<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT02980822</url>
  </required_header>
  <id_info>
    <org_study_id>DKMiddelfart4</org_study_id>
    <nct_id>NCT02980822</nct_id>
  </id_info>
  <brief_title>Patient Reported Outcome After Surgical Treatment of DDD in Scandinavia</brief_title>
  <official_title>Comparison of Baseline Characteristics and Patient Reported Outcome After Surgical Treatment of Degenerative Lumbar Disc Disease in Scandinavia</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Sygehus Lillebaelt</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Sygehus Lillebaelt</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      Purpose: The incidence of surgery for Degenerative lumbar Disc Disease (DDD). According to&#xD;
      the national spine registries in Sweden, Norway and Denmark, there is a difference in&#xD;
      surgical incidence between these countries. The cause for this difference is not known. It&#xD;
      may reflect a difference in incidence of lumbar disc hernia, but with a similar&#xD;
      socio-economic and ethnical background in these countries, it is more likely that the&#xD;
      differences are due to varying surgical indications. Comparing indications for surgery,&#xD;
      patient reported outcome and factors predictive for outcome after surgery for lumbar disc&#xD;
      decease in these countries could provide information about optimal indications for surgery.&#xD;
&#xD;
      Hypotheses: (i) there are no differences in patient-reported outcome after surgery between&#xD;
      these countries, (ii) there are no differences in indications for surgery between these&#xD;
      countries and (iii), factors that predict outcome are similar in these countries.&#xD;
&#xD;
      Method of research: By using data from three Nordic national spine registers, investigators&#xD;
      will compare baseline data, indications for surgery and patient reported outcome one year&#xD;
      after surgery for lumbar disc decease. Register based studies have advantages such as large&#xD;
      sample sizes, reflecting real life, but they also have limitations such as lower follow-up&#xD;
      rates than clinical trials. A non-response analysis will be performed to take this into&#xD;
      account.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      This is an observational register based study, with prospective data registration and a&#xD;
      retrospective study design. Included are individuals treated surgically for a lumbar disc&#xD;
      herniation between the ages of 18 through 65 years, without a history of previous lumbar&#xD;
      spine surgery. Surgery has been performed in Denmark, Norway or Sweden during 2011, 2012 or&#xD;
      2013. Data will be presented according to the STROBE criteria.&#xD;
&#xD;
      The registers&#xD;
&#xD;
      All registries have the aim of studying outcome after spine surgery. All departments and&#xD;
      patients participate voluntarily. At the time of admission, the patient reports data&#xD;
      consisting of information on social factors, comorbidity and previous surgery. After surgery,&#xD;
      the surgeon records diagnosis and type of surgery performed.&#xD;
&#xD;
      The Swespine Register has included individuals treated with surgery for DDD since 1993.&#xD;
      During the last decade, the number of departments participating in the registry has varied&#xD;
      between 35 and 41 of the 42 to 45 departments providing spinal surgery services in Sweden.&#xD;
      Coverage is approximately 90%. The completeness (number of patients reported to Swespine at&#xD;
      the time of surgery) is approximately 80%.&#xD;
&#xD;
      The Norwegian Spine register, NORspine, is based on experiences from the Swespine register&#xD;
      and previous validation studies from a local clinical registry, and was founded in 2007. In&#xD;
      total 36 of 40 centers performing lumbar spine surgery in Norway report to NORspine. Coverage&#xD;
      is approximately 90%. The completeness is approximately 65%.&#xD;
&#xD;
      The Danish spine register, DaneSpine, is based on Swespine and was acquired by the Danish&#xD;
      Spine Society from the Swedish Society of Spinal Surgeons in 2009 and has successively been&#xD;
      implemented. In total 17 of 19 centers performing lumbar spine surgery in Denmark report to&#xD;
      DaneSpine. Coverage is approximately 90%. The completeness is approximately 60%.&#xD;
&#xD;
      Quality assurance As for all studies, there is a risk that loss to follow-up may bias the&#xD;
      results. Solberg et al. (2011) studied 633 patients, who were operated on for degenerative&#xD;
      disorders of the lumbar spine in Norway, and found that a loss to follow-up of 22% would not&#xD;
      bias conclusions about overall treatment effects. There were no indications of worse outcomes&#xD;
      in the non-responders group. In a similar one-center study of the DaneSpine. Højmark et al.&#xD;
      (2016) found that a loss to follow-up of 12% at did not seem to bias the conclusions that can&#xD;
      be drawn from DaneSpine at that center. Preliminary data indicates that predictors of outcome&#xD;
      after lumbar disc herniation surgery are comparable with data in a study with a very high&#xD;
      follow-up rate and with the Swespine register.&#xD;
&#xD;
      Data handling&#xD;
&#xD;
      Anonymized individual level data from all three registers will be pooled in one database. The&#xD;
      cohort will be divided by country for comparisons.&#xD;
&#xD;
      Missing data and out of range data&#xD;
&#xD;
      In case of missing data case exclusion analysis by analysis, will be used. Out of range data&#xD;
      will be deleted.&#xD;
&#xD;
      Analysis&#xD;
&#xD;
      The data will be cleaned by excluding patients with missing or incorrect date of surgery,&#xD;
      missing date for follow-up, previous lumbar spine surgery and surgery other than discectomy&#xD;
      only.&#xD;
&#xD;
      After data cleaning, we aim to perform blinded statistical analyses, in which the independent&#xD;
      statistician performing the analyses is unaware of group belonging (i.e. country). The code&#xD;
      will not be broken until the analyses and interpretations have been performed.&#xD;
&#xD;
      Comparisons of indications for surgery&#xD;
&#xD;
      Analysis of baseline data will include age at surgery, sex, anthropometrics, number of&#xD;
      smokers, Oswestry Disability Index, numeric rating scale leg pain, numeric rating scale back&#xD;
      pain, EQ-5D, number on sick leave, employment status, and duration of leg and back pain and&#xD;
      presented as mean (SD), mean (95% confidence interval), or number (%).&#xD;
&#xD;
      Variables will be analyzed by analysis of variance, Chi-square or logistic regression tests.&#xD;
      Data will be presented as crude (unadjusted) data to elucidate any differences between the&#xD;
      countries.&#xD;
&#xD;
      Comparisons of outcome&#xD;
&#xD;
      Comparisons of the change of the outcome variables from baseline to 1 year, as well as&#xD;
      comparisons of the actual value at 1 year will be performed. Analysis of covariance,&#xD;
      Chi-square or logistic regression tests and the crude (unadjusted) data will be presented.&#xD;
&#xD;
      In addition, baseline variables will be used as covariates in the analysis of covariance and&#xD;
      the adjusted data presented.&#xD;
&#xD;
      Non-response analysis A non-response analysis will be performed comparing all available&#xD;
      baseline variables between those that responded to the 1 year follow-up with those that did&#xD;
      not respond.&#xD;
&#xD;
      Sample size&#xD;
&#xD;
      A study of similar character has never been performed before. Due to the nature of the study,&#xD;
      the sample size is not formulated in the guise of power, risk level, or clinical difference.&#xD;
      The number of patients participating in the study is estimated to 3500. The sample is so&#xD;
      large that differences in the Oswestry Disability Index of as low as 2 points may be detected&#xD;
      (power 90%, significance level 5%), but in the interpretation the minimal important&#xD;
      difference of 10-15 points in the Oswestry Disability Index often referred to has to be taken&#xD;
      into account.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Active, not recruiting</last_known_status>
  <start_date>January 2011</start_date>
  <completion_date type="Anticipated">March 2017</completion_date>
  <primary_completion_date type="Anticipated">March 2017</primary_completion_date>
  <study_type>Observational [Patient Registry]</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Cohort</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <target_duration>1 Year</target_duration>
  <primary_outcome>
    <measure>Change in Oswestry disability index version 2.1 (from 0; no disability to 100; maximum disability)</measure>
    <time_frame>Baseline and 1 year postoperative</time_frame>
  </primary_outcome>
  <secondary_outcome>
    <measure>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.</measure>
    <time_frame>Baseline and 1 year postoperative</time_frame>
  </secondary_outcome>
  <secondary_outcome>
    <measure>EQ-5D according to the British tariff (UK-TTO; from -0.59; worst possible health to 1; perfect health).</measure>
    <time_frame>baseline and 1 year postoperative</time_frame>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Return to work rate</measure>
    <time_frame>Baseline and 1 year postoperative</time_frame>
    <description>Preoperative and postoperative work rate</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Additional surgery in the same segment of the lumbar spine</measure>
    <time_frame>During 1 year</time_frame>
  </secondary_outcome>
  <number_of_groups>1</number_of_groups>
  <enrollment type="Actual">3500</enrollment>
  <condition>Spinal Diseases</condition>
  <condition>Surgery</condition>
  <condition>Degeneration Disc</condition>
  <arm_group>
    <arm_group_label>Sweden, Denmark, Norway</arm_group_label>
    <description>Group: Degenerative lumbar disc disease patients treated in Sweden and included in the Swespine register&#xD;
Group: Degenerative lumbar disc disease patients treated in Norway and included in the NORspine register&#xD;
Group: Degenerative lumbar disc disease patients treated in Denmark and included in the DaneSpine register</description>
  </arm_group>
  <eligibility>
    <study_pop>
      <textblock>
        Included are individuals treated surgically for DDD between the ages of 18 through 65&#xD;
        years. Surgery has been performed in Denmark, Norway or Sweden during 2011, 2012 or 2013&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  All patients operated due to DDD in the Scandinavian countries during 2011, 2012 or&#xD;
             2013&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
        No history of previous lumbar spine surgery.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>65 Years</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Mikkel Ø Andersen, MD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Sygehus Lilleaelt</affiliation>
  </overall_official>
  <verification_date>December 2016</verification_date>
  <study_first_submitted>November 30, 2016</study_first_submitted>
  <study_first_submitted_qc>December 1, 2016</study_first_submitted_qc>
  <study_first_posted type="Estimate">December 2, 2016</study_first_posted>
  <last_update_submitted>December 2, 2016</last_update_submitted>
  <last_update_submitted_qc>December 2, 2016</last_update_submitted_qc>
  <last_update_posted type="Estimate">December 5, 2016</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Sygehus Lillebaelt</investigator_affiliation>
    <investigator_full_name>Karen Hoejmark Hansen</investigator_full_name>
    <investigator_title>Research Nurse, Head of the national DaneSpine office</investigator_title>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Spinal Diseases</mesh_term>
    <mesh_term>Intervertebral Disc Degeneration</mesh_term>
  </condition_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT02980822
org study id: DKMiddelfart4
nct id: NCT02980822
lead sponsor: 
has dmc: No
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.
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.
observational model: Cohort
time perspective: Prospective
measure: Change in Oswestry disability index version 2.1 (from 0; no disability to 100; maximum disability)
time frame: Baseline and 1 year postoperative
measure: 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
measure: 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
measure: Return to work rate
time frame: Baseline and 1 year postoperative
description: Preoperative and postoperative work rate
measure: Additional surgery in the same segment of the lumbar spine
time frame: During 1 year
arm group label: Sweden, Denmark, Norway
description: 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
study pop: 
sampling method: Probability Sample
criteria: 
gender: All
minimum age: 18 Years
maximum age: 65 Years
healthy volunteers: No
last name: Mikkel Ø Andersen, MD
role: Principal Investigator
affiliation: Sygehus Lilleaelt
responsible party type: Principal Investigator
investigator affiliation: Sygehus Lillebaelt
investigator full name: Karen Hoejmark Hansen
investigator title: Research Nurse, Head of the national DaneSpine office
mesh term: Spinal Diseases
mesh term: Intervertebral Disc Degeneration