Reviewer's report 
 Cholecystectomy in Sweden 2000 - 2003: a nationwide study on procedures, patient characteristics, Title: 
and mortality 
 3  3 May 2007 Version: Date: 
 Alexandros Polychronidis Reviewer: 
Reviewer's report: 
General 
In this retrospective, nationwide study, the authors compared the characteristics and postoperative 
long-term mortality of patients undergoing either laparoscopic or open cholecystectomy. 
Patients undergoing open cholecystectomy were older, more likely to have acute disease presentation or cholelithiasis-associated complications, accompanying comorbidity, and repeated hospital admissions before surgery. It was also more likely to have concomitant interventions along with cholecystectomy. After 
surgery, patients undergoing open cholecystectomy had longer hospital stay and a higher probability of 
repeat admissions because of either biliary disease or cardiac and pulmonary comorbidity. Interestingly these patients had a higher mortality than the corresponding general population not only in the early postoperative period but also during the 9-month follow-up period for ages younger than 69 years. 
It is likely that the complications of cholelithiasis, the advanced age and the concomitant comorbid 
conditions have dictated the choice of open cholecystectomy instead of the laparoscopic procedure and 
these factors probably explain the findings of this study. Overall, the aim of this study is well defined, the methods are sufficient, the results are adequately 
presented and the discussion is in concordance with the major findings of the study. 
Although several of the findings in this study have been previously reported by other studies comparing 
laparoscopic cholecystectomy with the open procedure, the large scale and the multi-institutional nature of 
this study provide it with sufficient strength to be published in BMC medicine. 
------------------------------------------------------------------------------- 
Major Compulsory Revisions (that the author must respond to before a decision on publication can be 
reached) 
------------------------------------------------------------------------------- 
Minor Essential Revisions (such as missing labels on figures, or the wrong use of a term, which the author 
can be trusted to correct) 
A minor revision refers to the expression “…patients selected for these procedures.” (Introduction section, 
last paragraph, lines 1-2) which is misleading since there were no selection criteria set and should be 
replaced (for example: …patients undergoing either laparoscopic or open cholecystectomy) 
------------------------------------------------------------------------------- 
Discretionary Revisions (which the author can choose to ignore) 
 Appropriate or potentially appropriate for BMC Medicine: an article of importance in its Which journal?: 
field 
 Accept for publication in BMC Medicine after minor essential revisions What next?: 
 Acceptable Quality of written English: 
 No Statistical review: 
Declaration of competing interests: 
I declare that I have no competing interests 
Reviewer's report 
 Cholecystectomy in Sweden 2000 - 2003: a nationwide study on procedures, patient characteristics, Title: 
and mortality 
 3  3 May 2007 Version: Date: 
 Alexandros Polychronidis Reviewer: 
Reviewer's report: 
General 
In this retrospective, nationwide study, the authors compared the characteristics and postoperative 
long-term mortality of patients undergoing either laparoscopic or open cholecystectomy. 
Patients undergoing open cholecystectomy were older, more likely to have acute disease presentation or cholelithiasis-associated complications, accompanying comorbidity, and repeated hospital admissions before surgery. It was also more likely to have concomitant interventions along with cholecystectomy. After 
surgery, patients undergoing open cholecystectomy had longer hospital stay and a higher probability of 
repeat admissions because of either biliary disease or cardiac and pulmonary comorbidity. Interestingly these patients had a higher mortality than the corresponding general population not only in the early postoperative period but also during the 9-month follow-up period for ages younger than 69 years. 
It is likely that the complications of cholelithiasis, the advanced age and the concomitant comorbid 
conditions have dictated the choice of open cholecystectomy instead of the laparoscopic procedure and 
these factors probably explain the findings of this study. Overall, the aim of this study is well defined, the methods are sufficient, the results are adequately 
presented and the discussion is in concordance with the major findings of the study. 
Although several of the findings in this study have been previously reported by other studies comparing 
laparoscopic cholecystectomy with the open procedure, the large scale and the multi-institutional nature of 
this study provide it with sufficient strength to be published in BMC medicine. 
------------------------------------------------------------------------------- 
Major Compulsory Revisions (that the author must respond to before a decision on publication can be 
reached) 
------------------------------------------------------------------------------- 
Minor Essential Revisions (such as missing labels on figures, or the wrong use of a term, which the author 
can be trusted to correct) 
A minor revision refers to the expression “…patients selected for these procedures.” (Introduction section, 
last paragraph, lines 1-2) which is misleading since there were no selection criteria set and should be 
replaced (for example: …patients undergoing either laparoscopic or open cholecystectomy) 
------------------------------------------------------------------------------- 
Discretionary Revisions (which the author can choose to ignore) 
 Appropriate or potentially appropriate for BMC Medicine: an article of importance in its Which journal?: 
field 
 Accept for publication in BMC Medicine after minor essential revisions What next?: 
 Acceptable Quality of written English: 
 No Statistical review: 
Declaration of competing interests: 
I declare that I have no competing interests 
Please review this paper.
user
Reviewer's report 
 Cholecystectomy in Sweden 2000 - 2003: a nationwide study on procedures, patient characteristics, Title: 
and mortality 
 3  3 May 2007 Version: Date: 
 Alexandros Polychronidis Reviewer: 
Reviewer's report: 
General 
In this retrospective, nationwide study, the authors compared the characteristics and postoperative 
long-term mortality of patients undergoing either laparoscopic or open cholecystectomy. 
Patients undergoing open cholecystectomy were older, more likely to have acute disease presentation or cholelithiasis-associated complications, accompanying comorbidity, and repeated hospital admissions before surgery. It was also more likely to have concomitant interventions along with cholecystectomy. After 
surgery, patients undergoing open cholecystectomy had longer hospital stay and a higher probability of 
repeat admissions because of either biliary disease or cardiac and pulmonary comorbidity. Interestingly these patients had a higher mortality than the corresponding general population not only in the early postoperative period but also during the 9-month follow-up period for ages younger than 69 years. 
It is likely that the complications of cholelithiasis, the advanced age and the concomitant comorbid 
conditions have dictated the choice of open cholecystectomy instead of the laparoscopic procedure and 
these factors probably explain the findings of this study. Overall, the aim of this study is well defined, the methods are sufficient, the results are adequately 
presented and the discussion is in concordance with the major findings of the study. 
Although several of the findings in this study have been previously reported by other studies comparing 
laparoscopic cholecystectomy with the open procedure, the large scale and the multi-institutional nature of 
this study provide it with sufficient strength to be published in BMC medicine. 
------------------------------------------------------------------------------- 
Major Compulsory Revisions (that the author must respond to before a decision on publication can be 
reached) 
------------------------------------------------------------------------------- 
Minor Essential Revisions (such as missing labels on figures, or the wrong use of a term, which the author 
can be trusted to correct) 
A minor revision refers to the expression “…patients selected for these procedures.” (Introduction section, 
last paragraph, lines 1-2) which is misleading since there were no selection criteria set and should be 
replaced (for example: …patients undergoing either laparoscopic or open cholecystectomy) 
------------------------------------------------------------------------------- 
Discretionary Revisions (which the author can choose to ignore) 
 Appropriate or potentially appropriate for BMC Medicine: an article of importance in its Which journal?: 
field 
 Accept for publication in BMC Medicine after minor essential revisions What next?: 
 Acceptable Quality of written English: 
 No Statistical review: 
Declaration of competing interests: 
I declare that I have no competing interests 
assistant