Review for 10.1186/1471-230X-14-153 (2014)

Reviewer's report
Title:Mortality following acute pancreatitis: social deprivation, hospital size and
time of admission: record linkage study
Version:2Date:23 November 2013
Reviewer: Camilla Nøjgaard
Reviewer's report:
Review of the manuscript:
Mortality following acute pancreatitis: social deprivation, hospital size and time of
admission: record linkage study
This manuscript is a register study. The questions posed by the authors are well
defined and methods are appropriate and well described. It fullfilles the standards
for reporting and I find the discussion and conlusions well balanced and
adequately supported by the data. I think limitations of the work overall are
clearly stated and acknowledgement are clearly stated. The title convey the
findings and the writing is more than acceptable.
Minor Essential Revisions:
1. Study strength and limitations:
This is a pure register study with the problems it can bring. The strength is the
size of study. Unfortunately, the register lacks information about alcohol intake,
tobacco use, BMI, severity of acute pancreatitis and treatment. The last is
mentioned in the discussion but I would recomment that you also mention the
other lacks of information. I am impressed that you are able to distinguish
between the different aetiologies by using the DRG-codes alone. Have you
validated this?
2. Deprivation:
It is surprising that social deprivation is not significantly correlated with mortality.
How is the deprivation calculated exactly? Which register has been used to make
this scale and how is this parameter validated? Is the parameter only based on
the postcode or could you supply with information from any social registers?
3. Month of admission and recruitment of junior doctors each August
The hypothesis: ”EWTD is bad for the patients and leads to a higher mortality”.
Do you only recruit new young doctors in august? In my country we recruit new
doctors all year around so it would not be possible to test this hypothesis by
comparing the different months. Could the drop in working hours per week not be
a positive thing for the patient? It might lead to a more enthusiastic and awoke
doctor if the doctor haven't been to work 60 hours this week... You might mention
this part of the discussion too in the manscript.
You find a higher mortality for alcoholic pancreatitis in august-october. This
finding do not have to be connected to the recruitment of young doctors. It could
be related to t.ex. a higher alcohol intake these months.
4. Analysis
In figure 3 you have not defined the red and green box-plots. Is it August?
5. Underlying cause of death
p. 10: gallstone is stated as the cause in 13% How can that be tru?
6. Mortality according to size of hospital:
You are surprised to find a higher mortality in the largest hospitals. In my country,
patients are distributed to the different hospitals by a specific pre-hospital
selection. The doctor that sends the patient to the hospital sets a hypothetic
diagnosis. He/she contacts a ”central distribution center” and then the most ill
patients with a specific diagnosis are distributed to the largest hospitals while
patients less ill and with other diagnosis are send to smaller hospitals. If this is
also the case in UK, it might explain some of the results.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing interests.