<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/NCT03260218</url>
  </required_header>
  <id_info>
    <org_study_id>TJA2017</org_study_id>
    <nct_id>NCT03260218</nct_id>
  </id_info>
  <brief_title>Protocol for Observational Study of Post op Delirium Following Total Joint Arthroplasties</brief_title>
  <official_title>Protocol for a Single-Centre Prospective Observational Study of Postoperative Delirium Following Total Joint Arthroplasties Among South East Asians</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Singapore General Hospital</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Singapore General Hospital</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      The incidence of post-operative delirium in the South-east Asian population is not known.&#xD;
      Through a prospective, single centre, observational study, the investigators aim to&#xD;
      characterize the incidence and risk factors of delirium in older adults undergoing elective&#xD;
      total joint arthroplasties (TJA). The study will recruit eligible patients (65 - 90 years old&#xD;
      undergoing elective TJA), with a targeted sample size of 500. Patients will be screened for&#xD;
      dementia and Confusion Assessment Method (CAM) scores obtained pre and post operatively.&#xD;
      Other data such as preoperative Charlson comorbidity index (CCI), post op complications using&#xD;
      Post operative Morbidity Survey (POMS), pain scores, readmission rates and length of hospital&#xD;
      stay (LOS), functional and health-related quality-of-life (HRQoL) will also be collected and&#xD;
      analysed.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      BACKGROUND&#xD;
&#xD;
      Modern studies have evaluated the risk factors and incidence of postoperative delirium in&#xD;
      post-TJA patients. In current literature, incidence ranges from 0-10%. However, the&#xD;
      epidemiology of these studies mainly focused on non-Asian populations. The investigators hope&#xD;
      to determine both the incidence and risk factors of postoperative delirium in patients&#xD;
      undergoing TJA with a focus on the Asian population. This is especially relevant in today's&#xD;
      ageing Asian population.&#xD;
&#xD;
      AIMS&#xD;
&#xD;
      To characterize the incidence and risk factors of delirium in older adults undergoing&#xD;
      elective total joint replacement surgery.&#xD;
&#xD;
      HYPOTHESIS&#xD;
&#xD;
      The incidence of postoperative delirium following elective TJA is low compared to Western&#xD;
      studies. Age, gender and use of opioids perioperatively are risk factors for postoperative&#xD;
      delirium following elective total joint replacement surgery.&#xD;
&#xD;
      DESIGN: Prospective observational study.&#xD;
&#xD;
      SETTING: Academic medical center.&#xD;
&#xD;
      DURATION: July 2017 - Dec 2017&#xD;
&#xD;
      STUDY POPULATION: Individuals aged 65 to 90 years old undergoing elective total joint (hip or&#xD;
      knee) replacement surgery.&#xD;
&#xD;
      METHODOLOGY:&#xD;
&#xD;
      Preoperative data&#xD;
&#xD;
      Before the operation, each patient will be interviewed to assess their baseline cognitive&#xD;
      status. The Mini-Mental State Examination (MMSE) will be used, which is a 11-question&#xD;
      screening tool used to evaluate the cognitive aspects of mental function. A score of 0-30 can&#xD;
      be obtained with higher values denoting better cognitive function. A score of &lt;24 suggests&#xD;
      cognitive impairment. A MMSE test modified for use in Singapore will be use, due to cultural&#xD;
      and climate differences. In addition, the test will be administered in English, Chinese or&#xD;
      Malay, according to the language the participant is most well-versed in. The Chinese and&#xD;
      Malay versions of MMSE have similar test questions and are scored the same way as the English&#xD;
      version. Sensory impairment will be assessed during the preoperative interviews. Patients&#xD;
      will be asked to wear their visual or hearing aids during these interviews. A patient will be&#xD;
      considered to have visual or hearing impairment if the research member conducting the&#xD;
      interview is unable to perform the interview normally due to the sensory impairment, such as&#xD;
      raising his/her voice for a patient with impaired hearing. The grip strength of each patient&#xD;
      will also be measured using the JAMAR® Plus+ Digital Hand Dynamometer (Sammons Preston Inc,&#xD;
      Bolingbrook, IL). The patient baseline characteristics will be obtained from the medical&#xD;
      records. Perioperative data is available through the Preoperative Evaluation Clinic (PEC)&#xD;
      database as well as the Orthopaedic Diagnostic Centre (ODC) total joint registry, which will&#xD;
      be prospectively entered into the REDCap™ database. This will include data regarding&#xD;
      patient's demographics, smoking history, alcohol history, pre-existing medical conditions,&#xD;
      preoperative medications. Each patient will also be rated preoperatively by an&#xD;
      anaesthesiologist in the PEC based on the American Society of Anaesthesiologists (ASA)&#xD;
      physical status classification. For analysis, the investigators will be calculating each&#xD;
      patient's perioperative risk based on the Charlson Comorbidity Index (CCI). Preoperative&#xD;
      laboratory results, including data about haemoglobin or creatinine level, will also be&#xD;
      collected.&#xD;
&#xD;
      Intraoperative data&#xD;
&#xD;
      Data regarding the surgery will be collected. Intraoperative data includes type of&#xD;
      arthroplasty performed (total hip or total knee arthroplasty), type of anaesthesia (spinal,&#xD;
      general or other anaesthesia), use of femoral nerve block, intraoperative drug use,&#xD;
      tourniquet time, intra-articular injections and blood transfusion (number of pints&#xD;
      transfused). Occurrence of hypotension, which is defined as a mean arterial pressure &lt;60mmHg,&#xD;
      and its duration will also be recorded.&#xD;
&#xD;
      Postoperative data&#xD;
&#xD;
      Primary outcome&#xD;
&#xD;
      The primary outcome will be the presence of postoperative delirium following TJA. Each&#xD;
      patient will be assessed for delirium on postoperative day (POD) 1, 2 and 3 in the wards at&#xD;
      7am as well as the day of discharge. Delirium will not be evaluated on POD 0 due to&#xD;
      difficulty in differentiating delirium from the effects of residual anaesthesia. The&#xD;
      Confusion Assessment Method (CAM) will be used to detect postoperative delirium and delirium&#xD;
      severity. Delirium is said to be present if the patient meets the CAM criteria for any of the&#xD;
      postoperative assessments. Patients assessed to have delirium will be referred to the&#xD;
      psychiatrists for further management.&#xD;
&#xD;
      Short-term secondary outcomes&#xD;
&#xD;
      Postoperative complications will be quantified by the Postoperative Morbidity Survey (POMS).&#xD;
      This survey will be conducted on the day-of-discharge and there will be surveillance for up&#xD;
      to 30 days following index surgery. Postoperative delirium and delirium severity will be&#xD;
      assessed using CAM. Hospital-based outcomes will be obtained from the medical records.&#xD;
      Perioperative data is available through the PEC database as well as the ODC total joint&#xD;
      registry. All perioperative data and clinical outcomes will be analyzed. The incidence of&#xD;
      postoperative delirium will be calculated using standard formula. Regression analysis will be&#xD;
      performed to identify risk factors for delirium. The incidence of 30 day post operative&#xD;
      complications will also be screened for and collected using the Post-operative Morbidity&#xD;
      Survey (POMS), at the point of discharge and 30 days from date of surgery.&#xD;
&#xD;
      Long-term secondary outcomes&#xD;
&#xD;
      Longer-term outcomes such as functional and health-related quality-of-life (HRQoL) outcomes&#xD;
      will also be recorded by the ODC total joint registry at 6 months, 1 year, 2 years and 5&#xD;
      years postoperatively. Knee function will be measured using the new Knee Society Knee Score&#xD;
      (KSKS) and Function Score (KSFS)29. The KSKS and KSFS each range from 0 (worst) to 100&#xD;
      (best). In addition, the Oxford Knee Score (OKS)31 will also be used, which is a 12-item,&#xD;
      patient-assessed questionnaire designed specifically for use in patients undergoing TKA. Each&#xD;
      item is scored from 1 (least difficulty/severity) to 5 (most difficulty/severity), and&#xD;
      individual item scores are summed to yield an overall score ranging from 12 (no pain or&#xD;
      limitation) to 60 (severe pain or limitation). HRQoL will be assessed based on the 36-Item&#xD;
      Short Form Health Survey (SF-36) to obtain a baseline score. It consists of 36 questions&#xD;
      categorised into 8 domains (physical functioning, bodily pain, role limitations due to&#xD;
      physical health problems, role limitations due to personal or emotional problems, emotional&#xD;
      well-being, social functioning, energy/fatigue, and general health perceptions). Higher&#xD;
      scores indicate better health status and quality of life. Days alive and out of hospital&#xD;
      (DAOH) will also be determined for each patient at 1 month, 6 months and 12 months to assess&#xD;
      overall impact of postoperative delirium on morbidity and mortality. DAOH will be calculated&#xD;
      based on death date (if present) and duration of all subsequent hospitalisations until the&#xD;
      follow-up date. This will be recorded as a percentage by dividing DAOH by total potential&#xD;
      follow-up period, which is the time period between the operation and the respective dates of&#xD;
      follow-up (1 month, 6 months and 12 months).&#xD;
&#xD;
      Postoperative risk factors&#xD;
&#xD;
      Other postoperative data will be collected as variables for risk factors. Postoperative pain&#xD;
      at rest will be evaluated using the pain Visual Analog Scale (VAS) during the same visit as&#xD;
      CAM on POD 1, 2 and 3. Each patient will score pain experienced at rest on a scale, with 0 =&#xD;
      no pain and 10 = maximum pain. Sensory impairment will also be assessed during the&#xD;
      postoperative interviews similar to the preoperative assessments.&#xD;
&#xD;
      Data Management&#xD;
&#xD;
      Patient data will be kept confidential throughout the study. All electronic study data entry,&#xD;
      storage and analysis will be done according to institutional data security policy, using&#xD;
      password protected data in secure systems. The patient data collected will be de-identified&#xD;
      and the key kept securely separated with access limited to principal investigator and&#xD;
      co-investigators. A study-related identification number given to each patient will be used on&#xD;
      the case report form. Research members will enter the de-identified data into the REDCap™&#xD;
      (Research Electronic Data Capture) tool hosted on a secure server at Singapore General&#xD;
      Hospital. The hardcopy of the research data will be securely stored within the department.&#xD;
      The softcopy of research data will be saved in a password-protected file and will be stored&#xD;
      in institution approved login-protected system and encrypted hard-drive. Only study members&#xD;
      will have access to the data.&#xD;
&#xD;
      Power and sample size calculations&#xD;
&#xD;
      The sample size will be calculated based on the incidence of postoperative delirium. Based on&#xD;
      existing literature, the estimated incidence of postoperative delirium following TJA is&#xD;
      around 10%. Using this estimate, a minimum sample size of 150 patients will be needed to&#xD;
      detect the incidence with a precision of 5% and power of 80%. The sample size of 200 patients&#xD;
      is needed to measure incidence to account for attrition.&#xD;
&#xD;
      However, this study will also be analysing the factors which may be correlated to&#xD;
      postoperative delirium by logistic regression. A study population size of 500 will thus be&#xD;
      targeted to be able to run a multiple logistic model while minimising the limitation of a&#xD;
      small number of events of postoperative delirium.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Recruiting</last_known_status>
  <start_date type="Actual">July 3, 2017</start_date>
  <completion_date type="Anticipated">December 31, 2017</completion_date>
  <primary_completion_date type="Anticipated">December 31, 2017</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Case-Only</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>Post operative delirium incidence</measure>
    <time_frame>Up to 30 days</time_frame>
    <description>Measured using confusion assessment method (CAM) tool</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Post operative complications</measure>
    <time_frame>Up to 30 days post operatively</time_frame>
    <description>measured using post operative morbidity survey (POMS)</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>incidence of post operative nausea and vomiting (PONV)</measure>
    <time_frame>post op day 1</time_frame>
    <description>the total number of patients experiencing PONV</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Length of hospital stay</measure>
    <time_frame>up to 12 months</time_frame>
    <description>the total number of days stayed in hospital during this elective admission</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Hospital readmission rate</measure>
    <time_frame>30 days post operative</time_frame>
    <description>the percentage of patients being readmitted for a complication related to the surgery</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>functional and health-related quality-of-life (HRQoL)</measure>
    <time_frame>6 months , 12 months</time_frame>
    <description>tools used to assess knee function, ADL status, emotional and social wellbeing</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Days Alive and Out of Hospital (DAOH)</measure>
    <time_frame>1 month, 6 months, 12 months</time_frame>
    <description>measures the death rate and total summation of days spent outside of hospital following the surgery</description>
  </secondary_outcome>
  <enrollment type="Anticipated">500</enrollment>
  <condition>Postoperative Delirium</condition>
  <eligibility>
    <study_pop>
      <textblock>
        Patients aged between 65 and 90 undergoing elective total joint (hip or knee) replacement&#xD;
        surgery in Singapore General Hospital&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Non-Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Patients undergoing elective total knee or total hip arthroplasty&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Patients who are deemed to lack mental capacity to give consent.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>65 Years</minimum_age>
    <maximum_age>90 Years</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_contact>
    <last_name>Hairil Abdullah, MBBS</last_name>
    <phone>63265519</phone>
    <email>hairil.rizal.abdullah@singhealth.com</email>
  </overall_contact>
  <overall_contact_backup>
    <last_name>Hairil Rizal Abdullah, MBBS</last_name>
    <phone>63265519</phone>
    <email>hairil.rizal.abdullah@singhealth.com</email>
  </overall_contact_backup>
  <location>
    <facility>
      <name>Singapore General Hospital</name>
      <address>
        <city>Singapore</city>
        <zip>169608</zip>
        <country>Singapore</country>
      </address>
    </facility>
    <status>Recruiting</status>
    <investigator>
      <last_name>Hairil Rizal Abdullah, MBBS</last_name>
      <role>Principal Investigator</role>
    </investigator>
    <investigator>
      <last_name>Hamid Razak, MBBS</last_name>
      <role>Sub-Investigator</role>
    </investigator>
    <investigator>
      <last_name>Eileen Sim, MBBS</last_name>
      <role>Sub-Investigator</role>
    </investigator>
    <investigator>
      <last_name>Si Jia Lee, MBBS</last_name>
      <role>Sub-Investigator</role>
    </investigator>
    <investigator>
      <last_name>Rachel Seet, MBBS</last_name>
      <role>Sub-Investigator</role>
    </investigator>
    <investigator>
      <last_name>Ervin Sethi, MBBS</last_name>
      <role>Sub-Investigator</role>
    </investigator>
  </location>
  <location_countries>
    <country>Singapore</country>
  </location_countries>
  <verification_date>August 2017</verification_date>
  <study_first_submitted>August 18, 2017</study_first_submitted>
  <study_first_submitted_qc>August 21, 2017</study_first_submitted_qc>
  <study_first_posted type="Actual">August 24, 2017</study_first_posted>
  <last_update_submitted>August 29, 2017</last_update_submitted>
  <last_update_submitted_qc>August 29, 2017</last_update_submitted_qc>
  <last_update_posted type="Actual">August 31, 2017</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <keyword>postoperative delirium</keyword>
  <keyword>elderly</keyword>
  <keyword>total joint replacement</keyword>
  <keyword>risk factors for delirium</keyword>
  <keyword>postoperative confusion</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Delirium</mesh_term>
    <mesh_term>Emergence Delirium</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/NCT03260218
org study id: TJA2017
nct id: NCT03260218
lead sponsor: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
The incidence of post-operative delirium in the South-east Asian population is not known.
      Through a prospective, single centre, observational study, the investigators aim to
      characterize the incidence and risk factors of delirium in older adults undergoing elective
      total joint arthroplasties (TJA). The study will recruit eligible patients (65 - 90 years old
      undergoing elective TJA), with a targeted sample size of 500. Patients will be screened for
      dementia and Confusion Assessment Method (CAM) scores obtained pre and post operatively.
      Other data such as preoperative Charlson comorbidity index (CCI), post op complications using
      Post operative Morbidity Survey (POMS), pain scores, readmission rates and length of hospital
      stay (LOS), functional and health-related quality-of-life (HRQoL) will also be collected and
      analysed.
BACKGROUND

      Modern studies have evaluated the risk factors and incidence of postoperative delirium in
      post-TJA patients. In current literature, incidence ranges from 0-10%. However, the
      epidemiology of these studies mainly focused on non-Asian populations. The investigators hope
      to determine both the incidence and risk factors of postoperative delirium in patients
      undergoing TJA with a focus on the Asian population. This is especially relevant in today's
      ageing Asian population.

      AIMS

      To characterize the incidence and risk factors of delirium in older adults undergoing
      elective total joint replacement surgery.

      HYPOTHESIS

      The incidence of postoperative delirium following elective TJA is low compared to Western
      studies. Age, gender and use of opioids perioperatively are risk factors for postoperative
      delirium following elective total joint replacement surgery.

      DESIGN: Prospective observational study.

      SETTING: Academic medical center.

      DURATION: July 2017 - Dec 2017

      STUDY POPULATION: Individuals aged 65 to 90 years old undergoing elective total joint (hip or
      knee) replacement surgery.

      METHODOLOGY:

      Preoperative data

      Before the operation, each patient will be interviewed to assess their baseline cognitive
      status. The Mini-Mental State Examination (MMSE) will be used, which is a 11-question
      screening tool used to evaluate the cognitive aspects of mental function. A score of 0-30 can
      be obtained with higher values denoting better cognitive function. A score of <24 suggests
      cognitive impairment. A MMSE test modified for use in Singapore will be use, due to cultural
      and climate differences. In addition, the test will be administered in English, Chinese or
      Malay, according to the language the participant is most well-versed in. The Chinese and
      Malay versions of MMSE have similar test questions and are scored the same way as the English
      version. Sensory impairment will be assessed during the preoperative interviews. Patients
      will be asked to wear their visual or hearing aids during these interviews. A patient will be
      considered to have visual or hearing impairment if the research member conducting the
      interview is unable to perform the interview normally due to the sensory impairment, such as
      raising his/her voice for a patient with impaired hearing. The grip strength of each patient
      will also be measured using the JAMAR® Plus+ Digital Hand Dynamometer (Sammons Preston Inc,
      Bolingbrook, IL). The patient baseline characteristics will be obtained from the medical
      records. Perioperative data is available through the Preoperative Evaluation Clinic (PEC)
      database as well as the Orthopaedic Diagnostic Centre (ODC) total joint registry, which will
      be prospectively entered into the REDCap™ database. This will include data regarding
      patient's demographics, smoking history, alcohol history, pre-existing medical conditions,
      preoperative medications. Each patient will also be rated preoperatively by an
      anaesthesiologist in the PEC based on the American Society of Anaesthesiologists (ASA)
      physical status classification. For analysis, the investigators will be calculating each
      patient's perioperative risk based on the Charlson Comorbidity Index (CCI). Preoperative
      laboratory results, including data about haemoglobin or creatinine level, will also be
      collected.

      Intraoperative data

      Data regarding the surgery will be collected. Intraoperative data includes type of
      arthroplasty performed (total hip or total knee arthroplasty), type of anaesthesia (spinal,
      general or other anaesthesia), use of femoral nerve block, intraoperative drug use,
      tourniquet time, intra-articular injections and blood transfusion (number of pints
      transfused). Occurrence of hypotension, which is defined as a mean arterial pressure <60mmHg,
      and its duration will also be recorded.

      Postoperative data

      Primary outcome

      The primary outcome will be the presence of postoperative delirium following TJA. Each
      patient will be assessed for delirium on postoperative day (POD) 1, 2 and 3 in the wards at
      7am as well as the day of discharge. Delirium will not be evaluated on POD 0 due to
      difficulty in differentiating delirium from the effects of residual anaesthesia. The
      Confusion Assessment Method (CAM) will be used to detect postoperative delirium and delirium
      severity. Delirium is said to be present if the patient meets the CAM criteria for any of the
      postoperative assessments. Patients assessed to have delirium will be referred to the
      psychiatrists for further management.

      Short-term secondary outcomes

      Postoperative complications will be quantified by the Postoperative Morbidity Survey (POMS).
      This survey will be conducted on the day-of-discharge and there will be surveillance for up
      to 30 days following index surgery. Postoperative delirium and delirium severity will be
      assessed using CAM. Hospital-based outcomes will be obtained from the medical records.
      Perioperative data is available through the PEC database as well as the ODC total joint
      registry. All perioperative data and clinical outcomes will be analyzed. The incidence of
      postoperative delirium will be calculated using standard formula. Regression analysis will be
      performed to identify risk factors for delirium. The incidence of 30 day post operative
      complications will also be screened for and collected using the Post-operative Morbidity
      Survey (POMS), at the point of discharge and 30 days from date of surgery.

      Long-term secondary outcomes

      Longer-term outcomes such as functional and health-related quality-of-life (HRQoL) outcomes
      will also be recorded by the ODC total joint registry at 6 months, 1 year, 2 years and 5
      years postoperatively. Knee function will be measured using the new Knee Society Knee Score
      (KSKS) and Function Score (KSFS)29. The KSKS and KSFS each range from 0 (worst) to 100
      (best). In addition, the Oxford Knee Score (OKS)31 will also be used, which is a 12-item,
      patient-assessed questionnaire designed specifically for use in patients undergoing TKA. Each
      item is scored from 1 (least difficulty/severity) to 5 (most difficulty/severity), and
      individual item scores are summed to yield an overall score ranging from 12 (no pain or
      limitation) to 60 (severe pain or limitation). HRQoL will be assessed based on the 36-Item
      Short Form Health Survey (SF-36) to obtain a baseline score. It consists of 36 questions
      categorised into 8 domains (physical functioning, bodily pain, role limitations due to
      physical health problems, role limitations due to personal or emotional problems, emotional
      well-being, social functioning, energy/fatigue, and general health perceptions). Higher
      scores indicate better health status and quality of life. Days alive and out of hospital
      (DAOH) will also be determined for each patient at 1 month, 6 months and 12 months to assess
      overall impact of postoperative delirium on morbidity and mortality. DAOH will be calculated
      based on death date (if present) and duration of all subsequent hospitalisations until the
      follow-up date. This will be recorded as a percentage by dividing DAOH by total potential
      follow-up period, which is the time period between the operation and the respective dates of
      follow-up (1 month, 6 months and 12 months).

      Postoperative risk factors

      Other postoperative data will be collected as variables for risk factors. Postoperative pain
      at rest will be evaluated using the pain Visual Analog Scale (VAS) during the same visit as
      CAM on POD 1, 2 and 3. Each patient will score pain experienced at rest on a scale, with 0 =
      no pain and 10 = maximum pain. Sensory impairment will also be assessed during the
      postoperative interviews similar to the preoperative assessments.

      Data Management

      Patient data will be kept confidential throughout the study. All electronic study data entry,
      storage and analysis will be done according to institutional data security policy, using
      password protected data in secure systems. The patient data collected will be de-identified
      and the key kept securely separated with access limited to principal investigator and
      co-investigators. A study-related identification number given to each patient will be used on
      the case report form. Research members will enter the de-identified data into the REDCap™
      (Research Electronic Data Capture) tool hosted on a secure server at Singapore General
      Hospital. The hardcopy of the research data will be securely stored within the department.
      The softcopy of research data will be saved in a password-protected file and will be stored
      in institution approved login-protected system and encrypted hard-drive. Only study members
      will have access to the data.

      Power and sample size calculations

      The sample size will be calculated based on the incidence of postoperative delirium. Based on
      existing literature, the estimated incidence of postoperative delirium following TJA is
      around 10%. Using this estimate, a minimum sample size of 150 patients will be needed to
      detect the incidence with a precision of 5% and power of 80%. The sample size of 200 patients
      is needed to measure incidence to account for attrition.

      However, this study will also be analysing the factors which may be correlated to
      postoperative delirium by logistic regression. A study population size of 500 will thus be
      targeted to be able to run a multiple logistic model while minimising the limitation of a
      small number of events of postoperative delirium.
observational model: Case-Only
time perspective: Prospective
measure: Post operative delirium incidence
time frame: Up to 30 days
description: Measured using confusion assessment method (CAM) tool
measure: Post operative complications
time frame: Up to 30 days post operatively
description: measured using post operative morbidity survey (POMS)
measure: incidence of post operative nausea and vomiting (PONV)
time frame: post op day 1
description: the total number of patients experiencing PONV
measure: Length of hospital stay
time frame: up to 12 months
description: the total number of days stayed in hospital during this elective admission
measure: Hospital readmission rate
time frame: 30 days post operative
description: the percentage of patients being readmitted for a complication related to the surgery
measure: functional and health-related quality-of-life (HRQoL)
time frame: 6 months , 12 months
description: tools used to assess knee function, ADL status, emotional and social wellbeing
measure: Days Alive and Out of Hospital (DAOH)
time frame: 1 month, 6 months, 12 months
description: measures the death rate and total summation of days spent outside of hospital following the surgery
study pop: 
sampling method: Non-Probability Sample
criteria: 
gender: All
minimum age: 65 Years
maximum age: 90 Years
healthy volunteers: Accepts Healthy Volunteers
last name: Hairil Abdullah, MBBS
phone: 63265519
email: hairil.rizal.abdullah@singhealth.com
last name: Hairil Rizal Abdullah, MBBS
phone: 63265519
email: hairil.rizal.abdullah@singhealth.com
facility: 
status: Recruiting
investigator: 
investigator: 
investigator: 
investigator: 
investigator: 
investigator: 
country: Singapore
responsible party type: Sponsor
mesh term: Delirium
mesh term: Emergence Delirium