Haltalin 1973.

Methods	Randomized controlled trial Generation of allocation sequence: unclear Allocation concealment: no Blinding: unclear Inclusion of all randomized participants: adequate, 100% Duration: not reported
Participants	Number of participants enrolled: 36 Number of participants analysed: 36 Loss to follow up: nil Inclusion criteria: infants and children; acute diarrhoeal disease; presumptive bacteriologic diagnosis of shigellosis; written informed consent from responsible legal guardian Exclusion criteria: infants under 1 month of age; known drug allergy; requiring specific antimicrobial therapy for concurrent infection
Interventions	(1) Nalidixic acid (13.75 mg/kg, orally, every 6 hours for 5 days) (2) Ampicillin (25 mg/kg, orally, every 6 hours for 5 days) Other interventions: Symptomatic treatment for fever and convulsions was ordered as necessary and was similar for both groups Fluid and electrolyte therapy and oral alimentation were given according to ward routine and was similar for both groups
Outcomes	(1) Number culture positive > 48 hours after start of treatment (2) Number culture positive > 5 days after start of treatment (3) Relapse (4) Number of days until culture negative (5) Diarrhoea > 5 days after start of treatment (6) Removed from protocol due to worsening (7) Number of days diarrhoea after start of treatment (8) Days until afebrile after start of treatment
Notes	Location: United States of America Setting: hospital, in‐patient based trial Follow‐up period: 5 days Antibiotic sensitivity pattern of Shigella isolates: 17/17, 100%, in the nalidixic acid group were sensitive to nalidixic acid and 19/19, 100%, in the ampicillin group were sensitive to ampicillin. Nalidixic acid sensitivity in the ampicillin group and ampicillin sensitivity in the nalidixic group is not reported. Funding source(s): John A. Hartford Foundation Sterling‐Winthrop Research Institute.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	"...randomly assigned"; but the method of sequencing not mentioned. In a previous trial done by the same author (Haltalin 1967) randomization was done based on the terminal digit number of the hospital record. The author could not be contacted for details since there was no mail ID. The journal's present editorial team did not have any details of the study.
Allocation concealment?	Unclear risk	Not mentioned
Blinding? All outcomes	Unclear risk	Not mentioned
Incomplete outcome data addressed? All outcomes	Low risk	No missing outcome data
Free of selective reporting?	Low risk	The study's prespecified outcomes, which were of interest in this review, have been reported
Free of other bias?	Low risk	The study appears to be free of other sources of bias