Los Angeles 1995.

Methods	Allocation by a table of random numbers with random permuted blocks, with a block size of six. Indicator cards in sealed, opaque, sequentially‐numbered envelopes kept by the principal investigator who was not involved in the randomisation. Once a participant consented, the resident in the emergency room telephoned the principal investigator.
Participants	Pregnant women with an estimated gestational age of less than 24 weeks, had one or more symptoms or signs of upper urinary tract infection (temperature greater than 38.4°C, flank pain, or costovertebral angle tenderness), and had a urinalysis suspicious for urinary tract infection. Exclusion criteria: clinical signs of sepsis, respiratory insufficiency, an initial temperature greater than 39.8°C, blood pressure less than 90/50, pulse greater than 140 beats per minute (sustained), creatinine greater than 1.4 mg/dl, white blood cell count greater than 20 per 10^9/l, a known allergy to cephalosporins, a history of anaphylactic reaction to penicillins, inability to tolerate oral intake, inability to follow instructions, or serious underlying medical illness, including a known renal or urological problem, and subjects who had received antibiotic therapy within two weeks of presentation.
Interventions	Outpatients (study group) (n = 60) received ceftriaxone 1 g IM in the emergency room during the observation period. A home health nurse evaluated the participants 18‐36 hours after discharge and administered a second injection of ceftriaxone 1 g. Participants then completed a 10‐day course of oral cephalexin, 500 mg four times a day. Inpatients (control group) (n = 60) received 1 g IV every 8 hours until they were non‐febrile for 48 hours. All the participants received acetaminophen, cooling measures, and IV fluids while hospitalised. Antibiotic therapy was changed for women with a worsening clinical picture or for those whose did not have clinical improvement at 72 hours.
Outcomes	Cure rates (colony counts in urine of less than 100,000 colonies/ml) (outpatients 57/60, inpatients 53/60); recurrent pyelonephritis (inpatients 3/60, outpatients 3/60); preterm delivery (outpatients 0/60, inpatients 1/60); need for change antibiotic (outpatients 0/60, inpatients 6/60); incidence of prolonged pyrexia (outpatients 0/60, inpatients 4/60).
Notes	Los Angeles, California, USA. April 1991 to July 1993. Authors educated participants who were candidates for outpatient treatment about pyelonephritis and instructed them on the warning signs of septic shock and respiratory insufficiency. The education was continued by visiting nurses who followed up the participants for the first 3 days after discharge. Authors conclude that the majority of patients with pyelonephritis in early pregnancy may be candidates for outpatient therapy.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	Allocation by a table of random numbers with random permuted blocks, with a block size of six.
Allocation concealment?	Low risk	Indicator cards in sealed, opaque, sequentially‐numbered envelopes kept by the principal investigator who was not involved in the randomisation.