Table 2.

Outcomes of gallstone-related events and operative rate by surgical comparison

Author, year	Definition of gallstone-related events	Gallstone-related events		Operative rate
		Surgery	Observation	Surgery	Observation
Vetrhus, 2002 [16] and 2004 [15] and Schmidt, 2011 [19]*	Complications of gallstones: acute pancreatitis, common bile duct stone(s), acute cholecystitis	5-year follow-up Pain-related admissions: 2 (1%) Complications: 1 (1%) 14-year follow-up Pain attacks: 8 (12%) Complications: 1 (1%)	5-year follow-up Pain-related admission: 12 (17%) Complications: 3 (4%) 14-year follow-up Pain attacks: 23 (33%) Complications: 3 (4%)	60/68 randomized (88%)	35/69 randomized (51%)
		Elective surgery	Urgent/early surgery	Elective surgery	Urgent/early surgery
Salman, 2005 [17]	“Complications during the waiting time”	9 (27.5%)	n/a	100%
Anwar, 2008 [18]b	“serial presentations with symptoms of gallstones”	1.2 visits/personc 0.3 visits/persond	n/a	100%
		Surgeon discretion	Restrictive strategy	Surgeon discretion	Restrictive strategy
Van Dijk, 2019 [20] e	“Gallstone complications”	38 (7%)	40 (8%)	404 (75%)	358 (68%)

^aStudies looked at same population, examined different outcomes at different timepoints

^bAnwar, 2008 defined urgent cholecystectomy as early/same-day

^cIn cohort that initially presented as an emergency

^dIn cohort that initially presented to outpatient

^eSurgeon discretion defined as operation based on standard care left to the discretion of the surgeon; restrictive strategy used the fulfillment of five pre-specified criteria as indication for operation