Abdomen, AcuteNCT02017977
Geographic Influences on Emergency Laparotomy Outcomes
An observational study of Abdomen, Acute, run by University of Edinburgh at 1 site in United Kingdom.
Trial summary
Introduction 'Emergency Laparotomy' is an umbrella term for a set of commonly performed procedures which are known to carry a significant risk of mortality and morbidity. Previous work has shown considerable inter-hospital variation in emergency laparotomy outcomes within the United Kingdom. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Abdomen, Acute
- How many people
- 40,000 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Jan 2001to Aug 2013
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: All Scottish adult residents undergoing emergency laparotomy during the study period
Who may be able to join
- All patients aged 18 years or older who undergo emergency laparotomy within the study period
Who cannot join
- Patients who are non-resident in Scotland
- Multiple laparotomies on a single patient will not be counted as separate index events unless ≥6 months have passed between previous discharge and new hospital admission.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
All Scottish NHS Hospitals
All Scottish Surgical Units
About this study
Introduction
'Emergency Laparotomy' is an umbrella term for a set of commonly performed procedures which are known to carry a significant risk of mortality and morbidity. Previous work has shown considerable inter-hospital variation in emergency laparotomy outcomes within the United Kingdom. It is unknown whether there are significant differences in outcomes following laparotomy which may be explained by geographic factors.
Read more
Aims
The aim of this study is to describe emergency laparotomy outcomes in Scotland as they vary by the urban-rural nature of the patient's home location and travel time from hospital.
Methods
This research study is a retrospective observational enquiry which will utilise administrative data from the Information Services Division (ISD) of NHS National Services Scotland. Patient episodes will be identified by a set of procedure codes for emergency laparotomy, and the urban-rural classification of patients will be derived from postcode data. Travel time from hospital will also be derived from postcode data. The investigators will study a 10 year period from January 2001 to December 2010.
The primary outcome measure will be risk-adjusted 30 day/inpatient mortality, and secondary outcome measures will be 30 day readmission rate, 30 day re-operation rate and post-operative length of stay.
Read the detailed description
The aim of this study is to explore the possibility that outcomes from emergency laparotomy may vary according to:
- the urban-rural nature of the patient's home location and
- travel time from hospital.
This is a retrospective study of all emergency laparotomies performed in Scotland during the period from 1st January 2001 - 31st December 2010. It will use routinely collected administrative data from the Information Services Division (ISD) of NHS National Services Scotland.
Emergency laparotomy will be defined as a non-elective abdominal procedure primarily on the gut tube; and such cases will be identified by the use of a set of procedural codes, which will be validated against local records.
Potentially significant confounding variables such as age, gender, and co-morbidity will be studied for their predictive value in a univariate model and included in a multivariate model if they remain significant. The primary outcome measure will be risk-adjusted 30 day/inpatient mortality, and secondary outcome measures will be 30 day readmission rate, 30 day re-operation rate, and post-operative length of stay.
The registry which will supply the data for this study is the Scottish Morbidity Record 01 (SMR01), the full title of which is the "General / Acute Inpatient and Day Case dataset" (see http://www.adls.ac.uk/nhs-scotland/general-acute-inpatient-day-case-smr01/?detail). SMR01 is collated and administered by ISD, and data submission is mandatory for all Scottish NHS providers of in-patient or day-case care. Approximately 1.4 million records are added each year. Diagnoses are coded according to International Classification of Diseases (ICD)-10 standards and procedures are coded according to the United Kingdom's Office of Population Census Statistics (OPCS) standards, the most recent of which is version 4.5.
The data quality in SMR01 is high and is assured by regular internal audits. In the 2010 audit of accuracy, Main Condition was recorded with an accuracy of 88% and Main Procedure was recorded with an accuracy of 94%. Where data inconsistencies are identified in the extract supplied for this study, further clarification will be obtained where possible with ISD's data retrieval support team. Data completeness is very high in SMR01. However, where significant volumes of data are missing or unusable, the need for data imputation will be explored.
The study period was decided on pragmatically by a desire to provide an assessment of contemporary practice, fully within the era of wide-spread laparoscopic surgery.
A power calculation also suggested that this would provide an adequate sample size to demonstrate mortality differences. A recent paper showed 30 day mortality for emergency laparotomy to be 14.9% (Saunders DI, Murray D, Pichel AC, Varley S, Peden CJ. Variations in mortality after emergency laparotomy: the first report of the UK Emergency Laparotomy Network. Br J Anaesth. 2012 Sep 1;109(3):368-75.)
It was decided that we wanted to be able to detect a mortality difference (absolute) of 2%. Alpha was specified as 0.05 and power 0.9. Using a chi-2 test in G Power 3.1.7, it was determined that a total N of 5221 was required to show this difference. In the study already cited, 35 hospitals submitted data on 3 months of practice, giving a total of 1853 patients. We extrapolated to estimate that one hospital completes 212 laparotomies per year. There are currently 31 adult surgical centres in Scotland, resulting in an estimate of 6,565 laparotomies per year. Even accepting the smaller size of Scottish hospitals, this demonstrates that a 10 year cohort should be more than adequate to detect a clinically significant difference in length of stay.
The investigators will use the Scottish government's own 8-fold urban-rural classification system (see http://www.scotland.gov.uk/Topics/Statistics/About/Methodology/UrbanRuralClassification) to investigate the possible relationship between patient geographical location and outcome. Urban-rural categories may be grouped for analysis, according to initial exploratory work.
The investigators will further calculate the approximate travelling time from patient home location (using postcode) to the treating hospital, by constructing isocrones at time/distance intervals from hospitals. Travel time will be analysed as a continuous and discrete variable.
- Conditions
- Abdomen, Acute
- Keywords
- Laparotomy, General Surgery, Hospitals,General, Hospitals,Rural, Hospitals,Urban, Rural Health Services, Geography, Medical, Outcome Assessment (Health Care)
- Medical subject headings
- Abdomen, Acute
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Urban-Rural Classification 1: Large Urban Areas | Settlements of over 125,000 people | |
| Urban-Rural Classification 2: Other Urban Areas | Settlements of 10,000 to 125,000 people | |
| Urban-Rural Classification 3: Accessible Small Towns | Settlements of between 3,000 and 10,000 people and within 30 minutes drive of a settlement of 10,000 or more. | |
| Urban-Rural Classification 4: Remote Small Towns | Settlements of between 3,000 and 10,000 people and with a drive time of over 30 minutes to a settlement of 10,000 or more. | |
| Urban-Rural Classification 5: Very Remote Small Towns | Settlements of between 3,000 and 10,000 people and with a drive time of over 60 minutes to a settlement of 10,000 or more | |
| Urban-Rural Classification 6: Accessible Rural | Areas with a population of less than 3,000 people, and within a 30 minute drive time of a settlement of 10,000 or more | |
| Urban-Rural Classification 7: Remote Rural | Areas with a population of less than 3,000 people, and with a drive time of over 30 minutes to a settlement of 10,000 or more | |
| Urban-Rural Classification 8: Very Remote Rural | Areas with a population of less than 3,000 people, and with a drive time of over 60 minutes to a settlement of 10,000 or more | |
| Travel Time - see below | Travel time will be analysed as a continuous and discrete variable. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mortality
Death as an in-patient or ≤30 days of procedure. Deaths will be recognised from SMR01 which is linked to the Registrar General's database of deaths.
Measured: Either within 30 days of procedure, or during continuous in-patient stay
Secondary outcomes (3)
Post-operative length of stay
(Whole) days from date of laparotomy to date of discharge. Because this is a retrospective study using a complete national data set, with the last admission 2.5 years distant from the time of data collection, we will use actual time period rather than censoring length of stay at a set point.
Measured: From date of laparotomy to date of discharge (whole days) - see below
Re-operation
The occurrence of an abdominal procedure either subsequent to laparotomy and within the index admission, or ≤30 days of discharge.
Measured: Within the index admission or within 30 days of discharge
Re-admission
Re-admission to any hospital specialty ≤30 days have elapsed since date of discharge.
Measured: Within 30 days of index discharge
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Dec 2013 (estimated)
- Study startJan 2001
- Primary completionDec 2010
- Study completionAug 2013
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Abdomen, AcuteStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Ecologic or community
- Time perspective
- Retrospective
- Enrolment
- 40,000 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Edinburgh
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Ewen M Harrison, FRCS, PhD, Principal investigator, University of Edinburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02017977
- Sponsor's protocol ID
- XRB13069-GEL
- Status last verified
- Dec 2013
- First submitted
- 21 Nov 2013
- Last updated
- 23 Dec 2013
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Dec 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Geographic Influences on Emergency Laparotomy Outcomes
- ClinicalTrials.gov ID
- NCT02017977
- Acronym / sponsor ID
- XRB13069-GEL
- Conditions
- Abdomen, Acute
- Keywords
- Laparotomy, General Surgery, Hospitals,General, Hospitals,Rural, Hospitals,Urban, Rural Health Services, Geography, Medical, Outcome Assessment (Health Care)
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 40,000 participants (estimated)
- Lead sponsor
- University of EdinburghUniversity, hospital or other
- Study start
- Jan 2001
- Primary completion
- Dec 2010 (actual)
- Study completion
- Aug 2013 (actual)
- First posted
- 23 Dec 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Introduction
'Emergency Laparotomy' is an umbrella term for a set of commonly performed procedures which are known to carry a significant risk of mortality and morbidity. Previous work has shown considerable inter-hospital variation in emergency laparotomy outcomes within the United Kingdom. It is unknown whether there are significant differences in outcomes following laparotomy which may be explained by geographic factors.
Aims
The aim of this study is to describe emergency laparotomy outcomes in Scotland as they vary by the urban-rural nature of the patient's home location and travel time from hospital.
Methods
This research study is a retrospective observational enquiry which will utilise administrative data from the Information Services Division (ISD) of NHS National Services Scotland. Patient episodes will be identified by a set of procedure codes for emergency laparotomy, and the urban-rural classification of patients will be derived from postcode data. Travel time from hospital will also be derived from postcode data. The investigators will study a 10 year period from January 2001 to December 2010.
The primary outcome measure will be risk-adjusted 30 day/inpatient mortality, and secondary outcome measures will be 30 day readmission rate, 30 day re-operation rate and post-operative length of stay.
Detailed description
The aim of this study is to explore the possibility that outcomes from emergency laparotomy may vary according to:
- the urban-rural nature of the patient's home location and
- travel time from hospital.
This is a retrospective study of all emergency laparotomies performed in Scotland during the period from 1st January 2001 - 31st December 2010. It will use routinely collected administrative data from the Information Services Division (ISD) of NHS National Services Scotland.
Emergency laparotomy will be defined as a non-elective abdominal procedure primarily on the gut tube; and such cases will be identified by the use of a set of procedural codes, which will be validated against local records.
Potentially significant confounding variables such as age, gender, and co-morbidity will be studied for their predictive value in a univariate model and included in a multivariate model if they remain significant. The primary outcome measure will be risk-adjusted 30 day/inpatient mortality, and secondary outcome measures will be 30 day readmission rate, 30 day re-operation rate, and post-operative length of stay.
The registry which will supply the data for this study is the Scottish Morbidity Record 01 (SMR01), the full title of which is the "General / Acute Inpatient and Day Case dataset" (see http://www.adls.ac.uk/nhs-scotland/general-acute-inpatient-day-case-smr01/?detail). SMR01 is collated and administered by ISD, and data submission is mandatory for all Scottish NHS providers of in-patient or day-case care. Approximately 1.4 million records are added each year. Diagnoses are coded according to International Classification of Diseases (ICD)-10 standards and procedures are coded according to the United Kingdom's Office of Population Census Statistics (OPCS) standards, the most recent of which is version 4.5.
The data quality in SMR01 is high and is assured by regular internal audits. In the 2010 audit of accuracy, Main Condition was recorded with an accuracy of 88% and Main Procedure was recorded with an accuracy of 94%. Where data inconsistencies are identified in the extract supplied for this study, further clarification will be obtained where possible with ISD's data retrieval support team. Data completeness is very high in SMR01. However, where significant volumes of data are missing or unusable, the need for data imputation will be explored.
The study period was decided on pragmatically by a desire to provide an assessment of contemporary practice, fully within the era of wide-spread laparoscopic surgery.
A power calculation also suggested that this would provide an adequate sample size to demonstrate mortality differences. A recent paper showed 30 day mortality for emergency laparotomy to be 14.9% (Saunders DI, Murray D, Pichel AC, Varley S, Peden CJ. Variations in mortality after emergency laparotomy: the first report of the UK Emergency Laparotomy Network. Br J Anaesth. 2012 Sep 1;109(3):368-75.)
It was decided that we wanted to be able to detect a mortality difference (absolute) of 2%. Alpha was specified as 0.05 and power 0.9. Using a chi-2 test in G Power 3.1.7, it was determined that a total N of 5221 was required to show this difference. In the study already cited, 35 hospitals submitted data on 3 months of practice, giving a total of 1853 patients. We extrapolated to estimate that one hospital completes 212 laparotomies per year. There are currently 31 adult surgical centres in Scotland, resulting in an estimate of 6,565 laparotomies per year. Even accepting the smaller size of Scottish hospitals, this demonstrates that a 10 year cohort should be more than adequate to detect a clinically significant difference in length of stay.
The investigators will use the Scottish government's own 8-fold urban-rural classification system (see http://www.scotland.gov.uk/Topics/Statistics/About/Methodology/UrbanRuralClassification) to investigate the possible relationship between patient geographical location and outcome. Urban-rural categories may be grouped for analysis, according to initial exploratory work.
The investigators will further calculate the approximate travelling time from patient home location (using postcode) to the treating hospital, by constructing isocrones at time/distance intervals from hospitals. Travel time will be analysed as a continuous and discrete variable.
Study design
- Observational model
- Ecologic or community
- Time perspective
- Retrospective
- Number of arms
- 9
| Arm | Type | Receives |
|---|---|---|
| Urban-Rural Classification 1: Large Urban Areas | – | –Settlements of over 125,000 people |
| Urban-Rural Classification 2: Other Urban Areas | – | –Settlements of 10,000 to 125,000 people |
| Urban-Rural Classification 3: Accessible Small Towns | – | –Settlements of between 3,000 and 10,000 people and within 30 minutes drive of a settlement of 10,000 or more. |
| Urban-Rural Classification 4: Remote Small Towns | – | –Settlements of between 3,000 and 10,000 people and with a drive time of over 30 minutes to a settlement of 10,000 or more. |
| Urban-Rural Classification 5: Very Remote Small Towns | – | –Settlements of between 3,000 and 10,000 people and with a drive time of over 60 minutes to a settlement of 10,000 or more |
| Urban-Rural Classification 6: Accessible Rural | – | –Areas with a population of less than 3,000 people, and within a 30 minute drive time of a settlement of 10,000 or more |
| Urban-Rural Classification 7: Remote Rural | – | –Areas with a population of less than 3,000 people, and with a drive time of over 30 minutes to a settlement of 10,000 or more |
| Urban-Rural Classification 8: Very Remote Rural | – | –Areas with a population of less than 3,000 people, and with a drive time of over 60 minutes to a settlement of 10,000 or more |
| Travel Time - see below | – | –Travel time will be analysed as a continuous and discrete variable. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- All Scottish adult residents undergoing emergency laparotomy during the study period
Key inclusion criteria (1 listed)
- All patients aged 18 years or older who undergo emergency laparotomy within the study period
Key exclusion criteria (2 listed)
- Patients who are non-resident in Scotland
- Multiple laparotomies on a single patient will not be counted as separate index events unless ≥6 months have passed between previous discharge and new hospital admission.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Mortality
Time frame: Either within 30 days of procedure, or during continuous in-patient stay
Death as an in-patient or ≤30 days of procedure. Deaths will be recognised from SMR01 which is linked to the Registrar General's database of deaths.
3 secondary outcomes
Post-operative length of stay
Time frame: From date of laparotomy to date of discharge (whole days) - see below
Re-operation
Time frame: Within the index admission or within 30 days of discharge
Re-admission
Time frame: Within 30 days of index discharge
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Dec 2013.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Ewen M Harrison, FRCS, PhD principal investigator
University of Edinburgh
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Abdomen, Acute, run by University of Edinburgh at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 Dec 2013. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mortality (time frame: Either within 30 days of procedure, or during continuous in-patient stay). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Dec 2013.