reference	Definition of UTI	Determination of circumcision status	Exclusion criteria	Origin of controls	Adjustment for confounding variables
Reference	Definition of UTI	Determination of circumcision status	Exclusion criteria	Origin of controls	Age	SES	Ethnicity
CSU, catheter specimen of urine; MSU, midstream urine; SES, socioeconomic status; SPA, suprapubic aspirate; UTI, urinary tract infection.
Newman et al²⁴	Bag urine or clean catch ⩾10⁷/l	Standard questionnaire	No fever >38°C or urine collected at presentation	Patients presenting to non-hospital outpatients with a fever	No	No	No
	CSU ⩾2×10⁶/l		Uncertain circumcision status
	SPA ⩾10⁴/l		Uncertain circumcision status

Craig et al²³	CSU/SPA ⩾10⁶/l	Direct questioning of parents or direct examination	Past history of UTI or urinary tract abnormality; neurological or skeletal abnormality predisposing to UTI	Patients presenting to hospital emergency department for any reason other than those diagnosed with UTI	Yes	No	No
	MSU ⩾10⁸/l

Rushton and Majd²⁵	MSU ⩾10⁸/l	Cases: “prospectively” found but not specified	Prolonged neonatal hospital admission or uncertain circumcision status	Patients admitted with febrile upper respiratory tract infection. Matched for age, race, and SES	No	Yes	Yes
Rushton and Majd²⁵	CSU ⩾10⁷/l	Controls: documentation in medical record but no further details given

Spach et al²⁶	MSU >10⁶/l growth along with one or more symptoms	Examination	No clear exclusion criteria	Patients without bacteriuria presenting to outpatient clinic	Yes	No	Yes

Crain and Gershel²⁷	Bag urine ⩾10⁴/l	Documentation in medical records no further details given	Absence of fever	Patients presenting to hospital with fever and without a discharge diagnosis of UTI	No	No	No
Crain and Gershel²⁷	CSU ⩾10⁴/l
	SPA ⩾10²/l

Kashani and Faraday²⁸	CSU/SPA ⩾10⁸/l	Documentation in medical record	Urinary tract abnormality, inadequate documentation of specimen type or age <1 month	Patients presenting to outpatients clinics for unrelated reasons	No	No	Yes

Herzog²⁹	CSU/SPA ⩾10⁷/l	Documentation in medical record or direct contact with family if unclear in medical records	Anatomical abnormality, past history of UTI, myelodysplasia, uncertain circumcision status or race, and equivocal culture results	Patients who presented to emergency with a febrile illness and had a SPA or CSU which was negative	Yes	Yes	Yes