Spinal DiseasesNCT02980822
Patient Reported Outcome After Surgical Treatment of DDD in Scandinavia
An observational study of Spinal Diseases and Surgery, run by Spine Centre of Southern Denmark.
Trial summary
Purpose: The incidence of surgery for Degenerative lumbar Disc Disease (DDD). According to the national spine registries in Sweden, Norway and Denmark, there is a difference in surgical incidence between these countries. The cause for this difference is not known. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Spinal Diseases, Surgery, Degeneration Disc
- How many people
- 3,500 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2011to 31 Jan 2019
- How long will I take part?
- 1 Year
- 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 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Included are individuals treated surgically for DDD between the ages of 18 through 65 years. Surgery has been performed in Denmark, Norway or Sweden during 2011, 2012 or 2013
Who may be able to join
- All patients operated due to DDD in the Scandinavian countries during 2011, 2012 or 2013
Who cannot join
- No history of previous lumbar spine surgery.
About this study
Official title: Comparison of Baseline Characteristics and Patient Reported Outcome After Surgical Treatment of Degenerative Lumbar Disc Disease in Scandinavia
Purpose: The incidence of surgery for Degenerative lumbar Disc Disease (DDD). According to the national spine registries in Sweden, Norway and Denmark, there is a difference in surgical incidence between these countries. The cause for this difference is not known. It may reflect a difference in incidence of lumbar disc hernia, but with a similar socio-economic and ethnical background in these countries, it is more likely that the differences are due to varying surgical indications. Comparing indications for surgery, patient reported outcome and factors predictive for outcome after surgery for lumbar disc decease in these countries could provide information about optimal indications for surgery.
Hypotheses: (i) there are no differences in patient-reported outcome after surgery between these countries, (ii) there are no differences in indications for surgery between these countries and (iii), factors that predict outcome are similar in these countries.
Method of research: By using data from three Nordic national spine registers, investigators will compare baseline data, indications for surgery and patient reported outcome one year after surgery for lumbar disc decease. Register based studies have advantages such as large sample sizes, reflecting real life, but they also have limitations such as lower follow-up rates than clinical trials. A non-response analysis will be performed to take this into account.
Read the detailed description
This is an observational register based study, with prospective data registration and a retrospective study design. Included are individuals treated surgically for a lumbar disc herniation between the ages of 18 through 65 years, without a history of previous lumbar spine surgery. Surgery has been performed in Denmark, Norway or Sweden during 2011, 2012 or 2013. Data will be presented according to the STROBE criteria.
The registers
All registries have the aim of studying outcome after spine surgery. All departments and patients participate voluntarily. At the time of admission, the patient reports data consisting of information on social factors, comorbidity and previous surgery. After surgery, the surgeon records diagnosis and type of surgery performed.
The Swespine Register has included individuals treated with surgery for DDD since 1993. During the last decade, the number of departments participating in the registry has varied between 35 and 41 of the 42 to 45 departments providing spinal surgery services in Sweden. Coverage is approximately 90%. The completeness (number of patients reported to Swespine at the time of surgery) is approximately 80%.
The Norwegian Spine register, NORspine, is based on experiences from the Swespine register and previous validation studies from a local clinical registry, and was founded in 2007. In total 36 of 40 centers performing lumbar spine surgery in Norway report to NORspine. Coverage is approximately 90%. The completeness is approximately 65%.
The Danish spine register, DaneSpine, is based on Swespine and was acquired by the Danish Spine Society from the Swedish Society of Spinal Surgeons in 2009 and has successively been implemented. In total 17 of 19 centers performing lumbar spine surgery in Denmark report to DaneSpine. Coverage is approximately 90%. The completeness is approximately 60%.
Quality assurance As for all studies, there is a risk that loss to follow-up may bias the results. Solberg et al. (2011) studied 633 patients, who were operated on for degenerative disorders of the lumbar spine in Norway, and found that a loss to follow-up of 22% would not bias conclusions about overall treatment effects. There were no indications of worse outcomes in the non-responders group. In a similar one-center study of the DaneSpine. Højmark et al. (2016) found that a loss to follow-up of 12% at did not seem to bias the conclusions that can be drawn from DaneSpine at that center. Preliminary data indicates that predictors of outcome after lumbar disc herniation surgery are comparable with data in a study with a very high follow-up rate and with the Swespine register.
Data handling
Anonymized individual level data from all three registers will be pooled in one database. The cohort will be divided by country for comparisons.
Missing data and out of range data
In case of missing data case exclusion analysis by analysis, will be used. Out of range data will be deleted.
Analysis
The data will be cleaned by excluding patients with missing or incorrect date of surgery, missing date for follow-up, previous lumbar spine surgery and surgery other than discectomy only.
After data cleaning, we aim to perform blinded statistical analyses, in which the independent statistician performing the analyses is unaware of group belonging (i.e. country). The code will not be broken until the analyses and interpretations have been performed.
Comparisons of indications for surgery
Analysis of baseline data will include age at surgery, sex, anthropometrics, number of smokers, Oswestry Disability Index, numeric rating scale leg pain, numeric rating scale back pain, EQ-5D, number on sick leave, employment status, and duration of leg and back pain and presented as mean (SD), mean (95% confidence interval), or number (%).
Variables will be analyzed by analysis of variance, Chi-square or logistic regression tests. Data will be presented as crude (unadjusted) data to elucidate any differences between the countries.
Comparisons of outcome
Comparisons of the change of the outcome variables from baseline to 1 year, as well as comparisons of the actual value at 1 year will be performed. Analysis of covariance, Chi-square or logistic regression tests and the crude (unadjusted) data will be presented.
In addition, baseline variables will be used as covariates in the analysis of covariance and the adjusted data presented.
Non-response analysis A non-response analysis will be performed comparing all available baseline variables between those that responded to the 1 year follow-up with those that did not respond.
Sample size
A study of similar character has never been performed before. Due to the nature of the study, the sample size is not formulated in the guise of power, risk level, or clinical difference. The number of patients participating in the study is estimated to 3500. The sample is so large that differences in the Oswestry Disability Index of as low as 2 points may be detected (power 90%, significance level 5%), but in the interpretation the minimal important difference of 10-15 points in the Oswestry Disability Index often referred to has to be taken into account.
- Conditions
- Spinal Diseases, Surgery, Degeneration Disc
- Medical subject headings
- Spinal Diseases, Intervertebral Disc Degeneration
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 |
|---|---|---|
| Sweden, Denmark, Norway | Group: Degenerative lumbar disc disease patients treated in Sweden and included in the Swespine register Group: Degenerative lumbar disc disease patients treated in Norway and included in the NORspine register Group: Degenerative lumbar disc disease patients treated in Denmark and included in the DaneSpine register |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Oswestry disability index version 2.1 (from 0; no disability to 100; maximum disability)
Measured: Baseline and 1 year postoperative
Secondary outcomes (4)
Numerical rating scale for leg pain (from 0; no pain to 10; maximum pain) . The numerical rating scale is used in Norway. The visual analogue scale (0-100) used in Sweden and Denmark will be converted to the numerical rating scale.
Measured: Baseline and 1 year postoperative
EQ-5D according to the British tariff (UK-TTO; from -0.59; worst possible health to 1; perfect health).
Measured: baseline and 1 year postoperative
Return to work rate
Preoperative and postoperative work rate
Measured: Baseline and 1 year postoperative
Additional surgery in the same segment of the lumbar spine
Measured: During 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Dec 2016 (estimated)
- Study start1 Jan 2011
- Primary completion31 Jan 2019
- Study completion31 Jan 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Spinal DiseasesStudies 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 3,500 participants (actual)
- Target duration
- 1 Year
Sponsor and investigators
- Lead sponsor
- Spine Centre of Southern Denmark
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Karen Højmark Hansen, Spine Centre of Southern Denmark
- Investigators
- Mikkel Ø Andersen, MD, Principal investigator, Sygehus Lilleaelt
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02980822
- Sponsor's protocol ID
- DKMiddelfart4
- Status last verified
- Jul 2024
- First submitted
- 30 Nov 2016
- Last updated
- 30 Jul 2024
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Jul 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Baseline Characteristics and Patient Reported Outcome After Surgical Treatment of Degenerative Lumbar Disc Disease in Scandinavia
- ClinicalTrials.gov ID
- NCT02980822
- Acronym / sponsor ID
- DKMiddelfart4
- Conditions
- Spinal Diseases, Surgery, Degeneration Disc
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 3,500 participants (actual)
- Lead sponsor
- Spine Centre of Southern DenmarkUniversity, hospital or other
- Study start
- 1 Jan 2011 (actual)
- Primary completion
- 31 Jan 2019 (actual)
- Study completion
- 31 Jan 2019 (actual)
- First posted
- 2 Dec 2016 (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.
Purpose: The incidence of surgery for Degenerative lumbar Disc Disease (DDD). According to the national spine registries in Sweden, Norway and Denmark, there is a difference in surgical incidence between these countries. The cause for this difference is not known. It may reflect a difference in incidence of lumbar disc hernia, but with a similar socio-economic and ethnical background in these countries, it is more likely that the differences are due to varying surgical indications. Comparing indications for surgery, patient reported outcome and factors predictive for outcome after surgery for lumbar disc decease in these countries could provide information about optimal indications for surgery.
Hypotheses: (i) there are no differences in patient-reported outcome after surgery between these countries, (ii) there are no differences in indications for surgery between these countries and (iii), factors that predict outcome are similar in these countries.
Method of research: By using data from three Nordic national spine registers, investigators will compare baseline data, indications for surgery and patient reported outcome one year after surgery for lumbar disc decease. Register based studies have advantages such as large sample sizes, reflecting real life, but they also have limitations such as lower follow-up rates than clinical trials. A non-response analysis will be performed to take this into account.
Detailed description
This is an observational register based study, with prospective data registration and a retrospective study design. Included are individuals treated surgically for a lumbar disc herniation between the ages of 18 through 65 years, without a history of previous lumbar spine surgery. Surgery has been performed in Denmark, Norway or Sweden during 2011, 2012 or 2013. Data will be presented according to the STROBE criteria.
The registers
All registries have the aim of studying outcome after spine surgery. All departments and patients participate voluntarily. At the time of admission, the patient reports data consisting of information on social factors, comorbidity and previous surgery. After surgery, the surgeon records diagnosis and type of surgery performed.
The Swespine Register has included individuals treated with surgery for DDD since 1993. During the last decade, the number of departments participating in the registry has varied between 35 and 41 of the 42 to 45 departments providing spinal surgery services in Sweden. Coverage is approximately 90%. The completeness (number of patients reported to Swespine at the time of surgery) is approximately 80%.
The Norwegian Spine register, NORspine, is based on experiences from the Swespine register and previous validation studies from a local clinical registry, and was founded in 2007. In total 36 of 40 centers performing lumbar spine surgery in Norway report to NORspine. Coverage is approximately 90%. The completeness is approximately 65%.
The Danish spine register, DaneSpine, is based on Swespine and was acquired by the Danish Spine Society from the Swedish Society of Spinal Surgeons in 2009 and has successively been implemented. In total 17 of 19 centers performing lumbar spine surgery in Denmark report to DaneSpine. Coverage is approximately 90%. The completeness is approximately 60%.
Quality assurance As for all studies, there is a risk that loss to follow-up may bias the results. Solberg et al. (2011) studied 633 patients, who were operated on for degenerative disorders of the lumbar spine in Norway, and found that a loss to follow-up of 22% would not bias conclusions about overall treatment effects. There were no indications of worse outcomes in the non-responders group. In a similar one-center study of the DaneSpine. Højmark et al. (2016) found that a loss to follow-up of 12% at did not seem to bias the conclusions that can be drawn from DaneSpine at that center. Preliminary data indicates that predictors of outcome after lumbar disc herniation surgery are comparable with data in a study with a very high follow-up rate and with the Swespine register.
Data handling
Anonymized individual level data from all three registers will be pooled in one database. The cohort will be divided by country for comparisons.
Missing data and out of range data
In case of missing data case exclusion analysis by analysis, will be used. Out of range data will be deleted.
Analysis
The data will be cleaned by excluding patients with missing or incorrect date of surgery, missing date for follow-up, previous lumbar spine surgery and surgery other than discectomy only.
After data cleaning, we aim to perform blinded statistical analyses, in which the independent statistician performing the analyses is unaware of group belonging (i.e. country). The code will not be broken until the analyses and interpretations have been performed.
Comparisons of indications for surgery
Analysis of baseline data will include age at surgery, sex, anthropometrics, number of smokers, Oswestry Disability Index, numeric rating scale leg pain, numeric rating scale back pain, EQ-5D, number on sick leave, employment status, and duration of leg and back pain and presented as mean (SD), mean (95% confidence interval), or number (%).
Variables will be analyzed by analysis of variance, Chi-square or logistic regression tests. Data will be presented as crude (unadjusted) data to elucidate any differences between the countries.
Comparisons of outcome
Comparisons of the change of the outcome variables from baseline to 1 year, as well as comparisons of the actual value at 1 year will be performed. Analysis of covariance, Chi-square or logistic regression tests and the crude (unadjusted) data will be presented.
In addition, baseline variables will be used as covariates in the analysis of covariance and the adjusted data presented.
Non-response analysis A non-response analysis will be performed comparing all available baseline variables between those that responded to the 1 year follow-up with those that did not respond.
Sample size
A study of similar character has never been performed before. Due to the nature of the study, the sample size is not formulated in the guise of power, risk level, or clinical difference. The number of patients participating in the study is estimated to 3500. The sample is so large that differences in the Oswestry Disability Index of as low as 2 points may be detected (power 90%, significance level 5%), but in the interpretation the minimal important difference of 10-15 points in the Oswestry Disability Index often referred to has to be taken into account.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 1 Year
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Sweden, Denmark, Norway | – | –Group: Degenerative lumbar disc disease patients treated in Sweden and included in the Swespine register Group: Degenerative lumbar disc disease patients treated in Norway and included in the NORspine register Group: Degenerative lumbar disc disease patients treated in Denmark and included in the DaneSpine register |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Included are individuals treated surgically for DDD between the ages of 18 through 65 years. Surgery has been performed in Denmark, Norway or Sweden during 2011, 2012 or 2013
Key inclusion criteria (1 listed)
- All patients operated due to DDD in the Scandinavian countries during 2011, 2012 or 2013
Key exclusion criteria (1 listed)
- No history of previous lumbar spine surgery.
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
Change in Oswestry disability index version 2.1 (from 0; no disability to 100; maximum disability)
Time frame: Baseline and 1 year postoperative
4 secondary outcomes
Numerical rating scale for leg pain (from 0; no pain to 10; maximum pain) . The numerical rating scale is used in Norway. The visual analogue scale (0-100) used in Sweden and Denmark will be converted to the numerical rating scale.
Time frame: Baseline and 1 year postoperative
EQ-5D according to the British tariff (UK-TTO; from -0.59; worst possible health to 1; perfect health).
Time frame: baseline and 1 year postoperative
Return to work rate
Time frame: Baseline and 1 year postoperative
Additional surgery in the same segment of the lumbar spine
Time frame: During 1 year
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 30 Jul 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.
Mikkel Ø Andersen, MD principal investigator
Sygehus Lilleaelt
Questions about this trial
What is this clinical trial studying?
An observational study of Spinal Diseases and Surgery, run by Spine Centre of Southern Denmark.
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 1 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 30 Jul 2024. Status can change between updates, so confirm with the study contact before making plans.
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?
Change in Oswestry disability index version 2.1 (from 0; no disability to 100; maximum disability) (time frame: Baseline and 1 year postoperative). 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 30 Jul 2024.