AppendicitisNCT02017951
Geographic Influences on Appendicectomy Outcomes
An observational study of Appendicitis, run by University of Edinburgh at 1 site in United Kingdom.
Trial summary
Introduction Appendicitis is a common condition which represents a significant resource burden for the Scottish National Health Service (NHS). It is unknown whether there are significant differences in outcomes following appendicectomy which may be explained by geographic factors. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Appendicitis
- 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 Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: All Scottish residents undergoing appendicectomy during the study period.
Who may be able to join
- All patients, of all ages, undergoing appendicectomy (OPCS code H01) during the time period January 2001 - December 2010.
Who cannot join
- Patients undergoing appendicectomy for whom this is incidental to a more major abdominal procedure.
- Patients non-resident in Scotland.
Trial locations and contacts
1 site in 1 country.
About this study
Introduction
Appendicitis is a common condition which represents a significant resource burden for the Scottish National Health Service (NHS). It is unknown whether there are significant differences in outcomes following appendicectomy which may be explained by geographic factors.
Read more
Aims
The aim of this study is to describe appendicectomy 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 procedure code for appendicectomy, and the urban-rural classification of patients will be derived from postcode data. Travel time from hospital will also be estimated through postcode data. The investigators will study a 10 year period from January 2001 to December 2010.
Primary outcome measures will be risk-adjusted 30 day/inpatient mortality, 30 day readmission rate, 30 day re-operation rate, length of stay and negative appendicectomy rates.
Read the detailed description
The aim of this study is to explore the possibility that outcome from appendicectomy 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 appendicectomies 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.
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.
There is no single appendicectomy outcome measure which is a literature standard, so all of the following will be evaluated as primary outcome measures: risk-adjusted 30 day/inpatient mortality, 30 day readmission rate, 30 day re-operation rate, length of stay and negative appendicectomy rates.
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 current practice, fully within the era of widely practised laparoscopic surgery. A power calculation also suggested that this would provide an adequate sample size to demonstrate differences.
Our power calculation- specific to length of stay- was based on Faiz O, Clark J, Brown T, Bottle A, Antoniou A, Farrands P, et al. Traditional and Laparoscopic Appendectomy in Adults. Ann Surg. 2008 Nov;248(5):800-6. In their cohort of 259,735 appendicectomies performed from 1996-2006, the geometric mean length of stay was 3.52, with SD 1.8. We decided that a difference of 0.5 days would be 'clinically significant'. We specified alpha 0.05 and Power 0.9, and an allocation ratio of 2 (allowing comparison of one tertile to two others). A two-sided t-test of difference between two independent means was performed in G*Power 3.1.7. This demonstrated that a total N of 616 was required to demonstrate this difference. According to ISD figures, there were 3,712 appendicectomy procedures performed in 2010/11, so with numbers available we will be able 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, depending on initial exploratory work.
The investigators will further calculate the approximate travelling time from patient home location (using postcode) to the treating hospital, by constructing isochrones at time/distance intervals from hospitals. Travel time will be evaluated as a continuous and discrete variable.
- Conditions
- Appendicitis
- Keywords
- Appendectomy, Hospitals,General, Hospitals,Rural, Hospitals,Urban, Rural Health Services, Geography, Medical, Outcome Assessment (Health Care)
- Medical subject headings
- Appendicitis
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 both a continuous and discrete variable. |
What is being measured
The primary outcome is the main question the study is designed to answer.
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 appendicectomy to date of discharge (whole days) - see below
Re-operation
The occurrence of an abdominal procedure either subsequent to appendicectomy 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
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
Negative Appendicectomy Rate
The rate of appendicectomies performed in which the appendix is found to be normal. This will be detected by the use of ICD-10 codes.
Measured: At time of index procedure
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 AppendicitisStudies 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 (actual)
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
- NCT02017951
- Sponsor's protocol ID
- XRB13069-GA
- Status last verified
- Dec 2013
- First submitted
- 21 Nov 2013
- Last updated
- 21 May 2024
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 May 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Geographic Influences on Appendicectomy Outcomes
- ClinicalTrials.gov ID
- NCT02017951
- Acronym / sponsor ID
- XRB13069-GA
- Conditions
- Appendicitis
- Keywords
- Appendectomy, 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 (actual)
- 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
Appendicitis is a common condition which represents a significant resource burden for the Scottish National Health Service (NHS). It is unknown whether there are significant differences in outcomes following appendicectomy which may be explained by geographic factors.
Aims
The aim of this study is to describe appendicectomy 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 procedure code for appendicectomy, and the urban-rural classification of patients will be derived from postcode data. Travel time from hospital will also be estimated through postcode data. The investigators will study a 10 year period from January 2001 to December 2010.
Primary outcome measures will be risk-adjusted 30 day/inpatient mortality, 30 day readmission rate, 30 day re-operation rate, length of stay and negative appendicectomy rates.
Detailed description
The aim of this study is to explore the possibility that outcome from appendicectomy 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 appendicectomies 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.
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.
There is no single appendicectomy outcome measure which is a literature standard, so all of the following will be evaluated as primary outcome measures: risk-adjusted 30 day/inpatient mortality, 30 day readmission rate, 30 day re-operation rate, length of stay and negative appendicectomy rates.
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 current practice, fully within the era of widely practised laparoscopic surgery. A power calculation also suggested that this would provide an adequate sample size to demonstrate differences.
Our power calculation- specific to length of stay- was based on Faiz O, Clark J, Brown T, Bottle A, Antoniou A, Farrands P, et al. Traditional and Laparoscopic Appendectomy in Adults. Ann Surg. 2008 Nov;248(5):800-6. In their cohort of 259,735 appendicectomies performed from 1996-2006, the geometric mean length of stay was 3.52, with SD 1.8. We decided that a difference of 0.5 days would be 'clinically significant'. We specified alpha 0.05 and Power 0.9, and an allocation ratio of 2 (allowing comparison of one tertile to two others). A two-sided t-test of difference between two independent means was performed in G*Power 3.1.7. This demonstrated that a total N of 616 was required to demonstrate this difference. According to ISD figures, there were 3,712 appendicectomy procedures performed in 2010/11, so with numbers available we will be able 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, depending on initial exploratory work.
The investigators will further calculate the approximate travelling time from patient home location (using postcode) to the treating hospital, by constructing isochrones at time/distance intervals from hospitals. Travel time will be evaluated 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 both a continuous and discrete variable. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- All Scottish residents undergoing appendicectomy during the study period.
Key inclusion criteria (1 listed)
- All patients, of all ages, undergoing appendicectomy (OPCS code H01) during the time period January 2001 - December 2010.
Key exclusion criteria (2 listed)
- Patients undergoing appendicectomy for whom this is incidental to a more major abdominal procedure.
- Patients non-resident in Scotland.
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
Post-operative length of stay
Time frame: From date of appendicectomy to date of discharge (whole days) - see below
(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.
Re-operation
Time frame: Within the index admission or within 30 days of discharge
The occurrence of an abdominal procedure either subsequent to appendicectomy and within the index admission, or ≤30 days of discharge.
Re-admission
Time frame: Within 30 days of index discharge
Re-admission to any hospital specialty ≤30 days have elapsed since date of discharge.
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.
Negative Appendicectomy Rate
Time frame: At time of index procedure
The rate of appendicectomies performed in which the appendix is found to be normal. This will be detected by the use of ICD-10 codes.
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 21 May 2024.
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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 Appendicitis, 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 21 May 2024. 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?
Post-operative length of stay (time frame: From date of appendicectomy to date of discharge (whole days) - see below). The study lists 5 primary outcomes in all. 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 21 May 2024.