Watt 1988.

Methods	Prospective, single site, randomised, double‐blind, placebo clinical trial.
Participants	Patients over 16 years of age presenting to a national infectious diseases hospital with suspected leptospirosis and either a positive rapid IgM‐based immunosorbent assay or a positive single serovar microagglutination assay, all later confirmed with multi‐serovar based serologic assays or culture. Only 7 participants had positive Leptospira cultures. The patients were predominantly men 20 to 40 years of age.
Interventions	1,500,000 units of parenteral sodium penicillin G administered four times daily for 7 days or a normal saline placebo.
Outcomes	Durations of fever and serum creatinine rise.
Notes	The trial was intended to focus on more severe disease but anuric patients or those so severely ill that they could not provide consent were excluded, and no deaths or requirements for dialysis occurred. Second infections were disqualifying, but the screening algorithm for potential co‐endemic diseases was not provided. Patients were categorised as severely infected if serum creatinine was > 177 µmol/L or the patients were clinically jaundiced.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	P. 433, "randomly assigned to receive sodium penicillin G or placebo," method of randomisation not disclosed.
Allocation concealment (selection bias)	Unclear risk	Not discerned.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not discerned.
Incomplete outcome data (attrition bias) All outcomes	Low risk	P. 433, "patients were followed up a week and a month after discharge;" p434, all leptospirosis patients completed therapy.
Selective reporting (reporting bias)	High risk	Pre‐defined outcome was time to defervescence and serum creatinine and whether outcomes in the Types of outcomes section were completely discerned was not discernible.
Other bias	Unclear risk	Not discerned.

ARDS = acute respiratory distress syndrome. 
 IgM = immunoglobulin M. 
 h = hour. 
 g = gram. 
 µmol/L = micromole. 
 > = greater than.