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Systematic ReviewSystematic Review
Open Access

Systematic review and pooled analysis of randomized controlled trials in countries of the Gulf Cooperation Council (GCC)

Methods and quality assessment

Khalid S. Alraddadi, Fayzah H. Al-Adwani, Rajaa M. Al-Raddadi, Sultan H. Alamri, Iman K. Ramadan and Ahmad A. Mirza
Saudi Medical Journal April 2023, 44 (4) 345-354; DOI: https://doi.org/10.15537/smj.2023.44.4.20220664
Khalid S. Alraddadi
From the Department of Primary Health Care (Alraddadi, Al-Adwani), National Guard Health Affairs, King Saud bin Abdulaziz University for Health Sciences; from the Department of Community Medicine (Al-Raddadi, Ramadan), and from the Department of Family Medicine (Alamri), Faculty of Medicine, King Abdulaziz University; from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Faculty of Medicine in Rabigh, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; from the Department of Community Medicine (Ramadan), Faculty of Medicine, Al-Azhar University, Cairo, Egypt; and from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
MBBS SBFM
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  • For correspondence: [email protected]
Fayzah H. Al-Adwani
From the Department of Primary Health Care (Alraddadi, Al-Adwani), National Guard Health Affairs, King Saud bin Abdulaziz University for Health Sciences; from the Department of Community Medicine (Al-Raddadi, Ramadan), and from the Department of Family Medicine (Alamri), Faculty of Medicine, King Abdulaziz University; from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Faculty of Medicine in Rabigh, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; from the Department of Community Medicine (Ramadan), Faculty of Medicine, Al-Azhar University, Cairo, Egypt; and from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
MBBS SBFM
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Rajaa M. Al-Raddadi
From the Department of Primary Health Care (Alraddadi, Al-Adwani), National Guard Health Affairs, King Saud bin Abdulaziz University for Health Sciences; from the Department of Community Medicine (Al-Raddadi, Ramadan), and from the Department of Family Medicine (Alamri), Faculty of Medicine, King Abdulaziz University; from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Faculty of Medicine in Rabigh, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; from the Department of Community Medicine (Ramadan), Faculty of Medicine, Al-Azhar University, Cairo, Egypt; and from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
MBBS ABCM
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Sultan H. Alamri
From the Department of Primary Health Care (Alraddadi, Al-Adwani), National Guard Health Affairs, King Saud bin Abdulaziz University for Health Sciences; from the Department of Community Medicine (Al-Raddadi, Ramadan), and from the Department of Family Medicine (Alamri), Faculty of Medicine, King Abdulaziz University; from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Faculty of Medicine in Rabigh, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; from the Department of Community Medicine (Ramadan), Faculty of Medicine, Al-Azhar University, Cairo, Egypt; and from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
MBBS SBFM
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Iman K. Ramadan
From the Department of Primary Health Care (Alraddadi, Al-Adwani), National Guard Health Affairs, King Saud bin Abdulaziz University for Health Sciences; from the Department of Community Medicine (Al-Raddadi, Ramadan), and from the Department of Family Medicine (Alamri), Faculty of Medicine, King Abdulaziz University; from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Faculty of Medicine in Rabigh, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; from the Department of Community Medicine (Ramadan), Faculty of Medicine, Al-Azhar University, Cairo, Egypt; and from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
PhD
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Ahmad A. Mirza
From the Department of Primary Health Care (Alraddadi, Al-Adwani), National Guard Health Affairs, King Saud bin Abdulaziz University for Health Sciences; from the Department of Community Medicine (Al-Raddadi, Ramadan), and from the Department of Family Medicine (Alamri), Faculty of Medicine, King Abdulaziz University; from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Faculty of Medicine in Rabigh, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; from the Department of Community Medicine (Ramadan), Faculty of Medicine, Al-Azhar University, Cairo, Egypt; and from the Department of Otolaryngology–Head and Neck Surgery (Mirza), Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
MBBS MSc
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Article Figures & Data

Figures

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  • Figure 1
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    Figure 1

    - Flow diagram of study selection.

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    Figure 2

    - Number of randomized-controlled trials published between 1990 and 2018.

  • Figure 3
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    Figure 3

    - Quality of randomized-controlled trials published between 1990 and 2018.

  • Figure 4
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    Figure 4

    - Trend of overall risk of bias of randomized-controlled trials based on Cochrane Collaboration Risk of Bias Tool between 1990–2018 years.

Tables

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    Table 1

    - Journal-related descriptions of randomized-controlled trials in countries* under Gulf Cooperation Councils from 1990 to 2018 (n=406).

    CharacteristicsnMinMaxMeanSD
    Impact factor of journal (2018-2019)3850.0670.763.546.9
    n%
    Impact factor of journal (2018-2019)<16616.3
    1-1030274.4
    >10163.9
    NA225.4
    Declaration of interestYes
    No conflict/competing interest15437.9
    Interest mentioned123
    No24059.1
    Type of funding sourceNone26364.8
    Academic-based7017.2
    Government/National Council235.7
    Private245.9
    Hospital-based204.92
    International council/agency51.23
    Non-government/non-profit organization10.25
    Publication in open access journalsYes11227.6
    No27467.5
    NA204.9

    *Saudi Arabia, Bahrain, United Arab Emirates, Kuwait, Oman and Qatar, NA: not applicable, SD: standard deviation

      • View popup
      Table 2

      - Demographic characteristics of randomized-controlled trials in countries* under Gulf Cooperation Councils (GCC) 1990 to 2018 (n=406).

      CharacteristicsnMinMaxMeanSD
      Sample size4041010600201.96639.1
      Overall mean age (in year)3220.5477.0033.8318.0
      Overall Proportion of females2920.42%100.0%46.62%29.5%
      n%
      Sample sourceGeneral population10.2
      Hospital/clinics37792.9
      Others286.9
      Geographical locationSaudi Arabia28870.9
      Kuwait5814.3
      Bahrain20.5
      UAE256.1
      Oman61.5
      Qatar215.2
      Collaboration within GCC countries61.5
      Registered protocolYes8621.2
      No32078.8
      Number of study centersSingle center35487.2
      Multi-center
      2 - 25399.6
      >2541.0
      Not numbered92.2
      Field of studyMedicine31978.6
      Dentistry5212.8
      Infectious disease133.2
      Oncology112.7
      Other112.7

      *Saudi Arabia, Bahrain, United Arab of Emirates, Kuwait, Oman, and Qatar, SD: standard deviation

        • View popup
        Table 3

        - Methodology of randomized-controlled trials in countries* under Gulf Cooperation Councils from 1990 to 2018 (n=406).

        Characteristicsn%
        Randomization ratio
        None36990.9
        1:1307.4
        1:1:120.5
        1:1:1:110.2
        2:110.2
        2:2:110.2
        3:110.2
        5:110.2
        Use of block randomization
        No36990.9
        Yes
        Single-block size163.9
        Multi-block size40.9
        Not disclosed block size174.3
        Type of design
        Parallel35787.7
        Cross-over317.6
        Cluster-based71.7
        Single group assignment61.5
        Split-mouth41.0
        Split-face10.2
        Intention-to-treat (ITT) and per protocol (PP) analyses
        ITT29271.8
        PP9623.7
        ITT and PP82.0
        NA102.5
        Reported overall rate of loss-to-follow up
        Yes6917.0
        No32980.8
        NA82.2

        *Saudi Arabia, Bahrain, United Arab of Emirates, Kuwait, Oman, and Qatar, NA: not applicable, ITT: intention-to-treat analysis, PP: per protocol analysis

          • View popup
          Table 4

          - Overall assessment of risk of bias using Cochrane Collaboration Risk of Bias Tool of randomized-controlled trials in countries* under Gulf Cooperation Councils from 1990 to 2018 (n=406).

          Variablesn%
          Random sequence generation
          Unclear risk15638.4
          Low risk19247.3
          High risk5814.3
          Allocation concealment
          Unclear risk22755.9
          Low risk10124.9
          High risk7819.2
          Selective reporting
          Unclear risk7618.7
          Low risk32880.8
          High risk20.5
          Other sources of bias
          Unclear risk32078.8
          Low risk6014.8
          High risk266.4
          Blinding of participants and personnel
          Unclear risk8921.9
          Low risk14134.7
          High risk17643.4
          Blinding of outcome assessment
          Unclear risk17242.3
          Low risk13132.3
          High risk10325.4
          Incomplete outcome data
          Unclear risk266.4
          Low risk34083.7
          High risk409.9
          Overall risk of bias
          Unclear risk18545.6
          High risk22154.4

          *Saudi Arabia, Bahrain, United Arab of Emirates, Kuwait, Oman, and Qatar

            • View popup
            Table 5

            - Association of quality of randomized-controlled trials (RCTs) with journal impact factor (2018-2019) and open access publication (n=406).

            Variable1990-20052006-2018
            Open access publicationJIF R (P-value)Open access publicationJIF R (P-value)
            Yes n (%)No n (%)Yes n (%)No n (%)
            Random sequence generation
            Unclear risk9 (69.2)43 (50.0)0.141 (0.166)31 (31.3)58 (30.9)0.145 (0.014)*
            Low risk2 (15.4)26 (30.2)55 (55.6)107 (56.9)
            High risk2 (15.4)17 (19.8)13 (13.1)23 (12.2)
            P-value0.4530.952
            Allocation concealment
            Unclear risk9 (69.2)60 (69.8)−0.003 (0.980)46 (46.5)95 (50.5)0.096 (0.107)
            Low risk1 (7.7)9 (10.5)32 (32.3)57 (30.3)
            High risk3 (23.1)17 (19.8)21 (21.2)36 (19.2)
            P-value1.0000.810
            Blinding of participants and personnel
            Unclear risk4 (30.8)18 (20.9)0.079 (0.440)21 (21.2)45 (23.9)0.073 (0.217)
            Low risk1 (7.7)29 (33.7)37 (37.4)61 (32.5)
            High risk8 (61.5)39 (45.4)41 (41.4)82 (43.6)
            P-value0.1620.699
            Overall risk of bias
            Unclear risk2 (15.4)37 (43.0)0.057 (0.577)47 (47.5)91 (48.4)0.095 (0.110)
            High risk11 (84.6)49 (57.0)52 (52.5)97 (51.6)
            P-value0.0710.902

            *Statistically significant (p<0.05), JIF: Journal impact factor, R: Spearman’s rho (spearman correlation coefficient)

              • View popup
              Appendix 1

              - Sources, search strategy, and number of records in the review.

              SourceSearch periodSearch strategyNumber of records
              Medline01/01/1990 to 06/29/2018Syntax used by Hayenes et al.
              (https://www.ncbi.nlm.nih.gov/books/NBK3827/#pubmedhelp.Clinical_Queries_Filters)
              For
              Category: Therapeutic
              Optimized for: sensitive/broad
              Sensitive/specific: 99%/70%
              (clinical[Title/Abstract] AND trial[Title/Abstract]) OR clinical trials as topic[MeSH Terms] OR clinical trial[Publication Type] OR random*[Title/Abstract] OR random allocation[MeSH Terms] OR therapeutic use[MeSH Subheading]).
              3469
              EMBASE01/01/1990 to 06/29/2018(clinical [Title/Abstract] AND trial[Title/Abstract]) OR clinical trials as topic[MeSH Terms] OR clinical trial[Publication Type] OR random*[Title/Abstract] OR random allocation[MeSH Terms] OR therapeutic use[MeSH Subheading]).1993
              Cochrane Central Register of Controlled Trials (CENTRAL)01/01/1990 to 06/29/2018Search trials, source (“Saudi Arabia” OR “Oman” OR “Kuwait” OR “Qatar” OR “Emirates” OR “Bahrain”), using search limits which included: All databases773
              ClinicalTrials.gov01/01/1990 to 06/29/2018Through clinicaltrials.gov, advanced search, status completed, country (gulf countries one by one), phase 3311
              Total6546 records
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            Systematic review and pooled analysis of randomized controlled trials in countries of the Gulf Cooperation Council (GCC)
            Khalid S. Alraddadi, Fayzah H. Al-Adwani, Rajaa M. Al-Raddadi, Sultan H. Alamri, Iman K. Ramadan, Ahmad A. Mirza
            Saudi Medical Journal Apr 2023, 44 (4) 345-354; DOI: 10.15537/smj.2023.44.4.20220664

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            Khalid S. Alraddadi, Fayzah H. Al-Adwani, Rajaa M. Al-Raddadi, Sultan H. Alamri, Iman K. Ramadan, Ahmad A. Mirza
            Saudi Medical Journal Apr 2023, 44 (4) 345-354; DOI: 10.15537/smj.2023.44.4.20220664
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