Lira 2001.

Methods	Study design: randomized clinical trial Number of study centers: 1 (State University of Campinas) Number randomized: 1025 (sample size calculations based on risk of adverse events) Study follow‐up: up to 60 days postsurgery
Participants	Country: Brazil Age: 66.5 ± 11.6 years, range 40 to 97 years (routine‐testing group = 66.4 ± 11.9 years; selective‐testing group = 66.7 ± 11.4 years) Gender: 547 men, 478 women (routine‐testing group: men = 279, women = 233; selective‐testing group: men = 268, women = 245) Inclusion criteria: people scheduled to undergo cataract surgery Exclusion criteria: less than 40 years old; undergoing surgery on the 2nd eye; were receiving general anesthesia; had a myocardial infarction within the preceding 3 months
Interventions	Intervention: routine testing with a 12‐lead electrocardiogram, a complete blood count, and measurements of serum glucose (n = 512) Comparison: selective testing defined by no preoperative testing unless the participant presented with a new or worsening condition that would warrant medical testing even if no surgery was scheduled (n = 513)
Outcomes	Primary outcome: rate of complications during the perioperative period Secondary outcomes: rate of cancellation of surgery; visual acuity
Notes	Study date: 10 February 2000 to 10 January 2001 Publication languages: English and Portuguese Surgery: extra capsular extraction performed by residents under training
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomization using blocks of 4 participants
Allocation concealment (selection bias)	Unclear risk	Not described
Masking (performance bias) Were the participants masked to the treatment group?	High risk	Participants either had preoperative testing done or did not.
Masking (performance bias) Were the physicians performing the preoperative tests masked to the treatment group?	High risk	Physicians performing the preoperative medical assessment knew for which participants to conduct preoperative testing.
Masking (detection bias) Were the primary outcome assessors masked to the treatment group?	Low risk	Medical events and treatments were recorded by an ophthalmologist or nurse using a standardized form during surgery. The researchers reviewing the forms for classifying adverse events were masked to the treatment assignments.
Masking (detection bias) Were the secondary outcome assessors masked to the treatment group?	Unclear risk	It was unclear who made the decision to cancel surgeries, or when those decisions were made.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Primary outcome data are presented for all participants who underwent surgery, thus for all participants at risk for complications due to cataract surgery.
Selective reporting (reporting bias)	Low risk	Reported the results for adverse medical events defined in methods section using a standardized form